RESUMEN
OBJECTIVES: Sn(2+) has promising erosion-inhibiting properties in solutions, but little is known about respective effects in toothpastes. In addition, biopolymers might have protecting potential. Aim of this study was to investigate the effects of Sn(2+) in toothpastes and of a biopolymer (chitosan) added to a Sn(2+) formulation on erosion/abrasion. METHODS: Enamel samples were subjected to cyclic erosion procedures (10 days; 0.50% citric acid, pH 2.5; 6× 2 min/day), and brushing (2× 15s/day, load 200 g) during immersion in slurries (2 min). The toothpastes were NaF formulations (NaF/1, NaF/2, NaF/3) and Sn(2+) formulations (NaF/SnCl(2), AmF/SnF(2), AmF/NaF/SnCl(2)) and AmF/NaF/SnCl(2)+0.5% chitosan. Declared concentrations of active ingredients in toothpastes were 1400-1450 µg/g F(-) and 3280-3500 µg/g Sn(2+). Negative controls were erosion only and placebo, positive control was a SnF(2) gel. Tissue loss was quantified profilometrically, Sn on enamel surfaces was measured by energy dispersive X-ray spectroscopy. RESULTS: Loss values (µm) for erosion only and placebo were 14.4 ± 4.5 and 20.2 ± 3.8, respectively, and 4.6 ± 1.9 for the positive control (p ≤ 0.001 each compared to erosion only). The other loss values were: NaF/1 16.5 ± 3.0, NaF/2 14.0 ± 2.7, NaF/3 12.6 ± 3.9, NaF/SnCl(2) 14.7 ± 5.1, AmF/SnF(2) 13.5 ± 4.8, AmF/NaF/SnCl(2) 12.4 ± 4.2, AmF/NaF/SnCl(2)+chitosan 6.6 ± 3.5 (except NaF/1 all p ≤ 0.01 compared to placebo). AmF/NaF/SnCl(2)/chitosan was more effective than all other toothpastes (p ≤ 0.01 each). Sn on the enamel surface ranged between 1.3 ± 0.3 and 2.8 ± 0.04 wt.% with no obvious relationship with efficacy. CONCLUSIONS: The NaF and Sn(2+) toothpastes without chitosan exhibited similar anti-erosion and abrasion-prevention effects. The experimental Sn(2+) formulation with chitosan revealed promising results similar to those of the positive control. CLINICAL SIGNIFICANCE: NaF toothpastes offer a degree of protection against erosion/abrasion, which is likely sufficient for most subjects with average acid exposures. For patients with initial erosive lesions, however, more effective toothpaste is desirable. The combination of Sn(2+) and a biopolymer appears promising in this context.
Asunto(s)
Quitosano/farmacología , Esmalte Dental/efectos de los fármacos , Compuestos de Estaño/farmacología , Abrasión de los Dientes/patología , Erosión de los Dientes/patología , Pastas de Dientes/farmacología , Aminas/farmacología , Ácido Cítrico/efectos adversos , Esmalte Dental/patología , Humanos , Concentración de Iones de Hidrógeno , Electrodos de Iones Selectos , Ensayo de Materiales , Placebos , Fluoruro de Sodio/farmacología , Espectrometría por Rayos X , Estaño/análisis , Fluoruros de Estaño/farmacología , Abrasión de los Dientes/prevención & control , Erosión de los Dientes/prevención & control , Cepillado Dental/efectos adversosRESUMEN
Concentrated tin- and fluoride-containing mouthrinses are effective erosion inhibitors in enamel and dentin. To test whether this is also true for solutions with lower concentrations, we conducted a randomized double-blind three-cell crossover in situ study with extra-orally performed erosive impacts (citric acid, 6 x 5 min/day) and an intra-oral rinsing protocol (1 x 30 sec/day) in 24 volunteers. The mouthrinses were a placebo, a NaF (500 ppm Fâ»), and an amine fluoride (AmF)/NaF/SnCl2 mouthrinse (500 ppm Fâ», 800 ppm Sn(2+)). Compared with the placebo, the NaF mouthrinse reduced substance loss by 19% in enamel and 23% in dentin (p ≤ 0.01 each); the AmF/NaF/SnCl2 mouthrinse reduced this parameter by 67% in enamel and 47% in dentin (p ≤ 0.001 each). AmF/NaF/SnCl2 was significantly more effective than NaF in both tissues (p ≤ 0.01). The mouthrinse containing Sn and F exhibited good efficacy, even under severe erosive conditions.