Fracture Resistance of Different Width of Zirconia Surveyed Crowns: an In vitro Study

Abstract

Purpose: To evaluate the fracture resistance of zirconia surveyed crowns with different rest seat designs. Materials and methods: Forty surveyed crowns (n = 20 / group) were made with different rest seats as follows: group 1; zirconia-based material with narrow media-occlusal rest seat; group 2; zirconia-based material with wide media-occlusal rest seat. Then 3M RelyX Luting Cement was used to bond the printed crowns to resin dies. Using Instron 5569 Universal, compression force was applied to the crowns until fractured, and then fracture resistance at maximum load was recorded. Statistical analysis was conducted using the Wilcoxon signed-rank test (α = 0.05) in SPSS (IBM, Armonk, NY, USA). Results: There was nostatistically significant difference in fracture resistance for both groups. Conclusion: Different designs of rest seats CAD/ CAM surveyed crowns can be used; however more research is necessary to measure clinical outcomes.