Department of Operative and Esthetic Dentistry, Faculty of Dentistry, University of Szeged, Szeged, Hungary.
Department of Oral Surgery, Faculty of Dentistry, University of Szeged, Szeged, Hungary.
Clin Oral Investig. 2023 May;27(5):2003-2011. doi: 10.1007/s00784-023-04927-1. Epub 2023 Feb 22.
The purpose was to evaluate the crack formation associated with different direct restorative procedures of the utilized resin composites (RC) right after and 1 week later of the restoration.
Eighty intact, crack-free third molars with standard MOD cavities were included in this in vitro study and randomly divided into four groups of 20 each. After adhesive treatment, the cavities were restored either with bulk (group 1) or layered (group 2) short-fiber-reinforced resin composites (SFRC); bulk-fill RC (group 3); and layered conventional RC (control). Right after the polymerization and a week later, crack evaluation on the outer surface of the remaining cavity walls was performed with a transillumination method utilizing the D-Light Pro (GC Europe) with the "detection mode." Between- and within-groups comparisons Kruskal-Wallis and Wilcoxon tests were used, respectively.
Post-polymerization crack evaluation showed significantly lower crack formation in SFRC groups compared to the control (p<0.001). There was no significant difference within SFRC groups and non-SFRC groups (p=1.00 and p=0.11, respectively). Within group comparison revealed significantly higher number of cracks in all groups after 1 week (p≤0.001), however, only the control group differed significantly from all the other groups (p≤0.003).
Post-polymerization shrinkage induced further crack formation in the tooth 1 week after the restoration. SFRC was less prone to shrinkage-related crack formation during the restorative procedure; however, after 1 week, besides SFRC, bulk-fill RC also showed less prone to polymerization shrinkage-related crack formation than layered composite fillings.
SRFC can decrease the shrinkage stress-induced crack formation in MOD cavities.
评估不同直接修复程序的树脂复合材料（RC）在修复后即刻和 1 周后与裂纹形成的关系。
本体外研究纳入 80 颗无裂完整的第三磨牙，具有标准 MOD 腔，随机分为 4 组，每组 20 颗。经粘结处理后，腔分别用块状（第 1 组）或分层（第 2 组）短纤维增强树脂复合材料（SFRC）、块状填充 RC（第 3 组）和分层常规 RC（对照组）进行修复。聚合后即刻和 1 周后，采用 D-Light Pro（GC Europe）利用“检测模式”的透照法对剩余腔壁的外表面进行裂纹评估。分别采用 Kruskal-Wallis 和 Wilcoxon 检验进行组间和组内比较。
聚合后裂纹评估显示 SFRC 组的裂纹形成明显低于对照组（p<0.001）。SFRC 组和非 SFRC 组之间无显著性差异（p=1.00 和 p=0.11）。组内比较显示所有组 1 周后裂纹数量明显增加（p≤0.001），但只有对照组与其他组有显著差异（p≤0.003）。
修复后 1 周，聚合收缩导致牙齿进一步产生裂纹。SFRC 在修复过程中不易产生与收缩相关的裂纹形成；然而，1 周后，除 SFRC 外，块状填充 RC 也显示出比分层复合填充物不易发生聚合收缩相关的裂纹形成。
SFRC 可减少 MOD 腔中收缩应力诱导的裂纹形成。
