2种桩系统修复前磨牙近中面洞型的抗力研究

Fracture behavior of premolar teeth with class Ⅱcavities restored by two post systems

目的比较研究根管治疗后前磨牙近中面洞型经3种方法修复后的抗力,并评价聚乙烯纤维桩系统(Ribbond桩)修复牙体缺损对修复体抗力的影响。方法 40颗完整离体单根前磨牙分成4组。第一组为对照组,另外三组根管治疗后预备近中面洞型。第二组使用复合树脂直接充填;第三、四组分别用石英纤维桩(DTLightpost)和Ribbond桩制作桩,复合树脂直接充填。热循环10000次后,置于INSTRON测试仪上测试断裂载荷,记录试件折裂时测试机读数及试件折裂模式。结果对照组、复合树脂组、石英纤维桩组、聚乙烯纤维桩系统组的断裂载荷依次为:(1191.04±362.59)N,(578.81±117.87)N,(909.33±250.20)N,(831.56±220.16)N。实验组断裂载荷均显著低于对照组(P<0.05),石英纤维桩和聚乙烯纤维桩系统两组间无统计学差别(P=0.50),且均高于树脂直接充填组(P<0.05)。结论使用石英纤维桩和Ribbond桩修复前磨牙近中面洞型均显著提高了抗折能力,且Ribbond桩能够显著改善折裂模式。

Objective To evaluate the effects of three restoration techniques and two post systems on the fracture load and fracture mode of endodontically treated premolars with classⅡcavities in an ex vivo setting.Methods 40 single-rooted premolars were divided into four groups.Group 1 remained untreated and served as control.The other three groups were endodontically treated and prepared with standardized MO cavities.Group 2 were restored with composite resin.Group 3 were restored with quartz fiber posts and direct composite,and in group 4,the Ribbond post system and direct composite were used.Each specimen was loaded in a universal testing machine until failure.Data were recorded and submitted to ANOVA and TuKey post hoc test.Results Mean fracture loads were：（1191.04±362.59）N,（578.81±117.87）N,（909.33±250.20）N and（831.56±220.16）N.Conclusion The use of quartz fiber post and polyethylene fiber post system in premolars with class Ⅱ cavities could significantly increase the fracture load and the polyethylene fiber post system improved the fracture mode significantly.