Evaluation of cariogenic potential
The cariogenic potential of a product is evaluated by measuring plaque-pH in vivo during and for thirty minutes after consumption of the product using an in-dwelling pH electrode. Using this method, the product is tested in at least four healthy volunteers two of which have a 3-4 day old plaque and two of which have a 5ľ7 day old plaque on the electrode which is mounted in a removable, restorative dental device, it surrounded by human enamel, and is facing the sound interdental surface of an adjacent, natural tooth.
The plaque pH curve of a test product is the resultant of at least two measured pH-values per minute. A product is considered to lack a significant cariogenic potential if it does not depress the pH of the interdental plaque below 5.7 by bacterial fermentation, neither during consumption nor during a period of 30 minutes following consumption. The pH curve must clearly show the time of consumption of the test product and the 30-minute period following consumption.
The proper functioning of the plaque-pH-measuring equipment and the plaque metabolism must be checked in each test by rinsing with 10 ml sucrose solution (10%) or by the consumption of a sugar-containing analogue of the test product. This positive control must depress plaque pH to values below 5.
If a range of products with different flavors is to be evaluated, one product must be tested in at least four different volunteers and each additional flavor variety in at least two different volunteers. Exceptions to this general requirement for testing may be made for products, which are substantially equivalent, with regard to the fermentability and acidity of their ingredients, to an already tested product of the same manufacturer.
Details of the plaque-pH test are described in a Standard Operation Procedure (SOP), which is followed by all test facilities accredited by Aktion Zahnfreundlich (Switzerland) for conducting such tests.