Longitudinal assessment of cytotoxicity and cytomorphological changes in buccal mucosa exposed to dental laboratory chemicals

AIM: To assess the cytotoxicity and cytomorphological changes in the buccal mucosa cells of 1st year dental students (DS) and dental technicians (DTs) upon exposure to laboratory chemicals. SETTINGS AND DESIGN: This observational longitudinal cohort and cross-sectional study was conducted at the Department of Prosthodontics, Yenepoya Dental College, Mangaluru, Karnataka, India. MATERIALS AND METHODS: The study involved a total of 45 participants: DT Group (n=15), DS Group (n=15), and Control Group (CG) (n=15). Cytotoxicity and cytomorphological alterations were assessed using the buccal mucosa cytome assay among all three groups. The 1st year DSs were followed up longitudinally for 18 months at three time intervals (T0, T1, and T2). STATISTICAL ANALYSIS USED: Kruskal-Wallis H-test and Mann-Whitney U-test were used for intergroup comparisons. Friedman ANOVA was used for longitudinal comparison within the DS group. Statistical significance was set at P < 0.05. RESULTS: Kruskal-Wallis H-test showed a statistically significant difference in micronuclei frequency among the DT group, DS group, and CG. The DT group showed the highest micronuclei and karyolytic cell frequency, followed by the DS group and CG. Friedman analysis of variance test showed a statistically significant increase in micronuclei frequency in DSs when followed up at T0 (beginning of the course), T1 (after 12 months), and T2 (after 18 months). CONCLUSION: Cytotoxicity was highest in the buccal mucosa of DTs, followed by DSs and CG. First-year DSs showed a progressive increase in cytotoxicity with increasing duration of exposure. Dental laboratories should have effective ventilation systems and dental personnel should strictly follow personal protective equipment guidelines to minimize exposure to laboratory chemicals.