Effects of Printing Parameters on the Fit of Implant-Supported 3D Printing Resin Prosthetics

Abstract

The purpose of the study was to investigate the influence of 3D printing parameters on fit and internal gap of 3D printed resin dental prosthesis. The dental model was simulated and fabricated for three-unit prostheses with two implants. One hundred prostheses were 3D printed with two-layer thicknesses for five build orientations using a resin (NextDent C&B; 3D systems, Soesterberg, The Netherlands) and ten prostheses were manufactured with a milling resin as control. The prostheses were seated and scanned with micro-CT (computerized tomography). Internal gap volume (IGV) was calculated from 3D reconstructed micro-CT data. IGV, marginal fit, and lengths of internal gaps were measured, and the values were analyzed statistically. For the 3D printed prostheses, IGV was smaller at 45°, 60°, and 90° compared to other build orientations. The marginal fit evaluated by absolute marginal discrepancy was smaller than other build orientations at 45° and 60°. IGV was smaller at 50 µm layer thickness than at 100 µm layer thickness, but the marginal fit was smaller at 100 µm layer thickness than at 50 µm layer thickness. The 3D printed prosthesis had smaller internal gap than the milled prosthesis. The marginal fit of the 3D printed resin prosthesis was clinically acceptable, and build orientation of 45° and 60° would be recommended when considering fit and internal gap.

Preliminary Study on the Assessment of the Marginal Fit of Three-Dimensional Methacrylate Oligomer Phosphine Oxide Provisional Fixed Dental Prostheses Made by Digital Light Processing

“…FDM uses a preformed polymer as a building material that uses the input of processing energy in the pre-deposition stage to obtain a polymer melt that can be applied using a fine print head or nozzle [11,17]. Although this study analyzed singe interim restorations by extrapolating the results, the FDPs of the present study obtained minor discrepancy results [16].…”

“…The results for the marginal discrepancy of the restorations confectioned at an orientation of 60 • and made of 100 µm-thick layers provided the best mean discrepancy values (50.0 ± 14.7 µm). Nevertheless, it must be noted that most of the 3D printed groups showed worse results than the milled ones [16].…”

Assessment of Compatibility between Various Intraoral Scanners and 3D Printers through an Accuracy Analysis of 3D Printed Models

“…They reported that the SLA technique showed a slightly higher deviation in specific parts of the guide, as compared to the DLP technique, and presented the cause of the difference between the mean deviation of the dental implant position [ 18 ]. Other studies reported that one of the advantages of DLP and SLA printers was less shrinkage as compared to other 3D technologies, including FDM [ 16 , 31 , 38 , 39 ].…”

“…It is necessary for 3D printed dental models to have high dimensional accuracy, while the 3D printing method and specifications that affect surface resolution are also important. Accuracy is determined mostly by the characteristics of SLA, DLP, and FDM printers, but material-related geometry of layer thickness and 3D printing build orientation could also influence the warpage effect and the dimensional accuracy of shrinkage [ 9 , 10 , 31 , 32 ].…”

“…In contrast, SM, which is also referred to as milling, involves cutting a block to the desired shape. Compared to SM, such as milling hard ceramic, AM, which lacks resolution and accuracy, can be used to produce complex structures without wasting material unlike SM where material is discarded after being cut [ 4 , 5 , 18 , 19 , 31 ].…”