Efeito protetor de enxaguatórios com diferentes fluoretos utilizados previamente aos desafios erosivos/abrasivos em esmalte e dentina / Protective effect of solutions with different fluorides used previously to erosive/abrasive challenges in enamel and dentin

Aim: To evaluate the protection offered by commercial mouthwashes containing sodium fluoride or stannous chloride associated with sodium fluoride to enamel and dentin, prior to erosive and abrasive cycling. Materials and Methods: Enamel and dentin samples were obtained from bovine incisors and subdivided into 3 groups (n=10), according to the fluoridated ingredient tested: FS (sodium fluoride - NaF (225 ppm)); FE (tin fluoride - NaF + SnCl2 (800 ppm Sn2+)); control (distilled water). The samples were submitted to an erosive/abrasive cycle with immersion in citric acid (lemon soda for 5 min, 4×/day, 5 days, with remineralization intervals in artificial saliva for 60 min). Abrasion was carried out with an electric brush (200 g/force) after the first and last cycles, 2x/day, and immediately afterward immersed in the tested solutions. Structure loss was obtained by optical profilometry. The data were subjected to analysis of variance and multiple comparison for each substrate separately. Results: For enamel there was a difference between the groups (p = 0.027), with the FS showing less loss of structure compared to the control 2.02 (±0.48). The FE group showed similar loss to the control and FS 2.32 (±0.58)ab. For dentin there was a difference between the groups (p = 0.011), with FE showing less loss of structure compared to the other groups, 0.82 (25% - 0.34; 75% - 0.95). Discussion: The protection of fluorides in erosive/abrasive challenges depends on the type and dental substrate. Conclusion: Mouthwash with sodium fluoride prior to erosive/abrasive challenges caused less loss of enamel surface, while for dentin, sodium fluoride associated with stannous chloride caused less loss of structure.

Objetivo: Avaliar a proteção oferecida por soluções para bochecho de fluoreto de sódio ou cloreto de estanho associado ao fluoreto de sódio ao esmalte e à dentina, previamente à ciclagem erosiva e abrasiva. Materiais e Métodos: Amostras de esmalte e dentina foram obtidas a partir de incisivos bovinos e subdivididas em 3 grupos (n=10), de acordo com o princípio ativo fluoretado testado: FS (fluoreto de sódio - NaF (225 ppm)); FE (fluoreto de estanho - NaF + SnCl2 (800 ppm Sn2+)); controle (água destilada). As amostras foram submetidas a um ciclo erosivo/abrasivo com imersão em ácido cítrico (refrigerante de limão por 5 min, 4×/dia, 5 dias, com intervalos de remineralização em saliva artificial por 60 min). A abrasão foi realizada com escova elétrica (200 g/força) após o primeiro e o último ciclos, 2×/dia, e logo em seguida imersos nas soluções testadas. A perda de estrutura foi obtida por perfilometria óptica. Os dados foram submetidos à análise de variância e comparação múltipla para cada substrato separadamente. Resultados: Para esmalte houve diferença entre os grupos (p = 0,027), tendo o FS apresentados menor perda de estrutura comparado ao controle 2,02 (±0,48). O grupo FE apresentou perda similar ao controle e ao FS 2,32 (±0,58)ab. Para dentina houve diferença entre os grupos (p = 0,011), sendo que o FE apresentou menor perda de estrutura comparado aos demais grupos 0,82 (25% - 0,34; 75% - 0,95). Discussão: A proteção dos fluoretos em desafios erosivos/abrasivos depende do tipo e do substrato dental. Conclusão: O bochecho com fluoreto de sódio previamente aos desafios erosivos/abrasivos apresentou menor perda de superfície em esmalte, enquanto para dentina o fluoreto de sódio associado ao cloreto de estanho apresentou menor perda de estrutura.

Protection of calcium silicate/sodium phosphate/fluoride toothpaste with serum on enamel and dentin erosive wear.

OBJECTIVE: To evaluate the effect of a toothpaste containing calcium silicate/sodium phosphate/fluoride associated or not to the boost serum (BS) against erosive tooth wear (ETW) on enamel and dentin. METHODOLOGY: Bovine enamel and dentin specimens were subjected to an erosion-abrasion cycling model (1% citric acid - pH 3.6 -2 min / artificial saliva - 60 min, 4×/day, 5 days). Toothbrushing was performed for 15 s (2 min exposed to slurry), 2×/day, with the toothpastes (n=10): control without fluoride (Weleda), Arg/Ca/MFP (Colgate Pro-Relief), Si/PO4/MFP (Regenerate-Unilever), and Si/PO4/MFP/BS (Si/PO4/MFP with dual BS - Advanced Enamel Serum-Unilever). The effect of treatments on the eroded tissues was assessed by surface microhardness in the first day, and surface loss (SL) resulting from ETW was evaluated by profilometry (µm) after three and five days. Additional dentin specimens (n=5/group) were subjected to 20,000 brushing cycles to verify the abrasivity of the toothpastes. Data were subjected to ANOVA and correlation tests (5%). RESULTS: For enamel, no difference in microhardness was observed among the treated groups, and similar SL was obtained after 5 days. For dentin, Si/PO4/MFP/BS resulted in higher microhardness values, but none of the groups presented significantly lower SL than the control. There was no significant correlation between SL and abrasiveness. CONCLUSION: The calcium silicate/sodium phosphate toothpaste and serum increased microhardness of eroded dentin, but they did not significantly reduce enamel and dentin loss compared to the non-fluoride control toothpaste. The abrasiveness of the toothpastes could not predict their effect on ETW.

