Comparison of Retention Between Conventional and CAD/CAM Duplication Techniques: A Within-Subject Controlled Clinical...

To compare retention and occlusal force distribution between a conventional technique and two 3D-printed CAD/CAM duplication techniques for refitted maxillary complete dentures.

In total, 20 completely edentulous individuals with preexisting complete dentures participated in this within-subject controlled clinical trial. Dentures were duplicated using three methods: Group I (conventional duplication), Group II (3D printing to create a separate base made of pink polymethyl methacrylate [PMMA] and teeth made of tooth-colored PMMA dentures), and Group III (3D printing of a single-unit denture with a veneered base made of pink photocurable resin). Occlusal force distribution was measured for the reference denture before duplication. Retention and occlusal force distribution were measured at the time of denture delivery. One-way ANOVA was used for group comparisons, and Bonferroni's post hoc test was used for multiple comparisons.

The highest mean retention was observed in Group II (36.53 ± 3.75), followed by Group III (35.01 ± 3.41) and Group I (27.95 ± 4.32), with a statistically significant difference between Group I and the other two groups. For occlusal force distribution, the highest mean difference was recorded in Group I (14.35 ± 3.25), followed by Group II (7.60 ± 1.84) and Group III (3.82 ± 0.91), compared to the reference denture with a statistically significant difference (P = .001).

Within the study's limitations, 3D-printed dentures showed superior retention and more balanced occlusal force distribution compared to conventional dentures. These findings imply that 3D-printing technology may improve prosthodontists, ability to construct duplicate dentures.