固化光源光照角度对牙本质粘结强度的影响

目的：通过改变发光二极管光固化灯光照角度研究复合树脂固化后牙本质粘结强度。方法：选取因正畸需要拔除的前磨牙20颗,随机分成4组。去除面釉质,暴露平的牙本质表面,酸蚀后涂布粘结剂。发光二极管光固化灯固化粘结剂20s,复合树脂堆砌树脂冠,高2mm。A组：发光二极管光固化灯光导棒与树脂粘结面成30°光照。B组：成45°光照。C组：成60°光照。D：成90°光照。4组均光照30s。用硬组织切片机将实验牙切成粘结面积约为1mm×1mm的柱状小条,将样本放置于微拉伸测试仪上,测试髓壁的牙本质粘结强度。结果：发光二极管光固化灯投照角度为30°时,牙本质粘结强度最大（P〈0.05）。结论：固化光源投照角度对牙本质粘结强度有影响,随着角度增加微拉伸粘结强度呈降低趋势。

Effects of Light Projected Angle on the Micro-tensile Bond Strength to Human Dentin

Objectives：To observe the effects of light-emitting diode（LED）curing light using different projected angle on the micro-tensile bond strength（mTBS）to human dentin.Methods：Twenty non-carious premolars were selected and randomly divided into four groups.Resin crowns（Single bond 3M USA,Z100 resin composite 3MUSA）with 2mm high were built up on flat superficial dentin surface exposed after removing and polishing perpendicular to the long axis of the tooth.We used LED curing light at an angle of 30°,45°,60°,90° to the dentin surface.After 24hstorage at 37℃ in water,all teeth were sectioned to obtain bar-shaped specimens with bonded surface area of approximately 1mm×1mm.Dentin mTBS was measured at across head speed of 0.5mm/min.Data were analyzed with one-way analysis of variance.Results：The results showed that the projected angle sources curing for adhesive affect significantly on mTBS to dentin（P〈0.05）.The highest bond strength values of LED curing light was 30°.Conclusion：Different projected angle sources influence mTBS to dentin.The bond strength results diminish as the angle increases.