Purpose: To evaluate an auto-cured resin as a direct pulp capping material on exposed pulp with or without a self-etching primer.
Materials and methods: Class V cavities were prepared on the facial surfaces of 90 intact monkey teeth, and the pulps were intentionally exposed with a carbide bur through the cavity floor. Each exposed pulp was capped with a commercially available adhesive resin system (Clearfil Liner Bond 2V: Group LB) or an auto-cured sealant resin (Teethmate-S) with and without the use of a self-etching primer (Group TMP and Group TM, respectively). The cavities were restored with an adhesive resin and a hybrid resin-based composite (Clearfil AP-X). Inflammatory cell infiltration and dentin bridge formation of the exposed pulp as well as protrusion of the exposed pulp tissue into the cavities were evaluated histologically at 3, 30 and 90 days.
Results: Slight inflammatory cell infiltration was the main inflammatory reaction of the exposed pulp, and the exposed area became occluded with dentin bridges as the observation period increased. However, significantly higher incidence of slight inflammatory cell infiltration was found in Group TM than in Group LB at 30 days (P<0.05). Group TM showed significantly higher incidence of protrusion of pulp tissue than Groups LB and TMP through all tested periods (P<0.05).