RESUMEN
OBJECTIVE: The aim of this study was to evaluate in vitro the post-core system retention to dentine surfaces treated with EDTA and Er:YAG laser irradiation and cemented with resin or a tradiational zinc phosphate cement. BACKGROUND DATA: One of the factors related to intracanal post-retention is the root canal wall preparation. METHODS: Forty-eight samples were divided into three groups: (1) G1 (control), dentine surfaces with no treatment, irrigated with distilled and deionized water; (2) G2, 1% NaCIO + 17% EDTA; and (3) G3, water and Er:YAG laser (8 Hz, 200 mJ, 60 J, 300 pulses). Each group was subdivided into two subgroups depending on the cement used: Panavia F or zinc phosphate. All specimens were submitted to tensile load in the Universal Instron Machine (Instron 4444) at 0.5 mm/min. RESULTS: Data were analyzed statistically with ANOVA and Tukey's test, which showed no significant difference (p > 0.01) between the dentine wall treatments performed with 1% NaCIO + 17% EDTA (6.80 Mpa) and water + Er:YAG laser (6.81 MPa), independent of the cement used; however, these were statistically different (p < 0.01) from the control group that presented the lowest values (4.82 MPa). Cementing with Panavia F and zinc phosphate presented similar results for adhesive resistance (p > 0.05). CONCLUSION: We conclude that the previous treatment of dentine walls with 1% NaCIO + 17% EDTA, or Er:YAG laser + water favored retention of the post-core system cemented with both resin and zinc phosphate cement.