of the teeth dentifrices are primarily composed of water detergent humectant binder flavoring agents and a finely powdered abrasive as the principal ingredient a dentifrice is considered to be an abrasive containing dosage form for delivering anti caries agents to the teeth u201d dentifrice formulations contain ingredients which must be dissolved prior to incorporation into the dentifrice formulation e g anti caries agents such as sodium fluoride sodium phosphates flavoring agents such as saccharin the various silica and toothpaste dentifrice properties described herein were measured as follows unless indicated otherwise the brass einlehner be abrasion test used to measure the hardness of the precipitated silicas silica gels reported in this application is described in detail in u s pat no 6 616 916 incorporated herein by reference involves an einlehner at 1000 abrader generally used as follows 1 a fourdrinier brass wire screen is weighed and exposed to the action of a 10 aqueous silica suspension for a fixed length of time 2 the amount of abrasion is then determined as milligrams brass lost from the fourdrinier wire screen per 100 000 revolutions the result measured in units of mg loss can be characterized as the 10 brass einlehner be abrasion.