Impact of multiple firings on fracture load of veneered zirconia restorations.
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BORIS DOI
Publisher DOI
PubMed ID
35385808
Description
OBJECTIVES
This investigation evaluated the impact of multiple firings during the veneering process of anterior all-ceramic restorations on the fracture load (FL) of zirconia crowns veneered with different ceramics (ZRT, ZRO, HFZ, STR).
METHODS
All-ceramic crowns with anatomically reduced zirconia frameworks were prepared using four different veneering ceramics (N = 192/n = 48 per veneering ceramic). The crowns were fired 2 and 10 times. Half of them were thermocycled (5000 cycles, 5 °C/55 °C, 20s). FL using Voss shear test was measured. Data was analyzed using ANOVA with partial eta squared and post-hoc Scheffé-test as well as t-test and Weibull analysis.
RESULTS
Regarding FL, greatest differences were among the number of firings (p<0.001, ηp2 = 0.369). FL was not influenced by the interaction of both number of firings and aging level (p = 0.231) and the interaction of number of firings and veneering ceramic (p = 0.222). Differences were found comparing FL values of ZRT and STR (p<0.001) and of HFZ and STR (p<0.001). No differences occurred among the veneering ceramics after 2 (p = 0.430) and after 10 firings (p = 0.057) in respect to initial FL. For all initially tested veneering ceramics, FL showed higher values after 10 firings (p≤0.001-0.014). When aged, ZRO, HFZ, and STR also provided higher FL values after 10 firings (p≤0.001). For ZRT, FL values differed between initial and aged testing after 2 firings (p = 0.001) with aged specimens providing higher FL values. After 10 firings, none of the veneering ceramics showed differences regarding FL values between initial and aged testing. Weibull modulus was higher for ZRT specimens after 10 firings when tested initially (m = 10.1) and for aged ZRT specimens after 2 firings (m = 11.1). Failures occurred either with chipping of the veneer or total fracture.
SIGNIFICANCE
Veneered zirconia restorations tested presented higher FL after 10 firings compared to 2 firings. Aging via thermocycling showed a positive effect on the FL.
This investigation evaluated the impact of multiple firings during the veneering process of anterior all-ceramic restorations on the fracture load (FL) of zirconia crowns veneered with different ceramics (ZRT, ZRO, HFZ, STR).
METHODS
All-ceramic crowns with anatomically reduced zirconia frameworks were prepared using four different veneering ceramics (N = 192/n = 48 per veneering ceramic). The crowns were fired 2 and 10 times. Half of them were thermocycled (5000 cycles, 5 °C/55 °C, 20s). FL using Voss shear test was measured. Data was analyzed using ANOVA with partial eta squared and post-hoc Scheffé-test as well as t-test and Weibull analysis.
RESULTS
Regarding FL, greatest differences were among the number of firings (p<0.001, ηp2 = 0.369). FL was not influenced by the interaction of both number of firings and aging level (p = 0.231) and the interaction of number of firings and veneering ceramic (p = 0.222). Differences were found comparing FL values of ZRT and STR (p<0.001) and of HFZ and STR (p<0.001). No differences occurred among the veneering ceramics after 2 (p = 0.430) and after 10 firings (p = 0.057) in respect to initial FL. For all initially tested veneering ceramics, FL showed higher values after 10 firings (p≤0.001-0.014). When aged, ZRO, HFZ, and STR also provided higher FL values after 10 firings (p≤0.001). For ZRT, FL values differed between initial and aged testing after 2 firings (p = 0.001) with aged specimens providing higher FL values. After 10 firings, none of the veneering ceramics showed differences regarding FL values between initial and aged testing. Weibull modulus was higher for ZRT specimens after 10 firings when tested initially (m = 10.1) and for aged ZRT specimens after 2 firings (m = 11.1). Failures occurred either with chipping of the veneer or total fracture.
SIGNIFICANCE
Veneered zirconia restorations tested presented higher FL after 10 firings compared to 2 firings. Aging via thermocycling showed a positive effect on the FL.
Date of Publication
2022-06
Publication Type
Article
Keyword(s)
All-ceramic restoration Chipping Fracture load Leucite ceramic Multiple firings Thermal properties Veneering ceramics Zirconia
Language(s)
en
Contributor(s)
Hensel, Justine | |
Reise, Michael | |
Liebermann, Anja | |
Stawarczyk, Bogna |
Series
Journal of the mechanical behavior of biomedical materials
Publisher
Elsevier
ISSN
1878-0180
Access(Rights)
restricted