A randomised, controlled and blinded histological and immunohistochemical investigation of Carisolv™ on pulp tissue

Objectives: This investigation was undertaken to test the hypothesis that Carisolv™ would show the same safety profile as physiologic saline when in direct contact with pulp tissue for 30 min. Furthermore, the sensory nerve fibre reaction in response to the injury was evaluated. Methods: Incisors and molars in 40 Sprague–Dawley rats were opened and the pulp tissue randomly exposed to either Carisolv™ or NaCl for 30 min. Observation periods ranged from 1 day to 1 week. Results: Light microscopic examination showed an almost identical cellular response in both test teeth and controls, which consisted of a localised inflammation represented predominantly by macrophages. Immunohistochemistry revealed an accumulation of beaded CGRP-immunoreactive fibres in immediate vicinity of the lesion, suggesting that the nerves had emitted small sprouts. Some fibres at this location were SP-positive, but very few, or no nerve fibres, displayed NPY-immunoreactivity. This innervation pattern was seen in both test and controls in similar distribution and at similar intensity. Conclusions: Results obtained in this study suggests the hypothesis to be valid, i.e. Carisolv™ does not seem to add appreciable adverse effects over and beyond what is caused by the experimental procedures. Furthermore, Carisolv™ does not seem to influence the distribution or neuropeptide expression of sensory nerve fibres in the pulp.