Dental adhesive systems used for bonding dental resins to enamel and dentin have evolved through several “generations,” with changes in chemistry, mechanism, number of bottles, application technique, and clinical effectiveness. The trend in the latest generation of dental bonding systems is to reduce the number of components and clinical placement steps. The introduction of i bond, a single-bottle dental adhesive system, is the latest of the new generation materials, and combines etchant, adhesive, and desensitizer in one component. This paper describes different dentin bonding agents, its evolution, mechanism of action and different commercially available dentin bonding agents and their role in the retention of pit and fissure sealant.