The effect of Er, Cr∶YSGG laser irradiation on the acquired acid resistance of enamel and dentin in vitro / 实用口腔医学杂志

ABSTRACT

Objective:To investigate the acid resistance of tooth hard tissues irradiated by different power outputs of Er,Cr∶YSGG laser.Methods:Samples in laser groups were irradiated using Er,Cr∶ YSGG laser with the power outputs of 2.5,3.5 and 5 W for enamel and 2 W,3 W and 4 W for dentin,respectively.The calcium and phosphate ion dissolved was measured after decalcification in lactate buffer solution for 24 h.The atomic percentage of calcium and phosphate on the surface of samples was examined by X-ray energy dispersive spectroscopy and the morphological changes were investigated by SEM.Results:In all laser groups of enamel samples except 2.5 W group calcium and phosphate ion dissolved less than in control group and block group (P＜0.05).There's no statistic difference between different power groups.Compared with control group and block group,Ca/P ratio increased(P＜0.05).There's no statistic difference of the atomic percentage of Ca and P on the surface of dentin samples between each 2 groups.SEM observation showed that the surface of the laser irradiated samples was rouph,the space among enamel fibers was increased,the dentin around dentinal tuble orifice was protruded and looked like collar flange.Conclusion:Er,Cr∶YSGG laser irradiation with a range of power is effective in increasing acquired acid resistance of dental hard tissue.There was no relationship between laser power outputs and acid resistance.