TY - JOUR
T1 - Do thermal treatments affect the mechanical behavior of porcelain-veneered zirconia?
T2 - A systematic review and meta-analysis
AU - Rodrigues, Camila da Silva
AU - Aurélio, Iana Lamadrid
AU - Kaizer, Marina da Rosa
AU - Zhang, Yu
AU - May, Liliana Gressler
N1 - Funding Information:
The authors are thankful to the Federal Agency for Support and Evaluation of Graduate Education (CAPES) (finance code 001) for the PhD scholarship. This study was in part supported by the U.S. National Institute of Dental and Craniofacial Research (Grant Nos. R01DE026279 and R01DE026772 ).
Publisher Copyright:
© 2019 The Academy of Dental Materials
PY - 2019/5
Y1 - 2019/5
N2 - Objectives: A systematic review of in vitro studies was conducted to assess the effect of thermal treatments on flexural strength or critical load to failure of porcelain-veneered zirconia (PVZ). Sources: Literature searches were performed up to June 2018 in PubMed/MEDLINE, Scopus and Web of Science databases, with no publication year or language limits. Data: From 393 relevant studies, 21 were selected for full-text analysis, from which 7 failed to meet the inclusion criteria. The 14 remaining papers were included in the systematic review: 8 for meta-analysis and 6 restricted to descriptive analyses. Hand searching of reference lists resulted in no additional papers. Study selection: In vitro studies using PVZ specimens testing the influence of thermal treatments on the fracture resistance to monotonic or cyclic loading. Papers evaluating cooling rate were divided into those applying fast cooling from above the porcelain glass transition temperature (Tg ), or from below it. Meta-analyses were performed separately for flexural strength and critical load to failure, using random effects at a 5% significance level. Conclusions: Delaying furnace opening at a temperature below the porcelain Tg is advised for PVZ restorations, in order to improve their fracture resistance. Additional information is required to confirm the apparent beneficial effect of self-glaze and repeated veneer firings on the mechanical properties of these restorations. Finally, in order to obtain conclusive and relevant evidence regarding thermal treatments and the fracture resistance of PVZs, future studies should concentrate on anatomically-correct crown specimens.
AB - Objectives: A systematic review of in vitro studies was conducted to assess the effect of thermal treatments on flexural strength or critical load to failure of porcelain-veneered zirconia (PVZ). Sources: Literature searches were performed up to June 2018 in PubMed/MEDLINE, Scopus and Web of Science databases, with no publication year or language limits. Data: From 393 relevant studies, 21 were selected for full-text analysis, from which 7 failed to meet the inclusion criteria. The 14 remaining papers were included in the systematic review: 8 for meta-analysis and 6 restricted to descriptive analyses. Hand searching of reference lists resulted in no additional papers. Study selection: In vitro studies using PVZ specimens testing the influence of thermal treatments on the fracture resistance to monotonic or cyclic loading. Papers evaluating cooling rate were divided into those applying fast cooling from above the porcelain glass transition temperature (Tg ), or from below it. Meta-analyses were performed separately for flexural strength and critical load to failure, using random effects at a 5% significance level. Conclusions: Delaying furnace opening at a temperature below the porcelain Tg is advised for PVZ restorations, in order to improve their fracture resistance. Additional information is required to confirm the apparent beneficial effect of self-glaze and repeated veneer firings on the mechanical properties of these restorations. Finally, in order to obtain conclusive and relevant evidence regarding thermal treatments and the fracture resistance of PVZs, future studies should concentrate on anatomically-correct crown specimens.
KW - Cooling protocols
KW - Glaze firings
KW - Heat treatment
KW - Mechanical properties
KW - Porcelain-veneered zirconia
KW - Repeated firings
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U2 - 10.1016/j.dental.2019.02.016
DO - 10.1016/j.dental.2019.02.016
M3 - Review article
C2 - 30846374
AN - SCOPUS:85062295706
SN - 1879-0097
VL - 35
SP - 807
EP - 817
JO - Dental Materials
JF - Dental Materials
IS - 5
ER -