Caries-preventing effect of a hydroxyapatite-toothpaste in adults: a 18-month double-blinded randomized clinical trial.

Background: Dental caries is a worldwide challenge for public health. The aim of this 18-month double-blinded, randomized, clinical trial was to compare the caries-preventing effect of a fluoride-free, hydroxyapatite toothpaste (test) and a toothpaste with sodium fluoride (1450 ppm fluoride; positive control) in adults.
Methods: The primary endpoint was the percentage of subjects showing no increase in overall Decayed Missing Filled Surfaces (DMFS) index. The study was designed as non-inferiority trial. Non-inferiority was claimed if the upper limit of the exact one-sided 95% confidence interval for the difference of the primary endpoint DMFS between test and control toothpaste was less than the predefined margin of non-inferiority (Δ ≤ 20%).
Results: In total, 189 adults were included in the intention-to-treat (ITT) analysis; 171 subjects finished the study per protocol (PP). According to the PP analysis, no increase in DMFS index was observed in 89.3% of subjects of the hydroxyapatite group and 87.4% of the subjects of the fluoride group. The hydroxyapatite toothpaste was not statistically inferior to a fluoride toothpaste with regard to the primary endpoint.
Conclusion: Hydroxyapatite was proven to be a safe and efficient anticaries agent in oral care.
Clinical Trial Registration: NCT04756557.
Competing Interests: JE, FM, and ESc are employees of Dr. Kurt Wolff GmbH and Co. KG, Bielefeld, Germany. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2023 Paszynska, Pawinska, Enax, Meyer, Schulze zur Wiesche, May, Amaechi, Limeback, Hernik, Otulakowska-Skrzynska, Krahel, Kaminska, Lapinska-Antonczuk, Stokowska and Gawriolek.)