Effect of Dental Rinse on Enamel Surface Loss in vitro

Objectives: To investigate the efficacy of an erosion protection dental rinse on enamel under erosive/abrasive conditions over 28 days compared to tooth brushing without the rinse. Methods: Sixty human enamel specimens standardised for flatness were mounted in acrylic blocks and divided into three groups: Fluoride-free control toothpaste, NaF toothpaste alone (1400 ppm F) and NaF toothpaste (1400 ppm) with elmex Erosion Protection dental rinse (NaF+rinse). pH cycling was carried out with 1.0 % citric acid (pH 3.6) for 2 mins 5 times daily. Test slabs were treated with a slurry of 1400 ppm NaF dentifrice for two minutes including 15 brushing strokes (200g) twice a day, before the first and after the last acid challenge. The control slabs were brushed with fluoride-free dentifrice. Immediately following the second treatment the slabs of one group were exposed to the rinse for 30 seconds with oscillation. Samples were kept incubated in artificial saliva (pH 6.8). Surface loss was assessed by profilometry after 7, 14 and 28 days. Results: After 7, 14 and 28 days there was a significantly higher surface loss of enamel for the fluoride-free group compared with the two test groups (p<0.001). Also after 7 and 14 days the NaF+rinse showed significantly more protection (1.59±0.59 and 2.58±1.03 ìm) compared with NaF (2.11±0.54 and 3.28±0.97 ìm). However, after 28 days the difference between the two test groups was not statistically significant. Conclusions: In this model both the 1400 ppm NaF toothpaste alone and together with a erosion protection dental rinse showed protection against erosion/abrasion for all three time periods. NaF plus rinse showed better protection for 7 and 14 days but not at 28 days, probably due to the selected erosive/abrasive challenge in our model. Supported by GABA