Evaluation of Different Sterilization Methods on the Uniformity of Diamond Dental Burs and the Change in the Cutting Edge of Carbide Burs by Electron Microscopy

Introduction: Dental burs are one of the most commonly used materials in dental offices and have, therefore, the highest risk of cross-contamination. Accordingly, sterilization of dental burs is highly recommended. Using the electron microscopy, this study aimed to evaluate the results of different sterilization methods on the uniformity of diamond dental burs and the change in the cutting edge of carbide burs. Materials and Methods: To assess the result of sterilization outcomes, 18 diamond and 18 carbide burs were randomly distributed among 3 groups of dri-clave, autoclave, and cold sterilization groups with 2 subgroups of 5 and 15 cycles of sterilization. A preassessment Scanning Electron Microscopy (SEM) was conducted and posttest SEM was performed after the sterilization cycles. Adobe Photoshop 2017 was used in grayscale of 12 to compare the difference between pretest and posttest results. The obtained data were analyzed by post-hoc Tukey test, Mann-Whitney U test, ANOVA and Kruskal-Wallis test in SPSS 21. The level of significance was considered as P<0.05. Results: In 5 cycles of sterilization of diamond burs, the best outcome was found by dri-clave and carbide burs, but autoclave was the best method in 5 cycles of sterilization (P<0.05). In 15 cycles of sterilization of diamond and carbide burs, the best method was autoclave which was significant in carbide burs. Conclusion: All of the sterilization methods caused corrosion, discoloration, and loss of integrity in carbide burs but the following changes were minimum in the autoclave method.