Dentin adhesion produces a hermetic seal and union between the restorative material and the surface of the tooth. If a correct treatment is applied, it becomes durable, protecting the tooth from bacteria, microorganisms and other media. Dentin is a humid tissue which must be treated in a correct way, with the adequate steps and products to obtain an excellent treatment. The present work has the objective of explaining the protocols to achieve an optimal dentin adhesion and the advantages of a correct dentin conditioning.