Thesis (M.Sc.)--Chulalongkorn University, 2011

Objective The aim of this study was to investigate the influence of the curvature of the finishing line on the marginal gaps of all-ceramic copings. Materials and methods An ivorine maxillary central incisor was prepared for three different abutment finishing line curvatures (1mm, 3mm and 5 mm vertical distance between labial or lingual margins and proximal margins), with a total of 36 copings being fabricated for each of these curvatures using Cercon, IPS e.max and Lava™ systems. The marginal gap width was measured using a stereo microscope, with the analysis of the data subsequently being undertaken by means of a two-way ANOVA test followed by a one-way ANOVA test (α = 0.05). Results A significantly higher mean marginal gap was observable for the 5 mm curvature group (Cercon, 76.59 ± 23.01 µm; IPS e.max, 106.44 ± 18.48 µm; Lava, 128.34 ± 20.79 µm) as compared to both the 3 mm curvature group (Cercon, 60.18 ± 9.74 µm; IPS e.max, 81.79 ± 16.20 µm; Lava, 99.19 ± 15.32 µm) and the 1 mm curvature group (Cercon, 38.3 ± 6.85 µm; IPS e.max, 52.22 ± 10.66 µm; Lava, 69.99 ± 6.77 µm). Conclusion The greater the finishing line curvature, the wider the marginal gaps for the three all-ceramic systems.