The influence of resin flexural modulus on the magnitude of ceramic strengthening

INTRODUCTION The aim was to determine the magnitude of ceramic resin-strengthening with resin-based materials with varying flexural moduli using a regression technique to assess the theoretical strengthening at a 'zero' resin-coating thickness. The hypothesis tested was that experimentally, increasing resin flexural modulus results in increased resin-strengthening observed at a theoretical 'zero' resin-coating thickness. METHOD Vitadur Alpha dentin porcelain disk (n=250) were condensed, fired, alumina particle air abraded and randomly assigned into ten groups. Groups were resin-coated at 50, 100 and 150μm with Venus Flow, Rely-X Veneer and Clearfil AP-X before biaxial flexure testing at 24h and the stress at failure calculated using a multilayer analysis. An analytical methodological approach was undertaken to predict the biaxial flexure stresses under boundary conditions that reflected the experimental test and a finite element model was used to verify the analytical prediction. RESULTS The magnitude of resin-reinforcement was significantly influenced by resin-coating type (P