Fish Bone–Derived Hydroxyapatite as a Sustainable Remineralizing Agent in Toothpaste: A Comprehensive Review

Hydroxyapatite is a biomimetic calcium phosphate mineral that closely resembles the inorganic component of tooth enamel and plays a significant role in enamel remineralization by replenishing lost calcium and phosphate ions. Owing to its high biocompatibility and ability to repair early enamel lesions, hydroxyapatite has gained increasing attention as an alternative or adjunct to fluoride in oral-care formulations.Fish bone, an abundant and underutilized biowaste, serves as a sustainable and cost-effective natural source of hydroxyapatite, offering chemical similarity to biological apatite while supporting environmental waste valorization.This review analyzed peer-reviewed articles published between 2010 and 2025 retrieved from databases including PubMed, Scopus, Web of Science, and Google Scholar.The reviewed literature indicates that fish bone–derived hydroxyapatite exhibits favorable physicochemical properties, effective enamel remineralization potential, and promising applicability in toothpaste formulations. However, the need for standardized extraction methods, long-term safety evaluations, and well-designed clinical studies is consistently emphasized across studies.