The effect of a calcium carbonate/perlite toothpaste on the removal of extrinsic tooth stain in two weeks.

OBJECTIVE: To assess the effect of a calcium carbonate/perlite toothpaste on the levels of extrinsic stain removed at two weeks compared to a silica control toothpaste. DESIGN: In this parallel group, double-blind study, subjects were stratified by natural baseline stain and tobacco use and allocated at random to one of the two study toothpastes. Subjects brushed with their allocated toothpaste twice daily for two weeks before extrinsic tooth stain was again assessed. SETTING: The study was performed at 4-Front Research UK Limited, Maldon, UK. PARTICIPANTS: 152 adult subjects with at least eight assessable incisors/ canines with natural extrinsic tooth stain completed the study. METHODS: The extrinsic tooth stain on the facial surfaces of incisors and canines was measured using the Macpherson modification of the Lobene Stain Index. RESULTS: Both of the toothpaste groups had significantly less stain after two weeks of use compared to the baseline value (p<0.001). Analysis of covariance on the sum of the whole mouth stain scores showed that the calcium carbonate/perlite toothpaste removed significantly more stain over the two week study than the silica control toothpaste (p<0.05). CONCLUSIONS: Twice daily brushing for two weeks with a calcium carbonate/perlite toothpaste removes more extrinsic stain than a silica control toothpaste.

The measurement of enamel and dentine abrasion by tooth whitening products using an in situ model.

OBJECTIVES: To determine the enamel and dentine wear of two whitening toothpastes using an in situ model with ex vivo brushing. METHODS: Human enamel/dentine (approximately 50:50) blocks (approximately 4 x 4mm) were placed in the upper buccal aspects of full or partial dentures of a group of 25 subjects. Subjects brushed the specimens ex vivo with either a calcium carbonate/perlite or silica containing whitening toothpaste under exaggerated conditions as compared to normal for 30 s, twice per day. Specimens were removed after 4, 8 and 12 weeks and the wear to the enamel and dentine was determined. Enamel wear was determined by change in Knoop indent length and dentine wear was determined from the enamel-dentine step height, measured using optical profilometry. RESULTS: The mean wear after 12 weeks was for enamel 0.27 and 0.19 microns, and for dentine 34.3 and 61.1 microns, for the calcium carbonate/perlite and silica toothpastes respectively. There were no significant differences between products after 12 weeks. The rate of wear was found to decrease throughout the duration of the study. CONCLUSION: There were no significant differences between the two whitening toothpastes in terms of enamel and dentine wear after 12 weeks brushing.