Alkhudhairy Fahad, AlKheraif Abdulaziz, Bin-Shuwaish Mohammed, Al-Johany Sulieman, Naseem Mustafa, Vohra Fahim
1 Department of Restorative Dental Sciences, College of Dentistry, King Saud University , Riyadh, Saudi Arabia .
2 Dental Health Department, College of Applied Medical Sciences, King Saud University , Riyadh, Saudi Arabia .
Photomed Laser Surg. 2018 Aug;36(8):431-438. doi: 10.1089/pho.2018.4437. Epub 2018 Apr 23.
The available evidence of Er,Cr:YSGG lasers on bleached enamel is limited and controversial. It is assumed that Er,Cr:YSGG laser will be effective in reversing the effect of bleaching on adhesive bond integrity of enamel to resin composite.
The study aimed to evaluate the efficacy of Er,Cr:YSGG laser on bond strength and microleakage of bleached enamel.
From the 80 samples, 60 samples were bleached (40% hydrogen peroxide) and divided into three subgroups. Twenty bleached samples in each subgroup were exposed to 10% sodium ascorbate (Gp A), Er,Cr:YSGG laser (50 Hz and 4.5 W) (Gp L), and no treatment (Gp B), respectively. Twenty samples were not bleached (Control-C). Using etch and rinse technique, resin composite was built-up on enamel and photopolymerized. Ten specimens in each group were tested for shear bond strength at a crosshead speed of 1 mm/min. Ten specimens in each group were tested for microleakage using 2% methylene blue. Data were analyzed using analysis of variance (ANOVA) and Tukey post hoc multiple comparisons test.
The mean bond strength of specimens in group L (30.83 ± 1.7000) was comparable with group A (31.38 ± 2.03) and was significantly higher than bleached specimens (9.49 ± 0.86) (p < 0.001). The highest mean microleakage values were observed in bleached group (630.32 ± 156.58). The mean microleakage among control (36.66 ± 27.33) and laser group specimens (55.32 ± 34.98) was comparable (p > 0.05).
Treatment of bleached enamel with erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser showed a significant reversal effect on the enamel bond strength and microleakage scores.
Er,Cr:YSGG laser (50 Hz, 4.5 W) treatment has the potential to restore the bond strength of bleached enamel to resin composite.
铒铬：钇钪镓石榴石（Er,Cr:YSGG）激光作用于漂白牙釉质的现有证据有限且存在争议。据推测，Er,Cr:YSGG激光可有效逆转漂白对牙釉质与树脂复合体粘结完整性的影响。
本研究旨在评估Er,Cr:YSGG激光对漂白牙釉质粘结强度和微渗漏的疗效。
从80个样本中选取60个进行漂白（40%过氧化氢），并分为三个亚组。每个亚组的20个漂白样本分别接受10%抗坏血酸钠处理（A组）、Er,Cr:YSGG激光处理（50Hz和4.5W）（L组）和不做处理（B组）。20个样本未进行漂白（对照组-C）。采用酸蚀冲洗技术，在牙釉质上堆积树脂复合体并光固化。每组10个标本以1mm/min的十字头速度测试剪切粘结强度。每组10个标本使用2%亚甲蓝测试微渗漏情况。数据采用方差分析（ANOVA）和Tukey事后多重比较检验进行分析。
L组标本的平均粘结强度（30.83±1.7000）与A组（31.38±2.03）相当，且显著高于漂白标本（9.49±0.86）（p<0.001）。漂白组的平均微渗漏值最高（630.32±156.58）。对照组（36.66±27.33）和激光组标本（55.32±34.98）的平均微渗漏情况相当（p>0.05）。
用铒铬：钇钪镓石榴石（Er,Cr:YSGG）激光处理漂白牙釉质对牙釉质粘结强度和微渗漏评分有显著的逆转作用。
Er,Cr:YSGG激光（50Hz，4.5W）处理有可能恢复漂白牙釉质与树脂复合体的粘结强度。
