Methods: Two of the zirconia groups were prepared by the MAD-CAM system (Celay and Zr-Zahn) , whereas the remaining two groups were prepared by the CAD-CAM system (LAVA and DC-Zirkon). The metal frameworks were used as a control group. 10 speciments from each group were prepared. Overall, 50 speciments were used. AstraTech implant abutment were used to prepare the copings.The sixteen points which were previously established were marked and the measurements were done with the light microscopy at x150 magnification. The marginal congruity of all of the samples were evaluated by taking the measurements of the avarage of the 16 points. The four zirconia groups were compared with each other in terms of mean marginal gap values and with the metal control group and the statistical evaluations performed.
Results: At the end of the research, the best values of the marginal fit were observed in the LAVA frameworks. The highest marginal gaps were determined with the metal frameworks. According to the results, the groups can be summarized as follows in terms of marginal gap , from the lowest to highest: LAVA (24,57±14,03µm) < Celay (64,89±25,20µm )< DC-Zirkon (110,18±36,47µm )< Zr-Zahn (112,11±22,61µm) < Metal (120,14±33,27µm)
Conclusion: Since the values are lower than 120µm (control group) in all of the zirconia groups, the results indicated that all four zirconia systems that were included in the research provided clinically acceptable and consistent marginal gap precision. When the mean marginal gaps of the LAVA and Celay groups were compared with the metal control group, The differences were statistically significant (p=0,001, p=0,001).The mean marginal gap of LAVA and Celay groups were determined as significantly lower than metal control group.