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

• Published in: The journal of advanced prosthodontics Vol. 12; no. 4; pp. 225 - 232
• Main Authors: Ryu, Ji-Eun, Kim, Yu-Lee, Kong, Hyun-Jun, Chang, Hoon-Sang, Jung, Ji-Hye
• Format: Journal Article
• Language: English
• Published: The Korean Academy of Prosthodontics 01.08.2020; 대한치과보철학회
• Subjects: Original; 치의학
• ISSN: 2005-7806; 2005-7814
• DOI: 10.4047/jap.2020.12.4.225

PURPOSEThis 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 METHODSThe 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. RESULTSMG, 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. CONCLUSIONThe 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°.