Status: June 2026 – All cited studies are peer-reviewed and publicly available on PubMed.
For decades, fluoride has been considered the gold standard in caries prevention. Almost every toothpaste in our drugstores contains this active ingredient. However, while its protective effect against caries is scientifically proven, discussions about the possible risks of over-fluoridation are growing. Recent research and alternative active ingredients like hydroxylapatite raise the question: Does it really have to be fluoride – or are there safer, equally effective options?
The effect of fluoride – undisputed, but not unproblematic
Fluoride hardens tooth enamel by incorporating into its outermost layer, making it more resistant to acids. Numerous clinical studies confirm that fluoride-containing toothpaste can reduce the risk of caries.
However, there are several critical aspects:
- Synthetic origin: The fluoride used in toothpastes is not a natural mineral but is industrially produced from compounds such as sodium fluoride or sodium monofluorophosphate.
- Limited acid protection: Fluoride forms a superficial protective layer (calcium fluoride-like deposits). However, this protection is pH-dependent and can be rapidly dissolved again with repeated acid exposure.
- Dental fluorosis: In children whose teeth are developing, even regular excessive intake of fluoride (e.g., by swallowing toothpaste) can lead to white or brownish spots on the tooth enamel.
How does fluorosis develop biochemically?
Fluorosis is the visible sign of a disturbance in enamel formation (amelogenesis):
- During tooth development, fluoride ions are incorporated into the mineralizing tissue.
- This alters the function of the enamel-forming cells (ameloblasts) and inhibits the breakdown of organic matrix proteins.
- The result is defective crystal formation in the tooth enamel – creating porous structures that clinically appear as white spots, later also as brownish discolorations or defects.
Hydroxyapatite: The natural building block of teeth
Hydroxyapatite (HAP) is not a new invention – it is the natural main component of our teeth: approximately 97% of tooth enamel and approximately 70% of dentin (tooth bone) consist of this mineral.
Biomimetic HAP in oral care products mimics the crystalline structure of natural enamel. The principle: Instead of hardening the enamel from the outside (like fluoride), HAP directly replaces lost mineral.
How Hydroxyapatite Works
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Biomimetic Integration: HAP particles deposit into microscopic defects and porous areas of the enamel. A 2023 human study by the University of Cluj-Napoca directly demonstrated that HAP particles integrate into the enamel surface and measurably supply calcium and phosphate (Florea et al., Biomimetics 2023). This means HAP can form a protective layer on the tooth surface and fill microscopic defects.
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Remineralization: HAP delivers calcium and phosphate – the building blocks of enamel – directly to the tooth surface. It thus remineralizes tooth enamel and demonstrably reduces caries risks.
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Sealing of Dentinal Tubules: HAP can seal open dentinal tubules, thereby reducing pain and cold sensitivity in exposed tooth necks. (e.g., Butera et al. 2022)
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Biofilm Modulation: Studies show that HAP can reduce the adhesion of bacteria to the tooth surface.
- It is biocompatible and safe - swallowing it poses no health risks whatsoever, as it is a body-identical substance.
Why the debate is important
Advocates of fluoride argue that the substance has been used for decades and its efficacy has been demonstrated in numerous studies. This is correct – however, this paradigm is based on a time when no equivalent alternative existed.
Current research shows: Hydroxyapatite can achieve a comparable efficacy to fluoride toothpastes in caries prevention in several clinical studies (Paszynska et al. (2021, 2023) & Cocco et al. (2025)), is completely safe and suitable for all age groups.
Conclusion: Time for a rethink
Fluoride has undoubtedly served dentistry well. However, the risks of over-fluoridation, especially in children, are real and scientifically proven. With hydroxylapatite, an active ingredient is now available that offers the benefits of fluoride without its disadvantages. Hydroxyapatite is a scientifically well-researched, biomimetic active ingredient that mimics and can support the natural tooth structure.
Current research shows particularly positive effects in the following areas:
- Remineralization
- Sensitivity Reduction
- Enamel and Surface Care
While research continues to grow, hydroxylapatite is now considered one of the most interesting alternatives or additions in modern, evidence-based oral care.
Studies & Sources
Fluoride and Fluorosis:
- Fejerskov O, et al. Dental fluorosis: A handbook for health workers. Munksgaard, 1996.
- DenBesten P, Li W. Chronic fluoride toxicity: dental fluorosis. Monogr Oral Sci. 2011;22:81–96. doi:10.1159/000327042
- WHO. Fluoride in Drinking-water. 2006.
- CDC. Dental Fluorosis Facts. 2020.
Limited acid protection of fluoride:
- Ten Cate JM. Fluoride mechanisms of action: a review. Acta Odontol Scand. 1999;57(6):325–329.
- Buzalaf MAR, et al. Fluoride and the oral environment. Monogr Oral Sci. 2011;22:1–15.
Hydroxyapatite as an alternative:
- Hannig M, et al. Effect of nano-hydroxyapatite on enamel surface roughness and microhardness in situ. J Nanosci Nanotechnol. 2013;13(8):4771–4777.
- Amaechi BT, et al. Remineralization of early caries by a nano-hydroxyapatite dentifrice. J Clin Dent. 2019;30(5):A1–A5.
- Paszynska E, et al. Comparative effectiveness of a hydroxyapatite and a fluoride toothpaste for prevention and remineralization of caries in children. Sci Rep. 2021;11:16618. doi:10.1038/s41598-021-95912-8
- Butera A, Gallo S, Pascadopoli M, Montasser MA, Abd El Latief MH, Modica GG, Scribante A. Home Oral Care with Biomimetic Hydroxyapatite vs. Conventional Fluoridated Toothpaste for the Remineralization and Desensitizing of White Spot Lesions: Randomized Clinical Trial. Int J Environ Res Public Public Health. 2022;19(14):8676. doi:10.3390/ijerph19148676.
- Cocco F, Salerno C, Wierichs RJ, Wolf TG, Arghittu A, Cagetti MG, Campus G. Hydroxyapatite-Fluoride Toothpastes on Caries Activity: A Triple-Blind Randomized Clinical Trial. Int Dent J. 2025;75(2):632–642. doi:10.1016/j.identj.2024.09.037.
- Florea A, Băbțan AM, Băciuț M, et al. Remineralization Induced by Biomimetic Hydroxyapatite Toothpastes on Human Enamel. Biomimetics (Basel). 2023;8(6):450. doi:10.3390/biomimetics8060450.