Comparative Evaluation of Dimensional Accuracy of Casting (Vertical Marginal Discrepancy) Produced with Supercast and Minalux Alloys

The fitness of a restoration is essential for its longevity, which is affected by different factors, including the type of the alloy used. Due to the production of Minalux nickel-chromium, beryllium-free, alloy in Iran, the aim of this study was to compare vertical margin discrepancy between Supercast and Iranian Minalux alloys.
In this experimental/observational study, 60 coping wax patterns were fabricated on a metal die which was prepared for porcelain-fused metal crown (PFM) with chamfer finishing line and divided into 2 groups of 30. In the first group, Supercast alloy and in the second group Minalux alloy were used. Castings were prepared and seated on the metal die after minimal internal surface adjustment. The vertical margin discrepancies were measured at four locations (buccal, lingual, mesial and distal) of the die and casting. Then the vertical margin discrepancy in each group was statistically analyzed with SPSS 22, using t-test (α = 0.05).
Mean vertical margin discrepancy in first group (Supercast alloy) was 117.35 µm, with 137.57 µm in the second group (Minalux alloy). The castings with Supercast alloy were significantly different (p value = 0.031) from the Minalux alloys.
The results show that the Supercast alloy, due to lower vertical marginal discrepancy compared to Minalux, is better for fabrication of dental restorations.