Vol. 23 No. 04 Oct-Dec 2014

Haroon Rashid¹                                  BDS, MDSc

Mustafa Naseem²                               BDS, MDPH

Fahim Vohra³                                     BDS, MFDS, M.Clin.Dent, MRDRCS

Saeed Ullah Shah⁴                             BDS

Amir Shehzad⁵                                    BDS

INTRODUCTION

Over the past two decades, provision of dental services has massively evolved in Pakistan. Dental practitioners predominantly treat the majority of patients with the need for tooth replacement, to the extent that very few patients are referred to specialist prosthodontists. These changes have partly occurred due to a lack of an established referral system among general dental practitioners (GDPs) and partly due to advancements in material sciences, dental equipment, clinical techniques and treatment planning ^1,[1].  Treatment planning is one of the critical aspects of undergraduate and postgraduate dental education and thus, has played its major role^[2].

Edentulism in Pakistan occupies an estimated 4.1% of the total population aged 65 years and above, with a projected increase to 9.3% by 2030^[3]. Since there has been an increase in the life expectancy of elderly individuals, prosthodontic treatment needs and thus, the number of adults over the age of 65 years seeking dental treatment has increased^[4],6. Statistics related to dental practice among European countries has shown private dental practitioners providing higher fixed prosthodontic treatments as compared to dentists in the public sector. By contrast, dentists in public health care report provision of higher number of removable prosthesis fabricated⁷. A similar trend of decrease in the provision of removable prosthesis as compared to fixed prosthesis among developing countries has been observed^8,9. Furthermore, it has been estimated that the requirment for removable partial and complete denture prosthesis may surpass the provision of these prosthesis by oral health care professionals during the upcoming 20 years ^10,11.

The provision of removable prosthesis for elderly patients (more than 50 years) is much common as compared to young adults (20-50 years). While selecting the available prosthodontic treatment options, dental practitioners usually consider age, gender, socio-economic status, educational level, oral health status and patients concerns and wishes¹². Moreover, span of edentulous ridge, the ridge types, the soft and hard tissue conditions usually determine the type of prosthesis to be fabricated. Whilst many factors are involved which may influence the outcome of prosthodontic treatment, aesthetics has always been one of the primary patient concern regarding prosthodontic replacement of teeth.

Contemporary treatment approaches such as implantsupported prosthesis has gained considerably during the past decade¹³. Surgical implant placements are relatively easy to perform and in experienced hands may take less than sixty minutes¹⁴. Implant supported prosthesis offer better retention and stability, however due to lack of patient awareness and implant education in Pakistan, this treatment modality is gaining popularity very slowly. A major concern for patients in need of implant retained restorations is the high cost of this treatment modality.

A baseline data related to the prosthodontic practices among practicing dentists in any population is critically important. From our knowledge from indexed literature there are no studies that report the trends in prosthodontic practices among GDPs in a Pakistani population. Such data is vital for understanding the current patterns in practice of GDP and for planning of widespread oral health care for the population. The purpose of the current survey was to gather baseline data about the different prosthodontic treatment practices among the dental practitioners belonging to various specialties of dentistry, residing in Karachi, Pakistan.

METHODOLOGY

The study population in this cross-sectional study was a sample of dentists in Karachi, Pakistan. Along with practitioner of various specialties, GDPs included in the study were graduate dentists and were currently employed, owning or working in private practice, must have two years of experience after basic dental qualification and also have a valid dental council (PMDC) practicing license. The Ethical Committee of College of Dentistry, Ziauddin University approved the study protocol and the study was conducted from December 2014 to February 2015. A self-designed-structured anonymous questionnaire in English language was used as the instrument for data collection. The questionnaire comprised of three sections:

1. Section one had four questions regarding the age, gender, years of experience and type of dental practice.
2. Section two enquired about the number of patients treated in a month by the GDP for different dental prosthesis. The dental prosthesis included, crowns, fixed partial dentures (FPD), acrylic and cast partial dentures, complete dentures and implant supported crowns, FPD and dentures.
3. Section three of questionnaire contained questions regarding the perceived change in the provision of dental prosthesis by the GDP in the last year (either positive or negative).

A pilot questionnaire distribution was performed among sixteen currently employed dentists in a tertiary care hospital to check the validity of the questionnaire. Sampling of tertiary care centers was done using simple random probability sampling method. From total of eleven tertiary care hospitals in the city six were randomly selected. Five hundred questionnaires along with a letter stating about the instructions, rationale and intention of the survey, were randomly distributed. Students of the research group collected data through personal visits to six dental institutions of Karachi. Descriptive statistics and analysis of the collected data was performed using Statistical Package for Social Sciences (SPSS) version 21 (SPSS, Chicago, Illinios, USA).

RESULTS

Fifty forms were rejected as they had incomplete responses. Out of the 500 surveys distributed, 150 questionnaires from practicing dentist were considered eligible for study. The response rate was 30 percent. Table 1 displays the distribution of the various specialties in dentistry represented by the respondents. Among the total respondents, 15.5% (n = 23) of participants belonged to teaching hospitals only and 84.6% (n = 127) practiced at both places (private practice and teaching hospital) (Table 2).

Table 3 displays perception of the dentists about the changes in provision of complete denture prosthesis for the patients. 82% reported that provision of complete dentures for their patients is either ”increasing” or ”not

LIST OF TABLES:

Table-1: Distribution of Specialties in Dentistry among the respondents

Table-2: Practicing Position of the respondents

Table-3: Trends in Complete Denture cases

Table 4: Trends in Removable partial denture (RPD) cases

Table 5: Trends in Implant cases

changing”. Respondent’s perception regarding the changes in removable partial denture therapy for their patients is shown in Table 4. 81.4% dentists reported that the activity in RPDs was ”increasing” or ”not changing”. As far as the implant-supported prosthesis (fixed and removable), very few numbers of the respondents (8%) reported that the service was ”decreasing” as shown in Table 5.

DISCUSSION

In the current survey, the rate of response of the questionnaires which were returned were low (30%) and the sample size of the current study can be termed limited. Although the sample collection involved only a single city, the hospital settings in the current study offered better facilitation for the data collection. The findings from the current survey can be termed restricted as it involved only dental practitioners of Karachi in selected areas. However; the sample size could be improved in future studies by targeting further localities in Sindh province. It is worth mentioning that in teaching hospitals, the preference for a particular type of prosthesis provided by the dentist is limited as compared to private practices. Lack of financial constraint for some patients, allows the dentist to execute ideal treatment plans for the patients.

The results of the current study showed that only 10% of the responding dentists belonged to the speciality of prosthodontics. Rest of the practitioners belonged to other specialties and were providing prosthodontic services on their own. Many studies have shown that the practitioners usually spend most of their time treating adults themselves and refer a very small number of

patients to specialist prosthodontists^3,4,15,16,17 and confirms that many treatments involve fixed restorations. A study was conducted by Ellis et al¹⁸ which focused on referrals to the restorative department of a general hospital in Europe. Their results indicated that referrals for prosthodontic treatment were low as compared to the referrals requests for endodontic and periodontal treatments. One possible explanation for the low referrals could be that the present study was conducted in Karachi city where the number of practicing specialist prosthodontists is low in comparison to specialists of other dental specialties (such as operative dentistry, orthodontics and oral surgery)¹⁹.

Although implants are not placed by most of the dentists, some of them did provide restorations over implants. In the present study, the respondents indicated growing activity in implant dentistry, with only 8% seeing a decrease in implant-supported FPDs and implantretained removable dentures. One possible explanation for these findings is the increased emphasis being put on implant training and continued professional training courses by implant companies and institutes at present for dental practitioners. it is worth noting that the majority of respondents were practicing in institutions and teaching hospitals, these individuals are known to be better connected to training and education related to innovations in dentistry and are exposed to better opportunities for development of clinical skills. Dental implants were introduced around 40 years ago and have been the focus of research in the field of dentistry²⁰. Levin P²¹ stated that the field of implant dentistry will grow at moderately low levels unless certain changes are made. His findings suggested that only 40% of the restorative dentists take up or participate in a case that involves implant prosthodontics.

The increasing trends of implant dentistry indicate a need for training and education not just for practitioners but also for undergraduates in relation to dental implants²². A comprehensive knowledge of diagnosis and treatment options in implant dentistry should be mandatory for undergraduate dental students²³.

Most of the respondents reported providing removable prosthodontic services and only 18% reported a decrease in complete denture treatment and 18.7% reported a decrease in RPD treatment. The use of removable dentures in Europe has declined possibly due to fall in the rates of Edentulism²⁴ and it seems that having artificial denture teeth is becoming less socially acceptable²⁵. Some studies have suggested that the need for removable prosthesis (partial and complete) will actually increase with time and it is likely that this demand will exceed the supply of dentists during the next 20 year period^6,27.

Furthermore it is worth mentioning that oral health diseases could be prevented and loss of teeth can be minimized by establishing innovative dental public health programs for the dental community²⁷.

CONCLUSIONS

Dental practitioners in Karachi are continuing to provide significant number of removable partial dentures, removable number of fixed prosthodontic restorations and provide a limited number of implant supported prosthesis. The provision of Implant supported restorations is showing a gradual increase.  The practice patterns and trends which were revealed in the current survey surely has potential implications for private dental practitioners, the patients seeking prosthodontic treatment, curriculum of dental schoolsand dental continuing education programs.

REFERENCES

1. Joshi A, Douglass CW, Feldman H, Mitchell P, JetteA. Consequences of success: do more teeth translate into more disease and utilization? J Public Health Dent 1996;56:190-197.
2. Manski RJ, Goodman HS, Reid BC, Macek MD.Dental insurance visits and expenditures among older adults. Am J Public Health 2004;94:759-764.
3. Hook CR, Comer RW, Trombly RM, Guinn JW 3rd, Shrout MK. Treatment planning processes in dental schools. J Dent Educ.2002;66:68-74.
4. Butt AM, Ahmed B, Parveen N, Yazdanie N (2009) Oral health related quality of life in complete dentures. Pak Oral & Dent J 30:397-402
5. Beck CB, Bates JF, Basker RM, Gutteridge DL,Harrison A (1993) A survey of the dissatisfied denture patient. Eur J Prosthodont Restor Dent 2, 73-78.
6. Manski RJ, Moeller JF, Maas WR. Dental services. An analysis of utilization over 20 years. J Am Dent Assoc 2001;132:655-664.
7. Kronstrom M, Palmqvist S, Soderfeldt B, CarlssonGE. Dentist-related factors influencing the amount of prosthodontic treatment provided. Community Dent Oral Epidemiol 2000; 28:185-194.
8. Kronström M, Palmqvist S, Söderfeldt B. Changes indental conditions during a decade in a middle-aged and older Swedish population. Acta Odontol Scand. 2001 Dec; 59:386-389.
9. Hugoson A, Koch G, Göthberg C, Helkimo AN, LundinSA, Norderyd O, Sjödin B, Sondell K. Oral health of individuals aged 3-80 years in Jönköping, Sweden during 30 years (1973-2003). II. Review of clinical and radiographic findings. Swed Dent J. 2005; 29:139-155.
10. Douglass CW, Shih A, Ostry L. Will there be a need for complete dentures in the United States in 2020? J Prosthet Dent 2002; 87:5-8.
11. Douglass CW, Watson AJ. Future needs for fixedand removable partial dentures in the United States. J Prosthet Dent 2002; 87:9-14.
12. Ghani F, Khan A.U. Factors influencing the type ofprosthetic restoration for partially dentate adults. JPMI 2010, Vol 24. No 01. 13-21.
13. Al-Shammari KF, Al-Khabbaz AK, Akar MH, AlAnsari JM, Wang HL. Implant recommendation as a replacement option after tooth loss for periodontal reasons. Implant Dent. 2006; 15:104-110.
14. Vohra FA, Rashid H. Implant retained as first choice of care for edentulous mandibles: a presentation of two cases. J Pak Dent Assoc 2012; 21: 182-187.
15. Fenlon MR, Glick S, Sherriff M. An audit of lettersof referral to a prosthodontic department in a dental teaching hospital. Eur J Prosthodont Restor Dent. 2008; 16:128-131.
16. Nash KD, Benting DG. Private practice ofprosthodontists in the United States: results from the 2008 & 2011 surveys of prosthodontists.  J Prosthodont. 2014;23:10-20.
17. Nash KD, Pfeifer DL, Sadowsky SJ, Carrier DD.Private practice of prosthodontists: current conditions of practice in the United States. J Prosthodont. 2010; 19:175-186.
18. Ellis SG, Ashley MP, Deans RF. A survey of referralsto a restorative dentistry department in a district general hospital. Eur J Prosthodont Restor Dent. 2001;9:5966.
19. Ghani F. Prosthodontics As A Dental Specialty InPakistan: Reflections On Its Historical Developments, Achievements And Future Plans. JPPA 2013; 01:6572
20. Laura Gaviria, John Paul Salcido, Teja Guda, andJoo L. Ong. Current trends in dental implants.J Korean Assoc Oral Maxillofac Surg. 2014;40:50-60.
21. Levin RP. Determining factors for implant referralrates. Implant Dent. 2002;11:312-314.
22. Lang NP1, De Bruyn H; 1st European ConsensusWorkshop in Implant Dentistry University Education. The rationale for the introduction of implant dentistry into the dental curriculum. Eur J Dent Educ. 2009;13 Suppl 1:19-23.
23. Hicklin SP1, Albrektsson T, Hämmerle CH; 1stEuropean Consensus Workshop in Implant Dentistry University Education. Theoretical knowledge in implant dentistry for undergraduate students. Eur J Dent Educ. 2009;13 Suppl 1:25-35.
24. Mojon P1, Thomason JM, Walls AW. The impactof falling rates of edentulism. Int J Prosthodont. 2004;17:434-440.
25. Ainamo J.  Changes in the frequency ofedentulousness and use of removable dentures in the adult population of Finland, 1970-80. Community Dent Oral Epidemiol. 1983;11:122-126.
26. Sijan Poudyal, Ashwini Rao, Ramya Shenoy, andHarsh Priya. Utilization of Dental Services in a Field Practice Area in Mangalore, Karnataka. Indian J Community Med. 2010;35: 424-425.
27. Wu B, Liang J, Landerman L, Plassman B. Trendsof Edentulism Among Middle-Aged and Older Asian Americans. Am J Public Health. 2013; 103:e76-e82.

