Department of Conservative Dentistry, Faculty of Dentistry, University of Indonesia, Depok, West Java, 16424, Indonesia.
F1000Res. 2023 Sep 8;12:660. doi: 10.12688/f1000research.133313.2. eCollection 2023.
35% Hydrogen peroxide (H O ) as an active material for internal bleaching can produce free radicals that can affect resin tag penetration into the dentinal tubules. Application of 10% and 35% green tea (GT) extract as an antioxidant after 2 minutes are expected to remove free radical residues and increase dentin shear bond strength and resin tags penetration depth after non-vital bleaching. 30 extracted healthy human premolars were cut horizontally 2 mm from the Cemento Enamel Junction margin to the crown part, then cut in a mesio-distal direction into two parts. The specimens were divided into five groups: normal dentin, post bleaching dentin, delayed 2 weeks, 10% GT, and 35% GT group. Non-vital walking bleach with 35% H O gel was done to all groups except control group. Soon after, 10% and 35% GT extract gel were applied on dentin for 2 minutes, then the specimens were rinsed-off with aquabidest for 2 minutes and dried. All specimens were etched and bonded with an etch-and-rinse adhesive system and filled with resin composite. The shear bond strength assessment was carried out using a Universal Testing Machine (UTM) with a cross-head speed of 0.5 mm/minute. Confocal laser scanning microscopy (CLSM) with a wavelength of 560 nm and a lens magnification of 40x was used to analyze the resin tag penetration. Data were analyzed by one way ANOVA and t-test. There was a significant difference in resin tag penetration depth and shear bond strength between applying 10% and 35% GT extract (p < 0.05). The 35% GT extract group resulted in a significantly longer resin tag penetration than the 10% GT extract group. The application of 35% GT extract is more effective than 10% GT extract as an antioxidant for increasing the shear bond strength of composite resin after internal bleaching.
35%过氧化氢（H2O2）作为一种活性物质用于内部漂白，可以产生自由基，从而影响树脂标记物渗透到牙本质小管中。预计在 2 分钟后应用 10%和 35%绿茶（GT）提取物作为抗氧化剂，可以去除自由基残留物，并在非活性漂白后增加牙本质剪切粘结强度和树脂标记物渗透深度。 30 颗提取的健康人前磨牙从牙釉质牙骨质交界处向冠部水平切割 2mm，然后沿近远方向切成两部分。标本分为五组：正常牙本质、漂白后牙本质、延迟 2 周、10%GT 和 35%GT 组。除对照组外，所有组均用 35%H2O2凝胶进行非活性行走漂白。之后，立即在牙本质上应用 10%和 35%GT 提取物凝胶 2 分钟，然后用 AquaBidest 冲洗 2 分钟并干燥。所有标本均用蚀刻-冲洗粘结系统进行蚀刻和粘结，并填充树脂复合材料。使用万能试验机（UTM）以 0.5mm/min 的十字头速度进行剪切粘结强度评估。使用波长为 560nm 和镜头放大倍数为 40x 的共焦激光扫描显微镜（CLSM）分析树脂标记物的渗透情况。数据采用单因素方差分析和 t 检验进行分析。 在应用 10%和 35%GT 提取物后，树脂标记物的渗透深度和剪切粘结强度有显著差异（p<0.05）。35%GT 提取物组的树脂标记物渗透深度明显长于 10%GT 提取物组。 应用 35%GT 提取物作为抗氧化剂比应用 10%GT 提取物更有效，可增加内部漂白后复合树脂的剪切粘结强度。
