The Effect of Pattern Materials on the Marginal Gap of Metal CopingsFabricated On Titanium Implant Abutments

Aims: This study was aimed to compare the effect of three different pattern materials on the vertical marginal discrepancy of Nickel-Chromium copings fabricated on titanium implant abutments. Methods: A titanium implant abutment was used to receive 30 Nickel-Chromium copings. The copings were constructed using pattern wax (group 1), acrylic pattern resin (group 2), and lightcured pattern resin (group 3). The marginal gap of the Nickel-Chromium copings was measured at 4 points on the abutmentimplant assembly by using a digital microscope. One-way ANOVA and post hoc tests were adopted for statistical analysis (α=0.05). Results: The mean marginal gap values of Nickel-Chromium copings fabricated from pattern wax, acrylic pattern resin, and lightcured pattern resin were 34.00, 31.78 and 25.87 μm, respectively. There was a statistically significant difference between groups 1 and 3 (p=0.02), whilst the difference between groups 2 and 3 and between groups 1 and 2 was not statistically significant (p>0.05). Conclusions: The marginal gaps of the copings, fabricated from tested pattern materials, were within the clinically acceptable range. Nevertheless, light-cure pattern resin had a better vertical marginal fit than acrylic pattern resin and pattern wax.