Polylactic Acid as a Material for Three-Dimensional Printing of Provisional Restorations

Can polylactic acid be a CAD/CAM material for provisional crown restorations in terms of fit and fracture strength?

“…These differences could be attributed to different types of blocks, thermocycling, types of scanners, technical features of milling machines than those used in this study. Since there is only one study that evaluated PLA as a provisional crown material and investigated the marginal fit of these restorations, the direct comparison of this recent study with the present study showed inconsistency with the findings of Molinero-Mourelle et al, who reported 122.89±26.04 µm average marginal gap value 22) . This controversy can be due to the production method of the provisional crowns as the authors benefit from 3D printing for the production, however, PLA provisional crowns of the present study were produced by CAD/CAM subtractive technology which was demonstrated to be a superior technique in the providence of provisional crowns.…”

“…In the present study, the smallest average marginal gaps were observed in the group PE (56.00±4.67 µm). However, the marginal gap values of the groups PM (61.15±4.44 µm) and PL (60.40±2.85 µm) were not far from the group PE and did not exceed the clinically acceptable marginal gap value 120 µm 22) . In a previous study that preferred to use PEEK as a coping material, the marginal gap value was 187.52±94.65 µm, which is almost three times more than the current study value 28) .…”

“…Group PL: Polylactic acid, PLA filament (L-PLA natural, ϕ=1.75 mm; ABG, Ankara, Turkey) Group PM: Polymethyl methacrylate (PMMA) disc (Ceramill A-Temp; Amann Girrbach, Koblach, Austria) Group PE: Polyetheretherketone (PEEK) disc (Ceramill PEEK; Amann Girrbach) The sample size for study groups tested (n=20 per group) was determined based on an initial power analysis (PS software; Dupont and Plummer, 1997) conducted according to similar previous studies (mean gamma count with 80% power and 5% significance level) 9,22) . A total of 60 samples were tested by performing all measurements 3 times and the results were recorded as mean and standard deviation.…”

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

“…A previous study of 3D provisional crowns made using the same methodology reported a mean marginal fit value of 122.89 µm in the marginal-fit discrepancy of the restorations made with polylactic acid (PLA) using a fused-deposition-modeling (FDM) 3D system. 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].…”

Recent Progress on 3D‐Printed Polylactic Acid and Its Applications in Bone Repair

“…Considering the relatively low glass transition temperature (55–60 °C) of pure PLA, low toughness and weak heat resistance, this limits its applications. For use in orthopedics, PLA needs to be compounded with other materials to produce materials with improved mechanical properties, or higher biocompatibility.…”