Fixed Prosthodontics, Department of Restorative Sciences, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8549, Japan.
Dent Mater J. 2009 Sep;28(5):602-9. doi: 10.4012/dmj.28.602.
This study was aimed at evaluating the fracture resistance of structurally compromised roots restored with four different post and core systems. Thirty-two bovine roots were uniformly shaped to simulate human mandibular premolar roots. The roots were divided into four groups based on the type of restoration: cemented cast post and core (Group MC), resin composite build-up (Group CR), resin composite and prefabricated glass fiber post build-up (Group FRC), and thick-layer dual-cured resin composite-reinforced small-diameter tapered cast post and core (Group CRM). After a static loading test, the failure mode and fracture resistance were recorded. Group CRM (719.38+/-196.73 N) exhibited a significantly high fracture resistance compared with the other groups (Group MC: 429.56+/-82.43 N; Group CR: 349.56+/-66.21 N; Group FRC: 398.94+/-112.71 N; p<0.05). In conclusion, Group CRM exhibited better mechanical properties for structurally compromised roots with no ferrules, although all types of restorations showed non-restorable fracture modes.
本研究旨在评估四种不同的桩核系统修复结构受损牙根的抗折能力。将 32 颗牛牙根均匀塑形，模拟人下颌前磨牙牙根。根据修复类型将牙根分为四组：粘固铸造桩核（组 MC）、树脂复合材料堆垛（组 CR）、树脂复合材料和预制玻璃纤维桩堆垛（组 FRC）以及厚层双固化树脂复合材料增强小直径锥形铸造桩核（组 CRM）。进行静态加载试验后，记录失效模式和抗折能力。组 CRM（719.38+/-196.73 N）的抗折能力明显高于其他组（组 MC：429.56+/-82.43 N；组 CR：349.56+/-66.21 N；组 FRC：398.94+/-112.71 N；p<0.05）。结论：尽管所有类型的修复体均表现出不可修复的折断模式，但对于无颈圈的结构受损牙根，组 CRM 表现出更好的机械性能。
