Impact of Two Different Designs and Materials on Fracture Resistance of Occlusal Veneers (In Vitro Study)

Document Type : Original Article

Authors

1 Fixed Prosthodontics Dept., Faculty of Dentistry, Mansoura University, Mansoura, Egypt

2 Professor, Fixed Prosthodontics Dept., Faculty of Dentistry, Mansoura University, Mansoura, Egypt

3 Instructor, Fixed Prosthodontics Dept., Faculty of Dentistry, Mansoura University, Mansoura, Egypt

Abstract

Abstract
Statement of the problem: Occlusal veneer restorations represent a minimal invasive alternative to traditional crowns in treatment of severely worn dentition. However, the data regarding the mechanical performance of occlusal veneers designs and materials are still controversial.
Aim of study: Evaluation of the effect of using two different designs and materials on fracture resistance of occlusal veneer restorations.
Materials and Methods: Thirty-two freshly extracted premolars were randomly divided into two main groups (n=16) according to preparation design: Group B: butt joint preparation design and Group M: Modified occlusal veneer design. Each main group was further subdivided into two subgroups (n=8) according to type of restorative material used for occlusal veneer fabrication: Lithium disilicate and polymer-infiltrated ceramic network. Occlusal veneer restorations were fabricated by CAD/CAM technology and then cemented to their corresponding teeth using dual cured adhesive resin cement. Fracture resistance test was done using universal testing machine. The load needed for fracture of each specimen was registered automatically in Newtons (N) by a special software. Data were collected, tabulated and statistically analyzed.
Results: Student's t-test results revealed that there was no statistically significant difference regarding the two variables (preparation design and material type). Also, Two-way ANOVA test results showed that there was no statistically significant difference regarding the interaction between the two variables in this study (P=0.309).
Conclusion: There was no effect of preparation designs and material types on fracture resistance of occlusal veneers.
The fracture resistance for all study groups exceeded the reported range of human masticatory forces.

Keywords