The Clinical Evidence
Rennou is Theodent's patented active: theobromine, from cacao, paired with a calcium and phosphate system. In a randomized double-blind study, it took 71 times more fluoride to match the remineralization theobromine achieved (Caries Research, 2013). In a separate study on exposed dentin, a theobromine toothpaste closed nearly all open tubules within three days; the fluoride toothpaste it was tested against closed almost none (Clinical Oral Investigations, 2015).
Every Theodent product is fluoride-free, SLS-free, and safe if accidentally swallowed. Rennou's components hold GRAS status with the FDA. Practices stock Theodent for patients with hypersensitivity or erosion, and for patients who decline fluoride.
What the studies found
It took 71× more fluoride to reach the remineralization theobromine achieved.
Caries Research 47(5), 2013A theobromine dentifrice reached near-complete occlusion of exposed dentin tubules in three days, in situ.
Clinical Oral Investigations 19(1), 2015Enamel crystals formed under theobromine measured 4× larger.
Global Journal of Medical, Pharmaceutical, and Biomedical Update, 2025The published research
More than twenty published studies examine theobromine, the active compound in Rennou. The selection below is grouped by what each one examines; every citation links to its publisher record, and the full dossier is available as a PDF.
Remineralization and enamel hardness
Amaechi B.T., Porteous N., Ramalingam K., et al. Remineralization of artificial enamel lesions by theobromine. Caries Research, 47(5), 399–405, 2013. doi
Kargul B., Ozcan M., Peker S., et al. Evaluation of human enamel surfaces treated with theobromine. Oral Health & Preventive Dentistry, 10(3), 275, 2012. doi
Golfeshan F., Mosaddad S.A., Ghaderi F. Toothpastes containing theobromine and caffeine on enamel microhardness. Evidence-Based Complementary and Alternative Medicine, 2021. doi
Thomas N.A., Shetty P., Thimmaiah C., et al. Remineralization potential of theobromine and fluoride, SEM-EDX study. Journal of International Dental and Medical Research, 14(4), 2021. record
Dentin-tubule occlusion and sensitivity
Amaechi B.T., Mathews S.M., Mensinkai P.K. Effect of theobromine-containing toothpaste on dentin tubule occlusion in situ. Clinical Oral Investigations, 19(1), 109–116, 2015. doi
Safety and formulation
Nakamoto T., Falster A.U., Simmons W.B. Theobromine: a safe and effective alternative for fluoride in dentifrices. Journal of Caffeine Research, 6(1), 1–9, 2016. doi
Nakamoto T., Falster A.U., Simmons W.B. The contrasting effects of caffeine and theobromine on crystallization: how the non-fluoride dentifrice was developed. 2022. doi
Antibacterial activity and stain resistance
Rafiq I.H., Dame-Teixeira N., Do T. The antimicrobial activity of theobromine against cariogenic microbes, an in vitro pilot study. BDJ Open, 10, 8, 2024. doi
Wulandari N.Y., Irawan B., Herda E. Theobromine toothpaste and prevention of enamel discoloration from coffee. Journal of Physics: Conference Series, 1073, 2018. doi
Download the full research dossier (PDF)
The researchers
Prof. Bennett T. Amaechi, Professor of Dentistry and Director of Cariology, UT Health San Antonio. An independent researcher; author of the head-to-head remineralization and tubule-occlusion studies.
Prof. Betül Kargül, Professor of Pediatric Dentistry, Marmara University, Istanbul. An independent researcher; author of studies on theobromine and human enamel surfaces.
Rennou Varnish, cleared by the FDA
Rennou Varnish, the professional varnish built on the same active, received FDA 510(k) clearance on May 27, 2025, indicated for the relief of dentin hypersensitivity through mechanical occlusion of dentinal tubules. Clearance K243777, Class II, 21 CFR 872.3260. It is the first fluoride-free cavity varnish cleared for professional use in the United States.
In the bench testing submitted with the clearance, a single application of 3% Rennou Varnish occluded dentinal tubules, deposited mineral within them, and penetrated deep into the tubules, performing at the level of a 5% sodium fluoride varnish.
Parlakyıldız Gökçe A.N., Keleşoğlu E., Sağır K., Kargül B. Remineralization potential of a novel varnish: an in vitro comparative evaluation. Journal of Clinical Pediatric Dentistry, 48(6), 173–180, 2024. doi. Both 1% and 3% Rennou remineralized enamel comparably to 5% sodium fluoride.
The clearance applies to the professional varnish, not to Theodent toothpaste.
For dental professionals
For a sample kit, wholesale terms, or Rennou Varnish, tell us about your practice. A member of the professional team follows up. Or write to info@theo-corp.com.