Objectives. This study compared the fracture strength of direct and indirect resin composite laminate veneers and evaluated the effect of a bidirectional E-glass woven fiber application at different locations at the cementation interface.
Methods. Standard preparations on canines (N = 50, 10 per group) were made using a depth cutting bur (0.7 mm depth) designed for laminate veneer restorations. Forty indirect laminates using a highly filled polymeric material (Estenia) and 10 direct laminates (Quadrant Anterior Shine) were prepared according to the manufacturer's instructions. Bidirectional E-glass woven-fiber sheet (0.06mm) (Everstick) was applied at different locations at the cementation interface. The control group received no fibers. The specimens were stored in water at 37 degrees C for 1 month prior to fracture testing performed in a universal testing machine where the load was applied from the incisal direction at 137 degrees (1 mm/min).
Results. No significant differences were found between the five groups (P > 0.01) (one-way ANOVA). While indirect laminate veneers showed mean fracture strength of 247 +/- 47N, direct laminate veneers revealed 239 104 N. The use of E-glass fibers at the cementation interface at different locations did not increase the fracture strength significantly (286-313 N) (P > 0.01). Failure analysis showed mainly cohesive fracture of the veneer restoration (20/50) and adhesive failure between the cementation interface and the laminate with fiber exposure (19/50) covering more than half of the restorations.
Significance. Direct and indirect resin composite laminate veneers showed comparable mean fracture strengths. The use of E-glass woven-fiber sheet at the cementation interface did not increase the fracture strength of the polymeric laminate veneers. (c) 2006 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
- E-glass fibers
- fracture strength
- particulate filler composites
- WOVEN GLASS-FIBERS
- BOND STRENGTH
- PORCELAIN VENEERS
- ELASTIC BEHAVIOR
- REINFORCED COMPOSITES
- RESIN CEMENTS