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Evaluation of Marginal/Internal Fit and Fracture Load of Monolithic Zirconia and Zirconia Lithium Silicate (ZLS) CAD/CAM Crown Systems
- Source :
- Materials, Volume 14, Issue 21, Materials, Vol 14, Iss 6346, p 6346 (2021)
- Publication Year :
- 2021
- Publisher :
- Multidisciplinary Digital Publishing Institute, 2021.
-
Abstract
- Fit accuracy and fracture strength of milled monolithic zirconia (Zi) and zirconia-reinforced lithium silicate (ZLS) crowns are important parameters determining the success of these restorations. This study aimed to evaluate and compare the marginal and internal fit of monolithic Zi and ZLS crowns, along with the fracture load, with and without mechanical aging. Thirty-two stone dies acquired from a customized master metal molar die were scanned, and ceramic crowns (16 Zi Ceramill Zolid HT+ and 16 ZLS Vita Suprinity) were designed and milled. Absolute marginal discrepancies (AMD), marginal gaps (MG), and internal gaps (IG) of the crowns, in relation to the master metal die, were evaluated using x-ray nanotomography (n = 16). Next, thirty-two metal dies were fabricated based on the master metal die, and crowns (16 Zi<br />16 ZLS) cemented and divided into four groups of eight each<br />eight Zi with mechanical aging (MA), eight Zi without mechanical aging (WMA), eight ZLS (MA), and eight ZLS (WMA). Two groups of crowns (Zi-MA<br />ZLS-MA) were subjected to 500,000 mechanical cycles (200 ± 50 N, 10 Hz) followed by axial compressive strength testing of all crowns, until failure, and the values were recorded. Independent sample t tests (α = 0.05) revealed no significant differences between Zi and ZLS crowns (p &gt<br />0.05)<br />for both internal and marginal gaps, however, there were significant differences in AMD (p &lt<br />0.005). Independent samples Mann–Whitney U and Kruskal–Wallis tests revealed significant differences between the two materials, Zi and ZLS, regardless of fatigue loading, and for the individual material groups based on aging (α = 0.05). Multiple comparisons using Bonferroni post-hoc analysis showed significant differences between Zi and ZLS material groups, with or without aging. Within the limitations of this study, the ZLS crown fit was found to be on par with Zi, except for the AMD parameter. As regards fracture resistance, both materials survived the normal range of masticatory forces, but the Zi crowns demonstrated greater resistance to fracture. The monolithic Zi and ZLS crowns seem suitable for clinical application, based on the fit and fracture strength values obtained.
- Subjects :
- Molar
Technology
Materials science
medicine.medical_treatment
ceramic
chemistry.chemical_element
internal gap
Crown (dentistry)
Article
CAD/CAM
nano-CT evaluation
Flexural strength
medicine
General Materials Science
Cubic zirconia
Composite material
Microscopy
QC120-168.85
fracture load
QH201-278.5
Monolithic zirconia
Fracture load
Engineering (General). Civil engineering (General)
TK1-9971
dynamic loading
Compressive strength
Descriptive and experimental mechanics
chemistry
marginal fit
Lithium
Electrical engineering. Electronics. Nuclear engineering
TA1-2040
monolithic
zirconia
lithium silicate
Subjects
Details
- Language :
- English
- ISSN :
- 19961944
- Database :
- OpenAIRE
- Journal :
- Materials
- Accession number :
- edsair.doi.dedup.....4380f52d951f87f2c89dd84388d5b1f9
- Full Text :
- https://doi.org/10.3390/ma14216346