| 4088 Deformation of dental hard tissues: An insight into non-carious-cervical-lesions | ||
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A. KISHEN1, K. TAN1, and A. ASUNDI2, 1National University of Singapore, Singapore, 2Nanyang Technological University, Singapore, Singapore The loss of dental hard tissues in the cervical region has been described as a complex, multifactorial phenomenon involving erosion, abrasion, tooth flexure, and their possible interactions. Objectives: The aim of this study was to investigate the spatial gradients in the in-plane deformation of the enamel and the dentine, and their possible role in the etiogenesis of non-carious-cervical-lesions. Methods: A digital moiré interferometer was used for this purpose. The interferometer consisted of two mutually coherent light beams from a diode laser (670nm), which were incident on the specimen-grating and generated a virtual-reference-grating. The digitized fringes obtained from the interferometer were used to determine the normal and shear strain gradients in the plane perpendicular to the long axis (lateral direction) and along the long axis (axial direction) of maxillary central incisors. Results: It was observed that the enamel experienced marked strains in the lateral direction, while the coronal dentine experienced marked strains in the axial direction. These strains displayed both normal and shear components. In the enamel, the cervical region experienced significantly higher strains in the lateral direction when compared to the incisal region (P<0.01), and there was no significant increase in strains in the axial direction with larger loads (P>0.6). In the coronal dentine, the cervical region on the facial side experienced significantly higher shear stain than the lingual side (P<0.01). With increase in applied loads, the shear strain in the enamel (lateral direction) and the coronal dentine (axial direction) concentrated at the cemento-enamel-junction of facial side. Conclusions: This study highlights a unique deformation pattern in the enamel and the dentine. The lateral deformation within the enamel and the axial deformation within the coronal dentine concentrated at the cemento-enamel-junction. This study supports the hypothesis that occlusal loading would contribute to the loss of dental hard tissues in the cervical region. | ||
| Seq #420 - Post/Core Studies, Preparations, Impression Materials, Biomechanics 12:30 PM-2:30 PM, Saturday, 13 March 2004 Hawaii Convention Center 321-B | ||
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