Marginal Toughness and Wear Resistance Test Methods for Composite Resins

Abstract

The purpose of this study was to investigate the properties of a new device for testing the marginal toughness and wear resistance of dental restorative materials.
The ODU wear test apparatus combined with the new device was used for these experiments. The following experiments were undertaken.
1. An amalgam (Spherical-D : AM), a chemical cure composite resin (Clearfil Posterior : CP) and a glass ionomer cement (Base Cement : BC) were tested to determine the range for this apparatus.
2. Four light cure composite resins such as PhotoClearfil A (PA), PhotoClearfil Bright (PB), Clearfil PhotoPosterior (PP), and Clearfil Composite Inlay (IN) were tested to evaluate the effect of heat treatment on marginal toughness and wear resistance.
3. Two types of wear, at the margin and at the bottom of the sample, were evaluated.
The following results were obtained.
1. The marginal toughness and wear resistance test showed that AM was the strongest, followed by CP and BC.
2. Wider marginal fracture and deeper wear obtained, as the number of loading cycles were increased.
3. AM and CP showed higher marginal toughness as the marginal angle increased. However, BC did not show any correlation between marginal toughness and the marginal angle.
4. AM, CP and BC showed higher wear resistance as the marginal angle increased.
5. Heat treatment significantly improved the marginal toughness of PA, PP and IN. Although the wear resistance of these resins was not improved, the wear resistance of PB was improved significantly. However, its marginal toughness was not improved.
6. PB had the largest difference in the depth of the two types wear, being significantly different from PA, PP and IN.
From these results, it was concluded that this apparatus was capable of evaluating the marginal toughness and wear resistance of restorative materials with physical properties ranging from those of amalgam to glass ionomer cement.