增效剂对脉冲Nd:YAG激光提高人牙齿抗酸性能的影响

The effect of initiator on pulsed Nd:YAG laser in the acid resistance of human teeth in vitro

目的:探讨应用增效剂对脉冲Nd:YAG激光提高人牙齿抗酸性能的影响.方法:50 个离体人牙的釉质、牙本质标本分成加增效剂组和不加增效剂组,2 组又分别分为5 个亚组(即:4 个不同的激光剂量组和空白组)进行处理.再将所有实验牙置于0.1 mol/L人工脱矿液(pH 4.5)37 ℃脱矿48 h,钙离子选择性电极测脱矿液内Ca2+溶出量.结果:激光剂量为20～ 40 J/cm2时,加增效剂组Ca2+溶出量低于未加增效剂组,除牙本质中的20 J/cm2亚组外,2 组间差异具有显著性(P<0.05).当激光剂量继续增大时,加增效剂组Ca2+溶出量与未加增效剂组间差异无显著性(P>0.05).结论:应用增效剂可增强低能量脉冲Nd:YAG激光对牙齿硬组织的作用效果,提高人牙齿的抗酸性能,有助于激光使用的安全性.

Objective:To investigate the effect of initiator on pulsed Nd:YAG laser in the acid resistance of human teeth in vitro. Methods:A total of 25 enamel-samples and 25 dentine-samples were divided into laser plus initiator (a layer of Beijing black ink) group and laser only group.Each of the two groups was divided into five subgroups.The samples in the 5 subgroups were irritated by Na:YAG laser with an energy(J/cm2) of 0,20,30,40 and 50 respectively. Then all samples were immersed in 0.1 mol/L lactic acid demineralization solutions(pH 4.5) for 48 h at 37 ℃. The concentration of Ca 2+ (×10 -6 g) dissolved in the solution was measured by the calcium selective electrode. Results:Laser of 20-50 J/cm2 decreased the Ca 2+ concerntration in demineralization solution(P<0.05). The initiator plus laser of 20-40 J/cm2 decreased Ca 2+ release of enamel samples more than the laser only group(P<0.05).However, no significant difference was observed between the initiator plus laser group and the laser only group when laser energy of 50 J/cm2 was applied to the blocks(P>0.05).The initiator plus laser of 30-40 J/cm2 decreased the Ca 2+ release of dentine samples than laser only group (P<0.05).Conclusion:Initiator may enhance the effect of pulsed Nd:YAG laser at low energy-level on acid resistance of human teeth.