Strength of 3Y-TZP and feldspathic porcelain subjected to different cooling methods
Braz. j. oral sci
;
13(2): 124-128, Apr-Jun/2014. tab, graf
Article
in English
| LILACS
| ID: lil-715609
ABSTRACT
AIM:
To investigate the effect of the cooling rate on flexural strength of monolayer and bilayer porcelain/zirconia (Y-TZP) bars.METHODS:
Forty-five specimens were made for each design group (PM) monolithic specimens of veneer porcelain Vita VM9 (Vita, Germany); (ZM) monolithic specimens of zirconia (ZiHP; ProtMat, Brazil); (PB) bilayer specimens zirconia/porcelain with porcelain on lower surface; and (ZB) bilayer specimens porcelain/zirconia with zirconia on lower surface. Each group was cooled by three different methods after porcelain sintering slow specimens were cooled inside the turned-off furnace; normal specimens were removed from the furnace and cooled in air at room temperature; and fast specimens were removed from the furnace at 910°C and cooled by compressed air for 10 s. Specimens were polished and flexural strength was measured in water at 37 °C (n=15). Maximum load at fracture was recorded, and equations for simple (monolayer) and composite (bilayer) structures were used to calculate the flexural strength. RESULTS were analyzed using one-way ANOVA (p<0.05) and Tukey test separately for each design.RESULTS:
The results of one-way ANOVA were statistically significant only for the PB group. The post-hoc Tukey test showed the highest flexural strength for fast cooling and the lowest for slow cooling; the normal cooling was statistically similar to both.CONCLUSIONS:
Cooling methods affected only the flexural strength of bilayer specimens with porcelain on low surface (under tension) when the slow cooling method was used...
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Index:
LILACS (Americas)
Main subject:
Zirconium
/
Dental Porcelain
/
Materials Science
Language:
English
Journal:
Braz. j. oral sci
Journal subject:
Dentistry
Year:
2014
Type:
Article
/
Project document
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Estadual Paulista/BR
/
Universidade Potiguar/BR
/
Universidade Tiradentes/BR
/
Universidade do Estado do Rio de Janeiro/BR
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