Histopathologic evaluation of pulpal tissue response to various adhesive cleanup techniques.

Introduction The aim of this prospective in-vivo study was to investigate the possible effects of temperature changes from various adhesive cleanup procedures on pulpal tissue. Methods The materials, consisting of 40 sound maxillary and mandibular premolars to be extracted during orthodontic treatment, were randomly assigned to 4 groups, with 1 group as the control. The teeth in the 3 study groups were etched; brackets were bonded and then debonded. The remaining adhesive was removed with a tungsten carbide bur by using a high-speed hand piece. The teeth in the control group were not etched and bonded. In group 1, the residual adhesive was removed with water cooling, and the teeth were extracted 24 hours later. In group 2, the residual adhesive was removed without water cooling, and the teeth were extracted 24 hours later. In group 3, the residual adhesive was removed without water cooling, and the teeth were extracted 20 days later. The teeth were prepared for histologic examination, and the number of vessels, vessel areas and perimeters, extravasation of red blood cells, vascular congestion, and inflammatory cell infiltration were evaluated to determine pulpal tissue changes. Results According to the findings from histologic and immunohistochemical evaluations, the coronal pulps of the teeth in groups 1 and 3 were almost similar to the control teeth, but some distinct pathologic changes were observed in group 2. Conclusions Adhesive removal without water cooling caused some vascular and pulpal tissue alterations, but these were tolerated by the pulpal tissues, so the changes were reversible.