CariFree has continued to be recognized alongside other prominent toothpaste brands, most recently in a study1 published in JADA May 2019. The study compared seven toothpastes, all currently on the market. Three use ionic calcium-phosphate compounds, one (CariFree CTx4 Gel 1100) contained nano-hydroxyapatite and three others contained only sodium fluoride.
The authors created in vitro carious lesions in enamel specimens and assigned them to each of the toothpastes for treatment. They then calculated the changes in microhardness before and after treatment. CTx4 Gel 1100 performed as well as any other product with a microhardness recovery of 27.3%, but not significantly better than just fluoride toothpaste without calcium. Here is where it gets interesting- the study was a lab bench in vitro study and did not account for the presence of biofilm or its important role in the demineralization and remineralization process.
Another study2 from JDR in 2015 showed the importance the biofilm has in the process of demineralization/remineralization. Our saliva is supersaturated with hydroxyapatite3, exactly as it occurs in nature. Hydroxyapatite is similar to calcium phosphate, but different in its composite and is the mineral enamel is innately made of. They found in the presence of a biofilm that a hydroxyapatite treatment resulted in a net mineral gain versus the sodium fluoride treatment which inhibited mineralization and a showed a net mineral loss.
In their discussion, they note “Dental biofilms play crucial roles in caries formation. They not only function as acid producers during caries formation but also may serve as reservoirs and diffusion barriers for caries preventive components.”
These findings are imperative to the importance of studying caries and preventive strategies within a biofilm model as we continue to see that hydroxyapatite is more beneficial than fluoride in mineralizing carious lesions when the biofilm is present.
- P. Frank Lippert and B. Karmjeet K. Gill, “Carious lesion remineralizing potential of fluoride and calcium containing toothpastes,” JADA, p. 7, 2019.
- L. H. R. E. L. C. J. L. J. t. C. W. C. a. D. D. M. Zhang, “Biofilm Layters Affect the Treatment Outcomes of NaF and Nano-hydroxyapatite.,” Journal of Dental Research, vol. 91(4), 2015.
- F. a. Kidd, “State of Saturation of Oral Fluids,” in Dental Caries. The Disease and its Clinical Management., Blackwell Munksgaard, 2003, pp. 54-58.