Summary: This paper summarizes the current knowledge in the area of dental adhesives. Dental adhesive agents are used as agents bonding dental materials to hard dental tissues.The paper describes the bonding mechanism to the hard dental tissues (micro-mechanical retention) and the factors influencing thereof. The paper discusses the role of different anatomical structure and chemical composition of dental enamel and dentin. In dental enamel, the authors highlight the role of a preparation technique (rotation or oscillatory technique) and the prepared surface conditioning (conventional etching, air abrasion, laser etch) and the adhesive mechanism thereof. In dentin, the influence of smear layer is being emphasized and the possibilities of its conditioning in a preparation for bonding are being discussed. The paper gives a historical overview of dental adhesive agents’ development according to the particular generations of dental adhesives (I.–VI. generation).

        Key words: enamel – dentin – adhesion – adhesive systems – smear layer – etching agent – conditioner – primer – total etching – bond – hybrid layer