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The effect of preparation taper on the resistance to fracture of monolithic zirconia crowns
- Source :
- Dental Materials, e427-e434
- Publication Year :
- 2021
- Publisher :
- Elsevier, 2021.
-
Abstract
- Objective Monolithic zirconia crowns have become a viable alternative to conventional layered restorations. The aim of this study was to evaluate whether the taper, and thus wall thickness, of the abutment or pre-defined cement space affect the fracture resistance or fracture mode of monolithic zirconia crowns. Methods A model tooth was prepared with a taper of 15° and a shallow circumferential chamfer preparation (0.5 mm). Two additional models were made based on the master model with a taper of 10° and 30° using computer-aided design software. Twenty monolithic 3rd generation translucent zirconia crowns were produced for each model with pre-defined cement space set to either 30 μm or 60 μm (n = 60). The estimated cement thickness was assessed by the replica method. The cemented crowns were loaded centrally in the occlusal fossa at 0.5 mm/min until fracture. Fractographic analyses were performed on all fractured crowns. Results The load at fracture was statistically significant different between the groups (p < 0.05). The crowns with 30° taper fractured at lower loads than those with 10° and 15° taper, regardless of the cement space (p < 0.05). The fracture origin for 47/60 crowns (78%) was in the cervical area, close to the top of the curvature in the mesial or distal crown margin. The remaining fractures started at the internal surface of the occlusal area and propagated cervically. Significance The fracture resistance of the monolithic zirconia crowns was lower for crowns with very large taper compared to 10 and 15° taper even though the crown walls were thicker. publishedVersion
- Subjects :
- Dental Stress Analysis
Chamfer
Materials science
medicine.medical_treatment
02 engineering and technology
Crown (dentistry)
03 medical and health sciences
0302 clinical medicine
Materials Testing
medicine
General Materials Science
Cubic zirconia
Dental Restoration Failure
Composite material
General Dentistry
Cement
Crowns
Monolithic zirconia
030206 dentistry
021001 nanoscience & nanotechnology
Dental Porcelain
Dental Prosthesis Design
Mechanics of Materials
Fracture (geology)
Computer-Aided Design
Zirconium
0210 nano-technology
Wall thickness
Abutment (dentistry)
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Dental Materials, e427-e434
- Accession number :
- edsair.doi.dedup.....b70ea4ea71f309c3b354a7f7bf3d4897