Department of Orthodontics and Dentofacial Orthopedics, Faculty of Medicine, University of Bern, Bern, Switzerland.
Am J Orthod Dentofacial Orthop. 2013 Aug;144(2):169-75. doi: 10.1016/j.ajodo.2013.02.030.
The objective of this trial was to compare the survival rates of mandibular lingual retainers bonded with either chemically cured or light-cured adhesive after orthodontic treatment.
Patients having undergone orthodontic treatment at a private orthodontic office were randomly allocated to fixed retainers placed with chemically cured composite or light-cured composite. Eligibility criteria included no active caries, restorations, or fractures on the mandibular anterior teeth, and adequate oral hygiene. The main outcome was any type of first-time lingual retainer breakage; pattern of failure (adapted adhesive remnant index scores) was a secondary outcome. Randomization was accomplished with random permuted blocks of 20 patients with allocation concealed in sequentially numbered, opaque, sealed envelopes. Blinding was applicable for outcome assessment only. Patients were reviewed at 1, 3, and 6 months and then every 6 months after placement of the retainer until completion of the study. Data were analyzed using survival analysis including Cox regression; sensitivity analysis was carried out after data imputation for subjects lost to follow-up.
Two hundred twenty patients (median age, 16 years; interquartile range, 2; range, 12-47 years) were randomized in a 1:1 ratio to either chemical or light curing. Baseline characteristics were similar between groups, the median follow-up period was 2.19 years (range, 0.003-3.64 years), and 16 patients were lost to follow-up. At a minimum follow-up of 2 years, 47 of 110 (42.7%) and 55 of 110 (50.0%) retainers had some type of failure with chemically cured and light-cured adhesive, respectively (log-rank test, P = 0.35). Data were analyzed on an intention-to-treat basis, and the hazard ratio (HR) was 1.15 (95% confidence interval [CI], 0.88-1.70; P = 0.47). There was weak evidence that age is a significant predictor for lingual retainer failures (HR, 0.96; 95% CI, 0.93-1.00; P = 0.08). Adhesive remnant index scoring was possible for only 66 of the 102 (64.7%) failures and did not differ between composites (Fisher exact test, P = 0.16). No serious harm was observed other than gingivitis associated with plaque accumulation.
The results of this study indicated no evidence that survival of mandibular lingual retainers differs between chemically and light-cured adhesives. The overall failure rate was 46.4%; however, this included any type of failure, which may have exaggerated the overall failure rate.
本试验旨在比较正畸治疗后用化学固化或光固化黏合剂黏合的下颌舌侧保持器的存活率。
在一家私人正畸诊所接受正畸治疗的患者被随机分配到用化学固化复合树脂或光固化复合树脂黏合的固定保持器。纳入标准包括下颌前牙无活动性龋坏、修复体或折裂，以及良好的口腔卫生。主要结局是任何类型的第一次舌侧保持器断裂；失败模式（改良黏附残余指数评分）为次要结局。采用 20 名患者的随机区组（随机排列）进行随机分组，分配隐藏在连续编号、不透明、密封的信封中。仅对结果评估进行盲法。患者在佩戴保持器后 1、3 和 6 个月进行复查，然后每 6 个月复查一次，直至研究结束。采用生存分析（包括 Cox 回归）进行数据分析；对失访患者进行数据插补后的敏感性分析。
220 名患者（中位年龄 16 岁；四分位间距 2 岁；范围 12-47 岁）按 1:1 的比例随机分为化学固化组或光固化组。两组的基线特征相似，中位随访时间为 2.19 年（范围 0.003-3.64 年），16 名患者失访。至少随访 2 年时，化学固化黏合剂组和光固化黏合剂组分别有 47/110（42.7%）和 55/110（50.0%）的保持器出现某种类型的失败（对数秩检验，P=0.35）。对意向治疗进行分析，风险比（HR）为 1.15（95%置信区间[CI]，0.88-1.70；P=0.47）。有微弱证据表明年龄是舌侧保持器失败的显著预测因素（HR，0.96；95%CI，0.93-1.00；P=0.08）。102 次失败中只有 66 次（64.7%）可以进行黏附残余指数评分，且两种复合材料之间没有差异（Fisher 确切检验，P=0.16）。除了与菌斑堆积相关的牙龈炎外，未观察到其他严重危害。
本研究结果表明，下颌舌侧保持器用化学固化黏合剂和光固化黏合剂的存活率没有差异。总的失败率为 46.4%；然而，这包括任何类型的失败，这可能夸大了总体失败率。
