The in vitro force levels generated by four differing methods of mechanical debonding techniques for ceramic brackets, using debonding pliers, were measured. The forces generated using wide (method W) and narrow blades (method N) were compared with those generated using a diagonally opposite corner application of the wide blades (method C) and incisal-gingival application of a pair of pointed blades (method P). Chemically retained ceramic brackets (Transcend) were bonded to bovine teeth using a filled, two-paste, chemically cured composite (Concise). After 24 hours storage at 37°C in water, each specimen was subjected to one of the four mechanical debonding methods in a custom-built jig, simulating the clinical application of conventional debonding pliers.A one-way ANOVA with a Tukey's honestly significant difference test revealed statistically significant differences in debonding strengths between the four methods at the 0.05 level of significance. The mean debonding strength generated by method C was 40 and 25 per cent lower than that for methods W and N, respectively. Scoring of the adhesive remnant index (ARI) revealed that the predominant bond failure site was at the bracket/adhesive interface for all groups. Macroscopically, no enamel damage or bracket fractures were observed.
使用脱粘钳测量了四种不同机械脱粘技术在体外产生的力
水平,这些技术针对陶瓷托槽进行比较。并将使用宽刀片(方法W)和窄刀片(方法N)产生的力与使用对角线相对角落应用宽刀片(方法C)和使用一对尖刀片进行切牙-牙龈应用(方法P)所产生的力进行了比较。
化学保持的陶瓷托槽(Transcend)通过填充的、双组分的、
化学固化复合材料(Concise)粘结到牛牙齿上。在37°C
水中存放24小时后,每个样本在一个定制的夹具中接受了四种机械脱粘方法之一,该夹具模拟了常规脱粘钳的临床应用。通过单因素方差分析(ANOVA)和Tukey诚实显著差异检验显示,四种方法的脱粘强度在0.05显著性
水平上存在统计学显著差异。方法C产生的平均脱粘强度比方法W和N分别低40%和25%。粘附残留指数(ARI)的评分显示,所有组的主要断裂位置都是在托槽/粘合剂界面。宏观上,没有观察到牙釉质损伤或托槽断裂。