Introduction: endodontically treated teeth usually need to be rehabilitated with posts that normally undergo a restoration. The material replacing lost dentin must guarantee appropriate clinical performance (post, cement, or rehabilitator) and closely integrate to dentin, forming a single unit. The goal of this article is to determine which cementation protocol for fiber glass posts shows the best adhesive strength in the presence of the push-out test. Method: a sample of 60 teeth were divided into two groups and subdivided into two subgroups, performing four cuts with an IsoMet ® 1000 Precision machine (Buehler) and a diamond disc (Isocut Wafering Blade-CBN HC) measuring 7 inches in diameter and 0.03 inches thick, obtaining three root disks: one of the cervical area, one of the middle zone, and another of the apical area. The groups were sorted out as follows: Group 1: 30 teeth filled with epoxy resin cement (Top Seal). Subgroups 1.1 (15 teeth) and 2.1 (15 teeth), which were treated with Condac 37% acid phosphoric, 2% chlorhexidine, Duolink cement, and prefabricated post. Group 2: 30 teeth filled with zinc oxide eugenol cement (Grossman). Subgroups 1.2 (15 teeth) and 2.2 (15 teeth), treated with 32% Uni-etch acid, Duolink cement, and prefabricated post. All samples were subjected to the push-out test using a universal machine (Instron, model: ELS-5, made in China, with 1 to 600 Kn load capacity). Samples were photographed with a digital camera AxioCam ERc5s ® Zeiss, stereo-microscope Stemi 2000-CG ® , in order to carry out an observational analysis of the results according to failure type. Results: failure