Modifications of Dental Adhesive Systems

Adhesion is the procedure of forming an adhesive joint. The initial substrate is termed adherend and the material producing the interface is termed the adhesive [1]. The functions of dental adhesives is to promote conservation of tooth structure and enable minimally invasive dentistry, reinforcement of weakened dentin or enamel, reduce marginal staining, reduce microleakag and may also reduce postoperative sensitivity when used appropriately [1]. The adhesive system should be non-toxic, provide adequate bond strength, resist wear, water sorption, provide sufficient wetting capacity and color stability [2]. The ultimate goal of a bonded restoration is to attain an intimate adaptation of the restorative material with the dental substrate. This task is difficult to achieve as the bonding process for enamel is different from that for dentin. That is, dentin is much humid and more organic content than enamel. This humid and organic nature of dentin makes bonding extremely difficult [3]. The purpose of this article is to review the main concepts regarding various adhesive systems.