Objective To investigate the influence of different kinds of post⁃core materials on fracture resistant ability of different walls during weakened root restoration. Methods Forty⁃eight human single root mandibular first premolars were randomly assigned to two groups(groupⅠwas repaired with quartz⁃fiber post⁃core and mental crown ,and groupⅡwas repaired with Co⁃Cr cast metal post⁃core and mental crown). Each main group was then divided into four subgroups of 6 specimens. All samples were tested on the universal test machine. We observed the fracture load and the fracture mode of the specimens. Results Cr⁃Co ally post⁃core group exhibited significantly higher resistance to fracture than quartz fiber post⁃core in the same number weakened root walls(P<0.05). With the increase in the quantity of weakened root walls ,the fracture resistance was significant decreased in the same post⁃core material(P<0.05). The possibility of repairable fractures in groupⅠwas significantly higher than that in groupⅡ(P<0.05). Conclusion Cr⁃Co alloy post⁃core can bear a higher bite ,but quartz fiber post⁃core has the most favorable fracture modes.%目的：探讨不同材质桩核修复对不同壁数薄弱残根抗折强度的影响。方法将48颗离体下颌单根前磨牙随机分为Ⅰ组（石英纤维桩核+金属全冠修复）和Ⅱ组（钴铬合金铸造桩核+金属全冠修复）。各实验组再按薄弱残根不同薄壁数目分为4组，Ⅱ组同Ⅰ组，各6颗样本牙。应用电子万能试验机进行抗折强度检测，测定各样本牙抗折强度，并观察断裂模式及部位，以判断可修复性。结果在薄壁数目相同的条件下，Ⅱ组的抗折强度显著高于Ⅰ组（P<0.05）；在桩核材质相同的条件下，随着薄壁数目增加，抗折强度显著降低（P<0.05）。Ⅰ组可修复折裂率大于Ⅱ组（P<0.05）。结论金属桩核抗折强度优于石英纤维桩核，但石英纤维桩核利于对薄壁残根的保护及再修复。
展开▼
