Journal Article Ppublish 1 citation
PubMed: 38734932 DOI: 10.1111/jopr.13865
Effect of preparation design and endodontic access on fracture resistance of zirconia overlays in mandibular molars: An in vitro study.
J Prosthodont 34(4):412-421
Authors: Carlos A Jurado, Kelvin I Afrashtehfar, Manuel Robles, Razan S Alaqeely, Hussain D Alsayed, Terry J Lindquist, Abdulaziz Alhotan
Affiliations
- Operative Dentistry Division, Department of General Dentistry, University of Tennessee Health Science Center College of Dentistry, Memphis, Tennessee, USA.
- Department of Reconstructive Dentistry and Gerodontology (RekGero), School of Dental Medicine, University of Bern, Bern, Switzerland.
- Evidence-Based Practice Unit (EBPU), Clinical Sciences Department, College of Dentistry, Ajman University, Ajman City, UAE.
- Prosthodontics Private Practice, Dental Clinics, Abu Dhabi, UAE.
- Artificial Intelligence Research Center (AIRC), Ajman University, Dubai, UAE.
- Department of Restorative Dentistry, Universidad del Valle De Mexico, Hermosillo, Sonora, Mexico.
- Department of Periodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
- Department of Prosthetic Dental Sciences, College of Dentistry, King Saudi University, Riyadh, Saudi Arabia.
- Department of Prosthodontics, The University of Iowa College of Dentistry and Dental Clinics, Iowa City, Iowa, USA.
- Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
Abstract
PURPOSE
To evaluate the fracture resistance of zirconia overlays, considering various preparation designs and the presence of endodontic access.
MATERIALS AND METHODS
Ninety translucent zirconia (5Y-PSZ) overlay restorations were divided into six groups (n = 15/group) based on different preparation designs, with and without endodontic access: chamfer margin 4 mm above the gingival level without (group 1) and with endodontic access (group 2); margin 2 mm above the gingival level without (group 3) and with endodontic access (group 4); overlay with no chamfer margin without (group 5) and with endodontic access (group 6). Restorations were bonded to mandibular first molar resin dies, and the groups with endodontic access were sealed with flowable resin composite. All restorations underwent 100,000 cycles of thermal cycling between 5°C and 55°C, followed by loading until fracture. Maximum load and fracture resistance were recorded. ANOVA with Tukey post-hoc tests were used for statistical comparison (α < 0.05).
RESULTS
Fracture resistance significantly varied among overlay designs with and without endodontic access (p < 0.001), except for the no-margin overlays (groups 5 and 6). Overlays with a 2 mm margin above the gingival margin with endodontic access (group 4) exhibited significantly higher fracture resistance compared to both the 4-mm supragingival (group 2) and no-margin (group 6) designs, even when compared to their respective intact groups (groups 1 and 5). There were no significant differences between the no-margin and 4-mm supragingival overlays.
CONCLUSION
The more extensive zirconia overlay for mandibular molars is the first choice since the 2 mm margin above the gingival level design withstood considerable loads even after undergoing endodontic access. A no-margin overlay is preferred over the 4-mm supragingival design as it preserves more tooth structure and there was no outcome difference, irrespective of endodontic access. Caution is warranted in interpreting these findings due to the in vitro nature of the study.
MeSH
Molar, Dental Restoration Failure, Prosthodontics, Dental Stress Analysis, Dental Prosthesis Design