Work

Three-dimensionally printed, noninvasive restorations in the treatment of localized tooth wear using the Dahl approach: A preliminary clinical trial

Year: 2026

Type: article

Abstract: STATEMENT OF PROBLEM: Localized tooth wear compromises function and esthetics, while conventional restorative options often require invasive preparation. Evidence on the long-term stability of 3-dimensionally (3D) printed restorations applying the Dahl concept is limited. PURPOSE: The purpose of this preliminary clinical trial was to evaluate the clinical feasibility and long-term stability of 3D printed, noninvasive restorations implementing the Dahl concept for managing localized tooth wear while preserving tooth structure and restoring vertical dimension of occlusion. MATERIAL AND METHODS: Five patients with localized tooth wear received 3D printed computer-aided design and computer-aided manufacturing (CAD-CAM) restorations fabricated using digital workflows. Intraoral scans were performed at baseline and follow-up visits at 6, 12, and 24 months after insertion. Quantitative movement was analyzed using 3D superimposition techniques to assess posterior tooth extrusion and anterior tooth intrusion. The Wilcoxon rank sum test and independent t test were used for statistical analysis (α=.05). RESULTS: Posterior tooth extrusion demonstrated a characteristic time-dependent pattern with progressive stabilization from 0.37 ±0.25 mm at 6 months to 0.31 ±0.23 mm at 24 months. Movement variability decreased substantially over time, indicating predictable treatment outcomes. Anterior tooth intrusion remained clinically absent throughout the observation period (median ≤0.07 mm), confirming the preservation of vertical positioning. The 3D superimposition analysis corroborated quantitative measurements, revealing controlled bilateral posterior movements while maintaining anterior stability. CONCLUSIONS: The provision of 3D printed, noninvasive restorations successfully implemented the Dahl concept, achieving predictable vertical dimension restoration with progressive occlusal stabilization over 24 months while preserving dental hard tissues.

Source: Journal of Prosthetic Dentistry

DOI: 10.1016/j.prosdent.2025.12.020