KNOWLEDGE, ATTITUDE AND PRACTICES OF PROSTHODONTIC PARAMEDICAL STAFF REGARDING DISINFECTION OF IMPRESSION MATERIALS

INTRODUCTION

Cross-infection control is an extremely important aspect of modern day dental setup. Although it is a century old belief, it has become even more important in today’s world of communicable infections carrying a high morbidity and mortality rate.¹ The oral micro-flora is very diverse due to the presence of a friendly environment.² This micro-flora is involved in the contamination of dental impression materials and prosthesis.² Source of transmission of diseases through these impression materials is by contact of oral tissues, blood and saliva. Immediate disinfection of impression materials after removal from mouth can minimize or prevent spread of infectious diseases greatly.³

American Dental Association and Centers for Disease Control and Prevention have recommendations regarding the disinfection protocol of the impression materials which should be considered as routine procedure in dental laboratories.³⁻⁵ There is a need of strong communication between dentists and paramedical staff to enforce cross-infection protocols. To achieve desirable results regarding disinfection of impression materials, laboratory staff should have proper training courses.⁶ Impressions are assumed to be loaded with microorganisms in those clinical settings where they are directly sent to the dental laboratory, without any disinfection. Therefore, the paramedical staff are at risk of cross-contamination from such contaminated impression.¹ Impressions are poured and casts are prepared from them as a routine dental procedure and therefore this cast also acts as a medium for the spread of microorganisms in the lab.⁸

For disinfecting impressions, the American Dental Association and Centre of Disease Control and Prevention (CDC) provided different strategies in 1988, 1991 and 1996.⁹,¹² Depending on the material, these guidelines recommend different methods for disinfection of impression materials.⁹–¹¹ The infectious diseases which are transmissible from these impression materials are hepatitis B, Tuberculosis, Herpes and AIDS.¹³–¹⁵ Disinfection protocols have also been developed to avoid the transmission of these diseases.⁹,¹¹,¹⁶,¹⁷ However, at the same time these protocols can affect accuracy of the impression material as well as detailed reproduction of the surface of these impressions.¹⁸ The dimensional effects of disinfecting agents and methods on impression materials have been described in many studies, however a lot of disagreement still exists.¹⁹,²⁰,²¹.

A recent study from India reported poor practices of dental auxiliaries for disinfecting impressions.² There is a lack of local data on this subject. Therefore, the aim of this study was to determine the knowledge, attitude and practices of paramedical staff (dental assistants, dental hygienist and laboratory technicians) working in prosthodontics department in nine dental colleges of Karachi towards disinfection of impression materials.

METHODOLOGY

This was a questionnaire based cross sectional, descriptive survey. It was conducted in Prosthodontics department of dental colleges in Karachi, Pakistan. Associate Dean Post Graduate Programs Dental faculty and MDS Program Director gave the approval of the study. In each dental college the head of the department was personally approached and objectives and methodology of the study were explained. The study was completed in two months time period. A total of 34 paramedical staff members were questioned. Since there is a lack of job description among technicians, assistants and hygienist in the institutes we have used a generalized terminology of paramedical staff for all categories. Using cross sectional single population formula with 95% confidence interval, 50% prevalence and 5% margin of error the sample size calculated was 384. But the total number of para medical staff working in prosthodontic department at that time period in following colleges was only 40. Out of 40 only 34 participants responded. The colleges included in the study were Dr Ishrat-ul-Ebad Khan Institute of Oral Health Sciences Karachi (DIKIOHS), Fatima Jinnah Dental College (FJDC), Jinnah Medical and Dental College (JMDC), Baqai Medical and Dental University (BMDU), Karachi Medical and Dental College (KMDC), Liaqat Medical and Dental College (LMDC), Hamdard College of Medicine and Dentistry (HCM&D), Altamash Institute of Dental Medicine (AIDM) and Sir Syed Medical and Dental College (SMDC). The paramedical staff were contacted, questionnaire distributed to them and then recollected on the same day except from those who are absent on that day. Therefore, the response rate of the study was 85%. The questionnaire consisted of information regarding experience of participants’ respective field, their education, any additional courses regarding their field, their knowledge about the impression procedures and disinfection of these materials. The questions were both open ended and closed ended type. Self report measures of the outcome was considered so no grading system was used in the study. The types of outcome measures included in the study were knowledge of the dental paramedical staff about daily uses and concentration of disinfection solution used in their respective departments, their attitude toward above mentioned knowledge, practice of infection control procedures, disinfection of impression materials, duration of disinfection, changes occur during disinfection and cleaning of impression trays.

For Statistical analysis, Statistical Package for Social Sciences (SPSS) version 16 was used. The collected data was analyzed by descriptive statistics and presented as frequency tables.

RESULTS

The Sociodemographic characteristics of the respondents.

