Comparative Study of Fracture Resistance of Different Ceramic Restorations
| Autor: | Marwa M Mogahed, Fatma A Hasaneen, Mahmoud Abdel Salam Shakal |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Glass-ceramic
Materials science Scanning electron microscope chemistry.chemical_element Fractography 030206 dentistry 02 engineering and technology 021001 nanoscience & nanotechnology law.invention 03 medical and health sciences 0302 clinical medicine chemistry Group (periodic table) law visual_art Fracture (geology) visual_art.visual_art_medium Cubic zirconia Lithium Ceramic Composite material 0210 nano-technology |
| Zdroj: | Egyptian Dental Journal. 67:1563-1569 |
| ISSN: | 2090-2360 |
| DOI: | 10.21608/edj.2021.60504.1478 |
| Popis: | Objective: Comparison of fracture resistance of different ceramic restorations. Methodology: 64 ceramic crowns were fabricated. They were divided into 4 equal groups according to the type of ceramic used (16 each). Group I: lithium disilicate, Group II: Zirconia reinforced lithium silicate, Group III: monolithic zirconia and Group IV: bilayered zirconia. Models of prepared teeth #14 were used as abutments. Eight sample specimens from each group were thermocycled between 55° C and 5° C. Fracture resistance was tested for the specimens. The load to fracture was recorded. Mean value for each group was calculated and differences between groups were tested for statistical significance. One fractured specimen from each group was scanned by scanning electron microscopy to determine the failure mode. Results: it was found that the highest fracture resistance mean value was recorded with monolithic zirconia group followed by lithium disilicate group then bilayered zirconia group while the lowest fracture resistance mean value was recorded for zirconia reinforced lithium silicate group and this was statistically significant. The four tested groups showed lower fracture resistance mean values after thermocycling. The fractography showed that surface defects were the origin of fracture in glass ceramic groups. While monolithic zirconia showed internal surface cracks. Conclusions: Within the limitations of this study, the following conclusions can be drawn: monolithic zirconia has the highest fracture resistance among the tested groups, while zirconia reinforced lithium silicate group has the lowest fracture resistance. Thermal aging significantly reduces the fracture resistance in the four tested groups. |
| Databáze: | OpenAIRE |
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