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目的比较激光和铸造2种底板托槽的粘接强度,分析托槽底板残余物,探讨拆除托槽对釉质表面的影响。方法选取2014年6月于哈尔滨医科大学口腔颌面外科因正畸拔除的上颌前磨牙40颗,其中选择激光底板和铸造底板托槽各20颗,粘接于离体上颌前磨牙后进行剪切、拉伸实验。再选取正畸结束患者拆除的前磨牙激光底板、铸造底板托槽各71个,对所有托槽底板粘接剂残余指数(ARI)进行计分,并随机抽取托槽进行底板粘接剂电镜观察。结果激光底板托槽抗剪切强度(SBS)和ARI高于铸造底板托槽,抗拉伸强度(TBS)低于铸造底板托槽(P<0.05);托槽底板残余粘接剂中均可检测到钙元素。结论激光和铸造两种底板托槽的粘接强度均能达到临床要求,拆除托槽对釉质表面有损伤。
Objective To compare the bonding strength of laser and casting two kinds of bottom brackets, analyze the bottom of brackets, and discuss the influence of bracket removal on the enamel surface. Methods Forty mandibular premolars extracted from oral and maxillofacial surgery in Harbin Medical University during June 2014 were selected. Twenty of the 20 laser brackets and the bottom brackets of the cast plate were selected and bonded to the isolated maxillary premolars. Tensile test. Then the pre-molars laser baseplate and casting baseplate brackets were removed from the orthodontic patients. Each 71 baseplate adhesive residue index (ARI) was scored, and brackets were taken randomly to observe the adhesiveness of the baseplate . Results The shear strength (SBS) and ARI of the laser floor bracket were higher than those of the cast floor bracket, and the tensile strength (TBS) of the laser floor bracket was lower than that of the casting floor bracket (P <0.05). Calcium was detected. Conclusion Both the laser and the cast two kinds of bottom brackets adhesive strength can meet the clinical requirements, remove the bracket on the enamel surface damage.