Objective

To modify the resin-based composite (RBC) restoration protocol for standardised Class II cavities in third molar teeth restored using conventional RBCs or their bulk fill restorative counterparts. Employing cuspal deflection using a twin channel deflection measuring gauge (during) and microleakage to determine marginal integrity (following) RBC restoration, the modified restoration protocol results were compared with traditional (oblique) restoration of Class II cavities.

Methods

Thirty-two sound third molar teeth, standardised by size and morphology, were subjected to standardised Class II cavity preparations and randomly allocated to four groups. Restorations were placed in conjunction with a universal bonding system and resin restorative materials were irradiated with a light-emitting-diode light-curing-unit. The cumulative buccal and palatal cuspal movements from a twin channel deflection measuring gauge were summed, the restored teeth fatigued thermally prior to immersion in 0.2% basic fuchsin dye for 24 h, before sectioning and examination for microleakage.

Results

Teeth restored using conventional RBC materials had significantly higher mean total cuspal movement values compared with bulk fill resin restorative restoration (all p < 0.0001). Teeth restored with Admira Fusion and Admira Fusion x-tra had significantly the lowest microleakage scores (all p < 0.001) compared with Tetric EvoCeram and Tetric EvoCeram Bulk Fill restored teeth. The microleakage scores for the range of RBC materials tested were significantly reduced (all p < 0.001) when the modified RBC restoration protocol was employed compared with the traditional Class II restoration technique.

Significance

Modification of the RBC restoration protocol of some conventional RBCs and bulk fill resin restoratives significantly improve bond integrity and could be translated as a validation of the limited clinical studies available on bulk fill materials in the dental literature where Class II cavities perform less well than Class I cavities following extended follow-up.

Clinical significance

The results of the current study add further weight to experimental protocols employing cuspal movement (during) and cervical microleakage (following) RBC restoration of standardised cavities in natural dentition to provide an indication of polymerization shrinkage stress at the tooth/RBC restoration interface in a ‘clinically meaningful context’.

中文翻译：

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修改树脂基复合材料（RBC）修复剂（常规填充剂和散装填充剂）的修复方案，以改善磨牙中的牙髓运动和微渗漏评分

客观的

修改树脂基复合材料（RBC）修复协议，以使用常规RBC或它们的大块填充修复牙齿修复的第三颗磨牙中的标准II类蛀牙。使用双通道挠度测量仪（在测量过程中）进行pal骨挠曲并进行微渗漏以确定边缘完整性（在RBC修复后），将改良的修复方案结果与II类腔体的传统（斜式）修复进行比较。

方法

通过尺寸和形态标准化的三十二颗健全的第三磨牙进行了标准化的II类腔准备，并随机分为四组。将修复体与通用粘结系统结合在一起，并用发光二极管光固化单元照射树脂修复体材料。将来自双通道挠度测量仪的颊侧和pa侧累积的运动相加，将修复后的牙齿在浸入0.2％碱性品红的情况下加热24小时，然后进行热疲劳，然后进行切片和微渗漏检查。

结果

与批量填充树脂修复相比，使用常规RBC材料修复的牙齿具有更高的平均总骨运动值（所有p  <  0.0001）。与Tetric EvoCeram和Tetric EvoCeram Bulk Fill修复牙齿相比，用Admira Fusion和Admira Fusion x-tra修复的牙齿的微渗漏评分最低（均为p <0.001）。与传统的II类修复技术相比，采用改良的RBC修复方案时，所测试的RBC材料范围的微渗漏评分显着降低（所有p <0.001）。

意义

某些传统RBC和散装填充树脂修复剂的RBC修复方案的修改可显着改善粘结完整性，并可转化为牙科文献中散装填充材料可用的有限临床研究的验证，在该研究中，II类腔体的性能不如I类腔体后续随访中发现腔体。

临床意义

本研究的结果进一步增加了采用protocols骨运动（期间）和子宫颈微渗漏（以下）自然牙列中标准牙洞的RBC修复的实验方案的重量，从而可在'R'牙/ RBC修复界面上提供聚合收缩应力的指示。具有临床意义的环境”。