Comparison of the Shear Bond Strength of Resin-Modified Glass Ionomer to Dentin of Primary Teeth after Different Dentin-Conditioning Methods

The present study aimed to compare the shear bond strength (SBS) of the resin-modified glass ionomer (RMGI) to primary dentin using different dentin conditioners.

The dentin surfaces of 80 primary molars were conditioned using four different methods etching with 37% phosphoric acid, 10% polyacrylic acid, 5% NaOCl, and no surface treatment. Dentin surfaces were restored with RMGI Fuji Π LC cylinders. After 24 h, the shear bond strength tests were performed using Universal Testing Machine. Statistical analysis was performed using One-Way ANOVA followed by Tamhane Post hoc Test. A p-value less than 0.05 was considered statistically significant.

Phosphoric acid produced the highest shear bond strengths, compared to all tested groups, which showed statistically significant differences with groups 3 and 4 (P=0.043, P<0.001). Subsequently, Polyacrylic acid showed a significantly higher SBS than group 4 (P=0.046). Conditioning with NaOCl significantly increased the bonding strength of RMGI compared to the untreated group (P=0.001). Untreated dentin had the lowest SBS compared to other tested groups.

The conditioning step effectively improved the SBS of RMGI to primary dentin. Dentin conditioning with 37% Phosphoric acid for 5 sec showed the highest shear bond strength of RMGI.