1. Assistant Professor, Department of Community Dentistry, Ziauddin College of Dentistry, Karachi, Pakistan.
2. Assistant Professor, Department of Prosthodontics, King Saud University, Saudi Arabia.
3. House Officer, Ziauddin College of Dentistry, Karachi, Pakistan.
4. House Officer, Ziauddin College of Dentistry, Karachi, Pakistan.

Corresponding author: “Dr Haroon Rashid ” < drh.rashid@hotmail.com >

Faiza Amin¹                                  BDS, MDS

Amir Akbar Sheikh²                  BDS, MSc

Ambrina Quershi³                     MPhil ,BDS, MDS

Muhammad Abbas⁴                   BDS, FCPS

INTRODUCTION

Transmissions of pathogens to Health Care Workers (HCW) is often due to their exposure to blood, tissue or other body fluids¹. For dentists crosscontamination from contaminated working atmosphere or from patients is the major risk factors^[1],[2]. Blood or saliva is considered as a direct carrier of infection, whereas contaminated equipment’s, surfaces and airway carry infection indirectly. AIDS, Hepatitis, Herpes and

Tuberculosis are very frequently passed to the HCW through patients and health care departments and this issue is of grave concern in dentistry^[1],5.

Dental impressions contaminated with patients’ blood and saliva cause contamination of the stone cast models.

Moreover, microbiological examination of these casts in many studies have shown pathogenic

microorganisms^3,4,6,7. A survey done on 400 Dental laboratories in USA found that that besides lack of knowledge about disinfecting procedures for impressions, dentists and labs disinfect impressions for longer than recommended durations because of the lack of awareness.

Moreover same scenario is observed in many developing countries. In a study conducted by Marya CM  et al⁸ the authors concluded that there is lack of commitment to high standards of infection control practice in dental colleges in India. On the other hand, a study conducted among the students and house officers in Pakistan by A. Saad at al⁹ in Lahore Pakistan reported that infection control protocols for the disinfection of do have knowledge and are following cross infection protocols for impression disinfection.

Considering the variability of data about cross infection control procedures of dental impressions performed in developing countries the aim of this was to assess the current practice  of cross infection control of dental impressions, also  to evaluate how dentists are communicating with lab personnel about impression disinfection, and finally to  detect the awareness about infection control practices in dental institutes of Karachi in prosthodontics department.

METHODOLOGY

A cross sectional study was conducted among registered practitioners working in the department of Prosthodontics in dental colleges of Karachi metropolitan city. Our target was to include all prosthodontics practitioners, including house officers, residents, faculty and consultants.  For the purpose all nine colleges were visited and ethical standards, in accordance with the guidelines provided by the World Medical Association Declaration of Helsinki were followed. Prior permission was taken from administrative heads of each dental institute after explaining the study objectives and methodology. A validated self-administrated questionnaire was used as data collection tool. The questionnaire assessed the information on duration of experience of the participant in their field, education and any additional courses in their field, their knowledge about the impression procedures and disinfection of these materials. The questions were both open and closed ended type and no grading system was used to quantify their knowledge.  For Statistical analysis, SPSS 16 was used. The collected data was analyzed by descriptive statistics and presented as frequency tables.

RESULTS

Sixty registered practitioner were identified at the data collection sites who were giving the selfadministrated questionnaire. Out of 60 questionnaires that were distributed, only 51 were returned, giving a response rate of 85%.  Out of 51 dentists 17 (33.3%) were males and 34 (66.7%) females.  The years of experience of the dentists is shown in Figure 1 where

Figure 1: Work experience in dentistry among study participants

almost more than half of the total participants had experience of less than 1 year. Majority of the respondents had basic registered degree of BDS, only few of them an added postgraduation degree.  Table 1 portrays the knowledge about Dental Impressions Disinfection among the study participants.

Table II shows the description of knowledge and practices of the study participants regarding disinfection protocols of dental impressions. Almost half of the total study participants working in the prosthodontics department reported of using antimicrobial soap for hand washing as their daily practice. It was interesting to find that 41% of the study group washed impression trays

before taking dental impressions. Moreover, only 1/3^rd of the practitioners disinfected impression material and more than 1/3^rd never practiced impression scrubbing after taking impression. It was also interesting to find out that majority of the study group stored dental impressions in tissue papers and only few in disinfectant soaked paper towels.

Tables III and Table 1V display the participants’ responses regarding the knowledge about appropriate

Table 1: Knowledge and practices about Dental Impressions Disinfection

Table II: Knowledge of respondents regarding methods of disinfection to disinfect impression materials.

Table III: Knowledge of respondents regarding type of disinfectants used for disinfecting impression materials.

methods and type of disinfectants used for different impression materials. It was observed that almost half of the total participants did not know about the methods and type of disinfectants used to disinfect dental impressions.

DISCUSSION

Dental Impressions, a prerequisite for all dental procedures have direct contact with saliva and blood and thus is a potential source of cross -infection. According to the British Dental Association (BDA) “infection control is a core element of dental practice”10. An impression, if not disinfected, can cross-contaminate the entire laboratory area, allowing microorganisms to travel back and forth from the laboratory to the clinical area. Although almost all of the respondents realized the importance of hand washing before and after the impression making, only half of them used the appropriate method of hand washing. The respondents are so entheustsic about washing protocols that majority of them besides washing their hands before and after impression making, washed impression trays before impression making. These results showed that majority of respondents were unaware of the correct protocol that should be followed for cross infection control. As washing trays before impression making will further decontaminate the impression trays through water contamination. Once trays are autoclaved then they should be directly insert in patient mouth with the gloves.

American dental association guidelines states that impression should be rinsed to removed saliva, blood and debris and then disinfect before being sent to the laboratory. When considering methods of disinfection for impression in the current study, majority of the respondents were unaware about the appropriate method of disinfection for different impression materials. A questionnaire based survey on contamination of alginate impression material revealed that only 50% clinics implement disinfection protocols for the impression materials, while others rinse impression material in running water only11. A survey in Taiwanese dentists revealed improved adherence to crossinfection control practices, however the handling of impressions was still a concern12. In our study, almost half of the respondents did not know the method for disinfection of Polyether impression material. Similar observations were made in another study13 where 42% dental health care providers knew about disinfection of dental impressions and use of different dilutions of the same product. Before disinfection only 2.6% brushed debris away where as 37.2% rinsed the impressions with water only. Almost a quarter (24.7%) of dentists did not inform the laboratory staff about disinfection and 95% paramedical staff received blood-contaminated impressions13. Similar results were reported in another study where 76% respondents used tap water only to clean the impressions.8 In another study, the knowledge about disinfection of impression materials among professors and students of public and private dental school was compared and they reported that most professors (66%) and students (81%) performed disinfection of the dental impressions14. In our study 43.2% respondents were ignorant of the method for disinfection of Alginate impression material. In another questionnaire based study authors reported that 30% laboratories receive known undisinfected work from dental surgery16 which included dental impressions (77%) and dentures (51%). Knowledge of laboratory directors about disinfection used and length
of time involved was assessed in another study and they reported that 23% had deficient knowledge of former and 47% of later and 45% confessed that they received inadequate instructions in disinfection techniques16. In the current study similar results were found that despite the fact that alginate is most commonly used material, 43% health care workers did not know which disinfectants can be used to disinfect alginate impression material. Shah R et al17 conducted a study on cross infection control within UK orthodontics departments in which they found that the majority of departments had policy in place to decontaminate impressions and at the chairside. Of those who decontaminated at the chairside, majority of departments informed the laboratory in writing that the impression had been decontaminated, whereas the remainder did not have policy in place to ensure this was done. ADA recommends disinfectants are chlorine compounds such as sodium hypochlorite solutions (1:10 dilution).

This study therefore strongly recommends that that is need to raise awareness and implement disinfection of impression materials in dental settings, which needs to be incorporated in the curriculum of Universities and dental schools.

CONCLUSION

From our findings, following conclusions can be drawn:

The results of this study showed that the majority of dentists in Karachi hospital have poor knowledge about the use of disinfecting agents, necessitating continuous educational programs in this respect. Majority of the participants did not have knowledge regarding the methods used for the disinfection of various impression materials. After the survey, authors concluded that disinfection techniques are still little practiced in prosthetic departments where most of the impressions are recorded, so there is an urgent need of implementing concepts of bio security in dental schools in Karachi Pakistan. This will absolutely decrease the risks of future complications related with contaminated impressions and will improves the quality of life of dentists, paramedical staff and patients.

REFERENCES

1. Amin F, Moosa SI, Abbas M. Knowledge, attitude and practices of Prosthodontic paramedical staff regarding disinfection of impression materials. J Pak Dent Assoc 2013;22(1):59-64.
2. Palenik CJ, Burke FJ, Miller CH. Strategies for dental clinic infection control. Dent Update. 2000; 27:710.
3. Silva SM, Salvador MC. Effect of the disinfection technique on the linear dimensional stability of dental impression materials. J Appl Oral Sci. 2004;12:244-249.
4. Egusa H, Watamoto T, Abe K, Kobayashi M, Kaneda Y, Ashida S, et al. An analysis of the persistent presence of opportunistic pathogens on patient-derived dental impressions and gypsum casts. Int J Prosthodont. 2008;21:62-68.
5. Kearns HP, Burke FJ, Cheung SW. Cross-infection control in dental practice in the Republic of Ireland. Int Dent J. 2001;51:17-22.
6. Bhat VS, Shetty MS, ShenoyKK.Infection control in the prosthodontics laboratory. J Indian Prosthodont Soc. 2007;7:62-65.
7. Fisher WT, Chandler HT, Brudvik JS. Reducing laboratory contamination.JProsthet Dent. 1972;27:221225.
8. Marya CM, Shukla P, Dahiya V, JnaneswarA.Current status of disinfection of dental impressions in Indian dental colleges: a cause of concern.J Infect DevCtries. 2011 15;5:776-780
9. A. Saad, A.W.Zubair, B.Fareeha. A survey on cross infection hazards associated with dental impression recording. PODJ 2012 32; 2: 248-252
10. Service BA. The control of cross infection in dentistry. 1991.
11. Sofou A, Larsen T, Fiehn NE, Contamination level of alginate impressions arriving at a dental laboratory.Clin Oral Investig. 2002;6:161-5.
12. Yumul Ç, Bilgin Z, GÜRSOY GÇ. The prevalence of Candida Albicans, Staphylococcus Aereus, Eschrichia Coli and Coliform Bacteroides in the Oropharynx of 415 aged children. 1993;19: 297-299.
13. Almortadi N, Chadwick RG. Disinfection of dental impressions – compliance to accepted standards.Br Dent J. 2010;209:607-611.
14. FM Ferreira, VR Novais, PCS Junior, C. J. Soares, A. J. F Neto. Evaluation of Knowledge about Disinfection of Dental Impressions in Several Dental Schools.RevOdontol Bras Central 2010;19:285-288.
15. Jagger DC, Huggett R, Harrison A.Cross-infection control in dental laboratories.Br Dent J.1995 5;179:9396.
16. Kugel G, Perry RD, Ferrari M, P. L. Disinfection and communication practices: A survey of U.S. Dental Laboratories. J Am Dent Assoc. 2001;131:786-792.
17. Shah R, Collins JM, Hodge TM, Laing ERA national study of cross infection control: ‘are we clean enough?’ Br Dent J. 2009 Sep 26;207:267-274.

