Efficacy of an Experimental Tin-F-Containing Solution in Erosive Tissue Loss in Enamel and Dentine in situ

Abstract

The aim of this study was to evaluate the effects of an experimental tin-containing fluoride solution on erosive tissue loss in human enamel and dentine using a cyclic de- and remineralization model in situ. The study was a three-cell (7 days each) crossover design involving 20 healthy volunteers. Samples were mounted on buccal shields of mandibular mouth appliances and worn for 24 h, except during meals and oral hygiene. Samples were demineralized extraorally with 0.05 M citric acid (pH 2.3) for 6 × 5 min per day. Fluoride treatment was performed intraorally once per day for 30 s after the first demineralization. Three solutions were used: placebo (negative control); NaF solution (positive control, 1,000 mg/kg F, pH 4.5), and an experimental solution (1,900 mg/kg Sn as SnCl₂, 500 mg/kg F as NaF, 500 mg/kg F as amine fluoride, pH 4.5). Tissue loss was determined profilometrically. In enamel, tissue loss was 33.6 ± 15.4 μm in the negative control group, 24.2 ± 9.2 μm (p ≤ 0.05) in the positive control group and 9.2 ± 3.4 μm (p ≤ 0.001) in the experimental solution group. The respective values for dentine were 47.8 ± 15.5 μm in the negative control group, 34.1 ± 9.3 μm (p ≤ 0.001) in the positive control group and 23.9 ± 6.4 μm (p ≤ 0.001) in the experimental solution group. The tin-containing solution was very effective in inhibiting erosive mineral in enamel in situ, even under severe conditions and with short application times, but was less effective in dentine.