Gabriele Miccoli, Gianfranco Gaimari, Marco Seracchiani, Antonio Morese, Tatyana Khrenova, Dario Di Nardo
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引用次数: 22
Abstract
Aim: Aim of the study was to evaluate effectiveness of different heat treatments in improving Ni-Ti endodontic rotary instruments' resistance to fracture.
Methods: 24 new NiTi instruments similar in length and shape: 12 M3 instruments, tip size 25 and .06 taper (United Dental, Shanghai, China), and 12 M3 Pro Gold instruments tip size 25 and .06 taper (United Dental, Shanghai, China), were tested in a 60° curved artificial root canal. Each group received a different heat treatment. Cycles to fracture were calculated for each instrument. Differences among groups were evaluated with an analysis of variance test (significance level was set at P<0.05.).
Results: Statistical analysis found significant differences (p<0.0213) between groups. The M3 Pro Gold instruments were significantly more resistant to fatigue (mean values = 1012, SD +/- 77) than M3 instruments (mean values = 748, SD +/- 62). No statistically significant differences were found between fragments' lengths (p>0,05).
Conclusions: An increased flexibility and the reduction of internal defects produced by heat treatments during or after manufacturing processes, may be responsible for improving resistance to cyclic fatigue and flexural stresses.
目的:评价不同热处理方法对提高镍钛根管旋转器械抗骨折性的效果。方法:采用24个长度和形状相近的新型NiTi器械，其中12个M3器械，尖端尺寸为25和0.06锥度(中国上海联合牙科公司)，12个M3 Pro Gold器械，尖端尺寸为25和0.06锥度(中国上海联合牙科公司)，在60°弯曲的人工根管内进行测试。每组接受不同的热处理。计算每个仪器的断裂周期。各组间差异采用方差分析检验(设显著性水平为:结果:经统计学分析，差异有统计学意义(p0,05)。结论:在制造过程中或之后的热处理中，灵活性的增加和内部缺陷的减少可能是提高对循环疲劳和弯曲应力的抵抗力的原因。
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