# Peri-implant soft tissue health and denture base adaptation of CAD/CAM milled versus 3D-printed implant-assisted mandibular overdentures: one-year randomized clinical trial

## TL;DR

This study compared the performance of CAD/CAM milled and 3D-printed implant-assisted mandibular overdentures over one year, focusing on denture fit and soft tissue health.

## Contribution

The study provides a direct comparison of denture base adaptation and soft tissue health between CAD/CAM milled and 3D-printed overdentures in a clinical setting.

## Key findings

- CAD/CAM milled overdentures showed significantly better denture base adaptation than 3D-printed ones.
- Both groups maintained similar and stable levels of peri-implant soft tissue health over the one-year period.
- Clinical parameters like plaque and gingival health increased over time but were not significantly different between the two groups.

## Abstract

This study aimed to compare denture base adaptation and peri-implant soft tissue health between CAD/CAM milled and 3D-printed mandibular implant-assisted overdentures. Twenty-four completely edentulous patients were enrolled and randomly allocated to two groups. After two dropouts, twenty-two patients completed the trial (11 per group). All patients received two implants in the mandibular canine region with ball attachments. The intervention group received a CAD/CAM milled mandibular overdenture, while the control group received a 3D-printed mandibular overdenture; both groups received a conventional maxillary complete denture. Peri-implant soft tissue health was assessed using clinical parameters, including Gingival Index (GI), Plaque Index (PI), Bleeding Index (BI), and Probing depth (PD) at insertion (T0), six months (T6), and one year (T12) after denture insertion. The adaptation of the denture base for both groups was assessed by digital surface matching software (Geomagic). Regarding peri-implant soft tissue health, clinical parameters increased significantly with time for both groups, and there was no significant difference in all parameters between the two groups at all observational times. The whole surface adaptation between the two groups was significantly different, with Group I showing significantly higher adaptation than Group II. Within the limitations of this study, CAD/CAM milled implant-assisted mandibular overdentures demonstrated superior denture base adaptation compared to their 3D-printed counterparts. This finding underscores the precision achievable with subtractive manufacturing for definitive prostheses. Regarding the peri-implant tissues, both groups maintained comparable and stable levels of plaque control and gingival health throughout the observation period.

Clinical Trial Registration Number: No. NCT06166446.