Turning Fish Bone Waste into Toothpaste
How Natural Hydroxyapatite from Sardinella fimbriata Could Support Sustainable Oral Care
From Seafood Waste to Oral Health Innovation
Fish processing industries generate large amounts of bone waste that often end up discarded. Yet, these bones are rich in hydroxyapatite (HAp)—a calcium-based mineral that makes up most of human tooth enamel and bone. In recent years, scientists have explored how this natural material can be reused for health applications, including dentistry.
A recent study published in BMC Oral Health investigates whether hydroxyapatite extracted from Sardinella fimbriata fish bones can be safely and effectively used as an ingredient in toothpaste. Beyond oral health, the research also highlights an environmentally friendly way to repurpose fishery by-products.
What Did the Researchers Do?
The research team conducted a laboratory-based experimental study to extract natural hydroxyapatite from Sardinella fimbriata fish bones using a high-temperature calcination process. This method removes organic materials and converts the bones into a calcium-rich powder suitable for further use.
To understand the quality of the extracted hydroxyapatite, the researchers analyzed:
Chemical composition, focusing on calcium content
Crystallinity, which reflects how closely the structure resembles natural tooth enamel
The hydroxyapatite was then incorporated into toothpaste formulations at different concentrations:
F0: 0% hydroxyapatite (control)
F1: 30%
F2: 40%
F3: 50%
Each toothpaste was evaluated for physical stability and sensory properties, including texture, taste, aroma, foam formation, pH, and overall acceptability.
Key Findings: High-Quality Hydroxyapatite and Stable Toothpaste
The fish bone-derived material showed high calcium content, with calcium oxide making up more than 60% of the powder. X-ray diffraction analysis revealed a crystallinity level of 82.9%, indicating a structure very similar to natural hydroxyapatite found in human teeth.
When used in toothpaste:
All formulations remained stable over 21 days, with no major changes in pH or foam production.
Higher hydroxyapatite concentrations increased toothpaste viscosity, making the product thicker and potentially improving adherence to tooth surfaces.
Sensory testing showed that all formulations were generally liked, but the toothpaste containing 50% hydroxyapatite (F3) was most preferred in terms of color, aroma, taste, and texture.
Importantly, adding hydroxyapatite did not alter the toothpaste’s appearance, which remained white and visually familiar to users.
Why Does This Matter?
Hydroxyapatite plays a key role in enamel remineralization and caries prevention, and its structure closely mimics natural tooth enamel. Using hydroxyapatite from fish bones offers two major advantages:
Biocompatibility – natural hydroxyapatite closely resembles human enamel, supporting safe use in oral care products.
Sustainability – transforming fish bone waste into a valuable dental ingredient supports circular economy practices and reduces environmental burden.
The findings suggest that toothpaste made with fish bone-derived hydroxyapatite could become a sustainable, non-fluoride alternative or complement in preventive oral care.
The Takeaway
This study demonstrates that hydroxyapatite extracted from Sardinella fimbriata fish bones can be successfully incorporated into toothpaste formulations. Among the tested options, the formulation containing 50% hydroxyapatite showed the best balance of stability and user preference.
While further clinical studies are needed to confirm long-term benefits for enamel remineralization and caries prevention, the research opens promising pathways for eco-friendly, science-based oral care products that benefit both human health and the environment.
Original Article Reference
Anwar, A. I., Ruslin, M., Marlina, E., & Hasanuddin, H. (2025). Physicochemical analysis and application of Sardinella fimbriata-derived hydroxyapatite in toothpaste formulations. BMC Oral Health, 25, 195.