Accuracy of trial complete dentures fabricated by using fused deposition modeling 3-dimensional printing: An in vitro study

Statement of problem: Three-dimensional (3D) printing technologies commonly used for trial complete dentures use photopolymerizing resins. Although effective, some clinical, process-related, and practical issues associated with them are still unclear. The option of using alternative printing technologies may help in overcoming limitations. Purpose: The purpose of this in vitro study was to evaluate the trueness of trial dentures fabricated by using 3D-printing fused deposition modeling (FDM). Material and methods: Ten maxillary and 10 mandibular digital complete trial dentures designed from intraoral scans were fabricated from polylactic acid by using a FDM 3D-printer. Each denture was scanned, and the scans were compared with the digital file of the designed denture by means of a surface-matching software program. The mean distance (both signed and absolute) was measured and recorded for the intaglio surface, as well as for the entire denture surface. Statistical analysis was performed to investigate the significance of the extent of measured distances, as well as differences between intaglio and global deviations; subgroup analysis for arch type was also performed (α=.05). Results: Mean values of the intaglio distance were not significantly different from zero (P=.223). The manufacturing accuracy of the intaglio surface was higher than that measured for the entire denture (P<.001), confirmed both by the averaged signed (0 mm and -0.028 mm, respectively) and the absolute mean deviations (0.06 mm and 0.08 mm, respectively). No significant differences were found between maxillary and mandibular trial dentures. Conclusions: 3D-printing may constitute a valid and practical option for accurate and affordable digital trial dentures.