Monkey pulpal response and microtensile bond strength beneath a one-application resin bonding system in vivo

Objectives: The aim of this in vivo study was to investigate the biocompati bility and microtensile bond strength of a one-application resin bonding sy stem. Methods: Class V cavities were prepared on the facial surfaces of 36 intact monkey teeth, and the cavities were restored with an experimental one-appl ication resin bonding system (TOF-I; Tokuyama Corp., Tokuyama, Japan) and a hybrid resin composite (PALFIQUE ESTELTTE; Tokuyama Corp., Tokuyama, Japan ). Histopathological changes of the restored teeth were evaluated at 3, 30 and 90 days after operation (N = 10). Microtensile bond tests were performe d at 3 and 90 days after operation (N = 10). Results: Only two of 30 pulps showed a slight inflammatory cell infiltratio n. There were no statistically significant differences in the incidence of slight inflammatory cell infiltration among time periods. Bacterial penetra tion along the cavity walls could not be detected in any specimen. The mean microtensile bond strength at 3 days after operation was 20.6 MPa, and tha t at 90 days was 14.9 MPa. Differences in bond strengths between the 3 day specimen and the 90 day specimen were statistically significant (p < 0.05). Conclusions: The one-application resin bonding system exhibited acceptable biologic compatibility to the monkey pulp. Although there were statisticall y significant differences in bond strengths between the 3 day specimen and the 90 day specimen, this material provided a hermetic seal, eliminating ba cterial microleakage. (C) 2000 Elsevier Science Ltd. All rights reserved.