The effects on the dental pulp of a composite resin and two dentine bonding agents and associated bacterial microleakage.

The pulpal reaction associated with a composite resin alone and composite resin used in conjunction with two dentine bonding agents was studied. Class V cavities were prepared on the labial surfaces of the canine teeth of 18 male ferrets. After acid etching of the enamel margins, the cavities were restored with either a composite resin alone or in combination with one of two dentine bonding agents, Scotchbond and Gluma. One cavity in each animal was filled with Kalzinol as a control. The animals were killed after 7, 14 and 28 days. After histological processing, the pulpal changes were assessed qualitatively and quantitatively according to standard criteria. There were variations in the pulpal response at all time intervals. The responses to the two dentine bonding agents were similar to those found with composite resin alone. No pulpal inflammation was observed in the control teeth. Gram-positive micro-organisms were identified at the interface of restoration and cavity wall, or within the dentinal tubules in virtually all cases in which pulpal inflammation was observed.