Applied Science Department, University of Technology, Baghdad, Iraq.
Laser and Optoelectronics Department, College of Engineering, Al-Nahrain University, Baghdad, Iraq.
Lasers Med Sci. 2024 Feb 16;39(1):64. doi: 10.1007/s10103-024-04023-0.
The present work aimed at assessing chemical, topographical, and morphological changes induced by Nd : YAG laser treatment of dental enamels by means of energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). Fifteen human enamel specimens were obtained, three of samples were kept untreated as a control while the others twelve samples were equally divided into four groups where each group have a three samples according to treating approach as: G1:(untreated);G2: (treated with Nd:YAG laser, 100 mJ/pulse,10 Hz/1064nm); G3(treated with Nd:YAG laser, 500 mJ/pulse, 10 Hz/1064nm); G4(treated with Nd:YAG laser 1000 mJ/pulse, 10 Hz/1064nm), and finally G5(treated with Nd:YAG laser, 1000 mJ/pulse, 10 Hz/532nm) respectively. Beside many craters and cracks, the AFM results showed fractures with depths of 19.23 nm, 174.7 nm, 216.9 nm, 207.4 nm and 156.5 nm and width of 559.2 nm, 833.4 nm, 1115 nm, 695.0 nm, and 5142 nm for all Groups respectively. The highest surface roughness was found in G5 with 111.4 nm while the lowest surface roughness was found in G1 to be 14.3 nm. The inside surface of the fissures was also rough. The SEM micrographs revealed modifications to the morphology. EDS was used to measure the phosphorous (P), calcium (Ca), oxygen (O), and carbon (C) percentages presented in crater areas and their surroundings, Ca, P, O, and C levels were observed to vary significantly at the crater and its rim, a lower percentage of C wt% were realized corresponding to laser treatment of 1000 mJ/Pulse laser energy. However, it was not feasible to recognize a specific chemical arrangement in the craters. It is also concluded that the higher depth and particular edge of ablated part when teeth were irradiated by laser with 1000 mJ/10Hz/1064nm.
本研究旨在通过能谱仪（EDS）、原子力显微镜（AFM）和扫描电子显微镜（SEM）评估 Nd:YAG 激光处理牙釉质引起的化学、形貌和形态变化。共获得 15 个人类牙釉质标本，其中 3 个标本作为对照未处理，其余 12 个标本等分为 4 组，根据处理方法分为：G1（未处理）；G2（用 Nd:YAG 激光处理，100mJ/脉冲，10Hz/1064nm）；G3（用 Nd:YAG 激光处理，500mJ/脉冲，10Hz/1064nm）；G4（用 Nd:YAG 激光处理，1000mJ/脉冲，10Hz/1064nm）和 G5（用 Nd:YAG 激光处理，1000mJ/脉冲，10Hz/532nm）。除了许多凹坑和裂缝外，AFM 结果显示，所有组的裂缝深度分别为 19.23nm、174.7nm、216.9nm、207.4nm 和 156.5nm，宽度分别为 559.2nm、833.4nm、1115nm、695.0nm 和 5142nm。所有组中表面粗糙度最高的是 G5，为 111.4nm，而表面粗糙度最低的是 G1，为 14.3nm。裂缝内部表面也很粗糙。SEM 显微照片显示形态发生了变化。EDS 用于测量坑洼区域及其周围的磷（P）、钙（Ca）、氧（O）和碳（C）百分比，坑洼及其边缘的 Ca、P、O 和 C 水平观察到明显变化，激光处理 1000mJ/Pulse 激光能量时，Cwt%的百分比较低。然而，在坑洼中无法识别出特定的化学排列。还得出结论，当用 1000mJ/10Hz/1064nm 的激光照射牙齿时，被烧蚀部分的深度更高，边缘更特殊。
