MARGINAL FIDELITY ACCORDING TO THE MARGIN TYPES OF ALL CERAMIC CROWNS

전부도재관의 변연형태에 따른 변연적합도에 관한 연구

Poor marginal fidelity resulting in a large marginal gap increases plaque accumulation, gingival inflammation and dental caries. The purpose of this study was to evaluate the marginal fit of three different cervical finishing methods of prepared teeth. A stereomicroscope was used to measure the space between the margin of restoration and the finishing line of prepared tooth. The results were statistically analyzed using the ANOVA and Multiple Range Test(Tukey's HSD). The results were as follows : 1. There were no significant differences concerning the types of tooth and positon (P>0.05), whereas the differences were statistically significant in case of cervical finishing methods (P<0.05). 2. There were statistically significant differences between before and after cementation (P<0.05). 3. In comparison according to variable margins after cementation, the gap discrepancies were increased in $130^{\circ}$ shoulder margin, chamfer margin and $90^{\circ}$ shoulder margin in ascending order, and there were significant differences between $90^{\circ}$ shoulder margin and chamfer, $130^{\circ}$ shoulder margin 4. In comparison according to variable margins, the gap discrepancies were increased in chamfer margin, $130^{\circ}$ shoulder margin and $90^{\circ}$ shoulder margin in ascending order, and there were significant differences between $90^{\circ}$ shoulder margin and chamfer, $130^{\circ}$ shoulder margin. 5. This study demonstrated a better marginal fit with all-ceramic crowns fabricated on chamfer and $130^{\circ}$ shoulder margin compared with $90^{\circ}$ shoulder margin.