Metadata|口腔医学数据集|材料科学数据集

Effect of Green Tea Extract Antioxidant on Dentin Shear Bond Strength and Resin-Tag Penetration Depth after Non-vital Bleaching This study aimed to evaluate the effect of 10% and 35% green tea (10% and 35% GT) extract as an antioxidant after 2 minutes of application on dentin shear bond strength and resin tags penetration depth after non-vital bleaching. This research was conducted at the Chemistry Laboratory, Faculty of Medicine, University of Indonesia, and the Dental Materials Research and Development Laboratory, Faculty of Dentistry, University of Indonesia, in March-April 2022. This study was approved by the Ethics Committee (10/Ethical Approval/FKGUI/III/2022; 09/Ethical Exempted/FKGUI/IV/2022) and conducted in accordance with the Declaration of Helsinki. Thirty extracted maxilla premolars for orthodontics reasons, free of caries, fractures, and defects included in this study. The teeth were soaked in a thymol solution (0.1%; pH 7.0) for 1-week post extraction. Then, after 1 week the teeth were placed in 4oC distilled water, and had to be used within 1 month post extraction. The root portion of each tooth was removed 2 mm below the cement-enamel junction with a double-side disc diamond bur (Buehler, Lake Bluff, IL, USA). The coronal portion was sectioned mesiodistally, and the buccal and palatal portions were used, and it is considered as one specimen each portion. The dentin surfaces of specimen were flattened using 600- and 1200-grit sandpaper and polished with felt discs (Arotec, Cotia, SP, Brazil) impregnated with alumina paste (0.5 μm). The specimens were washed ultrasonically in distilled water for 5 minutes to eliminate any residues. For shear bond strength test, the specimens were fixed in a self-cure acrylic 20 mm and for resin tag penetration test the specimens were fix in plasticine 1x1 mm. A mold with a diameter of 2 mm is glued over the specimen in the pulp chamber using plasticine. The specimens were randomly divided into 5 groups (For resin tag penetration test n=6, for shear bond strength test n=5). Group 1: Non-bleached without green tea extract (normal dentin/negative control group), Group 2: Bleached without green tea extract (post bleaching dentin/positive control group), Group 3: Bleached without green tea extract and delay for 2 weeks before being restored (delay 2 weeks). Group 4: Bleached+10% Green tea extract for 2 min (10% GT), Group 5: Bleached+35% Green tea extract for 2 min (35% GT). The shear bond strength assessment was done using a Universal Testing Machine with a 0.5 mm/minute cross-head speed. 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 by the fluorescence glow of rhodamine B.