Abstract
AIM: To evaluate the ability of two experimental toothpastes containing 0.1%w/w o-cymen-5-ol, 0.6%w/w ZnCl2 and 0.320%w/w NaF to reduce demineralisation of sound human enamel compared with control toothpastes. METHODS: Study 1: Specimens were treated with toothpaste slurries, followed by alternating periods in demineralising and neutral solutions. Demineralisation was assessed using surface microhardness (SMH). Study 2: Specimens were subjected to a 14 day cycling regime of alternating demineralisation/remineralisation with two toothpaste treatments per day, before and after demineralisation. Demineralisation was assessed by cross-sectional microhardness and mineral loss (ΔZ) was calculated. Test toothpastes were a) 0%w/w or 0.002%w/w NaF placebo, b) 0.055%w/w or 0.149%w/w NaF (dose response), c) 0.320%w/w NaF marketed product, d & e) 0.1%w/w o-cymen-5-ol, 0.6%w/w ZnCl2 and 0.320%w/w NaF (experimental toothpastes). RESULTS: Study 1: Mean±SE % of baseline hardness values were a) 48.0±2.1a, b) 66.7±1.7b, c) 82.9±1.9c, d) 91.7±1.4d and e) 94.6±2.1d. Study 2: Mean±SE ΔZ values were a) 2114±187a, b) 1206±132b, c) 303±89c, d) 19±73c, and e) -10±55c. Letters represent different statistical groupings (P<0.05). CONCLUSION: In study 1, both experimental toothpastes were statistically superior to the marketed product and in study 2; they were at least as effective as the marketed product at reducing caries lesion development.