Investigating the Cytotoxic and Anti-Bacterial Activity of Commercially Available Local Anesthetics: An In-Vitro Analysis

Eisha Imran                       BDS

Faisal Moeen                     BDS, MSc

Humayoon Satti               PhD

Lubna Rahman                M.Phil

OBJECTIVE: To evaluate and compare the influence of three local anesthetic dental formulations manufactured in France (Septodont), Korea (Medicaine) and Pakistan (HD-Caine) in terms of cytotoxicity and anti-bacterial activities.
METHODOLOGY:
90 commercially available local anesthetic cartridges of similar composition (2% lidocaine with epinephrine 100,000) viz. Septodont, Medicaine and HD-Caine were randomly collected from three different Pakistani cities and were assigned as Group S, Group M and Group H, respectively. The cartridges were further divided into three sub-groups each consisting of 10 cartridges to first evaluate cytotoxicity on Mesenchymal Stem Cells (MSCs) using a flow cytometer and secondly to investigate anti-bacterial activity by measuring zones of inhibition and through Broth Dilution Method against five bacterial strains.
RESULTS:
The results indicated that Septodont (94.5±0.1) and Medicaine (94.7±0.0) showed the highest viability percentage with no significant difference when the two were compared (P=0.6). HD-Caine (93.9±0.0) showed the least, being significantly (P<0.01) different from Septodont and Medicane. A statistically significant (P<0.05) difference was identified between the three study groups regarding the anti-bacterial activity. HD-Caine showed the highest anti-bacterial potential, followed by Medicaine and Septodont.
CONCLUSION:
Mild toxicity was observed by all the three groups in human MSCs, justifying their safe use in clinical practice. Additionally, Medicane and HD-Caine showed significant anti-bacterial activity indicating their possible use as sterile irrigants.
KEYWORDS: Dental anesthesia, Lidocaine, Epinephrine, Antibacterial activity
HOW TO CITE:
Imran E, Moeen F, Satti H, Rahman L. Investigating the cytotoxic and anti-bacterial activity of commercially available local anesthetics: An in-vitro analysis. J Pak Dent Assoc 2020;29(4):185-192.
DOI: https://doi.org/10.25301/JPDA.294.185
Received: 02 June 2020, Accepted: 28 July 2020

INTRODUCTION

Local anesthesia laid the foundation for pain management techniques in dentistry.1 and is indicatedin almost every dental procedure as it provides numbness to both hard and soft tissues of the oral cavity resulting in insensibility to pain while the patient remains conscious. Comparably secure and standardized anesthetic solutions are utilized these days but still these solutions require exploration, with an aspiration of bringing an innovation, which would enhance the beneficial effects and diminish the adverse effects of these compulsory drugs. Drugs used in these solutions may notably intrude with the normal physiological processes of the body, causing local and systemic side effects. “Pain at injection site2, pungent taste3, lack of desired effect due to inappropriate anesthetic technique4, ulceration and induced infection at sites of injection are the few local complications.
Systemic complications such as toxicity develop when toxic concentration of local anesthetic. Loss of consciousness and respiratory depression are few of its initial symptoms. Literature mentions the toxic effects of local anesthetics on different tissues, for example fibroblast, articular chondrocytes, human leukocyte and corneal endothelial cells,5-9 thus challenging their safety use. Therefore, an interrogation to check and compare the cytotoxic effects of locally available pharmaceutical solutions was required. Numerous in-vitro cytotoxic studies have been published on local anesthesia to assess their effects on cell viability using mammalian cell lines.7,10 Breu et al and Eckl et al studied the relationship of the viability of MSCs to the time of exposure at different concentrations of local anesthetic agents and deduced that MSC’s viability depends on the local anesthetic agent used, its concentration and the time of exposure. Cell viability was evaluated using Annexin-V stain and results were analyzed quantitatively using a flow cytometer.11 Another novel finding by Oliveira et al and Roderguez et al concluded apoptosis linked cell death and the detrimental effects of lidocaine when exposed to oral mucosa fibroblast; cells that are significantly involved in wound healing.12 Studies showed that lidocaine when used alone or in combination with other agents reported most adverse reactions.13 Likewise, studies documented the association of adverse effects with the preservatives used along with the local anesthetic agent like sulfite and hydrochloric acid.14
Practitioners need to emphasize on epinephrine’s indications and contraindications before using on patients especially the ones who are immunocompromised. The extensive use of epinephrine is linked with its ability to slow down the systemic absorption of the local anesthetic agent, resulting in lower plasma levels of the drug involved. However, they have potential to cause local and systemic reactions. Necrosis and ischemia of the nearby tissues are the local complications. Systemic complications include cardiovascular changes like palpitations and dysrhythmias.13
A clinician should take a proper history before administrating a local anesthetic. Reduced tolerance to local anesthetics has been reported in patients suffering from heart problems, thyroid dysfunction, anemia and diabetes. Drug clearance should be considered by the dentist before injecting lidocaine as it’s an amide and metabolized by the liver. Multitudinous in-vitro and in-vivo investigations have also assessed anti-microbial effects of local anesthetics, mostly showing positive activity and its advantageous implications during a number of clinical scenarios.15-19 Over the preceding years, anti-microbial activity of anesthetics allured surveillance by research teams. Aydin et al and Eyigort et al compared the anti-microbial activity of different anesthetic agents using Broth Dilution Method, their results revealed that lidocaine and prilocaine had strong antimicrobial activity in contrast to bupivacaine.20 Kesici et al established the correlation between the combined antimicrobial effects of local anesthetics and vasoconstrictors.
They performed these in-vitro approaches using disk diffusion method followed by MIC method and concluded that adrenaline has no anti-microbial properties of its own, however when used in combination with lidocaine, showed higher anti-bacterial potential.21 Considering that cytotoxicity and anti-microbial activity are important parameters for LA solutions and since no available literature addressing these properties is available for the most commonly used local anesthetic options in Pakistan, the objective of this investigation was to investigate and compare toxicity effects on cell lines from a Pakistani donor and anti-bacterial activity of lidocaine and epinephrine, manufactured by two international brands (Septodont and Medicaine) and one recently launched Pakistani manufactured LA solution (HD-Caine). The significance of exploring these parameters might help the safe use of locally manufactured anesthetics, which are generally averted over international brands.

METHODOLOGY

Three commonly used commercial local anesthetic solutions were selected. Details of these formulations are illustrated in Table 1.

Table 1: Details of the pharmaceutical solutions used in the study

Cytotoxicity Assay
In-vitro cytotoxicity of the three LA solutions was evaluated against bone-marrow derived MSCs from a twentyfour-year-old Pakistani male. These cells were attained from the repository of Air Force Bone Marrow Transplant Center (Islamabad, Pakistan). Cells were cultured in thermo scientific Biolite 130191 vented flask with 500mL high glucose Dulbecco’s modified Eagle’s medium (DMEM) (Gibco, Denmark) supplemented with 10% fetal bovine serum (FBS) (Gibco, Denmark) and 200 L heparin in 500mL media. Cells were expanded (Figure 1) at 37oC in a humified 5% CO2 incubator for 5 days.11 The MSCs cultures were then exposed to 0.25mL sample solutions (Septodont, Medicaine, HD-Caine) and Control (Dulbecco’s Phosphate Buffer Saline Solution (PBS) (Gibco, Denmark) for 1 hour. After 1 hour of treatment with the local anesthetic solutions, non-adherent
MSCs were removed and centrifuged. Cell pellets were washed with Dulbecco’s phosphate buffer saline solution (DPBS) (1x). Washing with saline (PBS) removes local anesthesia completely from the cells. Treated cells were again cultured (with DMEM and FBS) and kept overnight

Figure 1: Expanded Mesenchymal Stem Cells at 40x

 

The 7AAD-stain was used to measure cell viability.11 after exposure of MSC’s to treatment groups for 24 hours. Cell cultures from wells were suspended in eppendorf tubes and centrifuged at 660G/8min. They were then resuspended in 150 L volume FACS tubes. A 2 L of 7AAD stain was added in each FACS tube and incubated in dark for 25 minutes at 25oC before acquisition on (Beckman Counter) (NAVIOS) flow cytometer.

Antibacterial activity

Anti-bacterial activity of 2% lidocaine with 0.001% epinephrine in Septodont, Medicaine and HD-Caine along with Negative Control (0.9% Normal Sterile Saline) (NaCl) (Grow-cells,USA) and Positive Control (20 mL Ampicillin Sodium Salt) (Gibco, Grand Island-New-York) was tested against Staphylococcus aureus ATCC 6538, Bacillus Subtilis ATCC 6633, Pseudomonas aeruginosa ATCC 9721, Klebsiella pneumoniae ATCC 4619, and Staphylococcus epidermidis ATCC 1228. These bacterial strains were attained from stock cultures of Biotechnology Department, Quaid-e-Azam University, Islamabad, Pakistan.

Well-diffusion method

Tryptic soy broth (TSB) was prepared by autoclaving for 20 mins at 121oC to grow fresh cultures of these bacterial strains. The bacteria were inoculated in 10mL broth. The inoculated culture was kept in shaking incubator for 24 hours at 37oC. Test pathogens were swabbed on autoclaved petri dish containing Trypticase soy agar (TSA) media. A sterile borer was used on the surface of TSA plate to make 6mm deep wells. The wells were filled with 0.25mL of sample solutions, positive control (20 mL Ampicillin Sodium Salt (Gibco, Grand Island-New York) and negative control (0.9% Normal Sterile Saline (NaCl) (Grow-cells,USA). Subsequently, the plates were then placed in an incubator at 36oC for 24 hours. On the following day, Vernier calipers was used to measure the diameter of zones of inhibition.22

Broth Dilution Method

In a tube of TSB, the microbial growth of the five-bacterial species was inoculated and then these tubes were placed in an incubator at 37oC. A UV/VIS spectrophotometer (SAILAB, AY1708008, AE-S90MD) was used to set the turbidity index such that it equals to McFarland standard 105 organisms per mL. 2ml of all the three local anesthetic solutions (Septodont, Medicaine and HD-Caine) along with positive control (20 mL Ampicillin Sodium Salt (Gibco, Grand Island-New York) and negative control (0.9% Normal Sterile Saline (NaCl) (Grow-cells,USA) were poured in three different test tubes respectively. Further, 1mL of broth culture was introduced in each. Autoclaved, TSA agar plates were used to streak separate samples from the tubes and at that point, calibration of the dilution loop was set to 0.01mL. The subsequent step was to place these plates in an incubator for 24 hours at 37oC. The incubated plates were scrutinized for the emergence of bacterial colonies and counted manually.20

STATISTICAL ANALYSIS

Data were analyzed using the Statistical Package for Social Science (SPSS for Windows version 12, SPSS Inc., Chicago, IL, USA). Mean values (±SE) for various study
attributes viz. viability of mesenchymal monolayer cells, inhibitory zone diameter and number of bacterial colonies were calculated. Magnitude of variation of these attributes between three brands i.e. Septodont®, Medicaine® and HD-Caine® was ascertained through ANOVA, using completely randomized design (Snedecor and Cochran 1989). Post-hoc Tuckey analysis was implied to detect intergroup differences between mean values. Significance was considered at P<0.05.

