In vitro Efficacy of Experimental Chitosan-Containing Solutions as Anti-Erosive Agents in Enamel

Abstract

The present study evaluated the effect of chitosans with different viscosities, dissolved in an AmF/SnCl₂ solution, against erosion or erosion/abrasion. A total of 192 specimens were assigned to 2 × 6 groups (n = 16 specimens each): negative control, 4 chitosan solutions (groups Ch50, Ch500, Ch1000, and Ch2000, with viscosity of 50, 500, 1,000, or 2,000 mPas, respectively, 0.5% chitosan, 500 ppm F^-, 800 ppm Sn²⁺, pH 4.4), and positive control (500 ppm F^-, 800 ppm Sn²⁺, pH 4.3). One half of the groups was demineralized (experiment 1, E1; 10 days, 6 × 2 min/day, 0.5% citric acid, pH 2.8) and exposed to solutions (2 × 2 min/day); the other half was additionally brushed (15 s, 200 g) with non-fluoridated toothpaste before solution immersion (experiment 2, E2). Treatment effects were investigated by profilometry, energy-dispersive X-ray spectroscopy and scanning electron microscopy (SEM). In E1, all the chitosan-containing solutions reduced enamel loss by 77-80%, to the same extent as the positive control, except for Ch2000 (p ≤ 0.05), which completely inhibited tissue loss by the formation of precipitates. In E2, Ch50 and Ch500 showed best performance, with approximately 60% reduction of tissue loss compared to the negative control group (p ≤ 0.05 compared to other groups). SEM analysis showed differences between negative control and the other groups but only minor differences amongst the groups treated with active agents. In both E1 and E2, treatment with active agents resulted in surface enrichment of carbon and tin compared to negative control (p ≤ 0.001); brushing removed parts of carbon and tin (p ≤ 0.001). Chitosan shows different properties under erosive and erosive/abrasive conditions. Under erosive conditions high viscosity might be helpful, whereas lower viscosity seems to be more effective in cases of chemo-mechanical challenges.

Efficacy of Stannous Ions on Enamel Demineralization under Normal and Hyposalivatory Conditions: A Controlled Randomized in situ Pilot Trial

“…Chitosan shows notable antierosive as well as antierosive/antiabrasive effects under normal flow conditions if used in combination with stannous and fluoride ions in a toothpaste Schlueter et al, 2014;Carvalho and Lussi, 2014] or mouthrinse [Pini et al, 2016]. Chitosan is a cationic biopolymer able to bind with proteins [ Van der Mei et al, 2007], fluoride [Keegan et al, 2012], and other ions from saliva and enamel surface [Lussi & Carvalho, 2015], and abrasives from toothpastes [Lundin et al, 2008].…”

“…The best results can be achieved by the application of polyvalent metal cations, such as stannous ions containing fluoride preparations [Ganss et al, 2011Hove et al, 2014;Algarni et al, 2015]. A further increase in efficacy can be achieved if novel technologies, such as the addition of biopolymers like chitosan to F/Sn preparations, are used [Lussi and Carvalho, 2015] both under in vitro Carvalho and Lussi, 2014;Pini et al, 2016] and under in situ conditions [Schlueter et al, 2013[Schlueter et al, , 2014. Nevertheless, even if a good effect of the mentioned preparations has been shown under in situ conditions with healthy volunteers showing a normal saliva flow rate, nothing is known about the impact of saliva flow rate reduction (hyposalivatory conditions) on the efficacy of the erosion-inhibiting agents stannous ions, fluoride and chitosan.…”

An in vitro study on the influence of viscosity and frequency of application of fluoride/tin solutions on the progression of erosion of bovine enamel

“…Although the anti-erosive effect of a solution containing 500 ppm of fluoride and 800 ppm of tin was previously observed with a single daily application (Ganss, Neutard et al, 2010), it was further demonstrated that applying this solution twice a day could improve its efficacy (da Silva, Ramos-Oliveira, Mantilla, & de Freitas, 2017). It was hypothesized that the use of solutions with higher viscosity could improve the retention of fluoride and metal cations on tooth surfaces (Pini, Lima, Lovadino, Ganss, & Schlueter, 2016), and this could ultimately allow a lower frequency of application.…”

“…To the authors' knowledge, there is little information available on how the viscosity of fluoridated solutions would influence their protection against dental erosion. One investigation evaluated the effect of increasing the viscosity of a fluoride plus tin-containing solution using varieties of chitosan with different molecular weights (Pini et al, 2016). The authors observed that the more viscous solution presented a higher anti-erosive effect, however, it should be noted that chitosan is a positively charged polymer that can behave not only as a thickening agent, but also as film-forming molecule (Tharanathan & Kittur, 2003).…”

Avaliação in situ do efeito anti-erosivo da associação entre o fluoreto de sódio e o propileno glicol alginato

“…LPP foi outro polímero que conseguiu aumentar o efeito protetor do flúor no esmalte, frente a uma ciclagem erosiva(25) e erosiva/abrasiva(152) in vitro, porém, quando combinado com uma solução de flúor e estanho. Pini et al(153) testaram a perfilometria pode ser realizada utilizando-se um perfilometro de contato ou ótico. Em ambos os casos, a perfilometria vai quantificar a perda de superfície por meio do escaneamento da superfície do espécime, que vai gerar um perfil bi ou com as mucosas jugais(164).…”