11.15.05
Patent No. US 6,740,311 B2: Research-ers for P&G were awarded a patent for an abrasive dentifrice comprising an orally-acceptable carrier and a silica abrasive containing a precipitated silica with a particle size distribution ranging from 8-14 microns, a pellicle cleaning ratio of 70-140 and a radioactive dentin abrasion value of 100-250.