Fabrícia Araújo Pereira1, Livia Fávaro Zeola1, Giovana de Almeida Milito1, Bruno Rodrigues Reis1, Rodrigo Dantas Pereira2, Paulo Vinícius Soares3. 1. Operative Dentistry and Dental Materials Department, Federal University of Uberlandia, Rua Republica do Piratini S/N Bloco 4LA Sala 37 Campus Umuarama, Uberlândia, Minas Gerais, 38405-325, Brazil. 2. Department of Dentistry, United Universities of the North of Minas, Avenida Osmane Barbosa, 11111, Montes Claros, Minas Gerais, 39404-549, Brazil. 3. Operative Dentistry and Dental Materials Department, School of Dentistry, Federal University of Uberlandia, Rua Republica do Piratini S/N Bloco 4LA Sala 37 Campus Umuarama, Uberlândia, Minas Gerais, 38405-325, Brazil. paulovsoares@yahoo.com.br.
Abstract
OBJECTIVES: To evaluate the influence of restorative materials used on the rehabilitation of MOD cavities and loading type, on biomechanical behavior of wedge-shaped (WS) lesions in endodontically treated maxillary premolars. The investigation was conducted by 3D finite element analysis (FEA) and strain gauge test. MATERIALS AND METHODS: Six models were generated, with MOD cavities and endodontic treatment: A (MOD amalgam restoration), R (MOD composite restoration), AL (A + cervical lesion (L)), RL, ALR (A + cervical lesion restored with composite (LR)), and RLR. Each model underwent two compressive loading (100N): axial and oblique-45° angle to the long axis on the buccal cusp. The models were analyzed by von Mises criteria. For strain gauge test, 14 standardized maxillary premolars were treated according to the groups described for FEA. Two strain gauges were bonded on each sample submitted to compressive loading in a mechanical testing machine. RESULTS: A presented higher stress concentration and strain values than R. Oblique loading promoted highest stress concentration and strain rates for all groups. ALR and RLR presented similar stress-strain distribution pattern when compared to A and R. CONCLUSION: The interaction between MOD cavity restored with amalgam and oblique loading propitiated the highest stress concentration and strain values on cervical region and WS lesion. CLINICAL RELEVANCE: The MOD cavity restored with composite resin is a better option than amalgam to improve the biomechanical behavior of wedge-shaped lesion, avoiding dental failure. In addition, the occlusal interferences must be removed, allowing homogeneous contact distribution and preventing WS lesion progression.
OBJECTIVES: To evaluate the influence of restorative materials used on the rehabilitation of MOD cavities and loading type, on biomechanical behavior of wedge-shaped (WS) lesions in endodontically treated maxillary premolars. The investigation was conducted by 3D finite element analysis (FEA) and strain gauge test. MATERIALS AND METHODS: Six models were generated, with MOD cavities and endodontic treatment: A (MOD amalgam restoration), R (MOD composite restoration), AL (A + cervical lesion (L)), RL, ALR (A + cervical lesion restored with composite (LR)), and RLR. Each model underwent two compressive loading (100N): axial and oblique-45° angle to the long axis on the buccal cusp. The models were analyzed by von Mises criteria. For strain gauge test, 14 standardized maxillary premolars were treated according to the groups described for FEA. Two strain gauges were bonded on each sample submitted to compressive loading in a mechanical testing machine. RESULTS: A presented higher stress concentration and strain values than R. Oblique loading promoted highest stress concentration and strain rates for all groups. ALR and RLR presented similar stress-strain distribution pattern when compared to A and R. CONCLUSION: The interaction between MOD cavity restored with amalgam and oblique loading propitiated the highest stress concentration and strain values on cervical region and WS lesion. CLINICAL RELEVANCE: The MOD cavity restored with composite resin is a better option than amalgam to improve the biomechanical behavior of wedge-shaped lesion, avoiding dental failure. In addition, the occlusal interferences must be removed, allowing homogeneous contact distribution and preventing WS lesion progression.