title: Stress amplifications in dental non-carious cervical lesions.
abstract: This study aims to investigate the influence of the presence, shape and depth of NCCLs on the mechanical response of a maxillary second premolar subjected to functional and non-functional occlusal loadings using 3-D finite element (FE) analysis. A three-dimensional model of a maxillary second premolar and its supporting bone was constructed based on the contours of their cross-sections. From the sound model, cervical defects having either V- or U-shapes, as found clinically, were subtracted in three different depths. The models were loaded with 105 N to simulate normal chewing forces according to a functional occlusal loading (F1) vertically applied and two non-functional loadings (F2 and F3) obliquely oriented. Two alveolar bone crest heights were tested. Ansys™ FE software was used to compute stress distributions and maximum principal stress for each of the models. The presence of a lesion had no effect on the overall stress distribution of the system, but affected local stress concentrations. Non-functional loadings exhibited tensile stresses concentrating at the cervical areas and root surfaces, while the functional loading resulted in homogeneous stress distributions within the tooth. V-shaped lesions showed higher stress levels concentrated at the zenith of the lesion, whereas in U-shaped defect stresses concentrated over a wider area. As the lesions advanced in depth, the stress was amplified at their deepest part. A trend of stress amplification was observed with decreasing bone height. These results suggest a non-linear lesion progression with time, with the progression rate increasing with patient's age (deeper lesions and lower bone support).
authors: Department of Prosthodontics, School of Dentistry, Federal University of Espírito Santo, Vitória, Brazil.
authors: Jackeline Coutinho
authors: JC
authors: Guimarães
authors: Department of Prosthodontics, School of Dentistry, Federal University of Espírito Santo, Vitória, Brazil.
authors: Gabriela
authors: G
authors: Guimarães Soella
authors: Department of Operative Dentistry, School of Dentistry, Federal University of Santa Maria, Santa Maria, Brazil.
authors: Letícia
authors: L
authors: Brandão Durand
authors: Biomechanics Engineering Laboratory, Federal University of Santa Catarina, Florianópolis, Brazil.
authors: Françoà
authors: F
authors: Horn
authors: Department of Operative Dentistry, School of Dentistry, Federal University of Santa Catarina, Brazil.
authors: Luiz
authors: L
authors: Narciso Baratieri
authors: Department of Operative Dentistry, School of Dentistry, Federal University of Santa Catarina, Brazil.
authors: Sylvio
authors: S
authors: Monteiro
authors: Laboratory for Biomaterials Research, Dental Clinic 1, Operative Dentistry and Periodontology, Friederich-Alexander University of Erlangen-Nuremberg, Glueckstraße 11, 91054 Erlangen, Germany. Electronic address: rbelli@dent.uni-erlangen.de.
authors: Renan
authors: R
authors: Belli
mesh_terms: D001641:Bicuspid / Q000473:pathology* / Q000503:physiopathology*; D003198:Computer Simulation; D003430:Cross-Sectional Studies; D003799:Dental Stress Analysis; D020342:Finite Element Analysis; D006801:Humans; D008137:Longitudinal Studies; D008437:Maxilla / Q000502:physiology; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D019237:Tooth Cervix / Q000473:pathology* / Q000503:physiopathology*; D014092:Tooth Root / Q000502:physiology
keywords: Finite element analysis; Non-carious cervical lesions; Tooth deflection; U-shaped lesions; V-shaped lesions