Evaluation of the fracture strength of porcelain sectional veneers made from different sintered feldspathic porcelains: An in vitro study.

BACKGROUND: Porcelain sectional veneers with no preparation (no-prep) are an ultra-conservative choice for the esthetic treatment of the anterior teeth. They can be made from a sintered feldspathic porcelain, which gives a great appearance with small thickness, but there are still concerns about the fracture strength of this material.

OBJECTIVES: The aim of this study was to evaluate the fracture strength of porcelain sectional veneers made from 2 different sintered feldspathic porcelains.

MATERIAL AND METHODS: Twenty recently extracted human incisors were randomly divided into 2 groups according to the porcelain material (n = 10). The 1st group was applied the IPS Style® Ceram feldspathic porcelain and the 2nd group - GC InitialTM MC. The porcelain sectional veneers were fabricated following the manufacturers' instructions. After the veneers bonded with resin cement (Variolink® N), the fracture strength was measured using a universal testing machine (Instron®1195) at 1 mm/min until failure occurred. Failure modes were determined under a stereomicroscope.

RESULTS: The mean fracture strength for group IPS Style Ceram was higher than that for group GC Initial MC (182.7 N and 155.7 N, respectively). The lowest value was observed in group IPS Style Ceram (78 N) and the highest value - also in the group IPS Style Ceram (294 N). Student's t-test demonstrated no statistically significant differences between the 2 groups (p > 0.05).

CONCLUSIONS: There was no difference in the fracture strength of the porcelain sectional veneers for the 2 types of sintered porcelain used in this study. Cohesive failure within the porcelain sectional veneer was the most common mode of failure.