I have no new insights into GlaxoSmithKline’s decision to sell its Sensodyne Repair & Protect without NovaMin as the active ingredient in the US. GSK still will not talk to me anymore, and the dentist featured in the Repair & Protect commercials still has not returned my calls.
Nevertheless, I have received quite a bit of either email or comments about the original post, and two interesting but dubious theories keep showing up in this correspondence: 1) The US version of R&P actually contains NovaMin but the material is effectively hidden within the “inactive” ingredients; and 2) It is too hard to prove that NovaMin is effective.
Regarding the first theory, although I will defer anytime to the opinion of Bioglass inventor Larry Hench (45S5 Bioglass being the key ingredient in NovaMin), I see no possible way that “glycerin, PEG-8, hydrated silica, pentasodium triphosphate, sodium lauryl sulfate, flavor, titanium dioxide, polyacrylic acid, cocamidopropyl betaine, sodium saccharin” delivers the calcium and phosphate ions in a non-liquid method the way the glass-particle method does. Also, hiding active ingredients presumably would raise some transparency issues with the FDA.
Moving on to the theory about NovaMin’s effectiveness, it appears that there is readily available documentation in peer-reviewed publications.
For example, there is this study (courtesy of PubMed), conducted at the Armed Forces Medical Center, Pune, India, published in the Journal of Clinical Dentistry, “A clinical study comparing oral formulations containing 7.5% calcium sodium phosphosilicate (NovaMin), 5% potassium nitrate, and 0.4% stannous fluoride for the management of dentin hypersensitivity” by N. Sharma, S. Roy, A. Kakar, D.C. Greenspan, and R. Scott:
Objective: To determine and compare the clinical performance of formulations containing 7.5% calcium sodium phosphosilicate (NovaMin), 5% potassium nitrate, and 0.4% stannous fluoride for the management of dentin hypersensitivity.
Methods: This was a single-center, randomized, double-blind, parallel-group design with a duration of 12 weeks. The study included a total of 120 subjects and measured sensitivity to cold water and air blast by the use of a visual analogue scale. Measurements were taken at baseline, two, four, and 12 weeks.
Results: All three products significantly reduced sensitivity versus baseline at each time point, although the calcium sodium phosphosilicate (NovaMin) dentifrice reduced sensitivity significantly more than the others at the two- and four-week time points. At the two-week time point, for air and water, respectively, the dentifrice containing NovaMin reduced sensitivity 45% and 49%, the stannous fluoride gel 30% and 26%, and the potassium nitrate dentifrice 35% and 34%. At the 12-week time point, the dentifrice containing NovaMin reduced sensitivity 87% and 91%, stannous fluoride gel 87% and 85%, and potassium nitrate dentifrice 84% and 79%.
Conclusion: In this study, all three products were effective. Compared to the potassium nitrate and stannous fluoride formulations, the dentifrice containing NovaMin provided more substantial and significant improvements at the early time points.
Here are a few more samples from the PubMed database:
I am by no means an expert on FDA approval tactics and strategies, but I think it is pretty clear that Bioglass/NovaMin in toothpaste works.
Meanwhile, it does appear that some supplies of “Dr. Collins Restore” toothpaste containing NovaMin are still available to US consumers, at least online, from outlets such as Walgreens.