Effect of a chitosan additive to a Sn2+-containing toothpaste on its anti-erosive/anti-abrasive efficacy-a controlled randomised in situ trial

摘要

Objectives: It is well known that Sn2+ is a notable anti-erosive agent. There are indications that biopolymers such as chitosan can enhance the effect of Sn2+, at least in vitro. However, little information exists about their anti-erosive/anti-abrasive in situ effects. In the present in situ study, the efficacy of Sn2+-containing toothpastes in the presence or absence of chitosan was tested. Methods: Ten subjects participated in the randomised crossover study, wearing mandibular appliances with human enamel specimens. Specimens were extraorally demineralised (7 days, 0.5 % citric acid, pH 2.6; 6 × 2 min/day) and intraorally exposed to toothpaste suspensions (2 × 2 min/day). Within the suspension immersion time, one half of the specimens were additionally brushed intraorally with a powered toothbrush (5 s, 2.5 N). Tested preparations were a placebo toothpaste (negative control), two experimental toothpastes (F/Sn = 1,400 ppm F-, 3,500 ppm Sn2+; F/Sn/chitosan = 1,400 ppm F-, 3,500 ppm Sn2+, 0.5 % chitosan) and an SnF2-containing gel (positive control, GelKam = 3,000 ppm Sn2+, 1,000 ppm F-). Substance loss was quantified profilometrically (μm). Results: In the placebo group, tissue loss was 11.2 ± 4.6 (immersion in suspension) and 17.7 ± 4.7 (immersion in suspension + brushing). Immersion in each Sn2+-containing suspension significantly reduced tissue loss (p ≤ 0.01); after immersion in suspension + brushing, only the treatments with GelKam (5.4 ± 5.5) and with F/Sn/chitosan (9.6 ± 5.6) significantly reduced loss [both p ≤ 0.05 compared to placebo; F/Sn 12.8 ± 6.4 (not significant)] Conclusion: Chitosan enhanced the efficacy of the Sn2+-containing toothpaste as an anti-erosive/anti-abrasive agent. Clinical relevance: The use of Sn2+- and chitosan-containing toothpaste is a good option for symptomatic therapy in patients with regular acid impacts.