The effect of veneer on the marginal fit of the copings using different materials / 实用口腔医学杂志

ABSTRACT

Objective:To compare the marginal fit changes between after-and before-veneering of the copings using three kinds of materialsgold alloy,cp titanium and Ni-Cr alloy,so as to determine whether the fit changes was influenced with the veneer and their clinical significance.Methods:24 maxillary incisor acrylic resin PFM abutments fabricated by machine with the consolidated standard were divided into three groups,each abutment was waxed-up,invested,and casted with three kinds of materialsgold alloy,cp titanium and Ni-Cr alloy.For all groups,the copings were repositioned on their respective abutments,the marginal fit values of four points of each coping were measured.Furthermore,after three groups of copings were veneered with recommended porcelain,marginal fit values of same point of each abutment were remeasured.SAS software was used to carry out statistical analysis.Results:One way analysis of variance of marginal fit values revealed significant differences between before and after veneering in three groups,and the marginal fit value enhanced after veneered.Among three groups,cp titanium group had a significant difference when compared with other two groups(P