Marginal Misfit of 3D-Printed (Selective Laser Sintered), CAD-CAM and Lost Wax Technique Cobalt Chromium Copings with Shoulder and Chamfer Finish Lines: An In-Vitro Study

Abstract

Background and Objectives: The aim was to compare the Misfit of 3D-Printed, Selective laser melting (SLM), milled (Computer aided design-Computer aided manufacture CAD-CAM) and Lost wax technique (LWT) fabricated Cobalt chromium (CoCr) alloy copings on shoulder (SH), radial shoulder (R-SH) and chamfer (CH) finish line configuration. Materials and Methods: Ninety resin, second maxillary premolar teeth were prepared for metal-ceramic crowns, equally divided into (n = 30) SH, R-SH and CH margin preparations. For each preparation design (SH, R-SH and CH), CoCr copings were prepared using SLM, CAD-CAM and LWT. This resulted in nine study groups with 10 CoCr copings each. The marginal misfit of specimens was assessed with a high-resolution digital microscope. Misfit was evaluated in vertical and horizontal dimensions in μm. Data were analyzed using ANOVA and a post hoc multiple comparisons test. Results: For vertical misfit, the highest was observed in SLM samples with chamfer margin (167.96 ± 24.1), and the least was shown by CAD-CAM samples with radial shoulder (58.8 ± 12.53). CAD-CAM and shoulder margins showed the least vertical misfit. For horizontal misfit, the maximum was observed in SLM samples with shoulder margin (137.94 ± 37.85) and the least by LWT samples with chamfer (89.38 ± 14.81). Chamfer margins and LWT samples showed the least horizontal misfit among the group samples. Fabrication technique and finish line design play a critical role in reducing the marginal misfit of CoCr copings. Conclusions: For vertical misfit, SLM copings showed poor outcomes compared to CAD-CAM specimens, however comparable outcomes to Cast specimens. SLM copings showed comparable horizontal misfit outcomes to CAD-CAM specimens and low misfit compared to Cast copings, respectively. Vertical misfit was low with shoulder margins, and horizontal misfit was better with chamfer marginal configuration.

Influence of the Manufacturing Trinomial (Technology, Printer, and Material) on the Marginal and Internal Discrepancies of Printed Metal Frameworks for the Fabrication of Tooth-Supported Prostheses: A Systematic Review and Meta-analysis

“…Afterward, 12 articles were excluded because 5 studies analyzed the marginal and internal discrepancy values after completing ceramic veneering procedures, 1 investigation did not provide the quantitatively measured marginal and internal discrepancies, 3 studies did not provide the manufacturer of the metal printer used to fabricate the specimens, and 3 studies did not test metal AM techniques. A total of 31 articles (30 in vitro [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][55][56][57][58][59][60][61][62][63][64][65] and 1 clinical 54 ) were included in the present systematic review.…”

“…The selected articles were classified based on the evaluation method used to assess the fit of the Co-Cr frameworks, namely manufacturing accuracy, 35,36 the dual-scan 37,38 and triple-scan method, 39 stereomicroscope, [40][41][42][43][44][45] optical coordinate measurement machine (CMM), 46 microCT, 47,48 profilometer, 49 and silicone replica technique. [50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65] Additionally, each group was subdivided into six subgroups based on the manufacturer used to fabricate the SLM Co-Cr frameworks, namely 3D Systems, 35,62 Bego, 51,54 Concept Laser, [37][38][39]41,42,47,48,52,56,58 EOS, 36,40,…”

“…Six studies analyzed the marginal and internal discrepancies of the specimens using a stereomicroscope. [40][41][42][43][44][45] Two different SLM printer manufacturers were tested among the studies, namely EOS 40,[43][44][45] and Concept Laser. 41,42 Among the studies that tested EOS, three of them used the same EOS printer (EOS EOSINT M270) [43][44][45] but different Co-Cr powders (not provided, 43 SP2, 44 and MP 145 from EOS).…”

“…[40][41][42][43][44][45] Two different SLM printer manufacturers were tested among the studies, namely EOS 40,[43][44][45] and Concept Laser. 41,42 Among the studies that tested EOS, three of them used the same EOS printer (EOS EOSINT M270) [43][44][45] but different Co-Cr powders (not provided, 43 SP2, 44 and MP 145 from EOS). Disparities on the printer and Co-Cr powder were also found between the two studies that used a Concept Laser manufacturing method 41,42 (see Table 3).…”

The Biological Activity of Fragmented Computer-Aided Design/Manufacturing Dental Materials before and after Exposure to Acidic Environment

“…Regarding their biocompatibility, a study reported that ceramic materials offer better biocompatibility and cell response compared to polymers [ 17 ]. Many improved materials with superior mechanical qualities have been developed for CAD/CAM technology in the last decade [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. With the development of novel nanomaterials, the standards of dental care health also improved by altering the properties of biomaterials [ 26 ].…”