1. Assistant Professor, Dow Dental College Dow University of Health Sciences. Science of Dental Materials.
2. Assistant Professor, Ziauddin University. Department of Community Dentistry.
3. Associate Professor, Department of Community & Preventive Dentistry. Dr Ishrat ul- Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences.
4. Ziauddin University, Karachi.Corresponding author: “Dr Faiza Amin ” < drdentist2004@hotmail.com >

Ambrina Qureshi¹                                  M. Phil, BDS, MDS

Manu Batra²                                            BDS, MDS

Madiha Pirvani³                                    BDS, MDS

Aeeza Malik4                                           BDS

Aasim Farooq Shah⁵                           BDS, MDS

Mudit Gupta⁶                                          BDS, MDS

INTRODUCTION

Sustaining good oral health is vital to improve the general health and development predominantly in children of school going age. In every community and country the children, particularly of school going age, are the most important natural asset. Their well-being, capabilities, knowledge and energy will determine the future of villages, cities and nations around the world. Even though oral health is considered as an integral part of overall health, the global evidence report that around 90% of these school children worldwide experience poor oral condition .This suggests poor oral health as highly prevalent, where South East Asian countries are no exception.

India and Pakistan are two neighbouring nations who share common border in South East Asia.  The burden of oral diseases among adolescents in both countries is on higher side. The problems in both nations revolve around the level of attentiveness towards oral health among children, specifically those belonging to rural areas. It is pertinent to mention that almost 70% of the general population in both these countries belong to rural areas with low socio-economic status where the overall development is poor².

Many oral health problems are preventable and their early onset reversible through imparting oral health education since the very initial footstep of awareness. It has been reviewed that betterment in oral health may be anticipated through good understanding of an individual’s knowledge and perceptions about oral health³. The evaluation of baseline awareness may therefore act as an important indicator for planning successful oral health education programs in both the countries. Hence, the objective of this study was to evaluate the discrepancy in the oral health awareness and dental caries status of school going children of India and Pakistan.

METHODOLOGY

The study sample consisted of school students aged 12-15 years attending schools of rural areas of Moradabad and Karachi cities of India and Pakistan respectively. A two-stage sampling technique was used to produce representative samples from each location. In first stage, the schools were randomly selected. Four senior secondary government schools each from Moradabad (India) and Gulshan-e-Iqbal Town, Karachi city (Pakistan) were selected based on probability proportional to enrolment size (PPE). According to PPE, the schools with high number of regularly attending students were more likely to be selected than schools with low number of students regularly attending. In second stage, the students from these schools were randomly selected to be included in the study through simple random sampling procedure.

Before the start of study, permission was obtained from the ethical review board of the respective institutes involved in data collection. Prior permission was also obtained from respective school authorities. The time and date of the survey were intimated to the students well in advance and informed consents were obtained. Subjects with any systemic or oral disease, dental prosthesis, absence of any index teeth and non-consenting cases were excluded from the study. Selected participants were interviewed using a questionnaire prepared for assessing health awareness in children. The close-ended questionnaire was pre-tested among 25 school students each of Moradabad and Karachi, to confirm its validity (kappa >70%) and reliability (cronbach alpha >70%) and to avoid ambiguity. However, these students were not included in the final analysis. Following the pre-test, some modifications in the order of questions and terminologies were made in the final questionnaire.

Considering the influence of teachers on the students’ response, the school authorities were requested not to be present in the class during the procedure of filling the questionnaire. Students were assured that the information they provided would remain confidential and thus were encouraged to be truthful in their response. The students were instructed to give only single answer for each question, which they felt was the most appropriate.

Dental examination was then performed to identify the dental caries status of school children aged 12-15 years. Examination was conducted by properly gloved and masked single examiner in each setting on the permitted dates by the school administration on mobile dental units with the child supine, under the day time sunlight in school ground. Sterilized instruments (dental mirror, probe and tweezers) were used to execute the examination. Intra-examiner reliability of the single trained examiner was assessed on 10% of the sample subjects; however, inter-examiner reliability could not be measured.

Preliminary descriptive statistics (Mean and frequency percentages) was used to assess the distribution of responses of all study variables using SPSS package (version 20).

RESULTS

A total of 809 school children aged 12-15 years were examined in the present study, out of which there were 409 from India and 400 from Pakistan. Preliminary data description with respect to age and gender is reported in table-1. The mean age of Indian study participants was calculated as 13.21 ± 1.16 years and that of Pakistani was 13.06 ± 1.11 years.

Table 2 demonstrates the percentage distribution of study participants’ responses for each study variable. Majority of subjects from India (47.19%) cleaned their teeth once a day, whereas many from Pakistan (62.75%) cleaned their teeth twice a day. The number of subject who responded with “sometimes” and “never” was more

from India and none from Pakistan; although this number covered approximately 10% of the total participants from India.

Moreover, awareness regarding the use of fluoridated toothpaste was different in subjects from two nations. All subjects (100%) from Pakistan knew that their toothpaste does contain fluoride whereas majority of subjects (70.6%) from India were not sure whether their toothpaste contains fluoride or not while cleaning their teeth. According to this table, frequency of visit to a dentist during last 12 months was much higher among Indian children in comparison to Pakistani children. It was found that less than 1/2 of the Indian participants never visited a dentist in comparison to almost 3/4^th (83.25%) of the Pakistani participants during last 12 months. Furthermore, consumption of sweets in excess and as regular was slightly higher among Pakistani than Indian study participants.

Table 3 demonstrates the caries experience (mean DMFT) among the subjects. The decayed component was higher in Indian children in comparison to Pakistani

children which also led to a higher mean DMFT score among Indian children in contrast to Pakistani children.

DISCUSSION

Dental caries is still a major health problem in most industrialized countries as it affects 60-90% of schoolaged children and the vast majority of adults. At present, the distribution and severity of dental caries vary in different parts of the world and within the same region or country¹. In most developing countries, the levels of dental caries were low until recent years but prevalence rates of dental caries and dental caries experience are now tending to increase. This is largely due to the factors known to be associated with dental caries. It is suggested that social and biological factors in very early life influence dental caries levels later in life⁴. In addition, behavioural factors such as feeding patterns, tooth brushing, flouride intake and other factor related to education level of the mother, country of birth and gender of the child also generally influence the prevalence of dental caries5.

Worldwide, studies have highlighted differences in oral health knowledge, attitudes and practice between childern and adults6 as well as childern of different

strata⁷. This study, however, was planned to evaluate these differences among school going children of India and Pakistan. In an inter-country comparison, socio-economic status could be one of the most important confounding factors. To impound this confounding effect, public sector schools were selected from both the regions and socio-economic status was matched for both.

Toothbrush and toothpaste are commonly used to retain good oral hygiene⁸. However, the correct technique and frequency of tooth brushing, and concentration of fluoride in toothpaste are the laid down factors associated with prevention of dental caries⁹. From the results of the present study, it was seen that more than 80% of the children from India and Pakistan cleaned their teeth at least once a day, where majority from Pakistan (more than 60%) practiced tooth cleaning twice a day. Other concordant studies from Chepang Nepal¹⁰ and China¹¹ have also reported that 60% of children of similar age group brush their teeth at least once-a-day.  On the contrary, much lower tooth cleaning frequency (less than 30%) has been reported from Indian schoolchildren by Mathur et al¹²and Turkish school children by Bekiroglu et al¹³. The practice of cleaning twice in children from Pakistan may be attributed to Muslim religion, where traditionally Muslim children are taught to use miswak at about age six that helps develop practice of brushing more often than once¹⁴. Moreover, 100% of study participants from Pakistan reported that they used fluoridated toothpaste as compared to those of Indian counterparts where only less than 10% of participants reported that they use fluoridated toothpastes. Previous findings from various states of India and China have also reported that only 13-15 % of 12 year olds children use fluoridated toothpaste^15,16.  On the other hand, Mirza et al from Pakistan reported that nearly 60% students from Pakistani schools regarded fluoride as a tooth strengthening element and were properly aware about it¹⁷.

Regarding regular visits to dentist by children of this age group, we observed that participants from India visited dentist more regularly than those belonging to Pakistan. This trend in Pakistan is commonly observed elsewhere whereeven less than 10%of these particular age group children regularly visit dentist¹⁸. One reason that may be suggested is unavailability of the trained dental professionals specifically for children in Pakistan ¹⁷. In Pakistan, the government manages health care services since 1986-87, through the ministry of health, which provides the country with physicians, dentists and auxiliary health care workers. Dental surgeons have been recruited under this scheme, but unavailability of the dental equipment renders the program useless. Lack of dental insurance, high cost of treatment, long waiting period between appointments, phobia of the dentist and as well as the treatment are suggested as contributing factors of low percentage of regular checkups in Pakistan². Moreover, the high treatment cost in Pakistan may also be the main culprit in this difference. Adding to this, the present study also reported that sweets consumption was slightly higher in Pakistani children in comparison to Indian children, although this comparison may not be very significant in this study. Moreover, the sweet consumption, when compared to similar surveys from other regions in both the countries was relatively higher^19,20.

Mean DMFT in subjects from India in this study was observed to be higher as compared to the subjects from Pakistan. However, when it is compared to a study from another part of India (Chenai) the difference was more than double (DMFT= 3.94) than the current observation (DMFT= 1.9) in same age group children. On the other hand, the national data of India²¹ reported mean DMFT in 12 years old as 1.7, which is concurrent to the result of this study. Similarly, a previous study from Pakistan¹⁴ reported much higher DMFT (3.7) than that reported in the current study (DMFT= 1.0). Keeping in view the mean DMFT of Indian and Pakistani subjects of the current study the differences may be attributed to the fact that subjects from Pakistan reported to be brushing more often and that too with fluoridated tooth paste, than the subjects from India. Moreover, this may be attributed to the lack of Inter-examiner calibration that could not be conducted and measured due to the traveling distance between the two countries. However, the examiners were confident that the employed tool for examination was the DMFT index (decayed, missing, filled teeth) as recommended by World Health Organization (WHO). It is pertinent to mention that the DMFT Index is a general indicator of dental health status of the population (particularly among children), and is considered reliable. Lower the index, the better the dental health of the population. Although, it has been observed that despite more than 50% of study subjects visiting dentist, their decayed tooth component is still high with much reduced filled tooth component. Overall high decayed components, especially in Indian subjects, indicate the need for dental care, inadequate availability of dental services and less service utilization by the study population. Furthermore, difference in the number of Filled teeth ‘F’ component in the present population groups may be suggestive of the fact that these children may not have sufficient access to the dental services. We need to further look into the reasons for this aspect of inequality in service utilization in both the countries. However, it is still suggested that it is high time that public education emphasizing prevention and conservation  must come into action to rectify this situationwith special focus towards the countries with limited resources.

