Fully digital versus conventional workflow: Are removable complete overdentures equally good? A randomized crossover trial.

Introduction: Implant-supported removable complete overdentures (IODs) are a common treatment in case of edentulism and malfunctioning of the conventional denture. Manufacturing IODs in a conventional way (C-IODs) is time-consuming, but in a digital workflow, this can be done in three sessions. Digitally produced IODs (3D-IODs) are also more advantageous than C-IODs because lost or broken 3D-IODs can be swiftly reproduced as the digital design is always available.

Purpose: To prove in a non-inferiority study, with a margin of 0.3 point per Oral Health Impact Profile-20 (OHIP-20) question, that IODs made according to a fully digital workflow (3D-IODs), function as good as C-IODs with respect to patient-reported outcome measures (PROMs).

Materials and methods: This randomized crossover study included 36 fully edentulous patients who showed extreme resorption of the maxillary alveolar process, making denture retention difficult. After a maxillary bone augmentation and the installation of 4-6 implants, each patient wore both types of IOD for 1 year each, with the order reversed in two subsets of patients. The 3D-IODs and C-IODs were fabricated in advance for both jaws (at least two mandibular implants were already present). The OHIP-20 survey was performed at baseline, after 1 year (before the IOD switch), and after 2 years to determine patient satisfaction scores using a visual analog scale (VAS). The general health status was assessed using the Short Form (SF-36) questionnaire.

Results: Regarding the PROMs, patients preferred the 3D-IOD: the improvement on the overall OHIP scale (0-4), expressed as a mean, was 0.26 points greater than for the C-IOD (p < 0.001). This applied also to the VAS scale (1-100) with an increase of 7.37 points (p < 0.001). Regarding the SF-36 scale, only for the item "emotional well-being," the 3D-IOD scored significantly better (p = 0.033).

Conclusion: Compared with conventionally fabricated C-IODs, fully digitally produced 3D-IODs resulted in significantly higher OHIP-20 and satisfaction scores.