Abstract

This study describes regional variations of the organic contents of human dentin after acid- etching with two specific dentin conditioners, phosphoric acid, and a 10% citric acid/3% ferric chloride solution. The relationship between the resinous components of two third-generation dentin bonding systems and the dentin substrate is also described. The clinical success of these dentin bonding systems is dependent upon their physical and chemical interaction with dentin tissue. This investigation suggests two kinds of bonding mechanisms, either by mechanical interlocking of the methacrylates with microporosities created on dentin surfaces by specific etching agents or by chemical reaction with the organic and inorganic components of dentin. In addition, backscattered electrón imaging was performed to evalúate the relationship of the dentin organic components with the methacrylates included in the composition of the dentin bonding systems