Subcutaneous implantation of the light-activated pit and fissure resin-based sealant prototypes LAS-clear and LAS-opaque resulted in a mild transient tissue reaction

Abstract

The objective of this study was to evaluate the biocompatibility of the light-activated pit and fissure resin-based dental sealant prototypes, LAS-clear and LAS-opaque, after subcutaneous implantation in rats for 7, 30, and 60 days. The commercial light-activated resin-based sealants, Delton-clear (DC), Helioseal clear (HC), Helioseal opaque (HO), and Clinpro Sealant (CL) served as control. Twenty-four 8-week-old male Sprague-Dawley rats were used in this study. Two rows of three 5 mm subcutaneous incisions were created on the back of each rat parallel to the midline. The materials were randomly implanted and the incisions were closed using sutures. The implants were left in situ for 7, 30, and 60 days. The implanted samples and the surrounding skin were removed, sectioned, and stained for histopathological evaluation. Results revealed that the scores of inflammatory cell infiltration of the DC, HC, LAS-clear, HO, CL, and LAS-opaque groups were not significantly different at 7, 30, and 60 days post-operation (p>0.05). The average total inflammatory cell infiltration score was highest at day 7 and lowest at day 30. Even though all the material revealed a persistent inflammatory response mediated by lymphocytes and macrophages at all time point evaluation, the tissue reaction of all groups to material implantation was that of typical wound healing. The tissue response scores of the DC, HC, LAS-clear, HO, CL, and LAS-opaque were not significantly different at 7, 30, and 60 days post-operation. The tissue response observed was material encapsulation without marked pathology. The capsule thickness was gradually increased in a time-dependent manner. In conclusion, the LAS-clear and LAS-opaque materials were biocompatible with the subcutaneous layer.