Clinical Outcomes of 3D Printed Bridges in Patients With and Without Bruxism

OBJECTIVE: To evaluate the clinical performance of 3D-printed resin composite three-unit fixed dental prostheses (FDPs) in posterior regions in patients with and without bruxism over approximately 28 months. METHODS: Forty patients requiring replacement of a single missing posterior tooth were enrolled in this prospective clinical study conducted between April 2022 and January 2025 at the University of Siena, Siena, Italy. Patients were allocated to either a bruxism group (n = 20) or a non-bruxism group (n = 20), based on clinical signs and patient self-report using the STAB questionnaire. All abutments were prepared according to standardized guidelines and digitally scanned; FDPs were designed with CAD software and fabricated via DLP 3D-printing using a biocompatible resin composite. Prostheses were cemented with a self-adhesive resin cement. Clinical performance was assessed at baseline and scheduled recalls using modified USPHS criteria. Statistical analysis included t-tests or Mann-Whitney U tests for continuous data and Fisher's exact test for categorical variables (α = 0.05). RESULTS: After a mean follow-up of 28 months, most restorations in both groups were rated Alpha. One clinically unacceptable fracture occurred in the bruxism group, while no failures were recorded in the non-bruxism group. Restoration wear was significantly more frequent among bruxists (40%) compared with non-bruxists (10%) (p = 0.02). No significant between-group differences were observed for other USPHS parameters, and no biological complications occurred. CONCLUSIONS: 3D-printed resin composite FDPs showed favorable short-term clinical performance in both bruxist and non-bruxist patients, though bruxism was associated with increased wear. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01935796.