REFERENCES

1. Petersen PE, Bourgeois D, Ogawa H, Estupinan -Day S, Ndiaye C. The global burden of oral diseases and risks to oral health. Bull World Health Organ. 2005;83:661-9.
2. Khan AA, Ijaz S, Syed A, Qureshi A, Padhiar I, Sufia S, Khan MK, Haleem A, Qiamuddin, Baloch M. Oral Health in Pakistan- A situation analysis. Dev Dent 2004; 5:35-44.
3. Dawani N, Qureshi A, Syed S. Integrated schoolbased child oral health education. J Dow Univ Health Sci 2012; 6: 110-114.
4. Peres MA, Latorre MRDO, Sheiham A, Peres KGA, Barros FC, Hernandez PG, et al. Social and biological early life influences on severity of dental caries in children aged 6 years. Community Dent Oral Epidemiol. 2005;33:53-63.
5. Sufia S, Anwar S, Qureshi A, Farooq A, Khan A A. Maternal attitudes and practices towards 3 ½ & 4 ½ children in Pakistan. Proceeding Shaikh Zayed PGMI. 2006; 20, 87-94.
6. Butani Y, Weintraub JA, Barker JC. Oral healthrelated cultural beliefs for four racial/ethnic groups: assessment of the literature. BMC Oral Health. 2008;8(1, article 26).
7. Petersen PE. Inequality in oral health: the social context for oral health. In: Community oral health (chapter 3), Harris R & Pine C (Eds.). Community Oral Health. Copenhagen: Quintessence Publ. 2005.
8. Mumtaz R. The Fluridation Controversy. Pak Oral Dent J 2007; 27: 137-144.
9. Malik A, Qureshi A, Malik S. Prevention of Dental Decay: Role of Fluoride in Dentifrices. J Dow Univ Health Sci2013; 7: 59-62.
10. Prasai Dixit L, Shakya A, Shrestha M, Shrestha A. Dental caries prevalence, oral health knowledge and practice among indigenous Chepang school children of Nepal. BMC Oral Health. 2013;14:13:20.
11. Tiano AV, Moimaz SA, Saliba O, Saliba NA. Dental caries prevalence in children up to 36 months of age attending daycarecenters in municipalities with different water fluoride content. J Appl Oral Sci. 2009;17:39-44.
12. Mathur A, Avinash J, Mathur A, Gupta T. Oral health Attitude Knowledge Behavior and Consent towards Dental treatment among School children. J Orofacial Res 2011; 1:6-10.
13. Bekiroglu N, Tanboga I, Altinok B, Kargul B. Oral Health Care Behavior in a Group of Turkish Children. Iranian J Publ Health 2009;38:125-131.
14. Khan MA. Prevalence Dental Caries among 3-12 old children of Swat-Pakistan. Pak Oral Dent J 2009; 29:321326.
15. Bali RK, Mathur VB, Talwar PP, Chanana HB. National Oral Health Survey and Fluoride Mapping 20022003 India. Dental Council of India and Ministry of Health and Family Welfare (Government of India), 2004.
16. Zhu L, Petersen PE, Wang HY, Bian JY, Zhang BX. Oral health knowledge, attitudes and behaviour of children and adolescents in China. Int Dent J 2003; 53:289-298.
17. Mirza BAQ, Syed A, Izhar F, Khan AA Oral Health Attitudes, Knowledge, And Behavior Amongst High And Low Socioeconomic School Going Children In Lahore, Pakistan. Pak Oral Dent J 2011; 31(2).
18. Mohiuddin S, Saadat S, Qureshi A. Oral Health Knowledge, Attitude and Practices of Public School Children of Karachi, Pakistan. J Dow Univ Health Sci2011;5:126-128.
19. Petersen PE, Hoerup N, Poomviset N, Prommajan J, Watanapa A. Oral health status and oral health behaviour of urban and rural schoolchildren in Southern Thailand. Int Dent J 2001; 51:95-102.
20. Varenne B, Petersen PE, Ouattara S. Oral health behaviour of children and adults in urban and rural areas of Burkina Faso, Africa. Int Dent J 2006; 56: 61-70. 21. Mahesh Kumar P, Joseph T, Varma R, Jayanthi M. Oral health status of 5 years and 12 years school going children in Chennai city – An epidemiological study. J Indian Soc Pedod Prev Dent 2005; 23:17-22.

1. Assistant Professor, Department of Public Health Dentistry, Surendra Dental College and Research Institute, Sri Ganganagar, Rajasthan, India.
2. Assistant Professor, Department of Dental Materials, Dr. Ishrat-ul- Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences, Karachi, Pakistan 4. Department of Community & Preventive Dentistry, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences, Karachi, Pakistan.
3. Department of Public Health Dentistry, Kothiwal Dental College and Research Centre, Moradabad Uttar Pradesh, India.
4. Assistant Professor, Department of Oral Medicine & Radiology, Uttaranchal Dental & Medical Research Institute, Dehradun, Uttarakhand, India.
5. Associate Professor & Head, Department of Community & Preventive Dentistry, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences, Karachi, Pakistan

Corresponding author: “Dr Ambrina Qureshi ” < ambrina.qureshi@duhs.edu.pk >

As the year 2014 draws to a close, we enter the New Year with a fresh resolve and renewed enthusiasm. We would like to thank all the contributors and respected reviewers for their valuable contributions. We take pride in the fact that we are perhaps the only Dental Journal in Pakistan with 30 years of publication history that follows a peer review system and strict adherence to plagiarism checking. It is the result of these efforts that our journal has been indexed in the EBSCO database. The purpose of this communication is also to draw the attention of our prospective authors to future global oral health needsin general and that of our community in particular. We have had a plethora of papers published on oral health status over the past few years. Topics ranging from caries status, periodontal status, orthodontic needs, pan chaliagutka use, to smoking and its effects on oral health have been well documented. Similarly, KAP studies addressing various gaps in knowledge and quality of dental care have also been well represented on our journal space. Also, in-vitro studies on various physical and chemical properties of conventional composite have also been printed quiet frequently. Similarly, hospital data on patient demographics and reasons for attending the OPD are also over-reported. The editorial board has therefore, decided to discourage

studies in above mentioned areas unless there is a novelty in research design.For instance, caries demographics, instead of reporting caries incidence, prospective authors can perhapsattempt to relate it to certain dietary or social habit as done in a recent article 1. We would like to see more articles on conditions like erosion as it still remains under reported.Oral cancer is the second most common neoplasm affecting the male population of our region, more studies focusing its etiology or some un-discovered factors will be welcomed. Systematic reviews and MetaAnalysis should now be reported on vast amount of prevalence data to identify gaps in our knowledge.On behalf of the editorial board, I wish you all a very happy and prosperous 2015.

Dr Inayatullah Padhiar Editor-In-Chief

REFERENCES

1. Lempert S, M, Christensen L, B, Froberg K, Raymond K, Heitmann B, L, Association between Dairy Intake and Caries among Children and Adolescents. Results from the Danish EYHS Follow-Up Study. Caries Res 2015;49:251-258

Kashif Hafeez¹                                              BDS, MFDRCSI, FFDRCSI, FDSRCSEd

Aiyesha Wahaj²                                            BDS

INTRODUCTION

Feedback refers to the return of information about any related concurrent system or process which tends to produce an effect pertaining to the regulation or consecutive optimization of performance. Altogether it forms a complementary relevant and meaningful interaction between learner and the system^1,[1]. It should be both interactive and reinforcing as it guides the learner’s future performance.

ESSENTIAL COMPONENTS OF EDUCATIONAL FEEDBACK:^1,2,3.

Following are the components of feedback mechanism:

1. Feedback should be undertaken with a common goal in mind by the trainer and the trainee
2. It should be well timed and planned.
3. It should be based on first hand data.
4. It should be regulated in quantity and limited to behaviors that are remediable.
5. It should deal with specific performance, not generalizations.
6. It should deal with decisions and actions, rather than assumed intentions.

Feedback is interpreted as a staged comprehensive system between the learner, tutor and the institution. All aimed for one thing, to keep balance between the ongoing education processes. Feedback also helps to identify the learning problems in a supportive way. It constitutes the opinions, ideas and suggestions from all the entities which are considered to be essential parts of a learning system. In contrary to the standard our ongoing education system concentrates less on building effective feedback process. The students have limited access to the whole process. There is a lack of coordination both at the level of learner and the instructor. As a result, there is consistent deficit of professional knowledge development and its sharing. Feedback requires integration of opinions about educational process taken from learner, teacher and the institution. Later on the collected information is presented in a format and its result is to be interpreted as positive or negative in building efficient educational system.

POSSIBLE OUTCOMES ASSOCIATED WITH MEDICAL EDUCATIONAL FEEDBACK PROCESS

Following are the possible outcomes related to feedback system .They may be interpreted both in positive and negative format^4,5,6,7,8.

1. As an effective means of improving professional medical skills.
2. As a fundamental component of advance continuing professional education medical practice.
3. Goals may set upon precise standardization.
4. Unskilled environment may read it as personal judgment.
5. May find to be as time consuming.
6. Not consistent method due to lack of proper collection of data output.

The figure 1; shows the steps how feedback interlinks and improves the outcome of medical educational process if employed in an effective manner. It impacts the professional standard of an institution and also helps to build the reform plans which prioritize patient safety with advance clinical professional practice.

FEEDBACK CRITERIA FOR ENHANCING PROFESSIONAL MEDICAL EDUCATION

Feedback acts to enhance educational system ability to transform itself into a productive system .The feedback can be in both documented and electronic format. Professional regulatory bodies evaluate feedback exclusively as an ongoing process^7,8,9. The comprehensive stages through licensure, verification, data accountability and change in performance through these means favor the future recognized change in terms of both supervision and professional learning. Both tutors and students share benefits equally which include comprehensive understanding of required curriculum with evidence based practice. Medical educational constitutional policy must carry both educational development plans and all other contributory data,  evaluate it in different steps to check its timely progress .This process should be effective in all regions of the country7,8,9,10,11,12,13.

STAGED STANDARDIZATION IN EDUCATIONAL FEEDBACK SYSTEM:^12,13.

The staged standardization provides effective means to integrate advance professional education into the current education system. During the process, effectiveness is periodically assessed upon the feedback provided by both the learner and the institution. Following staged standardization components need to be assessed:

1. Teachers assessment based upon licensure.
2. Need to enhance or upgrade through annual certificationor recertification process.
3. Advanced professional development sessions.4. Practice evaluation based upon set standards and monitoring.
4. Teacher student interactions and assessment throughPerforma’s or electronic questionnaires.
5. Constant monitoring of professional developmentthrough evidence based practice.

BASIC STEPS FOR TRAINERS

Davidoff and Berg(1990), has suggested four basic steps for trainers in this process. The steps are as follows:¹⁴.

1. Plan,
2. Teach/act,
3. Observe and
4. Reflect

Supervision is the critical part of an educational system. It provides the learner an appropriate way to explore its expertise with basic standards of care towards their patients or living environment. It constitutes one of the building blocks of an institution. Any institution without proper supervision and standards, lack its basic ability to benefit the entire educational system. There are lots of other proponents but the learner needs supervision primarily. Every institution has its own set standardized criteria towards any subject or process. This can never be generalized in subjective manner until the data of proper feedback is studied¹⁵.

PENDLETON METHOD OF FEEDBACK

A common model for giving feedback in clinical education settings was developed by Pendleton (1984)¹⁶. It includes basic rules which encompasses objectives both from trainer and learner perspective. The method is as follows:

1. Check, learner wants the feedback and is ready for it
2. Let the learner give comments/background to the material that is being assessed.
3. The learner states what was done well.
4. The learner states what could be improved.
5. The observer(s) state how it could be improved.JPDA
6. An action plan for improvement is made.These rules explain the feedback system from the beginning and give the charge back to the learner. This can be utilized in short feedback sessions or for detailed long sessions.

FEEDBACK FOR GROUPS

When providing feedback for groups, an interactive session is very beneficial. This states to develop a comprehensive statement or interaction between the learners and the educator. The process essentially is constructed upon the learners own self-assessment, it should be detailed and collaborative, it help learners to take responsibility for their own learning needs. A structured approach requires the need that both the trainees and trainer must target what is expected of them during the feedback sessions. The salient points for giving feedback to groups are as follows¹⁵. .  Initiate .with the agenda of the trainees .  Target the outcomes what the session of discussion is trying to achieve.

.  Encourage the trainees to do self assessment and come up with problem solving firstly.

.  Interact with the whole group for problem solving.

.  Feedback should be detailed and descriptive.

.  Feedback should include, what has worked previously and what can be done in the future.

. Alternatives should be suggested.

. Solutions should be rehearsed to gain confidence

. Supportive attitude should be adopted.

. The whole group learns from this interactive session.

. Concepts, principles and research evidence should be quoted as and when needed.

. In the end, a structured plan and summary should be discussed.

