Meredith, Neil; (1992) An in-vitro analysis of the stresses in natural and restored human teeth. Doctoral thesis (Ph.D), UCL (University College London).

Preview

Text An_in-vitro_analysis_of_the_st.pdf Download (11MB) | Preview

Abstract

The distribution of stresses on intact, prepared and restored teeth during restoration and subsequent loading has been investigated in-vitro using a number of techniques. A review of the relevant literature covering experimental and numerical stress analysis techniques and their applications is given together with an assessment of the physical and mechanical properties of teeth and aesthetic dental restorative materials. In-vivo measurements of occlusal loads and in-vitro loading techniques to determine the fracture resistance of prepared and restored teeth are also discussed. A Knoop indentation technique was used to determine values for the micro-hardness and Young's modulus of human enamel and dentine. Results obtained were in good agreement with those published in the literature. Young's modulus and Poisson's ratio were established for a range of composite and polyalkenoate materials in four point bending and uniaxial tension, tested at a range of cross-head speeds and temperatures (0.05,0.1,0.2 mm/min at 23°C and 35°C). Full-field stress pattern analysis of intact, prepared and restored teeth under dynamic loading by measurement of thermoelastic emission revealed a significant difference in the distribution of stresses between specimen types. Regions of high stress were identified as potential sites for more detailed analysis using strain gauges. Rosette gauges mounted on teeth in-vitro were subjected to a range of restorative procedures and loaded (10-200N) at different rates (0.01-0.1 KNs'*) and positions. Strains measured during the restorative and loading procedures were used to calculate the magnitude and direction of the principal strains. Cavity preparation resulted in an increase in strains which was not reduced by placement of an amalgam or bonded composite restoration. Finite element models of the experimental specimens were used to investigate the stress distribution at the tooth-restoration interface, the effects of applied loads and the properties of restorative materials.

Download activity - last month

Export as JSONXMLCSV

Download activity - last 12 months

Export as JSONXMLCSV

Downloads by country - last 12 months

Export as JSONXMLCSV

Archive Staff Only

View Item