Abstract
The study aims to investigate the quality of dentin barriers and pulp reaction to EndoSequence Root Repair Material (ERRM) combined with low-level laser application. In eight dogs, pulps were exposed via class V, half of the samples received low-level diode laser at 870 nm. Thereafter, cavities were capped with fast-set or regular-set ERRM. The specimens were processed for histomorphological and immunohistochemical examination after 2 weeks and 2 months. Dentin bridges were observed in all samples, and 87.5% were complete. The low-level laser group had significantly more reparative dentin area than the non-lased group (p < 0.05). The dentin bridges were found to have an unprecedented tubularity of 43%-89%. Tiny dentin island formation was observed within the material particles. Initial mild-to-moderate inflammatory reactions were observed, which subsided after 2 months. RUNX2 and osteocalcin staining were evident for all samples at both time intervals. Low-level laser combined with bioactive ERRM is effective in inducing reparative dentin formation.