不同材质桩核修复漏斗状残根的抗疲劳强度

Resistance to cyclic fatigue of pulpless teeth with flared root canals restored with different post-and-core materials

目的探讨不同材质桩核修复对漏斗状前牙牙根抗疲劳强度的影响。方法30颗离体上颌中切牙均分为无领圈和有领圈2个实验组。各实验组再分为3部分,各5颗样牙。本分别用铸造金属桩核(MPC)、单纯复合树脂桩核(RCP)及预成碳纤维桩联合复合树脂桩核(FRC)进行修复。测定各样本牙疲劳强度并对实验结果进行双因素方差检验(α=0.05)。结果各实验组用FRC修复者与用其他2种材料者相比,均表现出明显高的平均疲劳强度(P<0.05)。预备牙本质领圈可明显提高不同材质桩核修复牙的疲劳强度(P<0.05)。结论FRC在提高前牙牙根抗疲劳强度方面具有明显优点。为提高前牙牙根的抗疲劳强度,预备牙本质领圈是必要的。

Objective To investigate the resistance to cyclic fatigue of maxillary incisors with flared canals restored with different post-and-core materials. Methods Thirty human maxillary central incisors were assigned randomly to two main groups (non-ferrule and 1-mm ferrule) of 15. Each main group was then divided into 3 groups of 5 specimens and restored with custom cast post-and-core (MPC), resin composite post-and-core (RCP), and resin composite core combined with prefabricated carbon fiber post (FRC), respectively. Every group was subjected to a cyclic fatigue test, and recorded the numbers of load cycles that occurred tooth fracture. All data were analyzed with two-way ANOVA and the Tukey HSD test at α=0.05. Results FRC revealed significantly higher fatigue strength than the other groups ( P <0.05). Preparing a dentin ferrule increased significantly fatigue resistance ( P <0.05). The favorable (retrieval) fracture pattern of the tested specimens was discovered only in RCP. Conclusions Using FRC may get a long fatigue life in restoring pulpless teeth with flared canals. Dentin ferrule preparation is necessary to enhance resistance of the restorations to cyclic fatigue.