SEM Evaluation of the Interface Between Filling and Root- End Filling Materials

The aim of this ex vivo study was to evaluate, by scanning electron microscopy (SEM), the presence of gaps at the interface between filling material and three root-end filling materials. Thirty human upper molars disto-buccal roots were instrumented and filled with gutta-percha and eugenol-based sealer. The apicoectomy was performed 2mm from the apex and retrograde cavities were prepared with ultrasonic points (3mm in deep). The samples were divided into three experimental groups (n=10): Group Iwhite mineral trioxide aggregate (MTA); Group IISuper EBA; and Group IIIPortland cement. The root-end filling materials were inserted into the retocavities using a MTA carrier. After 48h, the roots were transversally sectioned in order to obtain the apical 5mm. Next, each specimen was prepared longitudinally with crescent granulation of abrasives water-wet sandpapers in order to expose the filling and root-end filling materials. Then, the specimens were subjected to slow dehydration with silica gel, mounted onto specific stubs and coated with paladium coverage for SEM analysis of the interface between filling and root-end filling materials. The percentage of gaps at the interfacial area was calculated by using Image Tool 3.0 software. Super EBA presented the higher percentage of gaps (1.5 +/- 0.67%), whereas MTA presented the lowest values (0.33 +/- 0.20%; p=0.0004). Despite the statistical differences observed between Super EBA and MTA, all the root-end filling materials presented great adaptation to the filling material, presenting small amount of gaps. SCANNING 36:252-257, 2014. (c) 2013 Wiley Periodicals, Inc.