J Adv Prosthodont.  2020 Aug;12(4):225-232. 10.4047/jap.2020.12.4.225.

Marginal and internal fit of 3D printed provisional crowns according to build directions

• Ryu JE
• Kim YL
• Kong HJ
• Chang HS
• Jung JH

• KMID: 2505362
• DOI: http://doi.org/10.4047/jap.2020.12.4.225

Abstract

PURPOSE
. This study aimed to fabricate provisional crowns at varying build directions using the digital light processing (DLP)-based 3D printing and evaluate the marginal and internal fit of the provisional crowns using the silicone replica technique (SRT). MATERIALS AND METHODS. The prepared resin tooth was scanned and a single crown was designed using computer-aided design (CAD) software. Provisional crowns were printed using a DLP-based 3D printer at 6 directions (120°, 135°, 150°, 180°, 210°, 225°) with 10 crowns in each direction. In total, sixty crowns were printed. To measure the marginal and internal fit, a silicone replica was fabricated and the thickness of the silicone impression material was measured using a digital microscope. Sixteen reference points were set and divided into the following 4 groups: marginal gap (MG), cervical gap (CG), axial gap (AG), and occlusal gap (OG). The measurements were statistically analyzed using one-way ANOVA and Dunnett T3.
RESULTS
MG, CG, and OG were significantly different by build angle groups (P<.05). The MG and CG were significantly larger in the 120° group than in other groups. OG was the smallest in the 150° and 180° and the largest in the 120° and 135° groups.
CONCLUSION
The marginal and internal fit of the 3D-printed provisional crowns can vary depending on the build angle and the best fit was achieved with build angles of 150°and 180°

Keyword

Crowns; Printing; Three-dimensional; Dental marginal adaptation; Dental internal fit