COMPARATIVE PROFESSIONAL MEDICAL EDUCATION ASSESMENT

Our professional medical & dental educational system need strategic staged evaluation which is found to be essential worldwide. Professional educational criteria needs uniform standardization through core to layer. Optimization of proper feedback in every institution needs to be established. Comprehensive assessment through various means to effectively check professional competency is required. Medical educational policy needs to be established which evaluates data construction and its continuous upgrading at various professional educational levels. Professional educational system from primary till advance professional level must comprise of staged developmental sessions both for students and teachers. The only process which keeps the learner and the tutor interlinked is feedback communication between them. Educational criteria at all levels and their proof evaluation are required to assess the required progress in this regard. Process of decision making needs to be evaluated. Uniform constitutional data required to be set to analyze educational system from both student and teacher perspective so that it provides balanced productive results at professional evidence based practice.

POSSIBLE LIMITATIONS

The following are the basic possible limitations in implication of both interactive and reinforcing feedback process in professional medical education:^17,18.

1. Unsupported educational frame work
2. Concerns about resulting consequence
3. Time limit
4. Unprofessional clinical skills
5. Lack of knowledge about particular medical educational system.
6. Lack of evidence based clinical practice

RECOMMENDATIONS

Feedback sessions should be made mandatory during the training years and these sessions should form the basis of trainee’s career progression. Every institution in their constitution should emphasize the importance of learner’s led feedback. Tutors should realize that this is an opportunity for the trainees to reflect upon them and suggest what is beneficial for them.  A sense of confidence building is felt when trainer talks about the positives of the trainee’s progress. During the session the pre discussion summary allows to remember the key points. The session should be learner lead so trainee should realize that he is involved in all stages of the session. Problem solving should be done by the trainee; it reinforces the ownership of the problem. The trainee should formulate the future course of action that will augment his commitment and agreement to the future plans.

Continuation of the learning process should been forced in the end.

REFERENCES

1. Sachdeva A. Use of effective feedback to facilitate adult learning/ Journal of Cancer Education 1996;11:106118.
2. Salermo et al. Faculty development seminars based on the one minute preceptor improve feedback in the ambulatory setting. JGIM 2002;17:779-787.
3. Jack Ende, Feedback in clinical medical education. J Am Med Assoc.1983;250:777-781.
4. Hewson M et al. Giving feedback in medical education: verification of recommended techniques. JGIM 1998;13: 111-116.
5. Gil et al. Perceptions of medical school faculty members and students on clinical clerkship feedback. J Med Educ. 1984;59:856 – 864.
6. Irby et al. Factors affecting ratings of clinical teachers by medical students and residents J Med Educ 1987;55: 1-7.
7. Isaacson JH et al Resident Perceptions of the evaluation process. Society of General Internal Medicine. J Gen Intern Med 1995;10(suppl):89.
8. Eichna LW: Medical-school education, 1975- 1979: A student’s perspective. N Engl J Med 1980;303:727734.
9. Nadler DA: Feedback and Organization Development: Using Data-Based Methods. Reading,Mass, AddisonWesley Pub Co Inc, 1977.
10. Hyman RT: Improving Discussion Leadership. NewYork, Teachers College Press, 1980.
11. American Board of Internal Medicine, Benson JA Jr,Bollet AJ, Faber SJ, et al: Clinical Competence in Internal Medicine. Ann Intern Med 1979;90:402-411.
12. Klein RH, Babineau R: Evaluating the competence of trainees: It’s nothing personal. Am J Psychiatry 1974;131:788-791.
13. Beer M: Performance appraisal: Dilemmas and possibilities. Organizational Dynamics, 1981, winter, pp 24-36.
14. Davidoff, S., Berg, O.V.D. (1990) changing your teaching: the challenge of the classroom: Centaur publications.
15. Kilminster, S., Cottrell, D., Grant, J., Jolly, B. (2007). Effective educational and clinical supervision. Med Teach. 20079;29:2-19.
16. Pendleton D, Schofield T, Tate P & Havelock P; The Consultation: An Approach to Learning and Teaching: Oxford: OUP. 1984.
17. Sadler, D.R. Beyond feedback: Developing student capability in complex appraisal.Assessment & Evaluation in Higher Education.2010; 35: 535-550.
18. Orsmond, P., S. Merry, and K. Reiling. Biology students ‘utilization of tutors’formative feedback: A qualitative interview study. Assessment & Evaluation in Higher Education.2005; 30: 369-386.

1. Post graduate Orthodontic Fellowship Resident. Dr .Ishrat -ul- Ebad khan Institute of Oral Health Sciences.Karachi, Pakistan.  < aiyshwj@gmail.com >

Corresponding author: “Dr Kashif Hafeez ” < hafeezkashif@yahoo.co.uk >

Ashar Jamille¹                                              BDS, MClinDent

Farhan Raza Khan²                                    BDS, MCPS, MS, FCPS

INTRODUCTION

Dental amalgam has been used as a directly placed restorative material in the posterior dentition where it can withstand high masticatory forces1,2. Although, it has certain disadvantages such as mandatory cutting of the tooth substance for its retention and poor aesthetics but still its use in the profession has remained more or less steady2. Conventional amalgam derives its retention from mechanical preparations such as undercuts, grooves locks, slots and coves3. This mechanical cutting of tooth structure is one of the causes for post-operative sensitivity. Other causes of post-operative sensitivity are microleakage at tooth-restorative interface, cusp deflection, abrasion and tooth wear etc. Studies have shown that the primary cause of the post-operative sensitivity is microleakage at the interface of tooth structure and restoration4.
A major disadvantage of amalgam restorations is lack of adhesion to tooth structure which may comprise marginal seal. In recent years, the availability of bonded amalgam has changed the paradigm of clinical practice. Studies have shown that the bonding the alloy restoration to tooth structure reduces the amount of tooth substance removal5,7. Bonded amalgam also reduces the potential of post operative sensitivity by reducing microleakage8.
Although, it is established that bonded amalgam are equal or superior to conventional amalgam for less postoperative thermal discomfort but it’s not clear whether cavity design has any effect on the sensitivity. We hypothesized that bonded amalgam restoration may exhibit less post-operative sensitivity in Class I and II cavity preparations compared to conventional amalgam.

OBJECTIVE

To compare post-operative sensitivity in Class I and II preparations restored with conventional and bonded amalgam.

METHODOLOGY

It was a clinical trial conducted at the dental clinics of the Aga Khan University Hospital, Karachi where we used non-probability purposive sampling to recruit subjects with posterior teeth with class I or II cavities requiring restorations. We excluded the teeth that were non restorable, pulpally involved teeth or that exhibited pre-operative sensitivity or teeth with excessive cavity width where cusp capping was indicated. We calculated the sample size by using sample size calculator (Sample size Determination in Health Studies, WHO). We assumed that around 40% of bonded and 60% of conventional amalgam exhibit post-operative sensitivity. At a level of significance of 5% and power of the study 75%, the sample size requirement turned out to be 67 teeth. Since, we had two treatment groups so the total sample size requirement was 134 teeth. The protocol was approved by the ethics review committee of the Aga Khan University Hospital. Its reference was 1477-Sur-ERC-2010.

DATA COLLECTION

The patients at dental clinics of Aga Khan University Hospital who satisfy the inclusion criteria were included in the study. The data was collected on the prescribed proforma and the informed consent was obtained from them. The selected patients were divided into two groups. Group allocation was done by sealed envelope with equal number of treatment assigned. At baseline level, patients’ response to cold stimulus was tested using Ortho Ice (chill spray, Dentsply, USA) on a cotton bud for 10 seconds applied on the buccal surface of the tooth in question. Patients who demonstrated exaggerated response were excluded. Group A patients teeth were restored with conventional amalgam (Tytin, Kerr, USA) without applying any liner or base while group B participants were subjected to bonded amalgam (i.e. Tytin, Kerr, USA along with Panavia 21 adhesive, Kurray Dental Inc, Japan). Equal lengths of base and catalyst paste were dispensed. No additional liner or base was applied in this group. Local anesthesia 2 % lidocaine solution in 1.7 ml cartridge (Xylestesin-A, 3M, USA) was given using standard technique. Rubber dam isolation was obtained. Cavity preparation was done with standardized technique using high speed drill with 330L (SS White, USA) bur followed by low speed drill using round bur. Cavity preparation was smoothened with hand instruments.
Class II preparations were later subjected to Automatrix (a retainer-less matrix system by Dentsply, USA). Panavia 21 adhesive was applied in the bonded group only. Amalgam was placed in the prepared cavities using increments. Carving and burnishing was done and restorative material was allowed to set. Matrix band removed and occlusal adjustments were carried out in centric and lateral movements. Patients were reminded to mandatorily visit the next day for polishing. On the next day, the response to thermal stimulus was recorded using visual analogue scale pain. For practical purpose, we interpreted the results on an ordinal scale of No pain, mild pain, moderate pain and severe pain. These findings were recorded on the customized proforma.

DATA ANALYSIS

Data was analyzed on SPSS 19.0. The frequency distribution of the qualitative variables such as type of cavity, gender, type of treatment, pre-op diagnosis and postoperative sensitivity (outcome) were determined. Chi square test was applied to determine the difference between the post-operative sensitivity in the two treatment groups (bonded versus conventional amalgam). Similarly, Chi square test was also applied to determine the difference between Class I and Class II preparation. The level of significance was kept at 0.05. The confounding variables such as age, gender and type of cavity were controlled by randomized group allocation.

RESULTS

• Study groups had similar representation of the genders, arches and teeth type (table 1).
• There were 51 conventional and 42 bonded amalgams placed in Class I cavities while there were 16 conventional and 25 bonded amalgam placed in class II cavities. There was no statistically significant difference (p value 0.067)as shown in Figure 1.
• There was no statistically significant difference (pvalue 0.481) observed between the conventional and bonded amalgam for post-operative sensitivity as shown in Figure 2.
• However, there was a highly significant difference observed between Class I and Class II cavities for postoperative sensitivity (p <0.001) as shown in Figure 3.
• Table 2 shows that Class II preparations were found to be significantly associated with post-operative

Table 1: Distribution of study groups with respects to age, gender, arch and teeth

Figure 1: Distribution of teeth with respect to type of restoration and cavity design

Figure 2: Comparison of post-operative sensitivity (outcome) in the two treatment groups

Figure 3: Comparison of post-operative sensitivity (outcome) in Class I versus Class II preparation

Table 2: Cross tabulation for post-operative sensitivity in Class I versus Class II preparation in bonded versus conventional restorations

sensitivity than Class I. This association was irrespective of a restoration being conventional or bonded type.

DISCUSSION

It’s not uncommon to have some degree of postoperative sensitivity after amalgam restorations. The likely causes are microleakage at tooth restorative interface, tooth cutting, proximity of the cavity walls to the pulp, and the thermal conductivity of freshly placed metal alloy1. Thus, the higher sensitivity in class II restoration can easily be explained by the amount of missing tooth substance that is lost in tooth preparations and subsequently restored with bulk volume of the alloy1,3.
It is known that most amalgam restorations have an initial gap between the preparation walls and the restorative material that allows a slow movement of dentinal fluid. Application of cold stimulus may cause a sudden contraction of the fluid, resulting in a rapid increase in the flow, which is perceived by patient as pain4.
There are several amalgam bonding agents available on market such as All-Bond 2 (Bisco), Amalgambond Plus (Parkell), Optibond 2 (Kerr), Panavia EX and Panavia 21 (Kuraray). The active chemical agent in them is either 4-META (4-methacryloxy-ethyl trimellitate anhydride) or 10-MDP (10-methacryloyloxydecyl dihydrogen phosphate). Investigators have used these materials for not only improving retention8 of the restorative but have also suggested to use them for getting better resistance form and reduced post-operative sensitivity9,11. In addition to the chemistry of the adhesive, it is the method of condensing amalgam onto unset adhesive resin liner that does the job. It’s the creation of an intimate mechanical interlocking of amalgam with adhesive liner that is considered to offer retention and reduce post-operative sensitivity12,13. However, there is a convincing evidence that have shown that there is no
difference in post-operative sensitivity in cases with and without bonding agents thus have seriously questioned the benefits of using bonding agents for sensitivity management14,15. Our results are in agreement with Mahler14 where use of bonding agent failed to demonstrate any advantage in reducing post-operative sensitivity. There are studies on the effect of cavity liners16 and bases or even on cavity disinfection17 affecting postoperative sensitivity. But, there is very scarce data on any relationship with cavity design and bonding agents. Our study has addressed an important research question whether bonding agents are advantageous in Class II preparations. Nearly 50% of all Class II cavities exhibit mild to moderate post-operative discomfort. However, use of cavity adhesive failed to provide any benefit in such preparations. We infer that amalgam bonding agents are not protective against post-operative sensitivity. Lack of sensitivity in Class I cavities in both groups can simply be explained by less amount of tooth reduction and hence less microleakage around restorations. The primary strength of our study was that we had an adequate sample size that was calculated scientifically. We had equitable representation of the two genders, arches and teeth type (table 1). Although, there were more Class II cavities in the bonded amalgam group but the difference for their distribution was not statistically significant thus, within the limitations of our study, we were able to answer the research question for both classes of tooth preparations.
The main limitation of our study was that the cavity dimensions were not measured. The amount of tooth substance removed during tooth preparation varies with cavity dimensions and hence the proximity to the pulp. This has substantial impact on the post-operative sensitivity. However, as the teeth were randomly allocated so we assume that both arms get similar dimensions of cavity preparation. Another important limitation in our study was that our outcome was evaluated at just 24 hours interval. With clinical experience, we know that post-operative sensitivity is usually settled on its own in a week or two. Therefore, a follow up of sensitivity would have shown the progress of treatment in the two study groups. Moreover, our outcome of interest i.e. experience of post-operative sensitivity is a subjective entity as individuals may have different tolerance level, so its impossible to actually measure it on an objective criterion. Higher sensitivity in the class II restorations can also be explained by gingival trauma from matrix band and wedge placement rather than the restoration method employed.

