Evaluation the Shear Bond Strength of Two Glass Ionomer of Fuji II LC and Ketac N100 against Desensitized Dentin Using Laser and CPP-ACP Paste

Hypersensitivity is a short, sharp pain that can occur due to the response of the exposed dentin to touch and chemical stimuli. The best solution for hypersensitivity treatment is closing the dentin tubules by crystal deposition in tubule openings or melting the dentin hydroxyapatite. The present study aimed to investigate the effect of dentin desensitizers on the shear bond strength of dentin glass restorers.

In the present study, 60 healthy human premolar teeth were selected. The teeth surfaces were sheared 2 mm under the DEJ. The samples were divided into three groups of 20 each. Group 1: pure dentin, group 2: low-power laser diode with the intensity of 3.7 j/cm2, period of 5 min, and length of 0.66 µm on the dentin surface. Group 3: the CPP-ACP paste on occlusal dentin. Each group was divided into two subgroups of 10. The first subgroup was filled with Fuji II LC glass on the center of dentin's surface in plastic mold and the second with Ketac N100 nano-ionomer. Thereafter, the shear test of samples was performed and the shear bond strength was measured using ANOVA and Tukey tests.

In Fuji II LC groups, no significant difference was observed between the mean of shear bond strength in three groups of laser, control, and CP-CPP (P=0.086). However, in Ketac N100 group, the mean of shear bond strength of the laser-treated group was significantly higher than two subgroups of control and CPP-ACP (Plaser=0.035, Pcontrol=0.027).

Based on the findings of the present study, in CPP-ACP and Control groups, Fuji II LC glass ionomer had better results than Ketac N100. However, no significant difference was observed between the laser-treated groups using different glass ionomers.