RESULTS

Cytotoxicity Analysis of MSC viability using flow cytometer

Data acquisition for flow cytometry was done using Kaluza analysis software version 2.1. Interpretation of results, representing percentage viability are shown in Figure 2 (A)
Control (96.85%), (B) Septodont (94.20%), (C) Medicaine (94.74%) and (D) HD-Caine (93.93%). X-axis represent 7AAD positive and negative cells while Y-axis represent SS INT (side scatter) representing diversity and phenotype of the cells. From all the cells populated those negative for 7AAD were gated on 10o, representing viable cells.

Figure 2: Data acquisition representing percentage viability of mesenchymal stem cells after being exposed to (A) Control (B) Septodent (C) Medicaine (D) HD-Caine, using Kaluza software version 2.1

The results of viability obtained from flow cytomter indicated that there was no difference between Septodont (94.5±0.1) and Medicaine (94.7±0.0) (p=0.6) while the viability of HD-Caine was significanlty lesser than both Septodont, Medicaine and Control (96.6±0.0) (p<0.01). The mean percentage viablity values are shown in Figure 3,

Figure 3: Percentage viability of mesenchymal stem cells in Septodent, Medicaine and HD-Caine as compared to control

Table 2: Intergroup Mean Difference values, Standard Deviation (p values) of percentage viability for Septodont, Medicaine, HD-Caine and control

Antibacterial analysis
Well-Diffusion method
The diameter of zones of inhibition formed on different bacterial species when exposed to anesthetic solutions and control solutions are represented in Figure 4. The diameter of these zones was measured using a Vernier calipers. The

Figure 4: Petri dishes displaying zones of inhibition on (A) Staphylococcus aures (B) Klebseilla pneumonia (C) Bacillus subtilis (D) Staphylococcus epidermidis (E) Pseudomonas aeruginosa, when exposed to Septodent (S), Medicaine (M) HD-Caine (H), Positive Control (P.C) and Negative Control (N.C).

results revealed that Septodont, Medicaine, HD-Caine, Positive and Negative Control showed a significant difference (p<0.01) against Staphylococcus aureus and Staphylococcus epidermidis. A non-significant difference was shown between Septodont and negative control against Klebsiella pneumonia (p=1.0), Bacillus subtilis (p=1.0) and Pseudomonas aeruginosa (p=1.0) while the difference was significant (p<0.01) when compared with rest of the groups (Medicaine, HD-Caine and positive control). The greatest mean diameter after the positive control (antibiotic) was formed by HD-Caine against all the bacterial strains, indicating highest antibacterial activity followed by that for Medicaine while Septodont showed negligible antibacterial activity (Table 3).

Broth Dilution

Number of bacterial colonies of different bacterial species grown in three groups and control solutions revealed

Table 3: Comparative mean (SE) values of antibacterial activity for Septodont, Medicaine and HD-Caine

a,b,c within rows with different superscript letters differ at P<0.05.

Table 4: Intergroup Mean Difference values, Standard Deviation (p values) for antibacterial activity for Septodont, Medicaine, HD-Caine and control

a non-significant difference between Septodont and Medicaine for S.aureus (p=0.3) and B.subtilius (p=0.07), while a significant difference was shown between HD-Caine, positive and negative control (p<0.01) for these two bacterial strains. For S.epidermidis (p=0.07) and P.aeruginosa (p=0.1) a nonsignificant difference was found between Medicaine and HD-Caine, however the difference was significant between Septodont, positive and negative control (p<0.01). K.pneumonia showed a significant difference between all the groups (p<0.01). Comparative mean values of antibacterial activity by well diffusion and broth dilution method are illustrated in Table 3 while the intergroup differences are represented in Table 4.

DISCUSSION

Expeditious advancement of pharmaceutical industry constrains the need for screening and conducting biocompatibility tests on the newly launched drugs. The present study aimed at comparing the percentage viability of MSCs after being exposed to the three groups of local dental anesthetics namely Septodont, Medicaine, HD-Caine, and the Control.
The findings of this study regarding percentage viability knot well with the previous literature. Our results revealed that the percentage viability of MSCs decreased after being exposed to all the three groups as compared to control. The highest percentage viability was 94.7% which was statistically in-significant between Septodont (94.5±0.1) and Medicaine (94.7±0.0) (p=0.6). Even though the lowest percentage viability obtained was for HD-Caine, it should be clarified that this was in comparison to Septodont, Medicaine and Control (P<0.01). However, 93.9% of cells did survive when exposed to these cartridges and revealed few toxic effects when compared individually with PBS (control) under the
same standardized conditions.
These results were in consensus to the findings of Wu et al and colleagues, who investigated the effects of anesthetics on MSCs derived from rabbit adipose cells and concluded that 1% lidocaine showed little toxic effects when compared with other anesthetic agents at different concentrations.10 Similarly, Shoshani et al and Berger et al studied the effects
of lidocaine along with epinephrine and demonstrated that there was no effect on the viability of adipocytes after being exposed to this combination.23 In line with the ideas of
Celeste et al and colleagues, it was concluded that toxicity of lidocaine was dose and time-dependent, their study shed light on the fact that at low doses, lidocaine did not effect mitochondrial functions of fibroblast of the oral mucosa.12 Fedder et al and Beck et al reached a similar conclusion by exposing fibroblast to different anesthetic agents. Their
results demonstrated that lidocaine and ropivacaine slightly deformed the cells as compared to bupvicaine, which was more toxic and resulted in greater deformation.6
The MSCs are not only involved in wound healing after surgery but they also offer promising clinical applications in the dental world, which signifies that they will be in direct contact with the anesthetics being used. Studies have proved that these cells are sensitive to anesthetics so their safe use demands vigilance by clinicians and researchers. Toxicity
of anesthetics is linked to their lipophilicity, thus lidocaine being less lipophilic makes it less toxic when compared to other amide anesthetic agents, validating their secure use in dental practice.10 In case of clinical implications, a toxic anesthetic would augment the possibility of oral paresthesia, especially when administrating an inferior alveolar nerve block as studies report 89% chances of lingual nerve being involved.12,24 Secondly, muscular stiffness is also linked to the myotoxic effects of anesthetics resulting in degenerative changes in masseter and medial pterygoid.12,25 Another usual post-operative clinical complication, following a palatine block, is the occurrence of palatal ulceration or tissue necrosis, which is caused by anesthetic toxicity or high concentration of vasoconstrictors.26
Two limitations in implementing this study design were the use of the same anesthetic agent in the same concentration along with epinephrine, thus higher concentrations of lidocaine could not be evaluated neither estimation of their individual toxic effect was possible. Secondly an exposure time of 1 hour was done to mimic the clinical situations and shed light for practitioners regarding the biocompatibility of the three brands used. From interference of this data, it can be construed that these local anesthetic solutions have mild toxicity but immoderate use of drug via topical or parenteral route can lead to lidocaine toxicity or death.27 The FDA mentions standard safe doses and guidelines for safe use of anesthetic agents in clinical practice. For 2% lidocaine in combination with epinephrine, the maximum dosage is 7mg.Kg-1 . 28
The framework of the study design for anti-bacterial activity was bisected through two approaches and the findings were contrasted. The outcome of this study corroborated with what was found in the previous studies and all the three groups showed antibacterial activity.19,29,30 The findings observed by measuring the diameter of inhibitory zones showed a statistically, significant difference between the three groups (P<0.05). The highest anti-bacterial activity was observed in HD-Caine, followed by Medicaine while Septodont showed minimum anti-bacterial activity. This method was done as a screening test and the authenticity of these findings were then confirmed by broth dilution method and the number of bacterial colonies formed was counted. This later approach delivered significantly better findings due to its sensitivity. Septodont formed the highest number of bacterial colonies, thus showing the least anti-microbial potential, followed by Medicaine. HD-Caine, on the other hand, formed the least number of bacterial colonies, revealed highest anti-bacterial potential.
A similar deduction was drawn by Kesici et al, that lidocaine, when used in combination with epinephrine, showed anti-bacterial activity on S.aureus, E.coli and P.aeruginosa. His findings further demonstrated that epinephrine has a synergistic effect on lidocaine’s antibacterial activity.21 The approach used in our study suffered limitation since the cartridges used were in combination with epinephrine, hence the individual anti-bacterial activity of lidocaine and epinephrine could not be concluded. Aydin et al and Eyigort et al compared the anti-bacterial activity of lidocaine with other anesthetic agents such as ropivacaine and proposed that lidocaine has the highest anti-bacterial potential as compared to other local anesthetic agents depending on their concentration and time of exposure.20 Selection of bacterial strains was done on the basis of their unique characterization and are the common hospital pathogens.31 The significance of Staphylococcus-aureus as a common pathogen has been acknowledged in the literature. Oral cavity infections including ‘angular cheilitis32, jaw osteomyelitis33, mucositis34, endodontic infections35, parotitis36-38 are originated by S.aureus.39 Staphylococcalaureus strains are also known to have the potential to spread and colonize to other body parts or might spread to other patients resulting in cross infection.40 While, Bacillus subtilis is considered best to be studied for bacterial characterization and has acquired attention as probiotics.41 Pseudomonas aeruginosa works by removing the antibiotic from the cell’s interior, many antibiotics and disinfectants are ineffective against it.42 Klebsiella-pneumoniae, widely known for its antibiotic resistance activity is responsible for majority of infections in hospital and community43 and Staphylococcus epidermidis is a cause of most frequent occurring infections as a result of implants and catheters.44
The quest of exploring the anti-microbial activity of anesthetics contributes in letting the practitioners determine and differentiate the finest brand of anesthetics that could serve as prophylaxis for treating infectious diseases before a surgical procedure19 and which cartridges to be possibly used for irrigation in endodontics.45 The anti-microbial property of anesthetic agents augments the probability of false-negative results while obtaining culture specimens for diagnostic procedures46 thus for such cases, use of mild anesthetic agents at lowest concentration is recommended to optimize the culture yield.

CONCLUSION AND RECOMMENDATIONS

From a biocompatibility view point, minimal toxic effects were observed in all the test samples when compared with the control at proclaimed 2% concentration of lidocaine. Significant difference was revealed while assessing antimicrobial activity. Septodont showed the least antibacterial activity while Medicaine and HD-Caine showed the highest anti-microbial potential. For future investigations, MSCs should ideally be exposed to different local anesthetic agents and at different concentrations. Secondly, the type of cell death (necrosis/apoptosis) should also be evaluated using annexin V stain. Investigation of anti-microbial potential of anesthetics using fungal strains especially candida albicans can have additional implication in oral infections.

CONFLICT OF INTEREST

The authors proclaim no conflict of interest.

FUNDING

The study was conducted independently without any form of financial or otherwise assistance from any of the product manufacturers, hence free from any form of bias.

