粘结时间对微蚀刻底托槽粘结强度的影响

Influence of bonding time on bond strength of metallic orthodontic bracket with etching base

目的:对比微蚀刻底托槽粘结后不同时间的粘结强度,寻找合适的力的加载时机。方法:随机挑选对称性拔除上下颌第一前磨牙正畸患者30例,分为A、B、C三组进行全口微蚀刻底托槽粘结,分别在粘结后5 min,30 min,60min进行弓丝结扎,统计患者第一次复诊时托槽脱落率。将30例患者拔除的上颌第一前磨牙60颗,随机分成1～6组,每组10颗。1～6组离体牙粘结微蚀刻底直丝托槽,分别在粘结后5 min,10 min,15 min,30 min,60 min,24 h进行抗剪切强度(SBS)测定,并统计粘结剂残留指数(ARI),扫描电镜观察托槽粘结前后底板形貌。结果:微蚀刻底托槽在体外粘结后24 h抗剪切强度达到最大。结论:微蚀刻底托槽的粘结强度能够满足临床需要,临床医师可在托槽粘结后5 min进行力的加载。

Objective:To measure the SBS of bracket with etching base at different time after bond and to find the appropriate time to load the bracket.Method:A total of 30 patients were randomly divided into 3 groups(10 per group).480 bracket were bonded for them.They were loaded at 5 min,30 min,60 min seperately,and were observed for the first return visit.The failure of debond were recorded.Sixty youth maxillary first premolars extracted from the 30 patients above were randomly divided into 6 groups(10 per group).The shear bond test of group1～6 was performed at different debond time of 5 min,10 min,15 min,30 min,and 60 min and 24 hours.The chisquared test was used to determine signi?cant differences for the ARI scores among the groups(P ﹤0.05).Result:Highest shear bond strength was obtained with a debond time of 24 hours and the SBS was signi?cantly different(P <0.001).Conclusion:Bracket with etching base is to meet the clinical requirement.It is reliable to load the bracket 5 minutes after it is bonded.