Evaluation of the marginal accuracy of provisional restorations made of acrylic resins

Abstract

Aim: To evaluate the marginal accuracy of provisional crowns made with acrylics resins and to identify the surface(s) with the highest marginal discrepancy. Methods: A direct technique was used to fabricate 96 provisional restorations with 8 materials: Dencrilay, Dencôrlay, Dencôr, Vipicor, Duralay, Resinlay Speed, Refine Bright and Alike (n=12). The provisional crowns were made on a prepared molar-shaped metal die with a vinyl polysiloxane impression as a matrix. Marginal discrepancy of provisional restorations was analyzed at buccal, lingual, mesial and distal surfaces of metal die finish line in a stereomicroscope lupe at 100X. The images obtained were transferred to the Corel Draw X7 program and the distances from the cervical margins of the specimen to the reference lines were measured vertically. Comparisons were made with 1-way analysis of variance and the Tukey test (p <0.05). Results: The Alike resin exhibited the lowest marginal discrepancy (0.018 mm) and was significantly different from the Dencôrlay (0.037 mm), Filter Bright (0.034 mm), Duralay (0.033 mm) and Vipicor (0.032) resins. The buccal surface showed the highest marginal discrepancy (0.040 mm) compared to those of other surfaces (distal 0.029mm, lingual 0.028mm and mesial 0.024mm). Conclusion: The marginal adaptation of all materials and surfaces tested in this study were within a clinical acceptable limit. The Alike resin showed the best performance compared to Dencôrlay, Refine Bright, Duralay, and Vipicor resins. The buccal surface showed the highest marginal discrepancy than those of the other tested surfaces.