The paper analyzes in detail the evolution of clinical working procedures in the preparation of dentin for the realization of bonding of adhesion remedies. The importance is described as well as the possibilities to adjust the post-preparation layer (smear layer) for adhesion-conditioning, total etching, application of the primer and the bond.The authors clarify the origin of so called hybrid layer after the application of the primer and the bond (resin-dentin interdiffusion zone). Attention is drawn to the importance of various components of adhesion systems on the quality of the bond (acetone, alcohol,water solvents, active compounds etc.).The paper presents other factors, which participate in the quality of adhesion of composite materials (e.g. configuration C-factor, polymerization inhibitors, whitening substances etc.). Main methods for the evaluation of quality of the bond are presented (tensile, shear bond strength, micro-leakage). A survey of present adhesion systems is given as well as multi-step systems, one-bottle systems, self-etching systems.

        Key words: enamel – dentin – adhesion systems – post-preparation layer – total etching – primer – bond – hybrid layer – bond strength – C-factor