Comparison of Shear Bond Strength of Compoglass and Glass Ionomer to the Dentin of Primary Molars

Statement of Problem: 

There is limited information available regarding the adhesive ability of resin- modified glass ionomers and polyacid resin modified composites to primary dentin.

The aim of this study was to compare the shear bond strength of compoglass with and without phosphoric acid %37 with a resin- modified glass ionomer (Fuji II LC) to primary molars' dentin.

In this experimental study, 30 human extracted primary molars were used in this experimental study. The teeth were mounted in stone. After preparation, the specimens were randomly divided into three equal groups (n=10). In group I, the specimens were bonded with compoglass following the manufacture's instructions. In group II, after the specimens were etched with phosphoric acid %37, they were bonded with compoglass. In group III, the specimens were bonded with glass ionomer (Fuji II LC). Shear bond strength was measured for the bonded specimens using an Instron at a crosshead speed of 1mm/ minute. The results were analyzed using ANOVA and Tamhane test.

The mean value of shear bond strength of compoglass with and without acid was 14.19±2.47, and 10.20±2.58 Mpa, respectively. The mean value of shear bond strength of Fuji II LC was 6.11±1.12 Mpa. There were significant differences between compoglass with and without phosphoric acid and glass ionomer Fuji II LC (p= 0.001).

The findings showed that compoglass tested in this study had higher shear bond strength than glass ionomer (Fuji II LC). Also, the use of acid phosphoric before bonding in compoglass improved the shear bond strength.