GENERATION TIME PERIOD DEVELOPMENT 1950-1970 Experimentation with mineral acids for bonding acrylic to enamel, concern about etching of dentin, bonding agents not utilized with composites. Early 1970s Late 1970s Acid etching of enamel, enamel bonding agents Hydrophobic enamel bonding agents, hydrophilic dentin bonding agents, light cured components. 4 Mid to late 1980s Removal of dentin smear layer, acidic monomers and acidic pretreatments,, reduction of steps in bonding technique, multiuse bonding agents. 5 Early 1990s Etching to achieve hybrid layer in dentin, hydrophilic agents for both enamel and dentin, bonding to moist tooth structure, single bottle primer adhesives. 6 Mid to late 1990s Self etching primers and primer adhesives, light and dual cured options 7 Early 2000s No mix, self etching adhesives.
Conditioning of dentin is defined as an alteration of dentin surface including the smear layer with the objective of producing a substrate capable of micromechanical and possibly chemical bonding to dentin adhesive
1.Acid conditioners ;-several acids like phosphoric acid, maleic acid citric acid ,nitric acid, oxalic acid and hydrochloric acid