In vivo examination of the Scotchbond Multi-Purpose Dental Adhesive System in rat (vitalmicroscopic study).

: No data are available on the direct acute vascular effect of dental bonding materials on the dental pulp. This study investigated the effects of the components of a composite resin-bonding system on pulpal vascular diameter. Three groups of 10 male Sprague-Dawley rats (weighing 330 +/- 51 g) were used for this investigation. The first lower incisor of the rats was prepared for vitalmicroscopy. Changes in vessel diameter were recorded prior to, and at 5, 15, 30 and 60 minutes after the bonding agents (with/without etching) or saline (control) were administered on dentin as recommended by the manufacturer. In control rats, the vessel diameter was elevated slightly (2.96 +/- 4.08%) during the whole experiment. However, in the presence of bonding materials, an enhancement of 12.58 +/- 7.1% without etching and 13.11 +/- 8.6% with acid etching was registered as the increase in vascular diameter. There were significant (p < 0.05) differences between the control group and those treated with bonding agent components. Results suggested that resin composite bonding agents applied to a thin layer of dentin have an acute vasodilating effect on the dental pulp. The clinical significance of this vascular alteration in the dental pulp requires further study.