Evaluation of the bond strength of dentin bonding agents used to seal resected root apices.

A number of improved dentin bonding agents have recently become available, but have not been evaluated on apical radicular dentin. The purpose of this study was to compare the tensile bond strengths of four adhesive resins on resected root ends before and after blood contamination. Forty single-rooted human incisors were cleaned and shaped and obturated. The apical 3 mm was then resected at a 45-degree angle, bonded, and tested for tensile bond strengths using an Instron machine. The bonding systems evaluated included Prisma Universal Bond 3, Scotchbond MultiPurpose Dental Adhesive, Amalgambond, and All Bond 2. All bonding systems were then covered with Prisma APH light-cure composite resin. Results indicated that the bond strengths of the blood contaminated groups were significantly less than those of the control groups, except in the case of Amalgambond where no significant difference was noted. When the surface was contaminated with blood, Prisma Universal Bond 3 had significantly lower bond strengths, whereas Amalgambond had significantly higher bond strengths than the other subgroups.