Colgate Total contains triclosan which experts claim is proven to fight gingivitis, gum bleeding and inflammation.
Triclosan, first used as a hospital scrub in the 1970s, has been added to many products to reduce contamination.
Animal studies have shown that triclosan alters hormone regulation, but the US Food and Drug Administration (FDA) point out that data showing effects in animals do not always predict effects in humans.
Other studies in bacteria have raised the possibility that triclosan contributes to making bacteria resistant to antibiotics.
It has also been linked with an increase in allergies.
The FDA has said that while it has kept triclosan under review, it has not got enough evidence to recommend a change in consumer use.
Bloomberg News recently reported that the FDA approval process for Colgate Total 17 years ago raised new questions about how the product was evaluated.
It claimed that recently released parts of the Colgate Total application showed that the FDA relied on company-backed science.
Three scientists who reviewed the documents at Bloomberg’s request found that the FDA might not have conducted enough due diligence before approving the use of triclosan in the toothpaste.
However, Tom DiPiazza, a spokesman company said Colgate Total had been reviewed and approved by the US, Europe, Canada and Australia regulatory authorities as safe and effective.
The Health Products Regulatory Authority, formerly the Irish Medicines Board, said inclusion of triclosan in cosmetic products had been reviewed by the Scientific Committee on Consumer Safety (SCCS).
The SCCS is an independent committee of experts that provide opinions on cosmetic products and their report in June 2010 recommended specific precautionary measures relating to the inclusion of triclosan in cosmetics.
Among its recommendations was that triclosan should be used prudently and limited only to use in cosmetic products where a health benefit could be shown.
A wider review of the use of triclosan in consumer products and the impact of this on the environment is taking place at European level and the HRSA will be informed of the findings.