牙本质领圈对漏斗状桩核修复牙折裂强度影响的实验研究

An in vitro study evaluating ferrule effects on fracture resistance of pulpless teeth with flared canals restored with different post-and-core systems

关键词:  修复  桩核  牙本质领圈  折裂强度

Key words:  prosthodontics  post-and-core  dentin ferrule  fracture strength.

摘要:

［目的］ 探讨牙本质领圈对不同材质漏斗状桩核修复牙折裂强度的影响。［方法］ 30颗离体上颌中切牙被随机分成无领圈和有领圈两个实验组。各实验组再分成3个小组，分别用铸造金属桩核（MPC）、单纯复合树脂桩核（RCP）以及预成碳素纤维根管桩联合复合树脂桩核（FRC）进行修复。利用万能压缩试验机测定各标本牙的折裂强度，并对实验结果进行了双因素方差分析（α=0.05）。 ［结果］ 有牙本质领圈组比无领圈组表现出明显高的折裂强度（P<0.05）。两个实验组中，MPC均比FRC、RCP表现出明显高的折裂强度（P<0.05）。［结论］ 预备牙本质领圈可明显提高不同材质漏斗状桩核修复牙的折裂强度。

Abstract:

［Objective］ To evaluate the ferrule effects on resistance to fracture of endodontically treated maxillary incisors with flared canals restored with different post-and-core systems under static loading. ［Methods］ Thirty artificial flared canals were prepared in maxillary central incisors and 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. All samples were restored with complete cast crowns and subjected to static loading at 45 degrees to the longitudinal tooth axis until the roots fractured. The maximum fracture load was recorded. All data were analyzed with two-way ANOVA and the Tukey HSD test at α=0.05. ［Results］ Preparing a dentin ferrule increased significantly fracture strength (P<0.05). MPC revealed significantly higher fracture strength than the other groups (P<0.05). The retrievable fracture pattern of the tested specimens was discovered only in RCP. ［Conclusion］ Dentin ferrule preparation may enhance significantly fracture resistance of the restorations.