One-year clinical evaluation of class II bulk-fill restorations in primary molars: a randomized clinical trial

Abstract This double-blind, randomized clinical trial aimed to compare the clinical performance and clinical time to restore occluso-proximal cavities in primary molars withbulk-fillresin and conventional resin. A total of 140 class II restorations in primary molars of 65 participants (mean age of 6.7 + 1.5) were placed in two random groups:bulk-filland conventional resin. The restorations were evaluated using FDI criteria at the baseline, 6-month, and one year by a single calibrated examiner, and the clinical restorative time was measured with a digital timer. The success and survival of the restorations were evaluated with Kaplan-Meier graphs. The log-rank test compared the curves. Differences in restorative clinical time were compared using the Mann-Whitney U test. The level of significance was 5%. After one year, 115 restorations were evaluated. The success probability was 88.7% for Filtek Z350 XT and 85.9% for FiltekTM Bulk-fill, and for the survival probability, Filtek Z350 XT presented 90%, and FiltekTM Bulk-fill presented 93.7%. No significant difference was found between the success and survival curves (p=0.62), (p=0.51). The main reason for failure was marginal adaptation.Bulk-fillresinrequired 30% less time than the conventional resin (p<0.001).Bulk-fillresin presented similar clinical performance to the conventional resin and required less restorative clinical time. It is an option to restore class II lesions of primary molars.

摘要 本双盲随机临床试验旨在比较批量充填树脂（bulk-fill resin）与传统树脂修复乳磨牙咬合邻面洞的临床效果及临床操作时间。本研究共纳入65名受试者（平均年龄6.7±1.5岁）的乳磨牙II类洞修复体共140颗，将其随机分为两组：批量充填树脂组与传统树脂组。分别于基线、6个月及1年时，由1名经过校准的检查者采用FDI标准（FDI criteria）对修复体进行评估，同时通过数字计时器记录临床修复操作时间。采用Kaplan-Meier曲线评估修复体的成功率与留存率，通过对数秩检验（log-rank test）比较两组曲线差异；修复操作时间的组间差异则采用曼-惠特尼U检验（Mann-Whitney U test）进行分析，检验水准设定为5%。 随访1年时共评估115颗修复体。其中Filtek Z350 XT的修复成功率为88.7%，FiltekTM Bulk-fill的修复成功率为85.9%；在修复留存率方面，Filtek Z350 XT为90%，FiltekTM Bulk-fill为93.7%。两组的成功率曲线与留存率曲线均无显著统计学差异（p=0.62，p=0.51）。修复失败的主要原因为边缘适配性不佳。批量充填树脂的临床操作时间较传统树脂少30%（p<0.001）。 综上，批量充填树脂的临床效果与传统树脂相当，但临床修复操作时间更短，可作为乳磨牙II类病变修复的可选方案。