CONCLUSIONS

• There was no difference in the post-operative sensitivity in the conventional and the bonded amalgam restorations in the Class I preparations.
• Class II preparations were significantly associated with post-operative sensitivity than Class I preparations.
• This association was irrespective of the restoration being
  conventional or bonded type.
• Amalgam adhesive (Panavia 21) does not offer any significant protection against post- operative sensitivity in Class II preparations.

REFERENCES

1. Phillips. Amalgam restorations In: Anusavice, Kenneth, editor. Science of Dental materials. St Louis Missouri: Saunders; 2003 P. 495-543.
2. James B summit, J William Robbins, Thomas J. Hilton Richard S. Schwatz. Bonding to enamel and dentin In: Fundamentals of operative dentistry- A contemporary approach 3rd Edition Quintessence publishing Co, Inc 2006.
3. Staninec M. Retention of amalgam restorations: undercuts versus bonding. Quintessence Int. 1989; 20:347-
   351
4. Orchardson R, Gillam DG. Managing dentin hypersensitivity. J Am Dent Assoc. 2006; 137:990-8.
5. Berry TG, Summitt JB, Chung AK, Osborne JW. Amalgam at the new millennium. J Am Dent Assoc. 1998;129(11):1547-1556.
6. Smales RJ, Wetherell JD. Review of bonded amalgam restorations, and assessment in a general practice over
   five years. Oper Dent. 2000; 25:374-381.
7. Bonsor SJ, Chadwick RG. Longevity of conventional and bonded (sealed) Amalgam restorations in a private general dental practice. Br Dent J. 2009; 206:88-89.
8. Winkler MM, Moore BK, Allen J, Rhodes B. Comparison of retentiveness of amalgam bonding agent types. Oper Dent. 1997;22:200-208.
9. Browning WD, Johnson WW, Gregory PN. Clinical performance of bonded amalgam restorations at 42 months. J Am Dent Assoc. 2000; 131:607-611.
10. Ben-Amar A, Liberman R, Rothkoff Z, Cardash HS. Long term sealing properties of Amalgambond under amalgam restorations. Am J Dent. 1994;7:141-143.
11. Browning WD, Johnson WW, Gregory PN. Postoperative pain following bonded amalgam restorations. Oper Dent. 1997;22:66-71.
12. Nakabayashi N, Kojima K, Masuhara E The promotion of adhesion by the infiltration of monomers into tooth substrates. J Biomed Mater Res 1982; 16: 265- 273.
13. Setcos JC, Staninec M, Wilson NHF. The development of resin-bonding for amalgam restorations. Brit Dent Jour. 1999; 186:328-332.
14. Mahler DB, Engle JH. Clinical evaluation of amalgam bonding in Class I and II restorations. J Am Dent Assoc. 2000; 131:43-49.
15. Mahler DB, Engle JH, Simmsn LE, Terkla LG. Oneyear clinical evaluation of bonded amalgam restorations. J Am Dent Assoc. 1996; 127: 345-349.
16. Al-Omari QD, Al-Omari WM, Omar R. Factors associated with postoperative sensitivity of amalgam restorations. J Ir Dent Assoc. 2009; 55:87-91.
17. Al-Omari WM, Al-Omari QD, Omar R. Effect of Cavity Disinfection on Postoperative Sensitivity Associated with Amalgam Restorations. Oper Dent. 2006; 31:165-170.

CONFLICT OF INTEREST

There were no conflicts of interest or commercial benefits involved.

ACKNOWLEDGEMENTS

We acknowledge the dental section, Aga Khan University to provide the resources for the study.

1. Assistant Professor, Periodontics Fatima Jinnah Dental College, Karachi.
2. Assistant Professor, Operative Dentistry Aga Khan University & Hospital, Karachi.

Corresponding author: “Dr Farhan Raza Khan ” < farhan.raza@aku.edu >

Omair Majeed¹                                                              BDS

Tabassum Ahsan Quadeer²                                     BDS, FCPS

INTRODUCTION

In clinical orthodontics and dentofacial orthopedics it is becoming significant that the timing of treatment may be as crucial as the selection of relevant treatment protocol, because in the organization and development of a structure, time plays a viable role in determining the final morphological and dimensional result1,2.
Knowledge of the physiologic growth changes of the dentofacial complex is fundamental to orthodontic treatment planning3,4.
Because of individual variation in the timing of the pubertal growth spurt, chronological age is not a reliable tool for assessment of the development status. Other parameters, such as growth velocity, secondary sex changes, dental development and skeletal maturation have proven to be more accurate. The standard method to evaluate skeletal maturity has been the use of handwrist radiographs as skeletal maturation is generally determined by evaluating either the stage of ossification of bones of the hand and wrist, due to the large number of different types of bones available in this area5.
A method to assess skeletal maturation and a possible relationship to facial growth has used the morphology
of the cervical vertebrae6. Though the standard method of evaluating skeletal maturity has been a handwrist xray but in order to avoid taking an additional x-ray, some researchers sought to relate maturation with dental and
skeletal features other than the bones in the hand and wrist7. Interest in the maturational changes in both size
and shape of the cervical vertebrae dates back to the start of the century8.
Cervical vertebral maturation is an important diagnostic tool for evaluation of the pubertal growth spurt. It requires no additional x ray as the cervical vertebrae can be seen on a lateral cephalograph that is routinely done for orthodontics diagnosis and treatment planning9. Assessment of shape and size of the vertebrae gives the researcher an almost accurate idea as to the amount of growth remaining in a subject.
It has been proved by many researchers that cervical vertebral maturation has a high level of correlation with individual skeletal maturation10 and that the evaluation of the skeletal age was more efficient than that of the biological evaluation, by analyzing lateral cephalometric radiographs11.
The chronological age is not reliable in helping to establish the child’s stage of skeletal development12. It shows variability and therefore cannot accurately predict the amount of residual growth.
Ethnic and sex variations in the timing of skeletal maturation have also been noted13 according to which females are ahead of males at all levels of skeletal maturity, indicating early age of maturational development for females12.
To date, few international and very few local studies have compared chronological age and cervical vertebral maturation. The present study was conducted to determine the co-relation between the developmental age and the
chronological age. We hypothesized was that there is a strong co-relation between the developmental age and the chronological age.

METHODOLOGY

We used convenience sampling to gather the records of 53 subjects. This cross sectional study was done in the Department of Orthodontics at Bahria University Medical and Dental College, Karachi. Inclusion criteria’s for this study were male and female patients of Pakistani ethnicity, between 8-18 years of age, whose Cephalometric radiographs were available with high clarity and contrast. Records of the patients with congenital malformations of cervical vertebrae, and with a history of trauma to the vertebrae, were excluded from our study.
Records of the patients attending the orthodontic OPD for fixed/ removable orthodontic treatment at the Bahria University Medical and Dental College, and who fit our inclusion/exclusion criteria were selected. The chronological age was noted and confirmed by birth certificate; informed consent was taken from the patients that their records were being used for a study to cover the ethical issue. Our study was done on lateral cephalometric radiographs that are routinely taken for every orthodontic patient as an aid to treatment planning.
The odontoid process and the body of the second cervical vertebrae and the bodies of the third and fourth cervical
vertebrae were traced on acetate paper using 4H pencils on an illuminator. The anatomical changes observed in the concavity of the lower border and shapes of the vertebral body were studied in the following way:

Concavity of the lower border:

This is present when there is a distance of more than 1 mm between the middle of the lower border of the vertebral body and a line traced from the postero-inferior angle to the anteroinferior angle of the vertebral body. According to the concavity, six stages are defined:

Stage 1) All vertebrae have a flat lower border.
Stage 2) Concavity is present in the C2 lower border.
Stage 3) Concavity is present in the C3 lower border.
Stage 4) Concavity in C2 and C3 increases and a concavity is present in C4.
Stage 5) Concavity in all vertebrae.
Stage 6) Deep concavities in all vertebrae and the inferior angles are rounded.

Shape of the vertebral body:

This will be calculated at C3 and C4 and the following stages will be defined:
Stage 1) Upper border is tapered from the posterior to the anterior and wedge-shaped.
Stage 2) Wedge shaped C3 and nearly rectangular shaped C4 with absence of supero-anterior angles.
Stage 3) Rectangular shaped bodies.
Stage 4) Nearly squared bodies.
Stage 5) Squared bodies.
Stage 6) Rectangular shaped bodies with height greater than width.
Each stage was correlated with chronological age. Maturation was considered complete or positive when C5 (maturation) stage was achieved i.e. concavities seen in all vertebrae and the vertebrae C3 and C4 are square in shape.

STATISTICAL ANALYSIS

The collected data was analyzed by using SPSS version 22. Ratio (M: F) was computed to present gender distribution. Mean and standard deviation were computed to present age distribution. Frequency and percentages were used to present various stages of cervical vertebral maturation as stated in the operational definition. Spearman’s correlation coefficient was computed to determine correlation between chronological age and cervical vertebral maturation stages. Test of linear correlation was applied to compute p-value of significance at p< 0.05 level of significance. Age wise and gender wise stratification was done to control the confounding effect of these variables on correlation of two measurements.

RESULTS

In a total of 53 subjects, 22 were males and 31 were females (Table I) with the age range between 8 yearsand 18 years and a mean age range of 13.62 years (Table II).

Table I: GENDER DISTRIBUTION

Table II: AGE DISTRIBUTION

Table III: STAGES OF CERVICAL VERTEBRAL MATURATION

The most frequent cervical vertebrae stages in males were stage 4 followed equally by stage 1 and stage 3 (Table III). In females, the most frequent stages were stage 4 followed by stage 5. In age strata of 10-12 years, majority of male and female patients fell into stage 3 while in age strata of 12-14 years, majority of male and female patients fell into stage 4 (Table IV). Spearman rank order correlation coefficient between chronological age and cervical vertebral maturation stages was 0.90 for the sexes combined. Statistically insignificant correlations (p>0.05) were found between male and female subjects; at 0.93 and 0.85, respectively.

