玻璃纤维桩核与镍铬合金桩核修复牙组织抗折裂强度的体外实验

In vitro study of the fracture resistance of pulpless teeth restored with glass fiber post-core system versus Ni-Cr alloy post-core system

目的:传统桩核材料由于自身的局限性已不能满足临床需要,新型玻璃纤维桩核的强度有待证实。比较玻璃纤维桩核和镍铬合金桩核系统修复离体牙咀嚼抗折裂强度。方法:实验于2006-11/2007-09在辽宁医学院附属第二医院口腔实验室完成。选择因牙周病拔出的6个月以内的上颌中切牙40颗,患者对治疗及实验均知情同意,并自愿捐献。40颗离体牙按随机数字表法分为两组,玻璃纤维桩核系统组和镍铬合金桩核系统组,每组20个。行常规根管治疗后截除牙冠,分别用玻璃纤维桩核系统和镍铬合金桩核系统进行桩核及烤瓷冠恢复外形,包埋于底座后在INSTRON测试仪上进行抗折裂强度的测试,记录试件折裂时测试机上的读数以及试件折裂的模式。结果:①玻璃纤维桩核系统修复的牙体折裂时的负荷值高于镍铬合金桩核系统[分别为(1.29±0.46)kN,(0.93±0.58)kN]。②牙体组织折裂后可再次修复玻璃纤维桩核系统组18个,镍铬合金桩核系统组5个,玻璃纤维桩核系统的牙体组织折裂后可再次修复的可能性高于镍铬合金桩核系统修复的牙齿,差异性有显著性意义(P<0.01);牙体组织折裂后不可再次修复玻璃纤维桩核系统组2个,镍铬合金桩核系统组15个。结论:玻璃纤维桩核系统修复离体牙咀嚼抗折裂强度优于镍铬合金桩核系统。

AIM： The traditional post-core materials already can not meet the clinical needs due to their limitations. The intensity of new glass fiber post-core system waits for a proof. This study was designed to compare the fracture resistance of pulpless teeth restored with glass fiber post-core system and Ni-Cr alloy post-core system. METHODS： The experiment was carried out in the Stomatology Laboratory of the Second Affiliated Hospital of Liaoning Medical College from November 2006 to September 2007. With the informed consents of the donor patients, 40 maxillary central incisors were extracted due to periodontal disease, and then were randomly divided into two groups, each group containing 20 teeth. After schedule root canal therapy of 40 extracted teeth was performed, the crowns of these teeth were amputated. All these teeth were restored with glass~ fiber post-core-crown systems or Ni-Cr cast metal post-core-crown system, and then were mounted in resin blocks. Fracture resistance was measured with Instron universal testing machine. The reading data of the testing machine and the fracture pattern were recorded. RESULTS： ①The loading value of pulpless teeth restored with glass fiber post-core system was higher than that with Ni-Cr alloy post-core system [（1.29±0.46） kN, （0.93±0.58） kN].②After the fracture, 18 teeth were restored with glass fiber post-core system again, and 5 with Ni-Cr alloy post-core system. The possibility of secondary restoration in glass fiber post-core system was significantly higher than that in Ni-Cr alloy post-core system （P 〈 0.01）, while there were 2 teeth unrepalred with glass fiber post-core system again, and 15 with Ni-Cr alloy post-core system. CONCLUSION： The fracture resistance of glass fiber post-core system is superior to Ni-Cr alloy post-core system for the restoration of extracted teeth.