Trueness of Maxillomandibular Relationship in 3D-printed and Conventional Casts

Objectives

To compare the trueness of maxillomandibular relationship between articulated 3D-printed and conventional diagnostic casts in maximum intercuspation (MIP).

Methods

Reference casts were articulated in MIP, and scanned using a Coordinate Measurement Machine (CMM, n=1). Digital scans were made from the reference casts by using an intraoral scanner (IOS, n=10) (Trios 4; 3Shape A/S). IOS scans were processed to create 3D-printed casts by using MAX UV385 (Asiga) and NextDent 5100 (3DSystems) 3D-printers. The conventional workflow implemented vinylpolysiloxane (VPS) impressions and Type IV stone. Stone and 3D-printed casts were articulated and digitized with a laboratory scanner (E4; 3Shape A/S). The 3D-printed casts were scanned on two occasions: with and without positioning pins. Inter-arch distances and 3D-contact area were measured and compared. Statistical tests used were Shapiro-Wilk, Levene's, Welch's t-test, and 2-way ANOVA (α=.05).

Results

IOS group showed similar or better maxillomandibular relationship trueness than stone casts and 3D-printed casts (p<0.05). 3D-contact area analysis showed similar deviations between 3D-printed and stone casts (p>0.05). The choice of 3D-printer and presence of positioning pins on the casts significantly influenced maxillomandibular relationship trueness (p<0.05).

Conclusions

Articulated 3D-printed and stone casts exhibited similar maxillomandibular relationship trueness.

Clinical Significance

Although 3D-printing methods can introduce a considerable amount of deviations, the maxillomandibular relationship trueness of articulated 3D-printed and stone casts in MIP can be considered similar.