Effect of Three Veneering Techniques on Marginal Accuracy and Fracture Resistance of Zirconia Base Fixed Restoration (In-Vitro Study).

Abstract

Statement of the problem. Veneered zirconia restorations are frequently used for esthetic demands , however marginal accuracy and fracture resistance are among the critical factors that determine longevity and success of these restorations. These two items may be affected by veneering procedures. Purpose. The aim of this systematic review was to identify from in vitro studies the effect of veneering techniques on the marginal accuracy and fracture resistance of zirconia restorations. Materials and methods. The articles identified were screened by two reviewers according to inclusion and exclusion criteria. The reference lists of articles advanced to second round screening were hand searched to identify additional potential articles. Sources: An electronic search was conducted on PubMed/Medline, Cochrane, Google scholar, Sciencedirect and Springerlinnk databases with no limitations. Results . Study selection: 387 articles were identified, of which, nine met the inclusion criteria and formed the basis of this systematic review. Factors investigated in the selected articles included the sample size, type of restoration , die material ,preparation criteria , veneering technique , cementation , method of measuring fracture resistance , method of measuring marginal accuracy , results of fracture and results of marginal accuracy. Conclusions.Based on the currently available scientific evidence, The zirconia veneering technique significantly influences the fracture resistance of zirconia-based crowns, the layering veneering technique crowns recorded the highest failure loads, while the digital veneering technique crowns recorded the lowest failure loads, the combination