Histopathological analysis of corticosteroid-antibiotic preparation and propolis paste formulation as intracanal medication after pulpectomy: an in vivo study

Intracanal medication in pulpectomy therapy is used between appointments with the objective of reducing pain and inflammatory processes in pulp and periapical tissues. Propolis has been known as a natural antibiotic and has been subject of medical and dental research due to its therapeutic properties such as antibiotic, analgesic and anti-inflammatory effects. OBJECTIVE: The aim was to carry out an in vivo evaluation of the periapical tissue response to propolis paste when used as an intracanal medication in the teeth of dogs after pulpectomy. MATERIAL AND METHODS: 72 dog's incisors were selected for the experiment. After biomechanical preparation the root canal was filled with a corticosteroid-antibiotic preparation, experimental propolis paste, non-medicament (negative control) or non-pulpectomy at all (positive control). The medications were left inside the root canal for 7, 14 or 28 days. At the end of the experimental period histological sections were prepared and all laboratories processes for Harris hematoxylin and eosin staining was proceeded followed by the analysis using an optical microscope. Sections were classified according to a score representing the inflammatory events observed: the presence of polymorphonuclear neutrophils, polymorphonuclear eosinophils, lymphocytes and plasma cells, macrophages and/or giant cells, fibrous condensation and abscesses. RESULTS: There were statistically significant differences between the tissue reactions caused by the two substances being tested, after different experimental periods, with the periapical tissue that was in contact with propolis paste exhibiting fewer inflammatory reactions in comparison to corticosteroid-antibiotic preparation. CONCLUSIONS: The low tissue responses from propolis paste suggest that this material could be considered as an option for root canal medication after pulpectomy.