Objectives: This study examined the in vivo bonding ability to sound dentin of antibacterial adhesive systems incorporating an antibacterial monomer MDPB based on morphological evaluation of the resin-dentin interface.
Methods: Class V cavities were prepared on the buccal surfaces of the teeth of a beagle dog and a composite filling performed using (1) commercial self-etching system Liner Bond 2 (LB primer+LB bond), (2) experimental primer containing 5% MDPB and LB bond, (3) LB primer and experimental bonding-resin containing 2.5% MDPB, or (4) combination of experimental primer and bonding-resin. After 7 days, the tooth crown was cut and fixed in half-Karnovsky's solution, and the sectioned surface observed under scanning electron microscopy (SEM) after treatment with phosphoric acid and NaOCl. The ultrastructure of the bonding interface was also examined by transmission electron microscopy (TEM). Microtensile bond strengths (microTBS) of each group were measured using extracted teeth.
Results: SEM demonstrated that all groups produced a 1-2microm thick hybrid layer with funnel shaped resin tags, although the length of tags was shorter for the group in which MDPB-containing bonding-resin was used. TEM examination supported good adhesion of the comprehensive adhesive system employing MDPB-containing primer/bonding-resin, showing integrity between resin and dentin. There were no significant differences in microTBS among the four groups tested (p>0.05, ANOVA).
Significance: This study confirmed that the experimental antibacterial adhesive systems employing MDPB-containing primer or/and bonding-resin could produce an effective bond under in vivo conditions.