Department of Orthodontics, Hannover Medical School, Hannover, Germany.
Angle Orthod. 2011 Sep;81(5):907-14. doi: 10.2319/102210-616.1. Epub 2011 May 4.
To test the null hypothesis that stainless steel and ceramic brackets show no differences in biofilm adhesion.
Twenty adolescents (6 boys, 14 girls) who had received fixed orthodontic therapy for 18.9 ± 3.2 months were divided into a metal and a ceramic bracket group. Thirty brackets per group were taken from central incisors, canines, and second premolars and quantitatively analyzed for biofilm coverage with the Rutherford backscattering detection method. Five micrographs were obtained per bracket with views from the buccal, mesial, distal, gingival, and occlusal aspects, resulting in a total of 300 images. Biofilm formation between groups was compared using the Mann-Whitney U-test (α = .05).
Total biofilm formation was 12.5% ± 5.7% (3.3 ± 1.6 mm(2)) of the surface on metal and 5.6% ± 2.4% (1.5 ± 0.6 mm(2)) on ceramic brackets. Differences between groups were statistically significant (P < .05). A pairwise comparison of biofilm formation revealed significantly lower biofilm formation on ceramic brackets with respect to intraoral location (central incisor, canine, second premolar) and bracket surface (buccal, mesial, distal).
The hypothesis was rejected. The results indicate that ceramic brackets exhibit less long-term biofilm accumulation than metal brackets.
检验不锈钢和陶瓷托槽在生物膜黏附方面无差异的零假设。
20 名接受固定正畸治疗 18.9 ± 3.2 个月的青少年（6 名男性，14 名女性）被分为金属托槽组和陶瓷托槽组。每组各取 30 个托槽，分别来自中切牙、尖牙和第二前磨牙，并采用卢瑟福背散射探测法对生物膜覆盖率进行定量分析。每个托槽获得 5 张照片，包括颊侧、近中、远中、龈方和咬合面，共计 300 张图像。使用 Mann-Whitney U 检验（α =.05）比较组间生物膜形成情况。
金属托槽的总生物膜形成率为 12.5% ± 5.7%（3.3 ± 1.6 mm²），陶瓷托槽的总生物膜形成率为 5.6% ± 2.4%（1.5 ± 0.6 mm²）。组间差异具有统计学意义（P <.05）。对生物膜形成情况进行两两比较，发现陶瓷托槽的生物膜形成明显低于口腔内位置（中切牙、尖牙、第二前磨牙）和托槽表面（颊侧、近中、远中）。
该假设被拒绝。结果表明，陶瓷托槽的长期生物膜积聚量低于金属托槽。
