Comparison of Fracture Resistance and Failure Mode in Digitally Milled Restorations With Rapid Layering by Indirect Composite Resin: An in Vitro Study Publisher Pubmed



Ghodsi S¹ ; Zeighami S¹ ; Etemad M² Show Affiliations
Source: International Journal of Oral and Maxillofacial Implants Published:2021

Abstract

Purpose: To evaluate the fracture resistance and failure mode of implant crowns made by polyether ether ketone (PEEK), zirconia, and chromium-cobalt frames, veneered by milled composite resin. Materials and Methods: Thirty-six implant analogs were mounted in acrylic blocks, and solid abutments were secured (n = 12). Single-unit frameworks were milled from PEEK, zirconia, or chromium-cobalt, and cemented to indirect composite veneers fabricated by the rapid layering technique. After thermal cycling, the fracture resistance test was performed at a speed of 0.5 mm/min, and the results were statistically analyzed by one-way analysis of variance (ANOVA) and Tukey post hoc test (P <. 05). The failure mode was evaluated by a stereomicroscope ('10). Veneer failure without damage to other components was considered desirable (repairable). Results: The mean fracture resistances of PEEK, zirconia, and chromium-cobalt specimens were 2,037.24, 2,567.05, and 2,032.10 N, respectively. The Tukey post hoc test showed no significant difference between the PEEK and chromium-cobalt groups (P =. 99); however, the difference was significant between zirconia and PEEK or chromium-cobalt specimens (P =. 001). Failure mode was desirable in all chromium-cobalt (12 specimens), 9 zirconia, and 7 PEEK-based specimens. Conclusion: Zirconia-composite implant crowns had significantly higher fracture resistance. Given the range of maximum occlusal forces, all the specimens had clinically acceptable results. The failure mode was more desirable in chromium-cobalt, followed by zirconia-based crowns © 2021. by Quintessence Publishing Co Inc. All Rights Reserved.