Multi-factorial analysis of a cusp-replacing adhesive premolar restoration: A finite element study

Abstract 

Objectives

This study investigates the biomechanical interactions among restorative materials, cuspal preparation designs, and cement thickness in a cusp-replacing adhesive premolar restoration.

Methods

Twenty-seven, 3D finite element (FE) models designed in a typical MODL restoration with three restorative materials (CAD/CAM ceramic block, indirect resin composite and glass-ceramic), three cavity preparation designs (buccal cuspal reduction of 1.0mm, 1.5mm and 2.0mm in cuspal height) and three cement thicknesses (50μm, 100μm and 150μm) were constructed to perform the simulations. The ANOVA test was performed to determine the relative importance of the investigated factors and main effects for each of the three investigated factor levels (restorative material, preparation design and cement thickness) in terms of the principal stress values.

Results

The results indicated that the stress value in the restorative material was influenced primarily by the restorative material itself (95.49%). Preparation design was found as the major factor (>80%) affecting the stress values in the remaining tooth and luting cement.

Conclusions

Using a low modulus restorative material presented more favorable biomechanical performance and the cuspal height might be at least 1.5mm to critically reduce the stress values when cuspal-coverage treatment is considered. The investigated cement thickness only slightly affected the mechanical behavior of the cuspal replacement restoration.

Keywords: Cuspal-coverage, Cement thickness, Restorative material, Preparation design, Finite element analysis, Biomechanics