1321 Finishing-line Curvature Affects the Marginal Gap of All-ceramic Copings

Saturday, March 24, 2012: 9:45 a.m. - 11 a.m.
Presentation Type: Poster Session
C. ASAVAPANUMAS, Esthetic Restorative and Implant Dentistry, The Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand, and C. LEEVAILOJ, Associate Professor, Program director Director of the Esthetic Restorative and Implant Dentistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
Objectives: To investigate the influence of finishing line curvature on the marginal gap of three systems of all-ceramic copings.

Methods: An ivorine maxillary central incisor was successively prepared with three types of abutment finishing line curvatures (1, 3, and 5 mm vertical distance between labial or lingual margins and proximal margins). Thirty six copings for each curvature were fabricated with Cercon, IPS e.max, and Lava™ systems and the vertical marginal gap width was measured using a stereo microscope by one investigator. Two-way ANOVA followed by one-way ANOVA tests were used to determine statistical significance between the mean marginal gap for each abutment finishing line curvature and ceramic system.

Results: The 5 mm. finishing line curvature copings (Cercon, 76.59±48.50 µm ; IPS e.max, 106.44±42.12 µm ; Lava™, 128.34±42.81 µm) showed a significantly higher mean marginal gap than the 3 mm. curvature group (Cercon, 60.18±32.49 µm ; IPS e.max, 81.79±29.08 µm ; Lava™, 99.19±28.22 µm) and the 1 mm. curvature group (Cercon, 38.3±13.36 µm ; IPS e.max, 52.22±14.87 µm ; Lava™, 69.99±51.62 µm).

Conclusions: The greater the finishing line curvature, the larger the vertical marginal gaps in the three all-ceramic systems tested. Copings fabricated with the Lava system showed the greatest marginal gaps compared to the  IPS e.max and Cercon systems.

Keywords: CAD/CAM, Ceramics, Dental materials, Esthetics and Porcelain systems