Esmail Ziana, Wiltshire William, Pinheiro Fabio H S L, Frota Carolina M, França Rodrigo
Department of Preventative Dental Science, Division of Orthodontics, University of Manitoba, Winnipeg, Manitoba, Canada.
Department of Restorative Dentistry, University of Manitoba, Winnipeg, Manitoba, Canada.
Biomater Investig Dent. 2024 May 7;11:40585. doi: 10.2340/biid.v11.40585. eCollection 2024.
The purpose of this study was to evaluate the effect of orthodontic bracket base shape on shear bond strength (SBS) to human enamel and assess the nature of debonding fractures using the Adhesive Remnant Index (ARI). Orthodontic brackets with different-shaped bases (flower, heart, rectangle) were bonded to 120 extracted human third molars. Shear bond strength was measured using a Servohydraulic Test System at 24 h and 2 months after bonding. Adhesive Remnant Index scores were evaluated under 10x magnification to assess the amount of resin left on the tooth. The control bracket (rectangular base shape) had the highest mean SBS (26.8 ± 8.2 megapascals [MPa]), and significantly differed from the flower (17.2 ± 4.4 MPa) and heart (18.9 ± 3.5 MPa) base shapes ( < 0.001). The mean SBS between debonding times at 24 h (21.5 ± 7.4 MPa) and 2 months (20.4 ± 6.7 MPa) were not statistically significant > 0.05). Analysis of ARI scores showed a significant difference between flower-24 h versus heart-2 months ( = 0.039), flower-24 h versus heart-24 h ( = 0.004), and control-2 months versus heart-24 h ( = 0.015). Bracket base shape influenced SBS, with the rectangular base shape having a higher mean SBS compared to flower and heart base shapes. Variations in ARI scores occurred based on bracket shape and were of a mixed adhesive-cohesive nature. All bracket shapes had bond strengths above the clinically acceptable range of 6-8 MPa, and may thus provide adequate SBS in a clinical situation.
本研究的目的是评估正畸托槽底座形状对与人类牙釉质的剪切粘结强度（SBS）的影响，并使用粘结剂残留指数（ARI）评估脱粘骨折的性质。将具有不同形状底座（花形、心形、矩形）的正畸托槽粘结到120颗拔除的人类第三磨牙上。在粘结后24小时和2个月时，使用伺服液压测试系统测量剪切粘结强度。在10倍放大倍数下评估粘结剂残留指数得分，以评估留在牙齿上的树脂量。对照托槽（矩形底座形状）的平均SBS最高（26.8±8.2兆帕斯卡[MPa]），与花形（17.2±4.4 MPa）和心形（18.9±3.5 MPa）底座形状有显著差异（<0.001）。24小时（21.5±7.4 MPa）和2个月（20.4±6.7 MPa）脱粘时间之间的平均SBS无统计学显著差异（>0.05）。ARI得分分析显示，花形-24小时与心形-2个月（=0.039）、花形-24小时与心形-24小时（=0.004）以及对照-2个月与心形-24小时（=0.015）之间存在显著差异。托槽底座形状影响SBS，矩形底座形状的平均SBS高于花形和心形底座形状。ARI得分因托槽形状而异，具有混合的粘结-内聚性质。所有托槽形状的粘结强度均高于临床可接受范围6-8 MPa，因此在临床情况下可能提供足够的SBS。
