Effect of mangosteen peel extract as an antioxidant agent on the shear bond strength of orthodontic brackets bonded to bleached teeth

Abstract Introduction: The number of patients who seek orthodontic treatment that may have a history of tooth bleaching is increasing over the time. Bleaching may influence the decrease of the bond strength of orthodontic brackets. Objective: To determine and prove the effect of mangosteen peel (MP) extract to reverse the reduced shear bond strength (SBS) of orthodontic brackets after bleaching. Methods: A total of 150 maxillary first premolar teeth were randomly divided into 6 experimental groups as follow (n=25): negative-control (N: no bleaching), positive-control (P: bleaching + no treatment), and the treatment groups (bleaching + 10% sodium ascorbate (SA), 10% (MP-10), 20% (MP-20) and 40% (MP-40) MP extract gel). After treatment, the brackets were bonded with the resin-modified glass ionomer cement, SBS testing was performed using universal testing machine, and the adhesive remnant index (ARI) was examined using stereoscopic microscope after debonding. The SBS data were analyzed by analysis of variance (Anova) and the Tukey test. For the ARI, the Kruskal-Wallis test was performed. Result: There was significant SBS difference (p

引言：寻求正畸治疗且既往可能有牙齿漂白史的患者数量逐年攀升。牙齿漂白可能会降低正畸托槽的粘接强度。目的：明确并验证山竹果皮（mangosteen peel, MP）提取物对逆转牙齿漂白后正畸托槽剪切粘接强度（shear bond strength, SBS）降低的效果。方法：共计选取150颗上颌第一前磨牙，随机分为6个实验组（每组n=25）：阴性对照组（N组：未行牙齿漂白处理）、阳性对照组（P组：行牙齿漂白+无后续处理），以及治疗组（行牙齿漂白+10%抗坏血酸钠（sodium ascorbate, SA）、10%山竹果皮提取物凝胶（MP-10）、20%山竹果皮提取物凝胶（MP-20）及40%山竹果皮提取物凝胶（MP-40））。干预完成后，采用树脂改性玻璃离子水门汀粘接正畸托槽，通过万能试验机进行剪切粘接强度测试；托槽脱粘后，借助体视显微镜评估粘接残留指数（adhesive remnant index, ARI）。剪切粘接强度数据采用方差分析（Analysis of Variance, ANOVA）与Tukey检验进行统计学分析，粘接残留指数数据则采用Kruskal-Wallis检验进行分析。结果：各组剪切粘接强度存在显著组间差异（p