脉冲Nd:YAG激光照射对釉质耐磨性的影响

目的：研究激光照射对釉质耐磨性的影响。方法：用不同剂量的脉冲Nd:YAG激光照射人牙釉质，测量照射前后釉质硬度及磨耗率的改变，并用扫描电镜观察釉质表面形态的变化。结果：釉质的硬度随激光照射剂量的增大而显著降低，幅度最大者硬度仅达正常釉质的41%。釉质的磨耗率随激光照射剂量的增大而升高，最高可达正常釉质的3.83倍。釉质在激光照射下出现熔融与再结晶现象，表面变粗糙，晶体结构变疏松。结论：激光使釉质的耐磨性降低，机械强度降低，提示临床应用中不宜采用过高强度激光照射釉质。

Effects of laser irradiation on the abrasion rate of dental enamel

AIM:To understand the effects of laser irradiation on the abrasion rate of dental enamel. METHODS:Human enamel blocks were irradiated with pulsed Nd:YAG laser at different energy . The surface hardness and abrasion rate of enamel were examined before and after laser irradiation. Morphological changes of enamel were observed with SEM. RESULTS:The abrasion rate increased with the increased dose of laser irradiation, reaching 3.83 times of the control group. Hardness of the enamel decreased greatly, dropping to 41% of the control group. SEM examination revealed that melting and recrystallization occurred during laser irradiation. The enamel surface became rough and crystal structure became loose. CONCLUSION:Laser irradiation can decrease the mechanical intensity of enamel and increase its abrasion rate. So it is not recommended to apply high dose of laser irradiation on enamel clinically.