Protection against enamel demineralisation using toothpastes containing o-cymen-5-ol, zinc chloride and sodium fluoride

Aim: To evaluate the ability of two experimental toothpastes containing 0.1%w/w o-cymen-5-ol, 0.6%w/w ZnCl(2) 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 ZnCl(2) and 0.320%w/w NaF (experimental toothpastes). Results: Study 1: Mean ± SE % of baseline hardness values were a) 48.0 ± 2.1(a), b) 66.7 ± 1.7(b), c) 82.9 ± 1.9(c), d) 91.7 ± 1.4(d) and e) 94.6 ± 2.1(d). Study 2: Mean ± SE ΔZ values were a) 2114 ± 187(a), b) 1206 ± 132(b), c) 303 ± 89(c), d) 19 ± 73(c), and e) −10 ± 55(c). 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.