Alterations in plaque accumulation and gingival inflammation promoted by treatment with self-ligating and conventional orthodontic brackets

OBJECTIVE: The aim of the present study was to evaluate, comparatively, the periodontal response during orthodontic treatment performed with self-ligating and conventional brackets. METHODS: Sixteen Caucasian individuals of both sexes, aged between 12 and 16 years old and in permanent dentition were selected. Eight individuals were treated with conventional brackets installed on the lower dental arch and self-ligating brackets on the upper arch. Another eight individuals received self-ligating brackets in the lower arch and conventional brackets in the upper arch. The subjects received material and instructions for oral hygiene. Visible plaque index (VPI), gingival bleeding index (GBI) and clinical attachment level (CAL) were evaluated just after installation of orthodontic appliances, and 30, 60 and 180 days later. Mann-Whitney test was used to compare differences between groups (self-ligating and conventional), two-way ANOVA followed by Tukey's test was used to assess CAL at each site of each tooth. Significance level was set at 5%. RESULTS: No significant changes were found with regard to the assessed parameters (VPI, GBI and CAL) in either one of the systems. CONCLUSION: No significant changes were found with regard to the periodontal response to orthodontic treatment for the variables assessed and between subjects receiving passive self-ligating and conventional brackets. All individuals had received oral hygiene instructions and had their periodontal conditions monitored.研究目的：本研究旨在对比评估自锁托槽（self-ligating brackets）与传统托槽（conventional brackets）正畸治疗过程中的牙周组织反应。研究方法：选取16名年龄介于12至16岁、处于恒牙列阶段的高加索裔男女受试者。其中8名受试者在下牙弓安装传统托槽、上牙弓安装自锁托槽；另外8名受试者在下牙弓安装自锁托槽、上牙弓安装传统托槽。所有受试者均获得口腔卫生宣教材料及指导。分别在正畸矫治器安装完成即刻，以及30、60、180天后，评估可见菌斑指数（Visible Plaque Index, VPI）、牙龈出血指数（Gingival Bleeding Index, GBI）以及临床附着水平（Clinical Attachment Level, CAL）。采用曼-惠特尼检验（Mann-Whitney test）比较两组（自锁托槽组与传统托槽组）间的差异，采用双因素方差分析（two-way ANOVA）结合图基检验（Tukey's test）评估每颗牙齿各位点的临床附着水平，检验水准设定为5%。研究结果：两种矫治系统的各项评估参数（VPI、GBI及CAL）均未发现显著变化。研究结论：就本次评估的变量而言，以及在佩戴被动自锁托槽与传统托槽的受试者之间，正畸治疗对应的牙周组织反应未出现显著差异。所有受试者均接受了口腔卫生宣教，并接受了牙周状况监测。