Nd:YAG激光对3种树脂水门汀与牙本质粘接强度的影响

Effect of Nd: YAG laser on the bond strength of 3 resin cements to dentin

目的观察Nd:YAG激光照射前后树脂水门汀-牙本质粘接界面的微观形貌特征,评价Nd:YAG激光对3种树脂水门汀与牙本质间粘接强度的影响。方法选择人离体前磨牙30颗,分为颊、舌两部分,将试件随机分为激光组和对照组。激光组以0.8 W、10 Hz脉冲Nd:YAG激光作用于牙本质表面25 s,联合3种树脂水门汀RelyX ARC、Panavia F和RelyX Unicem充填;对照组直接使用树脂水门汀充填。然后测试剪切强度,在根管显微镜下观察断裂模式并分类。另选人离体前磨牙6颗,按照标准的牙本质粘接面预备后,使用Nd:YAG激光照射3颗牙牙本质表面,并联合充填不同的树脂水门汀,用扫描电镜观察Nd:YAG激光照射前后树脂水门汀-牙本质界面的微观形貌变化。结果激光照射可以提高自酸蚀树脂水门汀Panavia F和自粘接树脂水门汀RelyX Unicem与牙本质之间的剪切强度(P<0.05)。激光会降低全酸蚀树脂水门汀RelyX ARC与牙本质间的剪切强度(P<0.05)。根管显微镜下观察可见:试件断裂大部分发生在树脂水门汀-牙本质界面。扫描电镜观察可见:Nd:YAG激光照射后,全酸蚀亚组和自酸蚀亚组的混合层变薄、树脂突变短且少;自粘接亚组变化不明显,未见树脂突。结论 Nd:YAG激光照射后,可提高Panavia F和RelyX Unicem与牙本质的剪切强度,建议临床联合应用。

Objective To observe the microscopic characteristic of the bonding interface between resin cement and dentin before and after using Nd： YAG laser, and evaluate the effects of the Nd： YAG laser on the shear bond strength of 3 resin cements to dentin. Methods 30 human premolars were cut into nearly equal halves, prepared to expose the dentin and randomly divided into two groups： Laser group and control group. The teeth in the laser group were processed with pulse Nd： YAG laser（0.8 W, 10 Hz） for 25 s, and then the teeth were bonded using 3 resin ce- ments （RelyX ARC, Panavia F and RelyX Unicem） to dentin. All teeth in the control group were directly filled with 3 cements. The shear bond strength of specimens was measured. Each fractured specimen was examined under dental microscope. And 6 new human premolars were prepared into standard bonding specimens. After 3 teeth processed with pulse Nd： YAG laser, all teeth were bonded using 3 resin cements. To observe the microscopic characteristics of the bonding interface between resin cements and dentin. Results Nd： YAG laser on dentin surface could increase bond strength of Panavia F and RelyX Unicem （P〈0.05）. And the laser could decrease bond strength of RelyX ARC （P〈0.05）. Most of the fractured adhesive dentin surfaces were adhesive failure modes. Scanning electron microscope （SEM） observation demonstrated that Nd： YAG laser irradiation on dentin surface could decrease the hybrid layer and resin tags between the resin cements （RelyX ARC and Panavia F） and dentin. The interface between RelyX Unicem and dentin showed no obvious change, and resin tags were not observed. Conclusion Nd： YAG laser on dentin surface can increase bond strength of Panavia F and RelyX Unicem. Therefore, they can be used together in clinic.