Stress distribution in the closure of anterior maxillary diastemas using different restorative approaches: a finite element analysis.

Abstract

Objective: This finite element analysis study aims to evaluate the effects of restoring 1 mm and 2 mm diastemas in maxillary anterior incisors with different CAD-CAM materials on stress distribution and to compare full crown and laminate veneer restorations.

Materials and methods: Maxillary anterior tooth models simulating laminate veneer and full crown restorations were created. The experimental groups were categorized into four based on diastema width (1 mm and 2 mm) and CAD-CAM materials. Loads of 50 N, 150 N, and 250 N were applied vertically at 0° and obliquely at 30° and 60° angles to the central incisor's incisal midpoint. Von Mises stress values were analyzed numerically and visually with color-coded comparisons for all models.

Results: When laminate veneer restorations were used to close diastemas, the highest stress values under a 250 N vertical load and 2 mm diastema were observed in the lateral incisor. IPS E.max exhibited a stress value of 166.88 MPa for the superstructure, while Lava Ultimate recorded 35.49 MPa in the lateral incisor. Within the dentin, the highest stress was 45.92 MPa for IPS E.max and 65.74 MPa for Lava Ultimate in the lateral incisor. When full crown restorations were employed, the highest stress values under a 250 N vertical load were again recorded in the lateral incisor. IPS E.max showed a stress value of 198.03 MPa for the superstructure, while Lava Ultimate demonstrated 40.80 MPa. The highest stress values within the dentin were 65.20 MPa for IPS E.max and 65.74 MPa for Lava Ultimate in the lateral incisor.

Conclusions: This finite element analysis highlights that the type of restoration and diastema width significantly affect stress distribution in anterior teeth. IPS E.max material exhibited higher stress values, leading to more significant stress accumulation than other materials in laminate veneer and full crown restorations. Additionally, Lava Ultimate showed the highest stress values within the dentin. These findings underscore the importance of selecting appropriate CAD-CAM materials and restoration types to optimize stress distribution in diastema closures, providing critical insights for restoration planning.