Evaluation of the effect of diffrent sterilization/ disinfection methods on the fracture strength of extracted teeth

Abstract

Introduction: A variety of sterilization/disinfection methods for extracted teeth may affect dental structures. But no study has investigated the effect of different sterilization/disinfection methods on the fracture toughness of extracted teeth until now. Therefore, this study aimed to evaluate the effect of different sterilization methods on the fracture toughness of extracted teeth. Methods: In this study, 48 single-rooted premolars extracted for orthodontic reasons were used. The teeth were divided into 8 groups (n = 6) and after autoclaving kept in one of the five groups of solutions consist of thymol, chloramine T, sodium hypochlorite, normal saline, or PBS for one month. In the sixth group, the teeth only were kept in formalin solution for one month. In one group, the only autoclave was performed and no intervention was performed in the control group. Finally, the teeth were tested for fracture strength by a universal testing machine. One-way ANOVA test and Game-Howell post hoc test were used to compare the fracture toughness of the groups. A significant level was considered P <0.05. Results: The results of the study showed that the highest mean value of fracture strength belongs to the PBS group (1290.91 ± 88.97) and the lowest value belongs to the autoclave group (277.41 ± 16.80). Fracture strength in the groups of PBS, sodium hypochlorite and formalin was significantly higher than the control group (P <0.01). While the fracture strength in the only autoclaved group was significantly lower than the control (P =0.003). The fracture strength of the groups kept in chloramine thymol or normal saline after autoclave was not significantly different from the control group (P <0.05). Conclusion: This study showed that autoclaving of extracted teeth reduces the fracture strength, while storage in 1% formalin or PBS for one month increases the fracture strength. Also, keeping extracted teeth in 1% chloramine T, 0.1% thiol, or normal saline before autoclaving teeth does not affect tooth fracture strength and is recommended in studies to evaluate fracture strength.