A giant advert near Aldgate proclaims that Colgate’s brand of toothpaste is “Used by more than 70% dental professionals”. From this I guess we are supposed to infer that most dentists endorse Colgate’s toothpaste, however as I motorbiked past this advert it occurred to me that the meaning of this bold statement was ambiguous:
For starters, what is meant by the “Dental Profession” - they could have said “Dentists” or “Dental Practitioners”, these would have been more obvious things to say if they were actually true. The phrase “Dental Professional” might refer to any professional grade employee or subcontractor working for any company that makes at least one dental product or provides any kind of service to the dental industry. By this definition, Colgate’s endorsement-count would also include their own staff, plus the IT and accounts departments of any hospital that happens to have a dental department.
Were this the case, the fact that these people use the product may have nothing at all to do with an informed preference. The most this advert can be construed to mean is that their particular type of toothpaste is popular and therefore it cannot be all that bad.
Thinking about toothpaste I began reading the text on the side of a pump of “Colgate Oxygen” - the latest snazzy toothpaste that makes the following product claims:

“Colgate Oxygen Toothpaste releases fine bubbles of pure oxygen. Plaque and impurities are gently lifted away. For a clean mouth, like a breath of fresh air. And Colgate’s proven care and protection for your teeth and gums.”
Aside from the obvious bad grammar in this text, once again we see the Colgate company making some duplicitous claims about their product. It’s possible that Colgate Oxygen toothpaste, while not actually containing any gaseous oxygen may contain an agent which releases bubbles of oxygen… but under what circumstance? Is this oxygen the agent responsible for “gently lifting” “plaque and impurities”, or is that just a non-sequitur?

In any case, assuming the first claim (the mere existence of these oxygen bubbles), these must have been caused by a chemical reaction involving one or more of the ingredients in the product. Scanning through the list, the only likely candidate is calcium-peroxide: Traditionally this substance is used as a dental bleaching agent. In the presence of acids, calcium-peroxide breaks down to form atomic oxygen, however in the low concentrations present in a there is unlikely to be enough to form “bubbles of pure oxygen”; the substance produced might have more in common with the emissions from a photocopier than a “breath of fresh air”.