关键词: 切角缺损, 纳米树脂, 微渗漏

Abstract:

Objective    To evaluate microleakage of incisally fractured incisors restored with nanofilled composite resins.  Methods    Twelve previously extracted incisors were assigned to two groups （A and B） equally according to the size of tooth. The teeth were cut obliquely from the mesial incisal angle to simulate uncomplicated tooth fracture. Labial reduction of 0.5mm and dovetails in the lingual surfaces were prepared. Additional 2mm of the incisal edge were cut horizontally in group A. The teeth in both groups were restored with nanofilled composite resins using a multilayer technique. Thermal and mechanical cycling was used to simulate oral temperature and aging effect. Level of microleakage was assessed. Statistical analyses were conducted between the two groups. Results    Eleven of the twelve samples revealed microleakage，and one case had the leakage up to the medullary shaft wall. Difference between the two groups revealed no statistical significance. Conclusion    According to the results of this study，microleakage still exists when using nanofilled composite resins to restore incisally fractured incisors. Whether to reduce 2mm of incisal edge or not does not affect level of microleakage.

Key words: incisor fracture, nanofilled composite resins, microleakage