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  40. Smith A, Jackson M, Bagg J. The ecology of Staphylococcus species in the oral cavity. J Medi Microbi. 2001;50:940-6. https://doi.org/10.1099/0022-1317-50-11-940
  41. Lefevre M, Racedo SM, Denayrolles M, Ripert G, Desfougères T, Lobach AR, et al. Safety assessment of Bacillus subtilis CU1 for use as a probiotic in humans. Reg Toxicolo Pharmacol. 2017;83:54-65. https://doi.org/10.1016/j.yrtph.2016.11.010
  42. Schweizer HP. Efflux as a mechanism of resistance to antimicrobials in Pseudomonas aeruginosa and related bacteria: unanswered questions.
    Genet Mol Res. 2003;2:48-62.
  43. Tsay R-W, Siu L, Fung C-P, Chang F-Y. Characteristics of bacteremia between community-acquired and nosocomial Klebsiella pneumoniae infection: risk factor for mortality and the impact of capsular serotypes as a herald for community-acquired infection. Arch of Inter Medi. 2002;162:1021-7. https://doi.org/10.1001/archinte.162.9.1021
  44. Vuong C, Otto M. Staphylococcus epidermidis infections. Microbes infect. 2002;4:481-9. https://doi.org/10.1016/S1286-4579(02)01563-0
  45. Sculley P, Dunley R. Antimicrobial activity of a lidocaine preparation. Anesthesia progress. 1980;27:21.
  46. Johnson SM, Saint John BE, Dine AP. Local anesthetics as antimicrobial agents: A review. Surg infect. 2008;9:205-13. https://doi.org/10.1089/sur.2007.036

  1. Postgraduate Trainee, Department of Dental Materials, Riphah International University, Islamic International Dental College.
  2. Associate Professor, Department of Dental Materials, Riphah International University, Islamic International Dental College.
  3. Assistant Professor, Department of Biological Sciences, National University of Medical Sciences.
  4. PhD Scholar, Department of Biotechnology, Quaid-e-Azam University.
    Corresponding author: “Dr. Eisha Imran” < eishaimran@ymail.com >

Investigating the Cytotoxic and Anti-Bacterial Activity of Commercially Available Local Anesthetics: An In-Vitro Analysis

Eisha Imran                       BDS

Faisal Moeen                     BDS, MSc

Humayoon Satti               PhD

Lubna Rahman                M.Phil

OBJECTIVE: To evaluate and compare the influence of three local anesthetic dental formulations manufactured in France (Septodont), Korea (Medicaine) and Pakistan (HD-Caine) in terms of cytotoxicity and anti-bacterial activities.
METHODOLOGY:
90 commercially available local anesthetic cartridges of similar composition (2% lidocaine with epinephrine 100,000) viz. Septodont, Medicaine and HD-Caine were randomly collected from three different Pakistani cities and were assigned as Group S, Group M and Group H, respectively. The cartridges were further divided into three sub-groups each consisting of 10 cartridges to first evaluate cytotoxicity on Mesenchymal Stem Cells (MSCs) using a flow cytometer and secondly to investigate anti-bacterial activity by measuring zones of inhibition and through Broth Dilution Method against five bacterial strains.
RESULTS:
The results indicated that Septodont (94.5±0.1) and Medicaine (94.7±0.0) showed the highest viability percentage with no significant difference when the two were compared (P=0.6). HD-Caine (93.9±0.0) showed the least, being significantly (P<0.01) different from Septodont and Medicane. A statistically significant (P<0.05) difference was identified between the three study groups regarding the anti-bacterial activity. HD-Caine showed the highest anti-bacterial potential, followed by Medicaine and Septodont.
CONCLUSION:
Mild toxicity was observed by all the three groups in human MSCs, justifying their safe use in clinical practice. Additionally, Medicane and HD-Caine showed significant anti-bacterial activity indicating their possible use as sterile irrigants.
KEYWORDS: Dental anesthesia, Lidocaine, Epinephrine, Antibacterial activity
HOW TO CITE:
Imran E, Moeen F, Satti H, Rahman L. Investigating the cytotoxic and anti-bacterial activity of commercially available local anesthetics: An in-vitro analysis. J Pak Dent Assoc 2020;29(4):185-192.
DOI: https://doi.org/10.25301/JPDA.294.185
Received: 02 June 2020, Accepted: 28 July 2020
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Fracture Toughness of Resin Based Composites, Impregnated with Silver Nanoparticles and Bioactive Glass

Amjad Hanif                        BDS, MSc

Fazal Ghani                         BDS, MSc, FDSRCPS, PhD

OBJECTIVE: To investigate the effect, on fracture toughness (KIc), of impregnating silver nanoparticles (AgNPs) and bioactive glass (BAG) in resin based composites (RBCs).
METHODOLOGY:
During the period from August 2016 to May 2018, this study was performed at Peshawar Dental College (Pakistan) and Montreal University (Canada), using; a commercial RBC and experimental RBCs with or without BAG content (5-15wt%), and AgNPs (0.009%). Standardized specimens (n=6) were made in each of five RBCs (G1-G5). AgNPs were synthesized and characterized by uv-vis spectroscopy. With universal testing machine, the KIc for RBCs specimens was computed. SEM and dynamic light scattering (DLS) was used to assess the size and form of the prepared silica. One-way ANOVA and Tukey post hoc test were used for data analyses.
RESULTS:
KIc values varied both within and between RBCs groups. The commercial RBC had highest mean KIc (G1=1.03+0.24). Mean KIc values for the experimental RBCs were; G2=0.69±0.14, G3=0.9±0.13, G4=0.9±0.14 and G5=0.69±0.13. The only RBC groups that had statistically significant variations between their mean KIc values were; G1-G2 (p=0.017) & G1-G5 (p=0.017). SEM and DLS analysis of synthesized silica particles having round shape and sizes of 0.9-1µm. Uv-vis spectroscopy of AgNPs showed round shape with size up to 20nm.
CONCLUSION:
The KIc of the experimental RBCs with BAG (5-10 wt%) and AgNPs (0.009%) was not significantly different than the commercial RBC.
KEYWORDS:
Resin based composites, RBCs, Silver nanoparticles, AgNPs, Bioactive glass, BAG, Re-mineralizing resin based composite, Fracture toughness, KIc
HOW TO CITE:
Hanif A, Ghani F. Fracture toughness of resin based composites, impregnated with silver nanoparticles and bioactive glass. J Pak Dent Assoc 2020;29(4):179-184.
DOI:
https://doi.org/10.25301/JPDA.294.179
Received:
30 June 2020, Accepted: 25 August 2020

INTRODUCTION

Resin based composites (RBCs) have multiple applications in dental practice including; direct restorations, inlays, onlays, core build-up, fissure sealing and orthodontic bracket bonding.1 With the use of appropriate adhesive technique and their ease of handling, adequate bonding of RBCs to both enamel and dentin can be achieved.2 However, an associated drawback with RBC use is that they harbor more microorganisms than some other restorative materials.3 A common reason for replacing RBC restorations has been secondary caries occurring at the
restoration-tooth interface. Polymerization shrinkage during setting reaction as well as cyclic mechanical loading may result in the formation of marginal gap and micro-leakage and hence the harboring of microorganisms.4 Resin pores also allow bacteria inflicted plaque to cause infection. Since the initiation of secondary caries at the tooth-restoration interface frequently occurs in RBCs, therefore it is important to develop innovative RBCs that possess antibacterial properties as well as self-repairing ability through re-mineralization.5
The adding of various types of releasing or slow releasing agents has been considered to inculcate antibacterial properties in RBCs. These include silver, iodine, zinc, antibiotics, chlorhexidine and chitosan.6-7 For sustained antibacterial properties, immobilized antimicrobial agents have also been added to RBCs.6 Among these agents, silver or fillers implanted with silver ions have exhibited a promising antibacterial property without affecting the strength and mechanical characteristics of RBC. Silver containing biomaterials have exhibited effective antimicrobial activity against oral pathogens such as streptococcus mutans, candida albicans, lactobacillus acidophilus.8
Re-mineralizing effect can be achieved with the addition of unsalinized BAG filler to RBCs. BAG 45S5 represents the composition which is widely employed in orthopedics because of its ability to form hydroxyapatite crystals in physiological environment. The precipitation of hydroxyapatite can also be achieved in a methacrylate based composite material containing bioactive glass.9 Several studies have investigated new bioactive and antimicrobial restorative materials for prevention of recurrent decay. However, the majority of these materials exhibit inferior physical properties.6 Silanization of filler particles has been shown to improve the mechanical properties but leads to decline in bioactivity. Appropriate inculcation of bioactivity without affecting the mechanical properties of RBCs is an issue yet to be ascertained.9
Previous work has reported that some mechanical properties could decline with the addition of calcium phosphate bioactive fillers to the RBCs.10 This finding was confirmed by a recent study that investigated some other properties of experimental and commercial RBCs. The experimental RBCs included those with and without a fixed proportion of AgNPs and varying amounts of BAG.11 However, this study did not look at the possible effect, on KIc, of the AgNPs and BAG impregnations in the experimental RBCs. KIc is an important mechanical property that refers to the opposition of a brittle material to the proliferation of flaws under an applied stress. It can be related to the fatigue resistance of the material. KIc relies on the chemical composition and physical properties of the components of restorative material.12
The present study aims to investigate the effect, on KIc, of adding a fixed amount of AgNPs and various proportions of BAG (5-15%) in experimental RBCs. The mentioned additions, in the experimental RBCs, will be made to ensure each of the experimental RBCs maintain a 70% total filler content. We hypothesized that a larger proportion of BAG substituting the filler content in the RBC would result increased KIc.

METHODOLOGY

The present study is part of a multiphase research project comprising the synthesis and characterization of AgNPs and BAG and their incorporation to result some experimental RBCs.11,13-15 The study protocol and the publication of results were approved by the institute and university research and ethics boards (Riphah/26/17/011 March 03, 2016 and PRIME/ IRB/2019-179). The experimental work was conducted during the period August 2016-May 2018, at the Department of Dental Materials, Peshawar Dental College, (Pakistan) and Chemistry Department, Montreal University in Canada. The pilot phase for the research project / protocol to perfect the experimental resin manufacturing was done in the local setting. Once it was approved, then the further work including the fabrication of the specimens and their testing was done in the overseas setting.
The materials used for the synthesis of experimental RBC and their modifications are given in Tables 1-2. The proprietary RBC was used to make specimens to belong to the control group (G1). The unmodified experimental RBC was used to prepare specimens to comprise the G2 group. The experimental RBCs having 0.009% AgNPs and 5, 10 and 15 wt% of BAG-45S5 respectively to substitute the silica particles were used to fabricate specimens to make groups designated as G3, G4 and G5 respectively. First both the resin mixture and filler particles were mixed manually in a plastic container. Then the material was transferred to three roll mill (Exakt, TRM, Norderstedt, Germany) to obtain a homogenous material. In each of the five RBC groups, there were six specimens. Details of the various RBCs, their content are given in Table 2.
A single-edge notched beam (SENB) test was employed to calculate the KIc for the RBC specimens. The notch in the specimen was created by using the custom made threepiece brass mould used for fabricating the specimens. The notch to have a standardized dimension and location in each specimen was facilitated with a sharp blade-like v-shaped

Table. 1: Materials used for the synthesis of experimental RBCs

ridge in the mould surface. There was no direct involvement of the operator in the production of the notch in the specimens. The specimens fabrication as well as the testing procedure were that of the American Standards for Testing Materials (ASTM).16 Rectangular bar specimens (n=6) in each RBC having pre-specified dimensions (height=4 mm, width=2 mm and length=25 mm (Figure 1) were fabricated using a three-piece brass split mold so that on completion of curing,

