Laminate veneer removal is becoming a routine procedure at the dental clinic and the use of laser can facilitate its removal. This work aimed to evaluate the morphological, elemental, and optical changes in the remaining enamel after veneer removal using Er,Cr:YSGG laser. Forty‐four enamel slabs were prepared and randomly distributed into nine experimental groups, for bonding using lithium disilicate laminates with three different luting agents (Variolink Veneer, RelyX U200, and RelyX Veneer). Then each agent was debonded using Er,Cr:YSGG laser (2.78 μm) using two different protocols:3.5 W, 48.14 J/cm², 20 Hz non‐contact and 3.0 W, 48.14 J/cm², 20 Hz non‐contact. The morphological, optical, and elemental analysis of enamel was performed before cementation and after laser debonding, using scanning electron microscopy (SEM), optical coherence tomography (OCT), and energy‐dispersive X‐ray spectroscopy (EDS). The level of statistical significance adopted was 5%. The EDS analysis of enamel after debonding revealed a significant increase in silane and carbon, as well as a decrease in calcium and phosphate contents. Analysis showed the presence of residual cement in most experimental groups but the morphological analysis showed alteration of the enamel's prisms only in the groups that used RelyX Veneer and Variolink Veneer cements. There was no evidence of deleterious morphological changes resulting from irradiation. However, an increase in the optical attenuation coefficient by the OCT was observed due to the presence of the remaining cement. It can be concluded that the Er,Cr:YSGG laser, in the mean powers used, is efficient for veneer removal without causing deleterious effects for the enamel.

中文翻译：

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Er,Cr:YSGG 激光剥离层压单板后牙釉质的形态、光学和元素分析：初步研究

层压单板去除正在成为牙科诊所的常规程序，使用激光可以促进其去除。这项工作旨在评估使用 Er,Cr:YSGG 激光去除单板后剩余牙釉质的形态、元素和光学变化。制备了 44 块搪瓷板，并随机分配到 9 个实验组中，使用具有三种不同粘合剂（Variolink Veneer、RelyX U200 和 RelyX Veneer）的二硅酸锂层压板进行粘合。然后使用 Er,Cr:YSGG 激光 (2.78 μm) 使用两种不同的协议对每种试剂进行脱粘：3.5 W, 48.14 J/cm ² , 20 Hz 非接触式和 3.0 W, 48.14 J/cm ², 20 Hz 非接触式。使用扫描电子显微镜 (SEM)、光学相干断层扫描 (OCT) 和能量色散 X 射线光谱 (EDS) 对牙釉质在胶结前和激光剥离后进行形态、光学和元素分析。采用的统计显着性水平为 5%。脱粘后搪瓷的 EDS 分析显示，硅烷和碳含量显着增加，钙和磷酸盐含量降低。分析表明在大多数实验组中存在残留的骨水泥，但形态分析表明仅在使用 RelyX Veneer 和 Variolink Veneer 骨水泥的组中牙釉质棱柱发生了变化。没有证据表明辐射会导致有害的形态变化。然而，由于残留水泥的存在，观察到 OCT 的光学衰减系数增加。可以得出结论，在使用的平均功率下，Er,Cr:YSGG 激光可有效去除饰面，而不会对牙釉质造成有害影响。