Bonding mechanism of Compoglass to dentin in primary teeth

This study evaluated the bonding mechanism of Compoglass compomer to dentin in primary teeth. Buccal or labial dentinal surfaces of 20 human extracted, non carious primary teeth stored in 4 degrees C physiological saline solution were obtained by grinding on silicon carbide paper (final grit 600). The specimens were divided into two groups of 10 teeth each: (1) unetched dentin, Compoglass SCA, Compoglass; and (2) dentin etched with 10% phosphoric acid (Etch-AII), Compoglass SCA, Compoglass. The Compoglass SCA and Compoglass compomer were placed according to the instructions of the manufacturer, except Group 2 were the dentin was first etched with 10% phosphoric acid for 30 seconds. Twenty-four hours after placing the compomer over the treated dentinal surface, the specimens were dehydrated with a series of alcohol and freon. Then critically point dried. The specimens were split with a chisel and the compomer/dentin interface evaluation was performed with the SEM. The results showed that when the instructions of the manufacturer were followed (Group 1) the compomer showed a very close relation to the dentin with some tag structures penetrating the dentin. When phosphoric acid etching preceded the compomer placement a hybrid layer with tags penetrating the dentin was noted in most specimens.