phosphorus-radioisotopes and Tooth-Discoloration

These laboratory studies examined the stain removal efficacy and hard tissue abrasivity of a new dentifrice formulation--Crest Extra Whitening--based on the incorporation of elevated concentrations of a proprietary silica. Cleaning power assessments were made using a modification of the laboratory test method developed by Stookey and associates at Indiana University Oral Health Research Institute. Abrasion assessments were made using Radioactive Enamel and Radioactive Dentin Abrasivity (REA and RDA) measures. Results show that Crest Extra Whitening dentifrice produced statistically significantly improved stain removal when compared to a number of conventional dentifrices, including Crest Cavity Protection and Crest Tartar Protection, and a number of recently marketed cleaning and whitening dentifrices. Laboratory studies further demonstrated that the Crest Extra Whitening dentifrice produces dentin and enamel abrasivity similar to conventional silica dentifrices.

Topics: Aluminum Oxide; Animals; Bicarbonates; Cariostatic Agents; Cattle; Chemistry, Pharmaceutical; Color; Dental Calculus; Dental Deposits; Dental Enamel; Dentifrices; Dentin; Diphosphates; Phosphorus Radioisotopes; Radiopharmaceuticals; Silicon Dioxide; Sodium Fluoride; Surface Properties; Technology, Pharmaceutical; Tooth Bleaching; Tooth Discoloration; Toothbrushing

Dentine abrasion is an important possible side effect of individually used mechanical oral hygiene products. Since human teeth are sometimes not available in sufficient numbers for research purposes, bovine teeth are often used as a substitute for in vitro tests of dentine abrasion. The aim of the present comparative study was to determine the mechanical effects of a manual toothbrush and a standard abrasive on human and bovine dentine under standardized conditions. Roots of human and bovine teeth were radioactivated and subjected to standardized machine brushing using a manual toothbrush and a standard abrasive slurry. Dentine abrasion was assessed by measuring radioactive phosphorus contained in the slurry after brushing. Non-radioactive human and bovine roots were brushed in the same machine, and the generated surface roughness was assessed using profilometry. Artificially stained human and bovine roots were brushed as described, and the cleaning effect was expressed as the extent of stain-free surfaces after different brushing times. The results for abrasion and surface roughening found with bovine and human dentine suggest that if standardized methods are used, roots of bovine mandibular front teeth can be used in place of human roots for in vitro studies of the mechanical effects of toothbrushes and toothpastes on dentine. The use of bovine dentine for measuring the cleaning effects of these products is, however, not recommended.

Topics: Animals; Cattle; Dentin; Humans; Phosphorus Radioisotopes; Surface Properties; Tooth Abrasion; Tooth Discoloration; Tooth Root; Toothbrushing; Toothpastes