OBJECTIVE: Analysis of two adhesive systems of different composition by scanning electron microscopy (SEM) for immediate dentin sealing to be included in the protocol of direct pulp capping with MTA. METHOD: Ten extracted upper premolars separated into two groups, one corresponding to 5 samples of Clearfil SE Bond and Clear Esthetic Flow composite (Kuraray) and the other corresponding to 5 samples for Optibond FL and its Revolution Formula 2 composite (Kerr) which were handled according to the manufacturer’s instructions, axially cut and taken to SEM. RESULTS: Clearfil SE Bond (Kuraray) presented a greater penetration of the odontoblastic fibers, thus demonstrating its biocompatibility and its affinity in the ionic interaction with the inorganic composition of the dentin tissue. On the other hand, we observed that OptiBond FL (Kerr) generated the formation of a hybrid layer that diffuses through the dentinal tubules, this morphological layer is defined with a greater thickness in contrast to the Clearfil SE Bond group. However, it is important to mention the presence of spaces and the identification of lower penetration on the identification on the dentinal tubules. ONCLUSIONS: 1.- Clearfil SE Bondhas greater adhesion to dentin thanks to MDP and seeks the same action of interacting with hydroxyapatite, just as MTA helps its formation. That is why we propose to include immediate dentin sealing with an adhesive that includes this type of MDP monomer, within the RPD protocol because it seeks the same result as MTA by different ways, it could be included in the protocol because they have affinity for ions or clinical elements for the formation of dentin tissue and together, they can reach the formation of hydroxyapatite.