离体前磨牙邻面颈部龋一种新洞型抗折裂性能的实验研究

Experimental research on anti-fracture in new type of cavities in proximal cervical caries of extracted bicuspid

目的对邻面颈部龋一种新洞型及传统洞型进行抗折裂负荷测试,并对新洞型与传统洞型的抗折裂性能进行比较。方法收集200颗完整的离体前磨牙,随机分成A、B、C、D 4组,A组为对照组,B组制备成牙合面洞,C组制备成邻颊(舌)面洞+牙合面洞(即新洞型,简称“双洞型”),D组制备成邻牙合面洞,模拟根管治疗后行银汞充填,用微机控制电子万能测试机对离体牙进行抗折裂负荷测试,测试各组实验牙折裂时的压力强度值。结果牙体折裂时的压力强度均值分别是:A组4 523.17 N,B组2 357.41 N,C组2 343.25 N,D组1 784.22 N。经统计学分析:C组抗折力明显高于D组,C组与B组抗折力接近,B、C、D抗折力明显低于A组。结论新设计的“双洞型”抗折力优于传统的邻牙合面洞型。

Objective To test the fracture load of a new-type cavity and a traditional one in proximal cervical caries, and make a comparison between beth of them. Methods 200 intact bicuspid were collected and divided into four random groups （ A, B, C and D ） with 50 teeth each. Group A was made to be a contrast. The B, C, D groups were prepared to be three different types of cavities, which were called occlsual cavitives; buccal-adjecent （lignal） cavities with occlsual cavities （the new ＂double cavitives＂ ） and the oeclsual-adjecent cavities. They were filled with silver hydrargyrum after simulated RCT. The fracture load tests were performed on all the teeth with a universal electronic testing machine controlled by a computer. And the tests were also made on the pressure curves during the fractures of each group, Results average forces of anti-fracture were as follows： 4 523. 17 N in Group （A）, 2 357.41 N in Group （B）, 2 343.25 N in Group C and 1 784.22 N in Group D, Analysis of mechanics： Average force of anti-fracture in Group C is obviously higher than that in Group D, and the force in Group C is similar to that in Group B, and the force in Group B, C, D is obviously lower than that in Group A, Conclusion During the RCT in proximal cervical caries, the newly-designed type of ＂double cavities＂ has a good advantage of ensuring stronger anti-fracture over the traditional one.