DISCUSSION

There is a plethora of studies on cervical vertebral maturation, chronological age and residual growth in an individual and almost all of the published literature goes to show the associations between these entities. There is very little local published literature as regards to the association between chronological age and cervical vertebral maturation and this was the reason for choosing such a study so as to generalize this method to orthodontic practice in Pakistani population. The limitation of our study is that it had a very small sample size and so our results will have less reliability. However further studies can add on this to establish more reliable results. The change in shape and size of the cervical vertebrae in growing individuals has gained much popularity in the last decade or so as a biological indicator of skeletal maturity. Skeletal maturity is the most commonly used index in routine clinical work and is closely related to sexual and somatic maturity2. It is important to identify a subject’s maturational levels, as in doing so the clinician can easily make a decision as to the type of treatment that need to be given in a very suitable manner.
The cervical vertebral method devised by Lamparski and later modified by Hassel and Farman includes changes
in the lower border and shape of the cervical vertebrae. The method of Hassel and Farman is better than the method by Lamparski because it requires the assessment of three vertebrae only i.e. C2, C3 and C4. The use of the cervical vertebrae does not require an additional radiograph of the hand and wrist as just one lateral cephalometric radiograph of the head provides a practical means to estimate adolescent growth14. It is divided into six stages and denotes growth in a descending fashion from CVMS1 to CVMS 6. The amount of residual growth in different stages is different. It is 80-100% in INITIATION, 65-85% in ACCELERATION, 25-65% in TRANSITION, 10-25% in DECELERATION, 5-10% in MATURATION and little or no growth in COMPLETION15.
This knowledge of residual growth has a lot of clinical significance in the field of Orthodontics. The method can be used as a maturational index to detect the optimal time to start treatment of jaw (maxilla or mandible) deficiencies by means of functional jaw orthopedics. The peak of mandibular growth starts at CVMS2 and reaches a peak at CVMS3 and this is the time when mandibular deficiencies can be best treated by functional appliances.
In the correction of vertical problems of the face caused by deficiency of the mandibular ramus, height can be controlled with orthopedic treatment at the peak in mandibular growth (CVMS3)16. In a study by Gu and Mc Namara Jr,17 the peak increase in mandibular length was observed during the interval between CVMS3 and CVMS 4.
Similarly treatment of skeletal class III malocclusions occurs effectively before the onset of CVMS 1. The use of CVM method also showed that rapid maxillary expansion before the peak in skeletal growth velocity is able to induce more pronounced transverse craniofacial changes at the skeletal level. During or after the peak, changes produced by expansion are largely dentoalveolar in nature1.
In our study, we divided 53 subjects (31 males and 22 females) into five age groups. In this way we were able to find the coincidence of the CVM stages in different age groups (Table IV and V).

In both males and females, the most frequent CVM stage was CVMS4 and it mostly occupied the age range between 12-14 years, while the stage that marks the peak of growth i.e. CVMS 3 was found to lie in the age range of 10-12 years (Table IV).
In males only, the peak stages i.e. from CVMS 2 to CVMS 3 lied in the age range between 10 -12 years (Table V) which goes to show that that any mandibular deficiency showed be treated at this stage. Similarly Uysal et al18 in their study using Hassel and Farman’s method in a sample of 503 subjects also showed the peak of males to lie in the age group between 9-12 years.
However, CVMS1 (INITIATION) in males was found to lie in the age range between 8-12 years which shows that treatment of maxillary deficiency showed be done well before this age. In females only, the peak stage CVMS 3 was found to lie in the 10-12 years age group (Table V). Uysal et al18 also found the peak stage to lie in the same age group.
In our study, the Spearman rank order correlation coefficient between chronological age and cervical vertebrae maturation stages was 0.90 for the sexes combined. Statistically in-significant correlations were found for the male and female subjects: 0.93 and 0.85 respectively (Table V). Uysal et al18 also found the Spearman’s coefficient between both parameters to be 0.72 for the sexes combined and 0.68 and 0.82 for males and females respectively. Sukhia and Fida19 in their study

found the Spearman’s coefficient between CVM stages and chronological age to be 0.78 for both the sexes. In the study of Hassel and Farman22, the correlation coefficient was 0.77 for boys and 0.84 for girls. In the study of Roman et al, 20 the age range was 5-13 years and the correlation coefficients were 0.79 for boys and 0.85 for girls. Therefore our study clearly indicates a high correlation between CVM stages and chronological age.

CONCLUSION

We conclude that there was a statistically significant correlation between chronological age and cervical vertebral maturation stages and that the peak of growth lies in the age range between 10-12 years.

REFERENCES

1. Baccetti T, Franchi L, McNamara JA Jr. The cervical vertebral maturation (C VM) method for the assessment of optimal treatment timing in dentofacial orthopedics. Semin Orthod. 2005;11:119-129.
2. Rasool G, Bashir U, Kundi I: Comparative evaluation between cervical vertebrae and hand-wrist maturation for assessment of skeletal maturity in orthodontic patients. Pakistan Oral & Dental Journal Vol 30, No. 1,2010).
3. Malta LA, Ortolani CF: Quantification of cranial base growth during pubertal growth. Journal of Orthodontics, Vol. 36,2009, 229-235.
4. Bacceti T, Franchi L, Mc Namara JA Jr: Growth in the Untreated Class III Subject. Semin Orthod 2007;13:130-142.
5. Caldas MP, Ambrosano GMB, Neto FH: Use of cervical vertebral dimensions for assessment of children growth. J Appl Oral Sci. 2007;15:144-147.
6. Gabriel DB, Southard KA, Qian F, Marshall SD, Franciscus RG and Southard TE: Cervical vertebrae maturation method: Poor reproducibility. Am J Orthod Dentofacial Orthop 2009;136:478.e1-478.e7.
7. Vasquez MJ, Baccetti T, Franchi L and James A. McNamara JA Jr: Dentofacial features of Class II malocclusion associated with maxillary skeletal protrusion: A longitudinal study at the circumpubertal growth period. Am J Orthod Dentofacial Orthop 2009;135:568.e1-568.e7.
8. Bacceti T, Franchi L, Mc Namara JA Jr. An Improved Version of the Cervical Vertebral Maturation (CVM) Method for the Assessment of Mandibular Growth. Angle Orthod 2002;72:316-323.
9. Chen L, Liu J, Xu T and Lind J: Longitudinal study of relative growth rates of the maxilla and the mandible according to quantitative cervical vertebral maturation. Am J Orthod Dentofacial Orthop 2010;137:736.e1-736.e8
10. Kuc-Michalskaa M, Baccetti T: Duration of the Pubertal Peak in Skeletal Class I and Class III Subjects. Angle Orthod 2010;80:54-57.
11. Marcelino E, Tavano O, Carvalho IMM: Cervical vertebrae as growth and development estimator in cleft/ lip and palate patients. Salusvita, Bauru, v. 24, n. 1, p. 21-28, 2005.
12. Kamal M; Ragini, Goyal S: Comparative evaluation of hand wrist radiographs with cervical vertebrae for skeletal maturation in 10-12 years old children. J Indian Soc Pedod Prev Dent 2006;24:127-135
13. Soegiharto BM, Cunningham SJ, Moles DR: Skeletal maturation in Indonesian and White children assessed
    with hand-wrist and cervical vertebrae methods. Am J Orthod Dentofacial Orthop 2008;134:217-226.
14. Basaran G, Ozer T, Hamamci N: Cervical vertebral and dental maturity in Turkish subjects. Am J Orthod Dentofacial Orthop 2007;131:447.e13.e20
15. Hassel B, Farman AG. Skeletal maturation evaluation using cervical vertebrae. Am J Orthod Dentofacial
    Orthop. 1995;107:58-66
16. Wong RWK, Alkhal HA, Rabie ABM. Use of cervical vertebral maturation to determine skeletal age. Am J Orthod Dentofacial Orthop 2009;136:484.e1- 484.e6
17. Gu Y, McNamara JA Jr. Mandibular Growth Changes and Cervical Vertebral Maturation. Angle Orthod
    2007;77:947-953.
18. Uysal T, Ramoglu SI, Basciftci, sari Z. Chronological age and skeletal maturation of the cervical vertebrae and hand-wrist: Is there a relationship?. Am J Orthod Dentofacial Orthop 2006;130:622-628.
19. Sukhia RH, Fida M. Correlation among chronolgical age, skeletal maturity and dental age. World J Orthod
    2010;11:e78-e84.
20. San Román P, Palma JC, Oteo MD, Nevado E. Skeletal maturation determined by cervical vertebrae development. Eur J Orthod. 2002;24:303-311.
    

    ---

    1. Department of Orthodontics Bahria University Medical and Dental College.
    2. Assistant Prof. and Head Department of Orthodontics Bahria University Medical and Dental College
    Corresponding author: “Dr Omair Majeed ” < dromairis@hotmail.com >

Shahbaz Khan¹                                                                 BDS, MPhil (Scholar)

Muhammad Amber Fareed²                                       BDS, MSc, PhD

Muhammad Kaleem³                                                   BDS, MSc, PhD

Shahab Ud Din³                                                                 BDS, MSc, PhD

Kefi Iqbal⁴                                                                         BDS, MSc, PhD

INTRODUCTION

Majority of endodontic failures results due to leakage of irritants from pathologically involved root canals. When a conventional non-surgical procedure fails to save the tooth, surgical endodontic therapy is indicated. The outcome of surgical endodontic procedures relies on the complete prevention of bacterial leakage from root canal system into periapical tissues. Therefore, selection of a suitable endodontic filling material is of great importance for successful
endodontic treatment1. Over the years several materials were developed and suggested for surgical endodontic applications such as, amalgam, gutta percha, zinc phosphate cement, polycarboxylate cement, zinc oxide eugenol paste, ethoxy benzoic acid (EBA) cement, glass ionomer cements, composite resins and mineral trioxide aggregate (MTA)1,2. MTA was pioneered by Torabinejad and White for root end filling and endodontic repair procedures3. The
novel material was patented in 19954 and approved for endodontic applications in 19985 having commercial name ProRoot MTA (Tulsa Dental Products, Tulsa, OK, USA)6 . MTA was initially introduced in gray form (GMTA), however due to discoloration potential of GMTA white form of MTA (WMTA) was developed7.

Since inception, MTA rapidly gained acceptance among dentists and has been extensively investigated as a potential material to seal the pathways of communication between the tooth root canal system and the external surfaces8. Due to superior biocompatibility, bioactivity and sealing ability9, MTA is used for both surgical and non-surgical endodontic applications8.

The aim of part-1 updated review is to emphasize the current knowledge of compositional analysis, material characteristics, setting behavior, mechanism of action and physical properties of MTA. Whereas, part-2 updated review draw attention to the clinical applications of this promising material in root-end filling, perforation repair, vital pulp therapy, and apical barrier formation in addition to the comprehensive comparison of other MTA alternative materials available commercially. Therefore, a systematic research of previously published work in PubMed/MEDLINE (National Library of Medicine, Bethesda, MD), Scopus and Google Scholar databases were conducted from 1995 to November 2014 using different combinations of the following key words: “mineral trioxide aggregate”, “composition”, “clinical applications”, “mechanism of action”, “physical and biological properties”. The literature was screened by authors for relevancy and key findings of the current concepts of MTA are reported here.

2. MATERIAL CHARACTERISTICS

2.1 Composition of MTA

MTA was inspired and derived from an ordinary Portland cement (PC)10 therefore; MTA’s chemical composition is considerably similar to Portland cements. MTA is a complex chemical compound composed of various mineral phases which comprised of simple oxides of various elements11. Therefore composition of unset MTA powder is generally evaluated in terms of elemental composition, presence of simple oxides and mineral phase composition. Several studies evaluated elemental composition of MTA and reported that calcium, silica, bismuth and oxygen comprise the main elements present in MTA6,12,13. According to the MTA patent, calcium and silica are the main reactive elements whereas bismuth was added for radiopacity8,10. Both gray and white variant of MTA contains similar elements, except for the presence of iron in GMTA and comparatively low amounts of aluminum in WMTA6,13-16 (Tab. 1).
According to Torabinejad and White, the experimental

Tab. 1: Elemental composition, simple oxides and mineral phases of
GMTA and WMTA.

material used in the patent consisted of calcium oxide (50-75 wt %), silicon oxide (15-25 wt %) and aluminum oxide, together these oxides constituted 70-95 wt % of MTA10. The compositional imaging of both types of MTA presented oxygen distribution throughout crystalline and amorphous phases which indicated that all elements in MTA were present in their oxide form13. Furthermore, Asgary et al., evaluated the chemical differences between both variants of MTA and reported that WMTA contained relatively less amounts of iron oxide, aluminum oxide and magnesium oxide. The authors interpreted that less amount of iron oxide is responsible for the white color of WMTA13. The oxides of chromium, iron and copper which have free d electrons have strong colors. Whereas, oxides of elements where electrons cannot be easily excited such as aluminum, silicon, calcium and titanium are either colorless or white12. When the aforementioned oxides are blended together they produce mineral phases such as dicalcium silicate (C2S), tricalcium silicate (C3S), tricalcium aluminate (C3A) and tetracalcium aluminoferrate (C4AF)17. Song et al. reported that crystal structure of both types of MTA were similar and chemically contained calcium silicate phases and bismuth oxide14. Similarly, Camilleri et al., reported that X-ray diffraction analysis (XRD) showed both variants of MTA were purely crystalline and composed of identical mineral phases. The WMTA was primarily composed of C3S and bismuth oxide, while in GMTA, C3S, C2S and bismuth oxide constituted primary mineral phases6.

