Comparsion of color stability of interim restorations fabricated by 3D printer with those fabricated manually

Abstract

Introduction: : There are different methods and materials for fixed provisional restoration which include manual methods and digital methods. In some cases temporary prosthesis is used for a long term and color stability is considered as an critical factor. In this study, color stability of temporary prosthesis made by the of 3D printing and two manual methods is compared.

Method: In this study, a maxillary central teeth were prepared for all ceramic restoration. After impression taking, 90 dies were made. Samples were randomly divided into three groups (n=30). In each group different kinds of temporary material were used to make provisional full crowns including: 3D printed, auto-mix, and powder-liquid group. after cementation samples were immersed in three solutions (coffee, distilled water, and cola). The color of samples was evaluated by spectrophotometer and using CIE lab method. Color changes were measured by using NBS index. Finally, statistical analysis was done by SPSS17 software.

Results: In a comperehensive assesment the color change based on the technique and solution the highest level of color change was related to auto-mix method and coffee solution, and the lowest average of color change was related to powder-liquid method and distilled water. In 3D printed group, the level of color change ranged from 0.5 to 1.5 units. Where as in automixed group in coffee solution ranged from 3 to 6 units.

Conclusion: In the limitation of this study for a longer service automixed (Bis-GMA) materials are not recommendable.