Table. 2: RBC groups, their Klc values and statistical analyses

Figure. 1: Diagrammatic representation of the dimensions of the specimen and illustration of the fracture toughness test.15

the bar could be removed from the mold without the application of force. The mold was filled manually with the help of stainless steel spatula. The material was transferred into the mold in 1-2 mm increments. Each addition was polymerized for 20-sec with light-curing machine with an output of 750mW/cm2 and a wavelength of about 470nm.
On curing, each specimen was separated from the mold and further cured on each side for another 10-sec. Excess material on the sides of the specimen was then removed with 1000- grit sandpaper. Before calculation of the KIc, specimens considered suitable and defect-free remained stored in distilled water at 37C for a minimum of 24 hours. Three-point bending configuration was used to determine KIc in ambient temperature using UTM (Instron.5565 USA) at a cross head speed of 0.75mm/min and pre-set load of 50N.KIC was determined with the help of equation.16

 

Where α = 2(1+2 a/w) (1-a/w)2/3, KIC = Stress Intensity Factor, L= distance between supports, w = width of the specimen, b = thickness of the specimen and a =crack length. The shape and size of silica particles and BAG was
determined by using DLS (Malvern Zetasizer UK). AgNPs were synthesized following the standard procedure13 and were characterized with the help of uv-vis spectroscopy (Cary uv-vis Agilent technologies, USA). SEM analysis (JEOL, Model JSM-7600F, Japan) of fractured surface through the bulk of samples following mechanical characterization was used to observe the filler distribution and morphology.
Statistical package for social sciences SPSS software version 19 for windows was used for data analysis. Mean and standard deviation for KIc values for specimens in all the five groups were computed. Data analyses, using ANOVA and Tukey’s post hoc test was made to compare the level of significance of the differences from the mean values of KIc among the RBC groups. For the difference to be statistically significant, the P value was set as < 0.05.

RESULTS

The mean KIc values for all the RBC groups are given in Table 2. It can be seen that the commercial RBC(G1) exhibited higher value. It can also be seen that specimens in the experimental RBC with no BAG and AgNPs (G2) or
those containing AGNPs (0.009%) and BAG content of 15% had lower mean KIc values. The mean KIc values for both the experimental RBCs (G3 and G4) can be ranked next to the mean KIc value exhibited by the commercial RBC (G1). The significance or otherwise of the differences between the mean KIc values between the various RBC groups are also given in Table 2. These show that the only mean KIc values that were statistically significantly different were those between the RBC groups; G1-G2 and G1-G5.
The SEM images of the representative surfaces of the fractured RBC specimens are shown in Figure 2 (a-c). The silica particles were of round shape (Figure 2a) and their sizes ranged from 0.9 to 1.0µm. Average size of BAG particles determined by DLS was 512nm. Figure 2b shows that some of the filler particles appear detached from the matrix, leaving empty spaces indicating weak bonding between the filler and the matrix. The SEM image

Figure. 2: (a) SEM of synthesized silica particles at voltage of 5kv and 10,000 magnification. (b) SEM of experimental resin composite (G3) showing surface morphology. (c) SEM of commercially available resin composite (G1) showing surface morphology. (d) Thin films of photo-polymerized resin containing AgNPs.

(Figure 2c) of a specimen belonging to G1 group shows that the filler size is much smaller than the particles size in the specimens belonging to the other RBC groups. Surface appears rougher and filler particles are more densely packed when compared to the other RBC groups.

DISCUSSION

The Klc values (Table 2) for specimens in the various RBC groups were calculated by using a single-edge notchedbeam (SENB) test.16 This test has been considered reliable and valid in addition to being simple in terms of making specimens.17 Three-or four-point bending equipment is used for measuring the fracture toughness using a single-edge notched-beam. Both the methods are being commonly used in dental materials research.18 As mentioned earlier, the notch was created in a standardized manner in each specimen with no direct involvement of the operator in its production.
To provide valid and realistic comparison of the data, this study also included specimens made in commercial restorative material (Filtek 3M, Z250xt) so that the KIc value could act and provide as control group.19 The specimens made in the commercial RBC(G1) exhibited higher mean KIc value. The commercial RBC contained 82% filler in comparison to the 70% total filler content in the RBC specimens in the rest of the groups. A variety of filler percentages to resin matrix have been added with the range of 70-75%. With the 70wt% filler content, the viscosity of the resin paste was adequate as well as its handling. Most of the studies are in agreement that Klc toughness increases with an increase in the amount of filler. Ilea et al18 reported that the KIc was highest in the RBCs containing higher percentage of filler and not dependent on the extent of polymeric conversion in the resin matrix. The filler phase present in RBCs distributes the applied force into many components leading to deviation of the crack path and thus
hindering the proliferation of crack.17 Figure 2c belonging
to the RBC specimens from the G1 shows that the particle
size of filler is smaller than the experimental RBC and the
particles are well-condensed without any signs of detachment
of filler from the matrix indicating excellent silanization of
filler particles. Some studies have reported that matrix/particle
detachment can be harmful to the fatigue and fracture
performance of RBCs. Figure 2b shows small depressions
indicating sites of detachment of filler particles from the
matrix which also might be responsible for low KIc values
of the experimental RBCs when compared to those made in
the proprietary RBC.
The data in Table 2, show relatively higher KIc values
for both the G3 and G4 RBC specimens compared to those
in the G2 group. This indicates that BAG addition imparted
a beneficial effect. The data also show that further increase
of the BAG proportion in the experimental RBC and the
specimens made in it (G5) resulted in a decrease in Klc
though to a statistically insignificant extent. A likely
explanation for this finding could be the existence of increased
BAG aggregates in the resin matrix without chemical adhesion
between them. Smaller BAG content in the experimental
RBCs, could better deflect crack from the front originating
from the notch in specimen. In fact, it has been shown that
the stress intensity factor (Klc) will decrease at the tip of
crack with the change of direction, halting its unstable
growth.20 Moreover, there might be trans-particle fracture
due to which more energy would be needed to break the
BAG agglomerate leading to increase in fracture toughness.20
However, this phenomenon might not function at higher
concentration of the BAG in the resin matrix. This was
confirmed from the findings of the present study where an

increased BAG content in the RBC used for making
specimens in the group G5 did not result in further increase
in Klc but rather decreased it. While the exact cause for this
has yet to be identified, but it could likely be due to increased
amount of flaws, voids or porosities.18 Chatzistavrou, et al6
have also reported insignificant difference in the mechanical
properties of specimens compared to those in the control
samples made in the RBC having silver doped BAG with
BAG content of 5, 10 &15% respectively. However, in that
study mechanical properties were characterized by the method
of micro-tensile test that measured total bond strength of
dentin.
Uv-vis spectroscopy of photo polymerized resin films
indicated nano size (less than 20nm) and round shape of
silver particles. Based on a previous study13 that reported
antibacterial property of AgNPs, 0.009% AgNPs (0.03%
silver in resin) was incorporated in RBC. AgNPs with high
surface area and small size have adequate antibacterial
activity at low filler level. Antibacterial properties of AgNPs
at such low level (0.009%) in RBC need to be investigated
in future studies. Low silver salt concentrations (<0.028%)
results in minimal clumping. Since the concentration used
in this study is extremely low (0.009%) which is lower than
0.028%, it can be predicted that such a concentration of
AgNPs wouldn’t have adversely affected the mechanical
properties of RBC. However, it has been found that in-situ
reduction of silver ion competes with free radicals produced
by light activation. This might result in increased inactivation
of proliferating chain and thus leading to decreased
mechanical properties.13
In this study mode I fracture toughness of the RBC
specimens was determined which is particularly important
because it is the lowest stress at which crack proliferation
can initiate. Clinically this opening (tensile) mode of failure
is most closely linked to restorative materials in terms of
fracture type. Klc values may vary depending upon the mode
of fracture toughness and test method used.21 The results of
the single beam notch test are very sensitive to notch depth
and width and hence making comparison with other studies
difficult.18 The Klc values found in this study are within the
range (Mode 1, Fracture toughness, 0.55 -1.36 MNm-3/2)
reported in another study for commercial RBCs using
Brazillian disc method.21 The values of fracture toughness
calculated by Brazillian disc method are lower than the
values determined by single edge V notch beam test.21
Therefore, the fracture toughness values obtained by different
methods cannot be compared with each other.
Notwithstanding the individual variation and the
apparently lower fracture toughness values for the various
experimental RBC containing different proportions of BAG
and the fixed amount of AgNPs in comparison to the control
RBC, keeping in view the beneficial antibacterial and remineralizing effect of the AgNPs and BAG in the
experimental RBC, they could be further explored for use
in restoring non-stress bearing location (class 3 and 5 cavities).
For stress bearing areas such as class 2 and 4 cavities, ways
for improving fracture toughness of the experimental RBC
require further experimentation.
LIMITATIONS
Among the several limitations of this study, one was the
use of brass mold for fabricating RBC specimens. Brass
obstructs the penetration of light delivered by the visible
light curing unit affecting the polymerization process and
the degree of conversion. We minimized this effect by
following the protocol of incremental addition and curing
of each of the RBC layer placed in the mold. Another point
of interest related to this study is that the total filler content
used in the preparation of various experimental RBCs was
70 wt% compared to 82% in the commercially available
RBC (G1). As stated earlier, filler mass fraction has
considerable influence on Klc, therefore comparison between
G1 and the rest of the groups become difficult. Another
limitation of this study was that the influence of AgNPs and
BAG individually on the Klc values of the RBCs was not
determined, making the comparison of the values with other
studies difficult which have used either AgNPs or BAG
alone as additives in their RBCs.
CONCLUSIONS
In comparison to control RBC, lower Klc values were
reported for the experimental RBCs. However, these values
were only significantly lower for the experimental RBCs
groups including; G2 (without AgNPs and BAG) or G5
(AgNPs- 0.009% and BAG 15wt%).
The experimental RBCs containing AgNPs (0.009%)
and BAG (5-10wt%), because of their established antibacterial
and re-mineralizing effect may prove useful for restoring
non-stress bearing location in permanent teeth and all cavities
including the stress-bearing location in case of deciduous
teeth that receive lower masticatory loads.
ACKNOWLEDGEMENT
Denfotex Research Ltd, London SE1 1UL, UK kindly
donated Bioactive Glass for this research.
CONFLICT OF INTEREST
None declared.

AUTHORS CONTRIBUTION

AH: Conceived the idea, designed and conducted the research and prepared the research protocol and contributed to all drafts of the manuscript.
FG: Refined, perfected the experimental protocol, supervised and interpreted the data, revised and edited all the drafts including the final submitted manuscript and accepted responsibility as the corresponding author.

