Effectiveness of a combination of calcium hydroxide and the anchovy nano-extract on the odontoblast-like cell count and alkaline phosphatase expression in rats’ dental pulp

BACKGROUND: There is growing interest in the use and processing of natural products for potential applications in dentistry, including endodontic treatment. Anchovy (Stolephorus insularis) is one such natural product. OBJECTIVES: The aim of the present study was to evaluate odontoblast-like cells (OLCs) and alkaline phosphatase (ALP) expression in the pulp of Wistar rats after the administration of a combination of calcium hydroxide (CH) and the anchovy nano-extract as a potential material for pulp regeneration. MATERIAL AND METHODS: Fifty-four Wistar rats were divided into 3 groups: the control group (group 1) received CH and distilled water; the 1st treatment group (group 2) received a 1:1 ratio combination of CH and the anchovy nano-extract; and the 2nd treatment group (group 3) received a 1:2 ratio combination of CH and the anchovy nano-extract. Each group was further divided into 3 subgroups according to the observation periods of 7, 14 and 21 days. Pulp perforation was performed on the rats' maxillary right first molars, followed by the placement of the tested materials into the perforated pulp. The rats were sacrificed according to the respective observation periods. The specimens were processed, and evaluated histopathologically (staining with hematoxylin and eosin (H&E)) and through immunohistochemistry (IHC). The data were analyzed using the one-way ANOVA followed by the Tukey HSD post hoc test. Statistical significance was set at p < 0.05. RESULTS: There were significant increases in OLCs and ALP expression following the application of the anchovy nano-extract at both 1:1 and 1:2 ratios, with significant differences as compared to the control group (p < 0.05). The highest OLC count and ALP expression were observed on day 21. The higher 1:2 ratio resulted in faster OLC formation, which occurred on day 14; in the case of the 1:1 ratio, increased OLC formation occurred on day 21. Both ratios increased ALP expression on day 21. CONCLUSIONS: The application of a combination of CH and the anchovy nano-extract to the perforated pulp increased the number of OLCs and ALP expression.