Knowledge and awareness of dental students toward disinfection and handling of human extracted teeth – A questionnaire-based study

INTRODUCTION

Dentistry is a highly skilled profession, and various techniques are being implemented to improve the proficiency of the students. As a part of the dental curriculum, preclinical training is imparted to the students before entering the clinics to train them for working on patients with utmost precision.^[1]

To study the various cavity preparation techniques, root canal treatment in endodontics, properties of restorative materials, and other procedures students require extracted natural teeth to learn the basic treatment modalities. Extracted teeth are also being used for biomimetic restorations.

However, the extracted teeth which can be used by dental college students have been found the potential source of infection, which may possess greater risk of exposure to various transmissible pathogens and subsequent diseases. According to centers for disease control and prevention (CDC), it is advised to eliminate all pathogenic organisms thoroughly from the patient’s items. However, caution should be used in doing so to avoid spreading the disease.^[2]

Hence, it is of prime importance to implement disinfection and handling measures to increase awareness as per the protocol. Hence, this study aims to evaluate the knowledge, awareness, attitude, and perception toward disinfection and handling of extracted teeth.

MATERIAL AND METHODS

A questionnaire was formulated and validated by the subject professionals. Approval was obtained from the Institutional Ethical Committee, and the questionnaire was pretested on 15 subjects to rule out any uncertainty in the responses earlier than using on the real sample.

The questionnaire consisted of 12 questions, was designed to assess people’s knowledge, awareness, and perception about the management and cleaning of extracted teeth [Table 1]. The questionnaire was circulated among dental students in Central India in the electronic form through Whatsapp or Email. The research was carried out from August 2020 to March 2021. The data collected from the survey were evaluated in terms of each question, and their percentage values were calculated.

RESULTS

The questionnaire had been sent out to approximately a thousand subjects. Among them, 757 individuals’ responses were obtained and added to the study [Table 1].

Of the 757 respondents, 252 (33.3%) were male and 329 (66.7%) were female. Among these respondents, 33.7% were 2^nd year UG students, 23.3% were of 3^rd year UG students, 19.7% were 4^th year UG students, and 23.3% were intern.

Among all subjects, 603 (79.7%) practice their preclinical work on extracted teeth, while 154 (20.3%) opted for other options. Most of the students (39.1%) preferred to collect extracted teeth from institution due to more number of patients/outpatient department while 35.3% students collected the extracted teeth from institution as well as private clinics.

For storage of extracted teeth, 34.9% of students preferred normal saline, 22.7% used sodium hypochlorite, and 27% used any of two solutions while 15.4% remain neutral. Maximum respondents 73% were aware about infection transmission from extracted teeth, and therefore, 68.8% sterilize extracted teeth before use. For the disinfection of extracted teeth, different responses were noted, that is, 31.6% uses saline, 30.4% uses hydrogen peroxide (H₂O₂), 24.3% uses sodium hypochlorite, and 13.6% remain neutral.

About awareness of autoclaving of extracted teeth, 36.15 responded positively while 35.9% responded negatively and 28% respondents were not aware about it. The importance of wearing gloves, a facemask, safety glasses, and an apron while working has been appreciated by the majority of respondents. About 69.8% respondents were not encountered any infection while working on extracted teeth while 12.6% of them did no longer consider untoward incidence happening with the use of extracted teeth which could be infected. Almost 50.9% of participants were aware about the transmission of human immunodeficiency virus (HIV)/hepatitis B virus (HBV)/hepatitis C virus (HCV) infection through extracted teeth. Regarding disposal of extracted teeth, 28.6% of respondent were in favor of red garbage bin, 22.9% responded for yellow garbage bin, 19.5% uses any general garbage bag, and about 29.2% were not aware of it. The majority of respondents, that is, 85.4% – thought that statutory standards were necessary to handle extracted teeth.

DISCUSSION

In dentistry, dental personnel are at the high-risk category with increased possibilities of contamination due to transmission or cross contamination of microbiota. To understand the concepts of clinical work, dental students have to work on extracted tooth as it is an important preclinical activity for dental students before entering the clinics.^[3]

Extracted teeth are contaminated with blood and saliva, which is usually harbored in pulp, root, and periradicular tissue.^[4] These can be a probable source of infection for HIV, HBV, and HCV, along with other blood-borne pathogens. The extracted tooth is the main source of infection; therefore, disinfection of these teeth is of utmost importance before their use for preclinical or research work to prevent further contamination.^[2,5]

Disinfection is the process that reduces the microbial flora while sterilization process removes the spores over the surface. Various disinfectant or sterilizing agents are being used which includes sodium hypochlorite, H₂O₂, normal saline, glutaraldehyde, absolute alcohol, and chlorhexidine. As recommended by CDC, household bleach in 1:10 ratio should be used to store extracted teeth. Among all the sterilization methods, gamma radiation was very effective as they don’t change the mechanical properties of tooth structure.^[2,6] According to various literature, gamma radiation shown best results for sterilization of tooth without changing its structure and function.^[7,8]

According to a different study, soaking in 10% formalin solution for a week or autoclaving for 40 min at 121°C and 20Psi both effectively reduced the microbial load.^[1,9] About 87.5% of students in a study by Kumar et al. were requested to sterilize their teeth before receiving any treatment, indicating that they are conscious of safety issues and follow the proper precautions before working.^[10]

Among all the chemical substances, college students rarely use formalin, H₂O₂, or bleach.^[11] About 5.25% sodium hypochlorite and autoclaving are the most effective disinfection techniques. Better antibacterial properties are shown by 10% formalin, which penetrates the pulp chamber.^[12] Because formalin is thought to be carcinogenic when used in animal research, the CDC advised that teeth used in studies or for teaching reasons be cleaned with liquid chemical germicides or sodium hypochlorite.^[13] Sodium hypochlorite diluted with tap water in the ratio 1:10 is commonly used storage media.^[14]

In the present study, we observed that students used an apron, gloves, and facemask to prevent future cross-contamination. In accordance with recommendations from the CDC, extracted teeth should be handled with the same level of caution as biopsy specimens because they are clinical specimens containing human blood and may be contagious.^[2,15]

We found in our study that most students’ methods for sterilizing extracted teeth are ineffective, and that they should be educated more appropriately about sterilization techniques while handling extracted teeth and it is safer to follow CDC’s recommendations.

CONCLUSION

In the present study, we observed that the knowledge, attitude, awareness, and perception of dental students when it comes to disinfection and managing of extracted teeth which were acceptable. Based on the outcomes, instructing dental students for proper handling, that is, how to collect, store, and disinfect extracted teeth is the key concept which should be instilled in the minds of the students in the 1^st year of Bachleor of Dental Surgeon itself.