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  1. Assistant Professor, Department of Dental Material, Peshawar Dental College.
  2. Professor, Department of Prosthodontics, Peshawar Dental College.
    Corresponding author: “Prof. Dr. Fazal Ghani” < fazalg55@hotmail.com >

Fracture Toughness of Resin Based Composites, Impregnated with Silver Nanoparticles and Bioactive Glass

Amjad Hanif                        BDS, MSc

Fazal Ghani                         BDS, MSc, FDSRCPS, PhD

OBJECTIVE: To investigate the effect, on fracture toughness (KIc), of impregnating silver nanoparticles (AgNPs) and bioactive glass (BAG) in resin based composites (RBCs).
METHODOLOGY:
During the period from August 2016 to May 2018, this study was performed at Peshawar Dental College (Pakistan) and Montreal University (Canada), using; a commercial RBC and experimental RBCs with or without BAG content (5-15wt%), and AgNPs (0.009%). Standardized specimens (n=6) were made in each of five RBCs (G1-G5). AgNPs were synthesized and characterized by uv-vis spectroscopy. With universal testing machine, the KIc for RBCs specimens was computed. SEM and dynamic light scattering (DLS) was used to assess the size and form of the prepared silica. One-way ANOVA and Tukey post hoc test were used for data analyses.
RESULTS:
KIc values varied both within and between RBCs groups. The commercial RBC had highest mean KIc (G1=1.03+0.24). Mean KIc values for the experimental RBCs were; G2=0.69±0.14, G3=0.9±0.13, G4=0.9±0.14 and G5=0.69±0.13. The only RBC groups that had statistically significant variations between their mean KIc values were; G1-G2 (p=0.017) & G1-G5 (p=0.017). SEM and DLS analysis of synthesized silica particles having round shape and sizes of 0.9-1µm. Uv-vis spectroscopy of AgNPs showed round shape with size up to 20nm.
CONCLUSION:
The KIc of the experimental RBCs with BAG (5-10 wt%) and AgNPs (0.009%) was not significantly different than the commercial RBC.
KEYWORDS:
Resin based composites, RBCs, Silver nanoparticles, AgNPs, Bioactive glass, BAG, Re-mineralizing resin based composite, Fracture toughness, KIc
HOW TO CITE:
Hanif A, Ghani F. Fracture toughness of resin based composites, impregnated with silver nanoparticles and bioactive glass. J Pak Dent Assoc 2020;29(4):179-184.
DOI:
https://doi.org/10.25301/JPDA.294.179
Received:
30 June 2020, Accepted: 25 August 2020
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A Nation-wide Survey on Financial Impact of COVID-19 on Employers of Private Dental Practices of Pakistan

Huma Sarwar                         BDS, MDS

Navid Rashid Qureshi          BDS, MSc, FDSRCS

Siddiqua Fatima                    BDS

Meshal M Naeem                   BDS

Ahsan Inayat                          BDS

OBJECTIVE: To assess the financial impact of COVID-19 on employers of private dental practices of Pakistan in the month of April and May 2020.
METHODOLOGY: In this cross sectional study, the employers of dental practices of Pakistan were inquired about their financial management during COVID 19 outbreak. The data was analyzed using IBM-SPSS version 23.0. Percentages and Chi-square tests were used for statistical analysis at p <0.05.
RESULTS: 52.7% owners opened their practices whereas 37.8% of tenants’ clinics remained closed (p<0.01). 38.3% of tenant employers provided inadequate PPE whereas 53.2% owners provided adequate PPE to their staff (p=0.02). 64% of owners easily arranged PPE for staff whereas 70.4% tenants found it difficult to arrange PPE because of its high cost. Employers with less than 10 years of practice reported less than 5% whereas those with more than 10 years of practice reported up to 24% of revenue generation income (p<0.01). Most of the employers paid full salary to their employees. If this condition persists till the end of August, 40.8% employers (<10 years practice) planned to adjust staff salaries whereas 33% employers (>10 years of practice) planned to find innovative ways to lower their operating costs (p<0.01).
CONCLUSION: Due to minimal patient turnover, dental employers are facing incredible challenges in managing the expenses. Those with more than 10 years of practice are more economically stable as compared to the employers with less than 10 years of practice.
KEYWORDS: COVID-19, finances, dental clinic, Pakistan.
HOW TO CITE: Sarwar H, Qureshi NR, Fatima S, Naeem MM, Inayat A. A nation-wide survey on financial impact of COVID-19 on employers of private dental practices of Pakistan. J Pak Dent Assoc 2020;29(4):172-178.
DOI: https://doi.org/10.25301/JPDA.294.172
Received: 26 August 2020, Accepted: 07 September 2020

INTRODUCTION

All planning lost their substantiality when nature decided to show its wrath. The novel COVID-19 came under the limelight in December 2019 and was declared pandemic in first week of march by WHO.1
The transmission of the said infectious agent, infamously known as COVID-19 was initially baffling even to an astute mind. The course of occurrences and research suggested that it is caused by a virus and is transmitted rapidly if
contaminated hands touch mouth, nose or eyes or via sneeze droplets in the air. This is one of a kind natural bio destruction witnessed by this generation. With over 550,000 confirmed infectious cases globally, and 25,000 reported deaths, this phenomenon has resulted in the unprecedented confinement of thousands of people to the four walls of their dwellings; a lockdown that is caused by nature and not war.2
The pandemic is negatively affecting global economic growth beyond anything experienced in nearly a century. In China, the industrial production fell by 13.5% and numerous economic gurus’ predictions surfaced that the US economy could shrink by 24%.3 Current estimates and figures indicate that the virus has trimmed south Asian economic growth by 2.7%. Not a single sector was safe from the economic brutality brought forward by COVID-19. The reported global spillover of COVID-19 engulfed the travel industry, hospitality industry, sports industry, the financial sector like banks, financial market (stock market), event industry, entertainment industry, education sector, and health sector.4 Human imagination is yet to fathom the full impact and extent of the effects of the pandemic peak.
The dental industry was no exception in the ongoing health and economic fiasco; it too faced its fair share of turbulence. The impact of the COVID-19 crisis and lockdowns were significantly visible. Given the fact that many dental procedures result in aerosol production and the dentists have to work close to patients’ oral cavity; the dentist community was declared to be extremely vulnerable and prone to infection, as well as transmission of COVID-19.5,6 These risks and circumstances, compelled the health regulatory bodies to advise and limit the dental community to avoid elective dental procedure and to provide emergency treatment only.7,8,9 Unprecedented monetary challenges are being faced by the dental fraternity, as the practices have been limited to the cases pertaining to the dental emergencies only. The dentists of Pakistan can be parted in two main categories. Category 1 entails dentists who are small business employers, operating independently, or rather with a few partners. Category 2 encompasses the dentists who own practices in rental premises and are hence subjected to monthly rent payments (as additional expenses). Furthermore, the financial burden on employers can be divided into four categories; salaries, rent, supplies, and labs.
Due to the COVID-19 pandemic, additional personal protective barrier (PPE) cost has to be borne by the employers.
No visible policy to support private dental practices in this difficult time has been put forward by the governments or dental regulatory bodies of low-income and middle-income countries. With expenses of salaries / rent being the same, but diminishing revenues, the stress, and anxiety have significantly increased amongst the dentists throughout the world.10 Moreover, there is limited evidence about the economical downfall being faced by the employers of private dental practices of Pakistan. Given the unprecedented circumstances, the decision making is impeded by a lack of data, such as the challenges being faced by the dentists to strive for their professional excellence in this difficult time. Therefore, the objective of this study is to report the issues and economic impact of the COVID-19 outbreak on employers of private dental practices of Pakistan.

METHODOLOGY

This cross-sectional study was conducted in the private dental clinics of Pakistan. Ethical approval was obtained
from the Institutional Review Board of Liaquat College of Medicine and Dentistry (IRB# EC/36/20). The employers of the private dental clinics of Pakistan from all provinces were included in this study. Employers of the dental practices who declined to consent were excluded from the study. For sample recruitment, purposive sampling was performed. A pre-tested and validated survey form, comprising of 23 questions, was circulated through social media and email. The questionnaire was not adopted by any previous study and was designed exclusively by the Principal investigator and Co-investigators. The Pretesting of the form was executed by testing of the questionnaire via a sample of dental clinic employers from all provinces of Pakistan. For the determination of the internal consistency of the questionnaire, Cronbach Alpha was used with a value of 0.821. the sample size was calculated by using Openepi sample size calculator version 3.01 after assuming that COVID-19 has impact on 50% Dentists of Pakistan. At 5.03% margin of error and 95% confidence interval, the calculated sample size was 378. The questionnaire was divided into three sections. Section 1 comprised of questions about the demographic details of the participants. In Section 2, the participants were inquired about their years of experience, ownership of the practice (own property/ rental), the total number of staff including associate doctors, opening/closure status, and total working hours/day during COVID-19 lockdown. Information regarding average patient flow, revenue generated during April and May 2020, and the type of PPE provided to the staff was also obtained. In Section 3, questions were asked to assess the employers’ perspective on the difficulty faced by them to provide PPE and salary to staff, and if the patients should be additionally charged for the PPE and their concerns if the lockdown restrictions last until August. Data were stored and analyzed using IBM-SPSS version 23.0, Counts with percentages were used for baseline characteristics like gender, age group, marital status, number of children, and type of earner of all studied participants, across all provinces of Pakistan. Pearson Chi-Square test of independence was used to examine the association of clinical setup with the status of ownership, PPE outcomes, and the effect of COVID -19. P-values less than 0.05 were considered statistically significant.

RESULTS

The baseline characteristics of studied samples are shown in Table-1. Three hundred and seventy-nine employers participated in this study. Out of which 47% of data were received from Sindh, 34.8% from Punjab, 10.3% from Baluchistan, and 7.9% from KPK. Most of the respondents were male (78.6%) and the average reported age was between 41-50 years (36.7%). Most of the participants were married

Table 1: Basic demographic characteristics of Studied Samples (n= 379)

Table 2: Association of Clinical Setup characteristics with type of ownership of the Dental Practices

*p<0.05 was considered significant using Pearson Chi Square test

(84.7%) and had three children (33.5%). 43.5% of the respondents were the sole earners of their families. Table-2 reports the association of clinical setup details with the type of ownership of dental practices. According to the results, 49.1% of participants owned their dental practice whereas, 50.9% were tenants (had their dental clinic on a rental basis). 40.3% of owners and 39.4% of the tenants reported having 3-4 staff members. 52.7% of the owners opened their practices but had less than usual patient volume; whereas, 37.8% of the tenants chose to close their practices and catered to emergency patients only on need basis. Both the owners and the tenants resumed dental clinics for 2-4 hours/day (51.6% and 42.0% respectively). Less than 5% of the patient volume was experienced by both the owners, as well as, the tenants (50.5% and 56% respectively). Chi-square test gives significant association for the number of staff in practice, the opening of the dental practice, and the duration of a dental practice with the type of clinical setup for dental practice (p<0.05).
Association of the provision of PPE to the employees with the type of ownership of clinical set-up is demonstrated in Table-3. Most of the owners (53.2%) provided Bodysuit, N95 mask, surgical mask, Goggles, Face shield as PPE to their employees; whereas, 38.3% of the tenants provided Gown, Surgical mask, and goggles only (p=0.02). This association was found to be statistically significant (p<0.02).

