Er,Cr∶YSGG激光预备牙本质对充填材料粘结力影响的研究

Effect of Er,Cr∶YSGG Laser Irradiation on Bond Strength of Filling Materials

目的探讨Er,Cr∶YSGG激光预备牙本质对充填材料粘结力的影响。方法20颗完整无龋坏、无充填的离体正畸前磨牙,随机分成A(15颗)、B(5颗)两组。A组试验侧(颊侧)、对照侧(舌侧)分别用Er,Cr∶YSGG激光和传统牙钻处理牙本质表面,FujiⅨ充填,经500次冷热循环后,检测牙本质与充填材料之间抗剪切粘结强度,体视显微镜下观察粘结断面;B组试验侧(颊侧)、对照侧(舌侧)分别用Er,Cr∶YSGG激光和传统牙钻预备3 mm×3 mm的窝洞、洞深位于釉牙本质界下0.5 mm,经FujiⅨ充填,冷热循环后,扫描电镜下观察粘结界面的情况。结果A组试验侧和对照侧的抗剪切粘结强度分别为(3.79±0.38)MPa和(3.17±0.19)MPa,差异有显著意义(P<0.05)。为体视显微镜观察显示粘结断面充填物残余试验侧多于对照侧。B组试验侧牙体组织与充填材料间缝隙比对照侧小。结论用Er,Cr∶YSGG激光预备牙本质能增加充填物与牙体组织的粘结力。

Objective To analyze the effect of Er, Cr ： YSGG laser irradiation on bond strength of filling materials. Methods Twenty non-carious, intact, non-filled and extracted premolars were collected and randomly divided them into two groups, which were group A （fifteen）and group B （five）. All sample dentins from group A were processed by Er, Cr： YSGG restoration material. Then the teeth were thermocycled for 500 cycles, placed in test laser for the buccal suface and by bur for the lingual surface. Fuji IX was used as the machine for the shear bond strength examination and then observed under a stereomicroscope. Thereafter,class I cavities produced on the buccal and lingual surfaces cut by Er, Cr：YSGG laser and bur in group B separately. The cavites were made with the size 3 mm × 3 mm and 0. 5 mm below enamel dentin junction （EDJ）. Fuji IX was bonded to cavities and again thermocycled for 500 cycles. After that , the specimens from group B were observed under a scanning electron microscope. Results There was significant difference in the shear bond strength irradiated with Er, Cr： YSGG laser in group A （P 〈 0. 05）. The stereomicroscopy of laser-ablated specimens demonstrated more restoration material residues on the dentinal surface. Group B prepared by Er, Cr：YSGG laser-cut had a closer connection between dentin and filling materials than by bur-cut. Conclusions Er, Cr：YSGG laser can increase higher bond strength between dentin and filling materials.