The influence of various conditioner agents on the interdiffusion zone and microleakage of a glass lonomer cement with a high viscosity in primary teeth.

The smear layer, which occurs during cavity preparation procedures, does not constitute a stable substructure in the bond of restorative material to dental hard tissues. Depending on the dissolution of this material in the course of time, microleakage occurs between the tooth and restorative material. This study evaluated the effects of different conditioner agents (Fuji Cavity Conditioner, 10% maleic acid, 35% phosphoric acid and 3% hydrogen peroxide) on Fuji IX microleakage, Fuji IX-enamel and Fuji IX-dentin combination in Class I cavities prepared to standards having the dimensions of 4x3x2 mm3 in extracted primary molars. The restorations were then subjected to thermocycling procedures and soaked in the 0.5% basic-fuchsin dye for 24 hours. Some sections were taken, parallel to the long axis of the tooth in a mesio-distal direction, and evaluated under a stereo-microscope for leakage. Also, two samples of Fuji IX-enamel and dentin combinations were chosen randomly from each group for evaluation in scanning electron microscopy (SEM). The distribution of microleakage occurred as follows: Control Group > Hydrogen Peroxide > 10% Maleic acid > Fuji Cavity Conditioner = Phosphoric acid. The difference between microleakage scores obtained from the groups was statistically significant (p<0.05). The SEM evaluation revealed a close interface connection in all groups except for the control and hydrogen peroxide groups in the Fuji IX-enamel combination. In the Fuji IX-dentin combination, however, a close interface connection was observed except in the control group. In conclusion, the application of conditioner agents to Class I cavities restored with glass ionomer cement with a high viscosity in vitro either diminishes or completely eliminates microleakage.