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.