A total of 9 colleges were contacted for the study. All the colleges agreed to participate. Thirty Four (34) paramedical staff were included in the study by convenience sampling. There were 10 (37.0%) dental assistants, 12 (44.4%) dental technicians and 7 (18.5%) dental hygienists. Seven participants did not mention their field. There were 32 (94.1%) males and 2 (5.9%) females. (Table 1)

Knowledge regarding protocol followed for the disinfection of impression material before and after impression making. (Table 2)

Table 2 – Knowledge regarding protocol for disinfection of impression materials before & after impression making

The study revealed that the majority of participants (85.3%) knew that it was important to disinfect the impression after impression making. However, 52.9% of dental auxiliaries believed that dental labs were adequately instructed regarding disinfection techniques for different impression materials.

Knowledge regarding methods of disinfection of various 

Table 3 Knowledge regarding methods of disinfection of various impression materials.

impression material by the dental anxiety.

Fifteen participants (44.1%) did not have knowledge regarding the method used for the disinfection of alginate impression material, whereas the responses for other materials are given in table no. 3.

Attitudes and Practices for disinfection of commonly used impression materials

Table 4 reveals that 21 (61.8%) respondents were unaware of the type of disinfectant for alginate impression material. Glutaraldehyde was used for disinfection of alginate impression material mentioned by 11.8% of the participants, whereas 17.6% answered that sodium hypochlorite was used to disinfect the alginate impression material.

Attitude and practices for disinfection of other impression materials

Almost half of the respondents (52%) were unaware of duration for disinfection of alginate materials (figure no. 1). Similarly, 44% did not disinfect the impressions at all (figure no. 2).

impression material are shown in table 4.

Duration for disinfection of alginate material.

Almost half of respondents (50%) were unaware of duration for disinfection of alginate material.

Figure 2: Disinfection of impression in the lab after receiving from dental clinic.

Discussion

The regulatory body of the dental profession in Pakistan (i.e., the Pakistan Medical and Dental Council) recommends strict disinfection procedures, but no studies are available that demonstrate routine adherence to the guidelines. The present survey was designed to assess knowledge, attitude, and practices of prosthodontic paramedical staff working in dental colleges of Karachi towards disinfection of impressions. The risk of cross-infection from a patient to paramedical staff is a matter of concern. A high standard of hygiene and disinfection of dental materials, including dental impressions, is recommended in order to protect all the members of the dental team. Dentists and paramedical staff are at greater risk from infectious diseases because of the nature of their profession. Dental health care professionals can be exposed to these bacteria and viruses directly and indirectly through patient’s saliva, blood, skin, oral secretions, sharp infected instruments, and aerosols.

Universal procedures for cross-infection control, including sterilization of critical objects, disinfection of semi- and non-critical objects, and proper disposal of waste, are recommended to prevent transmission of infection. These procedures should be established, routinely exercised, and followed in all dental offices and laboratories as a part of a cross-infection control program. Since the 1980s, there has been increasing awareness among dental professionals about cross-infection control. In spite of this, many dentists and paramedical staff still do not practice this attitude in their work.

Jagger et al. conducted a questionnaire-based study addressing dental technicians and found that 56% of the laboratories did not know whether impressions coming from dental offices were adequately disinfected. Similar results were obtained in the present study, where 50% of the paramedics were unaware of the disinfection status. In this study, 41.2% of paramedical staff did not disinfect impressions when they received them from dental offices. A questionnaire-based survey of Taiwanese dentists revealed improved adherence to cross-infection control practices; however, handling of impressions remained a major concern.

The findings of the present study revealed that 61.8% of staff were unaware of the disinfectant used for alginate impression material. Additionally, 97.1% and 76.5% were unaware of the duration and concentration of disinfection respectively for alginate impression materials. Moreover, 82.4% of paramedical staff did not know about the method used for disinfection of polyether impression material. Similar results were reported by Marya et al., in a questionnaire-based study, where 76% of respondents used only tap water to clean impressions. However, a systematic review revealed improving standards in developed countries.

The American Dental Academy (ADA) provides various strategies for infection control in commercial dental laboratories, but the results of this survey show that in the majority of dental colleges, staff members are not aware of these guidelines, and even if they have knowledge about them, they do not follow them due to lack of facilities or proper protocols.

Conclusion

From the findings, the following conclusions can be drawn:

1. The majority of participants did not have knowledge regarding the method used for the disinfection of various impression materials.
2. Most respondents scored poorly in their attitudes toward disinfection procedures.
3. Almost half of the respondents were unaware of the duration required for disinfection of alginate impression material.
4. Most paramedical staff did not disinfect impressions at all.

Recommendations

Dental colleges in Karachi should not only ensure that disinfection protocols are followed routinely in each department but also train dental technicians and other dental auxiliary personnel in proper techniques.

reinforce of importance of following item.

ACKNOWLEDGEMENTS

Without ALMIGHTY ALLAH it was not possible to complete the task. We would like to thank our parents, family and friends for their support and cooperation. We would like to thank Dr. Arshad Hasan for his guidance and support. We would also like to thank Dr. Tahir Khan of the Epidemiology Department of Sindh Medical College for his meticulous support with statistical analysis.

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