EVALUACIÓN DE LA RESISTENCIA ADHESIVA MEDIANTE LA PRUEBA DE DESALOJO EN POSTES DE FIBRA DE VIDRIO CEMENTADOS EN DIENTES NATURALES USANDO DIFERENTES PROTOCOLOS DE CEMENTACIÓN

ABSTRACT 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. Methods: 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). Sub-groups 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). Sub-groups 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 types: cohesive to dentin (CD), adhesive to post (AP), adhesive to dentine (AD). Most frequent failures: Group 1, subgroup 1.1: middle zone (CD 80%). Subgroup 1.2: middle zone (AD 66.7%). Group 2, subgroup 2.1: apical area (AD 73.3%). Subgroup 2.2: apical area (AD 86.7%). Conclusions: there were no statistically significant differences between the Grossman and the Top Seal cements, but there was less adhesive strength with the Grossman cement, and lower resistance with the Uni-etch phosphoric acid and no chlorhexidine, compared to phosphoric acid plus chlorhexidine.