Marginal fit of cast titanium crown

Objective: Considering the difficulty of marginal fit of cast crown in titanium, this study evaluated the effect of the special liquid proportion of the investiment Rematitan Plus in the marginal fit of cast crown in commercially pure titanium (>99.56%). Methods: Individual polyvinyl siloxane impressions were used to duplicate steel stylized die and create set of epoxy resin (Epo-Thin, Buehler) master die, which represent a prepare of full-crown with 6-degree axial surface convergence angle and a 1mm wide shoulder. The investment Rematitan Plus (Dentaurum, Pforzheim, Germany) was mixed in three proportions of special liquid: G1 (50%), G2 (75%) and G3 (100%), and eight crowns of each were made. Each casting was cleaned individually in a solution (1% HF + 13% HNO₃) for 10 min again using the ultrasonic cleaner (Ultrasonic Cleaner, Odontobras) and was returned to the epoxy resin master die. After the seat under a load of 5N the distance separating the gingival margin of the crown and the shoulder of the epoxy resin die was measured at four fixed points around the die, using stereoscopy lens (CarlZeiss 10X) and imaging system Leica Qwin (Leica). Data of each experimental condition were analyzed using Kruskal-Wallis non-parametric test with the value of statistical significance set at P=.05. Results: The groups G2 (592.85 µm) and G3 (453.50 µm) showed levels of misfit marginal similar among themselves, and inferiors to the G1 (898.52 µm). Conclusion: The dilution of 50% of the special liquid of investment Rematitan Plus resulted in significant increase in the marginal misfit of cast commercially pure titanium crowns.