Kaya Büyükbayram Işıl, Güven Mehmet Esad, Ayman Deniz, Şener Yamaner Işıl Damla, Cakan Engin Fırat
Department of Endodontics, School of Dentistry, İstanbul Aydın University, Küçükçekmece, İstanbul, Turkey.
Department of Prosthodontics, School of Dentistry, Necmettin Erbakan University, Konya, İstanbul, Turkey.
J Appl Biomater Funct Mater. 2023 Jan-Dec;21:22808000231151832. doi: 10.1177/22808000231151832.
The aim of this study was to investigate the effects of fiber-reinforced composite base material on fracture resistance and fracture pattern of endodontically treated maxillary premolars restored with endocrowns using two different resin nanoceramic computer-aided design and computer-aided manufacturing (CAD/CAM) restorative material.
Forty extracted sound maxillary premolars with an occlusal reduction of 2 mm above the cementoenamel junction (CEJ) was performed following root canal treatment. Mesial interproximal box was prepared for each tooth at the margin of the CEJ and randomly distributed into four groups ( = 10) as follows: Group A, no resin build-up in the pulp chamber; Group B, 2 mm of fiber-reinforced composite (FRC) build-up (EverX Posterior, GC).; Group C, no resin build-up in pulp chamber; Group D, 2 mm of FRC build-up. Groups A and B were prepared with resin nanoceramic (RNC) consisting ceramic nanofillers (Lava Ultimate 3 M ESPE), while Group C and D were prepared with RNC consisting ceramic nanohybrid fillers (Cerasmart GC Corp). All samples were subjected to 1,200,000 chewing cycles (1.6 Hz, 50 N) and 5000 thermal cycles (5°C-55°C) for artificial aging on a chewing simulator with thermal cycles (CSTC). Samples that survived the CSTC test without being damaged were subjected to a load-to-fracture test.
The highest mean fracture strength was found in Group D (936.0 ± 354.7) and lowest in Group A (684.2 ± 466.9). Fracture strength was higher in groups where FRC was used as a base material than plain restorations. However, there were no significant differences between the Lava and Cerasmart groups with and without FRC ( > 0.05). Most of the samples were irreparably fractured under CEJ.
Using short FRCs as a resin base material did not significantly improve fracture resistance. Cerasmart and Lava blocks had similar fracture resistance and fracture pattern.
本研究旨在探讨纤维增强复合树脂基材料对采用两种不同树脂纳米陶瓷计算机辅助设计与计算机辅助制造（CAD/CAM）修复材料制作的全冠修复的根管治疗上颌前磨牙的抗折性能和折裂模式的影响。
选取40颗拔除的健康上颌前磨牙，根管治疗后在牙釉质牙骨质界（CEJ）上方进行2mm的咬合面预备。在每颗牙齿的CEJ边缘制备近中邻面盒，并随机分为四组（每组n = 10）：A组，髓腔内不堆积树脂；B组，堆积2mm纤维增强复合树脂（EverX Posterior，GC）；C组，髓腔内不堆积树脂；D组，堆积2mm纤维增强复合树脂。A组和B组采用含陶瓷纳米填料的树脂纳米陶瓷（Lava Ultimate 3M ESPE）制作修复体，而C组和D组采用含陶瓷纳米混合填料的树脂纳米陶瓷（Cerasmart GC Corp）制作修复体。所有样本在咀嚼模拟器上进行1200000次咀嚼循环（1.6Hz，50N）和5000次热循环（5°C - 55°C）的人工老化处理（CSTC）。在CSTC测试中未受损的样本进行抗折试验。
D组的平均抗折强度最高（936.0 ± 354.7），A组最低（684.2 ± 466.9）。使用纤维增强复合树脂作为基材料的组的抗折强度高于单纯修复组。然而，使用和未使用纤维增强复合树脂的Lava组和Cerasmart组之间无显著差异（P > 0.05）。大多数样本在CEJ下方发生不可修复的折裂。
使用短纤维增强复合树脂作为树脂基材料并未显著提高抗折性能。Cerasmart和Lava修复体具有相似的抗折性能和折裂模式。
