Marginal fit evaluation of implant supported interim fixed partial dentures fabricated using two manufacturing techniques: An in vitro study

Aim: This study compared the marginal fit of implant-supported interim fixed partial dentures manufactured using two manufacturing techniques. Materials and Methods: 3D printed model was constructed with two implants analogues replacing upper first premolar and first molar. Scan abutments, corresponding to CAD/CAM titanium bases, were screwed into implant analogues. The model was then scanned using Primescan AC intraoral scanner and scan file was imported into CAD software as STL file to finalize the design for fabrication of interim implant-supported fixed partial dentures. The CAD file of the designed interim IFPDs was sent to subtractive and additive manufacturing machines to fabricate 24 interim IFPDs, 12 per group. Interim IFPDs were then seated onto ti-bases and marginal gap was evaluated using stereomicroscope. Independent t-tests were performed to analyze data. Results: Regarding marginal gap, subtractively manufactured interim IFPDs showed statistically significant lower gap values than additively manufactured ones. Conclusion: The study exhibited a difference between the subtractively and additively manufactured interim IFPDs, showing that subtractively manufactured ones are of reliable marginal fit.