Mechanical interactions of cuspal-coverage designs and cement thickness in a cusp-replacing ceramic premolar restoration: a finite element study
The aim of this study was to investigate the biomechanical interactions between cuspal preparation designs and cement thickness in a cusp-replacing ceramic premolar restoration. The cavity was designed in a typical MODP (mesial-occlusal-distal- palatal) restoration failure shape when the palatal cusp has been lost. Twelve 3D finite element (FE) models with four cavity preparations (without coverage and with buccal cuspal coverage in 1.0, 1.5 and 2.0mm reducing in cuspal height) and three cement thicknesses (50, 100 and 150?m) were constructed to perform the simulations. The results indicated that enamel and cement stresses in designs with no buccal cusp replacement or a 1.0mm thick buccal cusp replacement were higher than the designs with 1.5 and 2.0mm thick replacement. No apparent differences were found in the dentin, enamel, and cement stresses based on cement thicknesses of 50, 100, or 150?m. This study concluded that when cusp replacement is indicated, reduction of the buccal cusp by 1.5mm at least could reduce stress.
cuspal-coverage cement thickness ceramic biomechanics finite element analysis