Evaluation of Marginal Gaps with Different Types of Luting Cements

Objective: the aim of this study was to evaluate and compare the marginal fit of 3-unit-fdps in different metal alloys made using 3 different production techniques cemented with 3 different cements in vitro.material-method: specimens were fabricated with 3 different fabrication techniques (induction cast, metal milling, laser sintering) and were evaluated within 9 groups. in addition, the marginal adaptation of metal-ceramic bridges after the firing cycles for porcelain veneers were examined and the scores were compared with the final marginal adaptations of the previously recorded scores. the evaluation was conducted within 40 points which were defined for a single abutment margins for each crown and a stereomicroscope was used for measurements.results: marginal gap values in 3 unit fixed partial brigde restorations produced with induction casting were 83,21 μm before cementation and 95,56 μm after cementation with zinc phosphate, 88,35 μm with polycarboxylate cement and 90,65 μm with dual cure resin cement in order. for the laser sintering production group gap values were 75,37 μm, 85,92 μm, 80,63 μm and 82,46 μm. gap values in direct metal milling group were 72,42 μm; 83,32 μm, 77,47 μm and 77,84 μm in order.conclusion: within the limitations of this study, all the groups were at the clinically acceptable levels except induction casting samples (p<0.05). nevertheless all recorded values are in clinically acceptable limits.