Examining marginal fit and fracture strength of porcelain laminate veneer restorations prepared with different systems

Aim: Determining marginal fit of PLV's prepared with two different preparation and manufacture technique before and after cementation, and evaluating fracture strength. Material and method: 72 maxillary 1. incisor teeth were used in this study. Two different PLV preparation design (bevel and overlap) and two PLV production technique (Cerec and heat-press technique) were used. The fit of restorations evaluated with μCT technique before cementation and after cementation with two types of resin cement (Variolink Veneer and Clearfil Esthetic Cement EX). Then, cemented samples were applied fracture test. Results: The marginal fit values of PLVs produced by IPS Empress Esthetic were found higher than produced by Cerec. Before cementation the lowest marginal fit values were shown by CB group and the highest values were shown by EO group. After cementation except EOV group at all groups were shown increase in marginal gap values. There was no significant difference between fracture strengths of 8 gruops. When the groups evalueted according to cement type, there wasn't any significant difference between Clearfil Esthetic EX groups, but in Variolink Veneer groups the groups with bevel preparation design were more successful. Conclusion: In our study, Cerec technique, according to the heat-press technique is preferrable, because it gives better results. While overlap preparation type gave higher values before cementation, the values obtained after cementation is identical to the bevel preparation design. Both types of preparation techniques may also be clinically recommended. Clinically Cerec PC feldspathic blocks can be used safely in PLV production.