Table 3: Association of provision of PPEs by employers to the type of ownership of Clinical set-up premises

*p<0.05 was considered significant using Pearson Chi Square test

Both the owners (81.7%) and the tenants of the dental clinics (73.5%) agreed that they did not provide PPE to all the staff. Furthermore, most of the owners (64%) disagreed that they found it difficult to arrange PPE because of high cost and 70.4% disagreed that PPE cost should be included in the patient treatment fee. On the contrary, 64.3% of tenants agreed that it was difficult to arrange PPE because of the high price and 76.1% agreed that the cost should be charged from patients. This association is also found to be statistically significant as the p-value is <0.01. Table-4 reports the effect of COVID-19 on revenue generation and expenditure according to the years of established dental practices. The results revealed that 65.4%

Table 4: Effect of COVID-19 on revenue generation and expenses according to the year of Clinical Dental Practice

*p<0.05 was considered significant using Pearson Chi Square test

of employers with less than one year of practice, 47.2 % of those with 1-3 years of practice, 58.5% with the practice of
3-5 years and 33.8% of employers with 5-10 years of established clinical set-ups reported that <5% of revenue was generated in April. On the contrary, 34.1% of employers with 10-15 years of practice and 32.1% of those with established set-up for more than 15 years reported the average revenue generated during April was 11-24% and 5-24%, respectively. The Chi-square test shows a statistically significant association between all the groups (p<0.01). Most of the employers, regardless of the year of experience, paid full salaries to their staff and employee dentists during April (p<0.01). Most dental clinics remained open and catered to emergency patients only during May. A statistically significant association between the employers of different years of clinical set-up was reported as the p-value was found to be less than 0.01. Table -5 demonstrates the future strategies planned by employers with regards to years of practice if the lock-down lasts until the end of August. According to the results, 40.8% of employers with less than 10 years of practice had planned to adjust the salaries of staff in the future and 23.4% planned

Table 5: Future strategies planned by employers with different years of experience if the current situation lasts until August

 

*p<0.05 was considered significant using Pearson Chi Square test

to find innovative ways to expand their patient base. On the contrary, 33% of employers with more than 10 years of
practice planned to find innovative ways to lower their operating costs, and 28.9% planned to find innovative ways
to expand the patient base. Pearson Chi-Square test gives a significant association between years of practice and future planning by employers with p<0.01.

DISCUSSION

The whole world is struggling to conform to the changing dynamics after the outbreak of the pandemic, and the global dental industry too bore no exemption in this regard. The COVID-19 pandemic has forced the dental industry around the world to modify the standard operating procedures and to provide emergency dental care only. The moral and ethical obligation to the patient and dental staff safety guided the global dental industry to limit the practices and abide by the laws of lockdowns. Amidst the time of such unexampled turmoil, the global dental community has endured both psychological and economic impacts.11 The current study is the first nationwide survey conducted to assess the financial impact of COVID-19 lockdown on employers of dental setups throughout Pakistan. The objective of our survey was to exclusively highlight the pecuniary difficulties and pressures faced by private dental practice employers with regards to COVID-19 crises, and to the concerned economical and health regulatory bodies of the region. The results of this cross-sectional study revealed that most of the respondents were males, married, and had three children on average. Similar results were reported in a study conducted among the dental practitioners of the UK where 70.4% were males, 80.9% were married and 47.1% had three children.12 In the present study, most of the participants were the sole earners of their families corroborating with the results of another study conducted in New Zealand reporting 63.5% dentists as principal earners in the family.13
The resulted stats signify the higher level and extent of liability endured by the dental employers of private practices for not only supporting their families but also being equally responsible for the personal and professional financial expenditures.
Our study revealed that the strength of dental clinic tenants equals the existence/strength of dental clinic owners.
The COVID-19 period rendered clear visibility of the walkin patients’ frequency, in comparison to the pre-COVID-19 period, which evidently was lower, even though private clinics (fully owned) remained open. The tenants on the other hand by choice closed their respective practices; however, they did cater to the emergency cases. American Dental Association reported that 75% of the dental practices are seeing only emergencies and the rest are completely closed.14 A survey by the Irish Dental Association conducted on 369 dentists reported a similar finding in which 52%
confined to emergency treatments only, whilst 18% completely closed their practices, coupled with 83%, which made changes in practicing hours.15 According to a survey conducted by Tada H et al., on 180 dental clinics in Hyogo, Japan, 46.7% reported a decrease in the number of patients, corroborating to the results of our study.16 Likewise, the British Dental Association also reported less than 25% of patient turnover than usual due to the suspended routine dental care.17 In a Polish cross-sectional study, Tysiac et al., reported that 71.2% of dentists suspended their dental practice and subsequently observed an evident decrease in the number of patients, after the COVID-19 outbreak. The authors associate the main reason for voluntarily suspension of dental clinics to mainly the shortage of PPE.18 Similar findings were reported by Irish Dental Association that 70% of dentists did not have access to gowns and 30% of dentists did not have unimpeded access to masks.19 Due to the increase in demand of PPEs and disinfectants for the healthcare providers, bearing the apparent utilization of the aforementioned items for the protection of patients and staff, not only have these become scant but rather expensive, as well. A recent report estimated a 1000% increase in PPE cost compared with preCOVID-19 times.20 Our study indicated that the tenant dental practitioners faced difficulty in providing PPE to staff because of high cost, corroborating to the results of an Iranian study.21
The owners on the other hand provided N95 masks, bodysuits, and face shields in addition to surgical masks, gowns, and goggles to their associate doctors. In a time when practices have experienced unprecedented declines in revenue, the rising cost of PPE has exacerbated the financial burden. This has forced practices to close or implement staff layoffs as indicated by the results of the present study. Moraes et al. revealed that the status of the Brazilian dentists got affected by 94%, and 84% impact on routinely practices was observed with an increased expenditure induced due to COVID-19 PPE practices and patient screening practices.22 An Indian study reported that the patients were charged additionally for PPE.23
Although, in our study, most of the tenants agreed that the cost of PPE should be included in patients’ treatment fees, yet charging patients an infection control fee may result in unethical custom. Induction of PPE cost in the aforementioned patient fee may have a significant impact on accessing care, especially for patients of a lower socioeconomic status. As suggested by Muzumdar et al, a more ethical and feasible approach would be to advocate for higher insurance reimbursement or coverage, or both, of appropriate Healthcare Common Procedure Coding System. This will enable the authorities to account for the increased cost of infection control, rather than charging the patients an infection control fee.24
Rather crippling losses were reported by the employers of private dental practices across Pakistan. This economical downfall of the dental industry is evident globally.1725 According to the American Dental Association, 7.9% of net revenue was generated during the lock-down period.14 The Irish Dental Association reported 76% dentists experienced financial loss, and about 70% amid the COVID19 outbreak. Half expect income to drop 90-100%.19 In the present study, most of the dental practice employers paid full salaries to their staff corroborating supporting the results of a cross-sectional study conducted in Iran.21 On the contrary, a US-based survey involving twenty thousand dentists reflected that only 27% paid the full salary to staff, whereas, 45% paid half the salary, and 28% did not pay at all.26
If this situation persists till the end of August, Pakistani dental employers, who bear less than 10 years of practice have planned to compensate for the financial crises by adjusting their staff salaries. On the other hand, dental employers with more than 10 years of clinical practice seemed more financially stable and planned to find innovative ways to lower their treatment costs. These results are in agreement with an Indian study concluding that the practitioners with less than 10 years of experience may face more hardships than those with more than 10 years of experience.27 Economists have painted a rather bleak picture for the world economy, as they foresee a downturn in the global economy, which, as predicted by them will lead to a worldwide recession in the long term. The Governments of many developed countries with high-income average have understood the gravity of this situation and have extended support to the dental practices. Numerous favorable financial plans have been laid by such governments. For instance, the government of the UK is ready to support the business owners by lending loans or credit, if they are facing difficulties in the payment of supplies or salaries to the staff.28 The dental practices of NHS, UK will receive funds to reimburse the losses due to the COVID-19 outbreak.17 The Canadian Government announced support of $27 billion, where the dentists can also apply for this support.29 According to IDA, the Irish Government will provide COVID-19 business load ranging from €5000 to € 50000 and the owners of dental practices can also apply for these loans.1530 St. Claire HealthCare in Morehead, Kentucky, USA has recently issued a statement in which they have mentioned that they are laying off a quarter of their staff temporarily, who are not directly involved in the care of patients with COVID-19.31
The Ministry of National Health Services, Regulation and Coordination, Pakistan has provided the guidelines for dentists and dental patients’ management during COVID1-19 pandemic on May 3rd 202032, but the government and the dental regulatory bodies have not yet set-up any economic response plan to support the local dental community, experiencing a major economic downfall. This research may assist the policymakers in preparing appropriate countermeasures during and after the COVID-19 pandemic.

CONCLUSION

The COVID-19 has immensely affected the financial stature and prospects of dentists in Pakistan. The extremely low patient frequency and revenue generation have posed rather substantial challenges for the dental clinic owners. The challenges primarily comprise the swift provision of PPEs, their costs, staff salaries, and other pertinent expenses. The owners and the practitioners with more than 10 years of practice were more financially stable and were able to manage the unforeseen circumstances. However, the tenant dentist employers and those who are new in this discipline have faced challenges in managing their expenses. The study affirmed that dentists are integrating PPE practices to cope with the current COVID-19 scenario. They are uncertain about the future and the incertitude that comes with their ability to pay their staff. It is, therefore, highly recommended that competent authorities from these countries should step up and support dental practices, which are on the brink of closure due to financial losses being endured by them due to the COVID-19 pandemic.

CONFLICT OF INTEREST

None to declare

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  1. Lecturer, Department of Operative Dentistry, Dr Irshad-ul-Ebad Khan Institute of Oral Health Sciences, Karachi Pakistan.
  2. Principal, Department of Oral and Maxillofacial Surgery, Liaquat College of Medicine and Dentistry, Karachi.
  3. MDS (Trainee), Department of Operative Dentistry, Altamash Institute of Dental Medicine.
  4. MDS Resident, Lecturer, Department of Periodontology, Dr Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Karachi Pakistan.
  5. MDS Resident, Department of Prosthodontics, Dr Irshad-ul-Ebad Khan Institute of Oral Health Sciences, Karachi.
    Corresponding author: “Dr. Huma Sarwar” < huma.sarwar@duhs.edu.pk >

A Nation-wide Survey on Financial Impact of COVID-19 on Employers of Private Dental Practices of Pakistan

