Damage sensitivity of dental zirconias to simulated occlusal contact
| Autor: | Yu Zhang, Márcia Borba, Marina R. Kaizer, Tomoyuki K. Okamoto, Michelle Zou |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Dental Stress Analysis
Ceramics Materials science Surface Properties medicine.medical_treatment 02 engineering and technology Article 03 medical and health sciences 0302 clinical medicine Materials Testing medicine General Materials Science Cubic zirconia Ceramic Composite material General Dentistry Tension (physics) 030206 dentistry 021001 nanoscience & nanotechnology Dental Porcelain Substrate (building) Mechanics of Materials visual_art visual_art.visual_art_medium Mastication Degradation (geology) Zirconium 0210 nano-technology Sensitivity (electronics) Dental restoration Damage tolerance |
| Zdroj: | Dent Mater |
| ISSN: | 0109-5641 |
| Popis: | Objective Mechanical damages can occur from dental restoration processing and fitting, or while it is in-service. This study evaluates the damage sensitivity of translucent zirconia (5Y-PSZ) relative to conventional 3Y-PSZ following mouth-motion simulations at various loads. Methods 5Y-PSZ and 3Y-PSZ discs were adhesively bonded to a dentin-like substrate and divided into groups according to the load (50 N or 200 N) and number of cycles (up to 106) used in the chewing simulation. Specimens were mounted with 30° inclination in an electrodynamic mouth-motion simulator, and subjected to contact-slide-liftoff cyclic loading in water. Surface and sub-surface damages were analyzed using a sectioning technique. After the simulation, specimens were removed from the substrate and loaded with the damaged surface in tension for biaxial strength testing to assess their damage tolerance. Results The strength of both ceramics underwent significant degradation after mouth-motion simulations. For 5Y-PSZ, the strength degradation was greater (∼60%) and occurred at a lower number of cycles than 3Y-PSZ. Herringbone cracks emerged on 3Y-PSZ and 5Y-PSZ surfaces under a 200-N load after 50 and 10 cycles, respectively. Meanwhile at a 50-N load, cracks formed at ∼1000 cycles in both ceramics. Further increasing the number of cycles only had moderate effects on the strength of both ceramics, despite an increase in surface and sub-surface damage. More significantly, a 50-N occlusal load can debase the zirconia strengths as much as a 200-N load. Significance Surface flaws produced during the chewing simulation are capable of significant strength degradation in zirconia, even after a small number of low-load cycles. |
| Databáze: | OpenAIRE |
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