Effects of Different Materials Post-core Restoration on Fracture Resistance of Weakened Roots / 中国医科大学学报

ABSTRACT

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.