Huma Sarwar                         BDS, MDS

Navid Rashid Qureshi          BDS, MSc, FDSRCS

Siddiqua Fatima                    BDS

Meshal M Naeem                   BDS

Ahsan Inayat                          BDS

OBJECTIVE: To assess the financial impact of COVID-19 on employers of private dental practices of Pakistan in the month of April and May 2020.
METHODOLOGY: In this cross sectional study, the employers of dental practices of Pakistan were inquired about their financial management during COVID 19 outbreak. The data was analyzed using IBM-SPSS version 23.0. Percentages and Chi-square tests were used for statistical analysis at p <0.05.
RESULTS: 52.7% owners opened their practices whereas 37.8% of tenants’ clinics remained closed (p<0.01). 38.3% of tenant employers provided inadequate PPE whereas 53.2% owners provided adequate PPE to their staff (p=0.02). 64% of owners easily arranged PPE for staff whereas 70.4% tenants found it difficult to arrange PPE because of its high cost. Employers with less than 10 years of practice reported less than 5% whereas those with more than 10 years of practice reported up to 24% of revenue generation income (p<0.01). Most of the employers paid full salary to their employees. If this condition persists till the end of August, 40.8% employers (<10 years practice) planned to adjust staff salaries whereas 33% employers (>10 years of practice) planned to find innovative ways to lower their operating costs (p<0.01).
CONCLUSION: Due to minimal patient turnover, dental employers are facing incredible challenges in managing the expenses. Those with more than 10 years of practice are more economically stable as compared to the employers with less than 10 years of practice.
KEYWORDS: COVID-19, finances, dental clinic, Pakistan.
HOW TO CITE: Sarwar H, Qureshi NR, Fatima S, Naeem MM, Inayat A. A nation-wide survey on financial impact of COVID-19 on employers of private dental practices of Pakistan. J Pak Dent Assoc 2020;29(4):172-178.
DOI: https://doi.org/10.25301/JPDA.294.172
Received: 26 August 2020, Accepted: 07 September 2020
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A Proposed Curriculum for 5-years BDS Programme in Pakistan and its Comparison with the Curricula Suggested by PMDC and HEC

Farhan Raza Khan                         BDS, MS, MCPS, FCPS

In Pakistan, whether to enforce a 4-year BDS course versus a 5-year course, is a matter of debate that warrants multiple deliberations. In USA and Canada, dentistry is 4-year long course but students can apply for admission into dental school only when they have already done 16 years of schooling (i.e. a 4-years of graduate university education is the pre-requisite). On the other hand, In UK & Ireland, students can apply for admission into dental colleges with 12-years of high school education. However, they follow a 5-years BDS programme. Similarly, there is much difference on the emphasis on various subjects taught
in the dental programmes. This paper critically appraises the PMDC and HEC advised BDS curricula in Pakistan and suggests an alternative curriculum that is more balanced in terms of subject distribution, assessment and above all contemporary to cater the evolving needs of the dynamic discipline of dentistry.
KEYWORDS: Dental; education; curriculum; Pakistan
HOW TO CITE: Khan FR. A Proposed curriculum for 5-years BDS Programme in Pakistan and its comparison with the curricula suggested by PMDC and HEC. J Pak Dent Assoc 2020;29(4):169-171.
DOI: https://doi.org/10.25301/JPDA.294.169
Received: 10 June 2020, Accepted: 24 August 2020

The dental school curriculum varies from institution to institution and country to country but most colleges and universities follow a general structure that is in the first two years of dentistry course, students spend most of their time studying basic biological & biomedical science. They learn the structure and function of the human body and the diseases that can affect it. Then in next 2 to 3 years (depending upon the course is 4 or 5 year-long) there is a gradual transition towards more clinically oriented subjects.1 The goal is to prepare dental graduates who possess strong knowledge base, right set of skills, and values essential to the practice of safe and ethical dentistry. Moreover, dental curriculum is built around some essential themes that could inculcate attributes such as professionalism, life-long learning and ability to critically evaluate, correlate and synthesize scientific evidence to help the graduate remain current and up-to-date in clinical practice.
In Pakistan, there are 55 recognized dental colleges.2 Presently, the Bachelors of Dental Surgery (BDS) course
is four-years duration.3 Its existing curriculum is devised by the statutory body of the country, Pakistan Medical &
Dental Council (PMDC). However, the institution responsible for other degree awarding courses in the country, Higher Education Commission (HEC) has also placed a 5-year long curriculum on their website for long4, but for various reasons this curriculum has not been made to any use as hardly any institution in the country follows it.
Whether to enforce a 4-years BDS course versus a 5-years programme, is a matter of debate that warrants multiple deliberations. In US and Canada, dentistry is 4-year long course but students there get admission into
dental school when they have already done 16 years of schooling (i.e. a 4 years of graduate university education is the pre-requisite). In UK & Ireland, students can apply for admission into dental colleges with 12 years of high school education. However, they follow a 5-years BDS programme. In simpler words, a dental graduate in UK & Ireland is generally three year younger than his North American counterpart. As medical and dental education in Pakistan and India, follow British system of education, 5 thus it’s imperative to align our BDS curriculum and assessment methodologies with the prototype so that dental graduates trained in Pakistan don’t face challenges when they apply for equivalence or when they go abroad for further education or apply for registration to practice outside Pakistan.
This paper is to critically appraise the PMDC and HEC advised BDS curricula and suggest an alternate curriculum
that is more balanced in terms of subject distribution, assessment and above all contemporary to cater the evolving
needs of the dynamic discipline of dentistry.

CRITICAL ANALYSIS AND PROPOSAL

The shortcomings in the PMDC curriculum (table 1) are: Firstly, it’s a four year curriculum which needs overhauling as the quantum of knowledge in dental sciences have grown so much in last 40 years that it’s not possible to cover the fundamentals of dental sciences in just four

Table 1: Existing curriculum by Pakistan Medical & Dental Council (PMDC)

Ω As per the state regulation, Pakistan Studies, Islamiat/ Ethics examination to be done at the end of first year.
*Source: PMDC website: http://www.pmdc.org.pk/

years. Moreover, the countries from which this four year BDS curriculum was adopted (UK, Ireland and Australia)
have already moved to the five year program in late 90’s. Thus, it’s likely that Pakistan too will follow their foot step
and will move to 5-years BDS programme soon.
Endodontics is entirely missing as a main subject. It should be specifically mentioned annexed to Operative Dentistry. Oral Medicine is being paired with Periodontology, it should have been synched with Oral Pathology instead. No mention of subjects such as Behavioral Sciences, Ethics, Implant Dentistry, Forensic Odontology etc. Although, Pediatric Dentistry has recently been recommended to be established as separate subject but so far only a few institutions have established its departments. The problem in Pediatric Dentistry teaching and assessment is the post graduate programme and availability of trained faculty.6,7
The limitations of the HEC dental curriculum (table 2) are: An unequal distribution of subjects throughout the length of the course. The final year is over burdened with too many subjects. Periodontology is taught in year 3 and then in year 5, skipping year 4 and not mentioned as which year its examination will be carried out. Similarly, Operative Dentistry is being taught in year 3 and 5, skipping year 4. Pediatric Dentistry is being merged with Operative Dentistry whereas Endodontics is absolutely ignored in the list of subjects. Again, year 4 is skipped for Oral Medicine, Oral Diagnosis & Oral Radiology. These three are clustered as one subject and repeated in year 3 and 5 too. Oral Medicine should have been paired with Oral Pathology to make more

Table 2: BDS Curriculum proposed by Higher Education Commission of Pakistan (HEC)

*Source: HEC website: https://hec.gov.pk

sense. Subjects such as Comprehensive Care Dentistry and Special Care Dentistry have been mentioned but there no
specialty residency programs in the country to train faculty in these subjects.
The strengths of the curriculum (table 3) proposed in this paper are: Its more balanced in terms of subject distribution, assessment and above all contemporary as it has subjects such as ethics, behavioral sciences, implant dentistry to cater the evolving needs of dentistry. However,

Table 3: Distribution of subjects in the 5-year long BDS course proposed in this paper

Ω As per the state regulation, Pakistan Studies, Islamiat/ Ethics examination to be done at the end of first year.

there is a question that there are lack of subject expert teachers in few of these disciplines, especially the newly proposed ones. For this, a solution has been proposed for identifying suitable subject teacher and the best alternate while keeping the circumstances of Pakistan dental academia in context. The first two years are preclinical years where student journals can be used for the formative assessment of the student. The third year is a blend of basic and clinical sciences whereas years 4 & 5 will be clinical years focused entirely on dental subjects. In addition to summative

Table 4: Allocation of faculty in subject of expertise and cross-subject allocation

*The alternate teaching faculty would a make shift (short term arrangement) for next 5 years only, once the number of adequate subjects specialist are available, this practice will be permanently stopped

assessment at the year-end, student log book in each subject could be used as an evidence of competence gained and
formative assessment throughout year.
Although a number of deliberations have been made by subject experts and dental educationists at the 1st Pioneer
Conference on Dental Education held at the Dental Institute of the Liaquat University of Medical & Health Sciences (LUMHS) Hyderabad, Pakistan on 14-15 November 2014 and at Pakistan Pioneer National Seminar on Dental Education organized by LUMHS held at Governor House Sindh (Pakistan) on 20 February 2015. The outcome of
such deliberations have yet to be translated into actions.
In conclusion, the limitations of PMDC and HEC templates have been appraised above. However, comparing the two
curricula, it seems that PMDC version is more practical compared to what HEC has suggested. In essence, the curriculum proposed here is a modified version of PMDC’s existing curriculum. Only fifth year is added, new subjects relevant to international and local practice needs are incorporated and existing subjects are redistributed.

CONFLICT OF INTEREST

None

FUNDING

None

REFERENCES

  1. American Dental Education Association. Dental school curriculum. https://www.adea.org/GoDental/Future_Dentists/Dental_School_ Curriculum.aspx [accessed 29 June, 2020].
  2. Pakistan Medical & Dental Council. Recognized dental college in Pakistan. http://www.pmdc.org.pk/recognizeddentalcollegesinpakistan/ tabid/167/default.aspx [accessed 29 July 2020].
  3. Pakistan Medical & Dental Council and Higher Education Commission Islamabad Pakistan. Curriculum of BDS. Published 2003. Available at: http://www.pmdc.org.pk/ LinkClick. aspx?fileticket=06HF%2Blta1uc%3D accessed 29 July 2020].
  4. Higher Education Commission Islamabad Pakistan. . Curriculum of bachelor of dental surgery (BDS). Five years programme -Revised 2011. https://hec.gov.pk/english/services/universities/RevisedCurricula/Documents/2010-2011/Draft-BDS-2011.pdf [accessed 29 July, 2020].
  5. Khan FR. Similarities and differences in specialty training of Conservative Dentistry and Endodontics (India), Operative Dentistry (Pakistan) and Restorative Dentistry- Endodontics (United Kingdom). J Pak Med Assoc. 2020;70:320-3. https://doi.org/10.5455/JPMA.2934
  6. Khan FR, Mahmud S, Rahman M. Pediatric dentistry training for dentists in Pakistan. J Pak Dent Assoc. 2013; 22:03-8.
  7. Khan FR, Mahmud S, Rahman M. The need of paediatric dentistry specialists in Pakistan. J Coll Physicians Surg Pak. 2013;23:305-7. PMID: 23552549.

