Zirconia fixed dental prostheses fabricated by 3D gel deposition show higher fracture strength than conventionally milled counterparts.
J Mech Behav Biomed Mater
; 135: 105456, 2022 11.
Article
in En
| MEDLINE
| ID: mdl-36150323
ABSTRACT
Zirconia restorations, which are fabricated by additive 3D gel deposition and do not require glazing like conventional restorations, were introduced as "self-glazed" zirconia restorations into dentistry. This in vitro investigation characterized the surface layer, microstructure and the fracture and aging behavior of "self-glazed" zirconia (Y-TZPSG) three-unit fixed dental prostheses (FDP) and compared them to conventionally CAD/CAM milled and glazed controls (Y-TZPC-FDPs). For this purpose, the FDPs were analyzed by (focused ion beam) scanning electron microscopy, laserscanning microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and a dynamic and static loading test. For the latter, half of the samples of each material group (n = 16) was subjected to 5 million cycles of thermocyclic loading (98N) in an aqueous environment in a chewing simulator. Afterwards, all FDPs were loaded to fracture. Y-TZPSG-FDPs demonstrated a comparable elemental composition but higher surface microstructural homogeneity and fracture strength compared to Y-TZPC-FDPs. Microstructural flaws within the FDPs' surfaces were identified as fracture origins. The high fracture strength of the Y-TZPSG-FDPs was attributed to a finer-grained microstructure with fewer surface flaws compared to the Y-TZPC-FDPs which showed numerous flaws in the glaze overlayer. A decrease in fracture strength after dynamic loading from 5165N to 4507N was observed for the Y-TZPSG-FDPs, however, fracture strength remained statistically significantly above the one measured for Y-TZPC-FDPs (before chewing simulation 1923N; after 2041N). Within the limits of this investigation, it can therefore be concluded that Y-TZPSG appears to be stable for clinical application suggesting further investigations to prove clinical applicability.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Dental Prosthesis
/
Flexural Strength
Language:
En
Journal:
J Mech Behav Biomed Mater
Journal subject:
ENGENHARIA BIOMEDICA
Year:
2022
Document type:
Article