A study of 3D printing parameters on fit of implant-supported 3-unit resin prosthesis

YCR88 ePOSTER BASIC RESEARCH

Background: There have been a few studies comparing the fit of 3D printing prosthesis according to parameters such as build orientation or layer thickness.

Aim/Hypothesis: To investigate the influence of build orientation and layer thickness on marginal fit and internal gap of implant supported three-unit resin prosthesis manufactured by 3D printing and to compare with the prosthesis made by milling.

Materials and Methods: An abutments model was fabricated for two implants supported three-unit resin prosthesis. One hundred prostheses were 3D-printed with two layer thicknesses (50 μm and 100 μm) for five build orientations (0°, 30°, 45°, 60° and 90°) using a resin material, and ten prostheses were manufactured with a milling resin. The prostheses were seated on the model and scanned with micro-CT. Internal gap volume (IGV) was calculated from 3D reconstructed micro-CT data. IGV, marginal fit, and length of internal gap were measured, and the values were analyzed statistically.

Results: For the 3D printed prostheses, IGV was smaller at 45°, 60°, 90° than other build orientations. The marginal fit evaluated by absolute marginal discrepancy was smaller at 45° and 60° than other build orientations. 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.

Conclusions and Clinical Implications: The fit of the 3D printed resin prosthesis was clinically acceptable, and comparable to that of the milled prosthesis, so the 3D printing manufacturing using resin materials provides adequate the fit for the use in implant dentistry.

Keywords: 3D printing, implant, milling, fit, resin