Ceramic Crowns bi-layered: a review of the literature on ceramics types, ceramic processing and residual tension

Abstract

INTRODUCTION: The usage of ceramic materials as a restoration strategy faces some problems, such as interferences between porcelain and zirconia, being the first one used as ceramic cover and the second one as infrastructure or coping. OBJECTIVE: review the literature on bi-layer ceramic crowns, through the types of ceramics, ceramic processing and residual stress.METHODOLOGY: Databases for this review were Bireme, Pubmed, Scielo and Virtual Libraries. Keywords were searched on Mesh. Inclusion criteria were Studies, Laboratorial and Clinical, Systematic Review and Meta-Analysis, papers and specific literature regarding the theme, in both English and Portuguese. Exclusion criteria were letter to the editor, clinical case and opinion piece, literatures that don’t face the theme and papers that analyze other odontological ceramics. Literature and papers were selected through summaries and abstracts. FINAL CONSIDERATIONS: Residual tension in bi-layers ceramics crowns with zirconia infrastructure and porcelain cover occur due to a lot of factors such as coefficient of thermal expansion, cooling speed, processing, and thickness of ceramic cover.