  1. Associate Professor, Operative Dentistry, Chief of Dental Services, Aga Khan University Karachi, Pakistan.
    Corresponding author: “Dr. Farhan Raza Khan” < farhan.raza@aku.edu >

A Proposed Curriculum for 5-years BDS Programme in Pakistan and its Comparison with the Curricula Suggested by PMDC and HEC

Farhan Raza Khan                         BDS, MS, MCPS, FCPS

In Pakistan, whether to enforce a 4-year BDS course versus a 5-year course, is a matter of debate that warrants multiple deliberations. In USA and Canada, dentistry is 4-year long course but students can apply for admission into dental school only when they have already done 16 years of schooling (i.e. a 4-years of graduate university education is the pre-requisite). On the other hand, In UK & Ireland, students can apply for admission into dental colleges with 12-years of high school education. However, they follow a 5-years BDS programme. Similarly, there is much difference on the emphasis on various subjects taught
in the dental programmes. This paper critically appraises the PMDC and HEC advised BDS curricula in Pakistan and suggests an alternative curriculum that is more balanced in terms of subject distribution, assessment and above all contemporary to cater the evolving needs of the dynamic discipline of dentistry.
KEYWORDS: Dental; education; curriculum; Pakistan
HOW TO CITE: Khan FR. A Proposed curriculum for 5-years BDS Programme in Pakistan and its comparison with the curricula suggested by PMDC and HEC. J Pak Dent Assoc 2020;29(4):169-171.
DOI: https://doi.org/10.25301/JPDA.294.169
Received: 10 June 2020, Accepted: 24 August 2020

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Post-COVID-19 Dentistry – Knowing its Unknown Future

Fazal Ghani                         BSc, BDS, MSc, CMP, PhD, FDSRCPS

DOI: https://doi.org/10.25301/JPDA.294.166

Futurology can never be an exact science, especially at the best times. To determine whether we predicted correctly or otherwise, we have to wait and live healthy for a very long time to evaluate what we had predicted. The COVID-19 pandemic, in relation to dentistry has caused so much concern that we all have many themes to write on. The situation is so unpredictably evolving, that any topic one embarks to write on, rapidly gets insignificant. But as said, reflections on any chosen area do really resonate with the spirit of what we are living though in these extraordinary times.1 A recent publication predicted some immediate and heavier impacts that the COVID-19 outbreak currently is having on dentistry and the dental healthcare professionals. 2
As such some suggestions and recommendations based on personal feeling were offered. Before the COVID-19 pandemic, no one could have seriously thought that it would bring so much financial, social and healthcare upheaval on global level. During the current pandemic, we witnessed dentistry as anything it used to be and it seems the situation may stay the same for some time in future. In fact, dentistry suffered so severely, so unexpectedly and so dramatically. The closure of dental practices, the delivery of education, training and assessment all had immense impacts and challenges that required immediate responses.2-4 In such a scenario, it is important for profession to plan pre-emptively for the challenges ahead.
Looking at the future for dental profession, it appears that most of us see a confused state and picture that is most
likely to stay same for some years to come. Prior to the COVID-19 pandemic, everyone had been witnessing a
significant rise in the global dental market with an everincreasing trend for further growth. However, since this pandemic, over the past few months, we are witnessing a really unfortunate perfect storm where leaders in professional bodies and health regulating ministries are clueless about a measured response. In fact, we the dental health professionals and the entire dental profession are experiencing a roller coaster ride.
Both dentists and dental healthcare workers (HCWs) and patients have fear of getting infected. This fear is in part a direct result of many deaths of HCWs including transmission to dental HCWs.5-7 Among us the aged dental practitioners are likely to be at higher risk. Although the dynamics of SARS-Cov-2 transmission are yet to be
understood, but considering the relatively higher density of the COVID-19 cases, in the urban locations, DHCWs working in the urban dental settings, might be at higher risk compared to those in rural locations. Some 25% dental practices have been reported to have considered closing.
Some two-third practices had been predicted as not sustainable beyond 3 months.8 Self-employed dental practices
are already suffering and calling for immediate support from governments. To reflect truly, the pandemic has impacted the entire spectrum of dental practice with some of these including; extreme down-trends in finances and liability related issues, increased hassle, increased vulnerability of own health as dental practitioner, low patient volumes, no elective surgery, increased costs for PPE and a profound fear of their timely availability; and more importantly total redesigning of dental operatory and adoption and incorporation of systems and platforms to manage patient staying remote from practice.2
Many dental health professionals are thinking of early exits and retirement as a more attractive option. The fear of
another COVID wave this fall or next year, when further financial support may be limited, a kind of coup-contrecoup to practices as dental practices struggle to recover.2
In fact, new attitudes to a career in dentistry are being developed.2 It is likely that the number of dental students
will reduce as well as those intending to register as dental practitioners. Private hospitals and corporations are likely to be more interested in buying dental practices from those practitioners who opt to leave early. Obviously, there would be a great concern about what could happen to and what to do for them. A proposed option for them might include their redeployment to alternative roles and careers.
In such a situation, doing nothing is not an option. Let us hope that there is availability of strong leadership. During
this pandemic, most of us are sheltering in homes and keeping in a locked-down state, none of us have been sleeping and have been really wondering, thinking and working from home. In fact, it has provided many of us the best time, with the greatest focus and attention, with everyone looking for new and fresh ideas, a time to think for change and respond. Everyone is looking to transform and innovate and get it right. Recently, Bill Gates said that pandemics remind us that helping others is not just the right thing to do but it is also the smart thing to do.9
We must admit that we remained so pre-occupied in profiting from advancements dentistry had made that we totally forgot that after AIDS, Ebola, SARS, MERS and Zika epidemic, there could be a pandemic called the COVID-19. We really never thought of being so engulfed and so challenged. Suddenly, we all faced a dentistry totally different; entirely going virtual with no face-to-face contact to provide dental care, dental education and training, interacting with and seeing our patients on the screen and examining them and diagnosing their conditions with reduced need for their physical presence. Patients want to know that going to dentist is safe and how long the policy of “avoid, restrict and abbreviate” will remain a practice. We resorted to the same approach for our trainees so they could continue gaining skills and competency in patients’ care, patient examination and diagnosis. There is the very real possibility that things will ever be the same. Perhaps, if we do things right, we can change all this for the better.
Need for new generation of dental practitioners trained for the way they will practice dentistry from now on is the
voice we hear. Also is the need for retraining those old fashioned enough like me, who, for one or other reasons
strongly believe in the benefits of providing in person dental consultation and care to patients and are reliant on the need for having presence of the patient for determining the severity of dental and orofacial pain and other conditions better diagnosed by physical observation. We now see that most initial level patient-dentist interaction could occur through the use of tele-dentistry platforms and over a video connection and smart or conventional phone. This is not exactly the usual office visit we all were trained on. Subsequent in person visits will follow the safety concerns including; keeping social distance in clinical and patient waiting areas, following thorough screening protocols for patients seeing and treating them while we are cloaked in PPE.
Several considerations to restructure the dental training programs are needed. These include the present oral
microbiology syllabus with more focus on infections transmissible through air, respiration, oral fluids and contact.
Training of dental students is needed in aspect of respiratory hygiene, strategies for reducing microbial / viral loads in oral fluid, disinfectants as adjunct to PPE, design of dental operatory including waiting areas/ clinic / dental hospital, air purification technology to help manage aerosol created during dental procedures. There is need for adopting more digital dentistry, use of patient management systems.
During the period of COVID-19 pandemic, there is a need for thorough pre-visit screening and well-controlled patient visits to clinic.3 Dental lasers have been shown to reduce the volume of aerosolized particles released during a dental procedure due to the reduced volume of water sprayed into the patient’s mouth during use. These lower volumes of water reduce the size of the aerosol cloud, likely making procedures safer for clinicians. Alternatively, highvolume suction apparatus must be used when performing aerosol generating procedures.
In addition to ensuring proper decontamination, sufficient time should be allowed for enough air circulation /  changes to occur and so to remove potentially infectious particles, The time for which the area should remain unused may have to be longer in case the patient has coughed and sneezed in the clinical area as well as longer duration dental procedures generating aerosol have been done for the patient. All surfaces will need to be cleaned. Staff will have to wear heavy-duty PPE. Waiting rooms will need to be rearranged and appointments staggered to allow for social distancing, according to measures set by local dental practice regulating body. Obviously, all these will add to increased overhead costs and more environmental concerns.
Time has come for dentistry to show it is different, for dental healthcare professionals to accept that there is so
much more that they can do, and perhaps the things that have surfaced through this outbreak, and all the rest that is shaking up the entire globe, can truly allow all of us to reinvent and renovate the dental healthcare system to become
one that is just, all-encompassing, and truly serving the best interests of our every patients. From now onward, we will always be living in an increasingly complex world and most scientists have agreed that they are living in one of the greatest times of change. This pace of change is still increasing. However, one thing for sure that could help us
is “innovation”. Innovation is not only the key to endless economic growth but the key to solving problem, however,
it is necessary that we focus on innovation without exploitation. New innovations enable growth and prosperity
in the same way – making things better and more efficient. But, none will innovate if they are content – there needs to
be an urge to find a better way to do things. Corporations and corporate leaders are the key actors today, with greater
possibility to influence the future – Far more than the governments. In fact, it may possibly be the best time, especially now, with the greatest focus and attention, with every one looking for new and fresh ideas, a time of change, when everyone is looking to transform and innovate and get it right …………….
That time has come now

REFERENCES

  1. Dougall A. Editorial – COVID-19 a personal reflection. Spec Care Dent 2020;40:216-18. https://doi.org/10.1111/scd.12468
  2. Ghani, F. (2020). Covid-19 Outbreak – Immediate and long-term impacts on the dental profession. Pak J Med Sci. 2020;36(COVID19-S4): S126-S129. https://doi.org/10.12669/pjms.36.COVID19-S4.2698
  3. Ghani F. Corona Virus Disease – 2019 (COVID-19) – Planning for Emergency Dental Practice and Dental Education. Acta Sci Dent Sci 2020:4:16-21. https://actascientific.com/ASDS/pdf/ASDS-04-0854.pdf
  4. Ghani F. Remote teaching and supervision of graduate scholars in the unprecedented and testing times. J Pak Dent Assoc 2020 J Pak Dent Assoc 2020;29 (Special Supplement) July:S36-42. https://doi.org/10.25301/JPDA.29S.S36
  5. Kursumovic E, Lennane S, Cook TM. Deaths in healthcare workers due to COVID-19 – the need for robust data and analysis. Anaesthesia 2020:1-4. Published: 12 May 2020. https://doi.org/10.1111/anae.15116
  6. Crist C. Almost 600 US healthcare workers have died from COVID-19. June 09, 2020. https://www.medscape.com/viewarticle/932028
  7. Rothe C, Schunk M, Sothmann P, Bretzel G, Froeschl G, Wallrauch C, et al. Transmission of 2019-nCoV Infection from an Asymptomatic Contact in Germany. N Engl J Med 2020;382:970-71. https://doi.org/10.1056/NEJMc2001468
  8. ADA News. HPI poll examines impact of COVID-19 on dental practices. Data to help shape ADA response to pandemic. April 01, 2020 (Accessed 09 June 2020). https://www.ada.org/en/publications/ada-news/2020-archive/april/hpi-poll-examines-impact-of-covid-19-on-dental-practices
  9. Dios PD. Editorial – COVID-19: Desolation and catharsis from old Europe. Spec Care Dent 2020; 40:213-14. https://doi.org/10.1111/scd.12466

  1. Professor & Head of Department of Prosthodontics & Dean Postgraduate Dental Sciences,
  2. Peshawar Dental College, Warsak Road, Peshawar 2516 (Pakistan).
    Corresponding author: “Prof. Dr. Fazal Ghani” < fazalg55@hotmail.com >