2.2 Particle morphology of MTA

Particle size and morphology of a biomaterial is important because it significantly affects the physical properties. For hydraulic materials such as MTA, a smaller particle size results in more surface area available to react with water which accelerates the setting reaction and provides greater early strength7. Moreover, the uniform particle size distribution have higher mechanical properties due to reduction of spreading in grit size18.
Many studies have investigated particle size and shape of MTA and reported that WMTA particles were finer in comparison to GMTA6,13,19. MTA particle size range is less than 1 µm to approximately 30 µm however; occasionally particles up to 50 µm were also reported. The particle size of bismuth range between 10-30 µm20.
Asgary et al., reported particles of 5-50 µm in GMTA and 5-25 µm in WMTA13. Camilleri et al. reported that both types of MTA contained irregular particles. WMTA contained small irregular particles with some elongated

needle like particles whereas, GMTA contained large irregular particles along with small as well as elongated particles (Fig. 1)6.

3. SETTING REACTION OF MTA

The setting reaction of MTA is a complicated process depending on the exact proportions of mineral phases, their purity and temperature of the mix21. On hydration calcium silicates present in MTA undergoes hydrolysis and produce calcium silicate hydrate and calcium hydroxide21. About one third of hydration products constituted by calcium hydroxide22 to renders MTA highly alkaline20. On hydration any excess calcium oxide readily reacts to form calcium hydroxide as:
CaO + H2O g Ca(OH)2 …21
Whereas, C2S and C3S react with water to produce calcium silicate hydrate (C-S-H) and calcium hydroxide
as:
2(3CaO.SiO2) + 6H2O g 3CaO2.SiO2.3H2O + 3Ca(OH)2 …22
and,
2(2CaO.SiO2) + 4H2O g 3CaO2.SiO2.3H2O + Ca(OH)2 …22
The C3S is most important mineral phase in MTA and engages in the formation of C-S-H to provide early strength. On the other hand, C2S reacts relatively slow and give later strength to the set material23. C3A present in MTA reacts with water to form calcium aluminates and (in presence of calcium sulphate) sulfate aluminates21.
The C-S-H, the major hydration product of MTA is an amorphous compound with varying stoichiometric values. The Ca:Si ratio in C-S-H generally varies between 0.8 and 2.1 with highly variable content of water23 therefore, set MTA can be described as calcium hydroxide contained within a silicate matrix6.

4. MECHANISM OF ACTION

The successful usage of MTA in endodontic applications can be attributed to its biocompatibility, bioactivity and mechanism of action. Parirokh and Torabinejad24 summarized the four actions of MTA after direct placement in contact with living tissues (Fig. 2);
(i) Creation of an inhospitable environment for growth of bacteria due to alkaline pH.

(ii) Formation of hydroxyapatite like mineral structure on its surface and provide the biological seal.
(iii) Formation of calcium hydroxide which dissociates to release Ca ions to promotes cellular attachment and proliferation.
(iv) Modulation of cytokine production and encouragement of hard tissue forming cells to differentiate and migrate.

4.1 Inhibition of bacterial growth

MTA is a potent growth inhibitor of staphylococcus aureus, enterococcus faecalis and pseudomonas aeruginosa as compared to amalgam, Geristore (Resin modified GIC), Super-Bond C&B (resin cement), Dyract (compomer) and Clearfil AP-X (composite)25. As discussed above, in the setting reaction of MTA, C-S-H and calcium hydroxide forms. The dissociation of calcium hydroxide in calcium and hydroxide ions results in an increased pH of MTA. Therefore, its antimicrobial properties can be attributed to elevated pH26. Torabinejad et al., reported alkaline pH (10.2) of MTA at initial stages after mixing which increases to 12.5 after an elapse of 3 hours27. A pH level of 12.0 can inhibit growth of most microorganisms including resistant enterococcus faecalis28.

4.2 Precipitation of apatite crystals

MTA releases majority of cationic components in tissue fluids and out of all ions, calcium is the most dominant one. Calcium being sparingly soluble in tissue fluids reacts with tissue phosphates and precipitates HA29. The chemical reaction responsible for the formation and precipitation of HA is:

10 Ca+2 + 6(PO4)-3 + 2(OH)-1 g Ca10(PO4)6 (OH)2 . . .29

This chemical reaction is well known in biological calcification processes which is favored at pH of 7.030 and takes place in the presence of biological environment both in-vivo and in-vitro with calcium containing materials31,32. A material which possess an apatitic surface layer in close contact with mineralized tissues can bond chemically to the later31. Therefore, surface precipitation of hydroxyapatite (HA) gradually continues to the internal structure and this may change the overall compositional constitution of MTA29. According to Sarkar et al., a series of physico-chemical reactions are responsible for the sealing ability of MTA. After placement in root canal, MTA dissociates gradually which leads to nucleation of HA crystals and subsequent precipitation of HA fills the microscopic spaces present between MTA and canal walls. A diffusion-dependant reaction between HA surface layer and dentine mineral structure occurs with course of time and the initial mechanical seal between MTA and dentine wall is converted to a chemical one29.

4.3 Cellular response and mineralization

Cellular response to MTA or its extracts have been extensively studied and reported to modulate expression of cytokines and other biological markers33-35. Studies have shown up-regulation of interleukin (IL- 1a , IL1b, IL-2, IL-4, IL-6, IL-8, IL-10, IL-18), osteocalcin, osteopontin, alkaline phosphatase and bone morphogenic protein-233 38. Abdullah et al., studied the effect of MTA, GIC and two variants of PC on expression of IL-1b, IL6, IL-18 and osteocalcin in a direct contact assay model and reported the up-regulation in cultures with direct contact in MTA and both variants of PC.

5 PHYSICAL PROPERTIES OF MTA

5.1 Compressive strength

Reactive phases of MTA possess different hydration rates, C2S hydrates slowly than C3S, therefore mechanical properties of MTA may take several days to reach their maximum7. MTA shows relatively less compressive strength compared to amalgam, glass ionomer cements and composites4,7 which can be influenced by powder/water ratio used, type of the liquid used for mixing, pH of the mixing liquid and the environment and storage conditions7,39-41.

5.2 Push out strength

A material used for repair of perforations should possess sufficient push out strength to resist dislodgement forces which are generated by functioning of the tooth7. MTA posses lower push out strength compared to IRM (reinforced zinc oxide-eugenol cement) and Super EBA (alumina-fortified cement) after immersion in intra canal bleaching materials42. Hydraulic nature and slow hydration rate of C2S makes push out strength of MTA liable to be influenced by pH, humidity, time after mixing and storage conditions7,42-43.

5.3 Porosity

A widely used technique for characterizing the distribution of pore sizes in cement-based materials (mercury intrusion porosimetry) employed for WMTA and white PC showed consistent presence of pores in both materials. However, pore volume observed in WMTA was significantly less compared to white PC44. Porosity in set structure of MTA is affected by powder/water ratio, addition of bismuth oxide, entrapment of air during mixing material and pH of the environment7,45-47.

5.4 Radiopacity

The addition of bismuth oxide renders MTA radiopaque6 which is sufficient to make MTA recognizable on radiographs4. However, radiopacity of MTA is less than amalgam and gutta percha48,49.

5.5 Solubility

Solubility of MTA is influenced by the powder/water ratio used for its mixing. A higher amount of water leads to more porosity and increases solubility in set structure of MTA by causing calcium released in greater amounts46.
Solubility in tissue fluids can jeopardize clinical performance of endodontic materials50. Several researchers have reported that MTA have little or no solubility4,51, however, in contrast, Fridland and Rosado reported increased solubility of MTA in a long term study52.

5.6 Marginal adaptation and sealing ability

Marginal adaptation and sealing ability of endodontic filling materials is of paramount importance since irritants that leaks from infected root canals to surrounding periradicular tissues accounts for majority of endodontic failures50. Several studies reported that MTA holds better marginal adaptation compared to amalgam, Super EBA, IRM and glass ionomer cement (GIC)53-55. The sealing ability of MTA was extensively evaluated by leakage studies (dye leakage, fluid filtration, protein leakage and bacterial leakage) and had shown superior sealing ability for MTA compared to amalgam, IRM and super EBA33,55-57. The setting reaction of MTA is accompanied with setting expansion which may reduce gaps between MTA and dentinal walls58. According to Torabinejad et al., dentine-biomaterial interface of amalgam, super EBA and IRM showed gaps (3.8-14.9 µm) while, the interface was free of any gaps in case of MTA55. A meta-analysis of studies on endodontic filling materials reported better prevention of dye and bacterial penetration for MTA compared to amalgam59, however extend setting reaction of MTA, pH of surrounding environment, thickness of MTA filling and dentinal wall can affect sealing ability of MTA33,60-61.

6. EFFECT OF BISMUTH OXIDE ON PHYSICAL PROPERTIES OF MTA

Radiopacity of a root end filling material is one of its basic requirements50. Bismuth oxide exhibit higher absorption of shorter wavelength X-ray radiations8 and due to its presence, MTA possess a radiopacity of 7.17 mm equivalent thickness of aluminum4. Torabinejad and White added 20% wt bismuth oxide in MTA to render it radiopaque. Both GMTA and WMTA consist of 75% wt. calcium silicate, 20% wt. bismuth oxide and 5% wt. calcium sulphate10. MTA contains 10-30 µm sized particles of bismuth oxide20 which are trapped in the amorphous phases of set GMTA and WMTA13. Several studies have evaluated the effect of bismuth oxide on properties of MTA. Kim et al. evaluated the effect of bismuth oxide addition on radiopacity and cytotoxicity of Portland cement and reported a linear correlation between the observed radiopacity and amount of bismuth oxide, whereas no difference was found in the amount of bismuth oxide and cytotoxicity of the material62.
Coutinho-Filho et al. evaluated MTA, PC and a combination of PC and bismuth oxide and revealed positive correlation between radiopacity and concentration of bismuth oxide. The outcomes of histological examination after subcutaneous implantation in rats suggested that all tested materials were biocompatible63 .
However, addition of bismuth oxide can affect physical and mechanical properties of MTA and reduce compressive strength by incorporating flaws and increased porosity in the set structure7,21,45. Bismuth oxide is simultaneously present in the set structure of MTA as unreacted filler and a part of C-S-H20. Darvell and Wu considered that bismuth oxide act as inert filler with no contribution in setting reaction of MTA21. Whereas, Camilleri reported relatively lower peaks for bismuth oxide in XRD pattern of hydrated MTA compared to unhydrated MTA and interpreted the lower peak heights to “use up” of bismuth in hydration mechanism and suggested that bismuth takes active part in setting reaction and replaces silica in C-S-H64.

7. CONCLUSIONS

This review systematically summarized the contemporary knowledge of MTA with respect to materials science and clinical dentistry. The last 15 years have seen major developments in the chemistry of MTA due to its potential use in dentistry and biocompatibility. The nature of setting reactions favors placement in endodontic procedures having moist environment as it consists of fine hydrophilic particles of natural minerals. MTA facilitates the formation of HA like mineral structure on its surface when it comes in contact with tissue fluids hence provide a biological seal. Hydration of MTA forms a colloidal gel that solidifies in due course however, the physical properties are influenced by various factors therefore, different results may be obtained during investigation of MTA’s physical properties.

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1. M.Phil Student, Department of Dental Materials, Army Medical College, National University of Sciences and Technology, Islamabad, Pakistan. Department of Operative Dentistry, Bolan Medical College, University of Balochistan, Quetta, Pakistan.
2. Associate Professor, Department of Dental Materials Science, FMH College of Medicine and Dentistry, University of Health Sciences, Lahore, Pakistan
3. Assistant Professor, Department of Dental Materials, Army Medical College, National University of Sciences and Technology, Islamabad, Pakistan.
4. Professor, Department of Dental Materials Science, Baqai Dental College, Baqai Medical University, Karachi, Pakistan.
   Corresponding author: “Dr Muhammad Amber Fareed ”<docamberfareed@hotmail.com >