Protection of calcium silicate/sodium phosphate/fluoride toothpaste with serum on enamel and dentin erosive wear

Abstract Objective To evaluate the effect of a toothpaste containing calcium silicate/sodium phosphate/fluoride associated or not to the boost serum (BS) against erosive tooth wear (ETW) on enamel and dentin. Methodology Bovine enamel and dentin specimens were subjected to an erosion-abrasion cycling model (1% citric acid - pH 3.6 -2 min / artificial saliva - 60 min, 4×/day, 5 days). Toothbrushing was performed for 15 s (2 min exposed to slurry), 2×/day, with the toothpastes (n=10): control without fluoride (Weleda), Arg/Ca/MFP (Colgate Pro-Relief), Si/PO4/MFP (Regenerate-Unilever), and Si/PO4/MFP/BS (Si/PO4/MFP with dual BS - Advanced Enamel Serum-Unilever). The effect of treatments on the eroded tissues was assessed by surface microhardness in the first day, and surface loss (SL) resulting from ETW was evaluated by profilometry (μm) after three and five days. Additional dentin specimens (n=5/group) were subjected to 20,000 brushing cycles to verify the abrasivity of the toothpastes. Data were subjected to ANOVA and correlation tests (5%). Results For enamel, no difference in microhardness was observed among the treated groups, and similar SL was obtained after 5 days. For dentin, Si/PO4/MFP/BS resulted in higher microhardness values, but none of the groups presented significantly lower SL than the control. There was no significant correlation between SL and abrasiveness. Conclusion The calcium silicate/sodium phosphate toothpaste and serum increased microhardness of eroded dentin, but they did not significantly reduce enamel and dentin loss compared to the non-fluoride control toothpaste. The abrasiveness of the toothpastes could not predict their effect on ETW.

Enhancing the Anti-Erosive Properties of Fluoride and Stannous with the Polymer Carbopol.

This in vitro study investigated whether Carbopol 980 polymer could potentiate the anti-erosive effect of solutions containing sodium fluoride (F) and sodium fluoride associated with stannous chloride (FS). The dissolution of hydroxyapatite treated with the experimental solutions (F [500 ppm F-], F + Carbopol [0.1%], FS [500 ppm F- + 800 ppm Sn2+], FS + Carbopol) was evaluated. Deionized water was the negative control, and a commercial mouth rinse (AmF/NaF/SnCl2; 500 ppm F + 800 ppm Sn2+; Elmex® Erosion Protection) was the positive control. The solutions were also evaluated in an erosion-rehardening protocol, with two treatments per day, using bovine enamel specimens (n = 15) and human saliva. The acid challenge was performed using 0.3% citric acid (pH 2.6) for 2 min. Microhardness was measured at different times: baseline, after the first erosive challenge, after treatment, and after the second erosive challenge. Based on microhardness values, the demineralization, rehardening, and protective potentials were calculated. The alkali-soluble fluoride on enamel surfaces was also measured. Data were analyzed using ANOVA and Tukey tests (α = 0.05). Groups treated with FS + Carbopol showed the lowest hydroxyapatite dissolution and the highest rehardening and protective potentials. The measurement of alkali-soluble fluoride on enamel surfaces was also higher in the FS + Carbopol group. Carbopol was able to significantly increase the protective effect of the fluoridated solutions in addition to optimizing the adsorption of fluoride on the enamel surface.

Randomized in situ trial on the efficacy of Carbopol in enhancing fluoride / stannous anti-erosive properties.

OBJECTIVE: To evaluate if the bioadhesive polymer (Carbopol 980) could potentiate the protective effect of sodium fluoride with stannous chloride (FS) solution on the control of enamel erosive wear. METHODS: Cylindrical bovine enamel specimens were polished and randomly allocated into three groups (n = 60): FS (500 ppm F- +800 ppm Sn2+ - positive control), FS + Carbopol (0.1% Carbopol), and ultrapure water (negative control). A randomized double-blind cross-over in situ model with three phases was used. In each phase, volunteers (n = 15) used a palatal appliance containing 4 specimens: two were submitted to an erosion model (2 h of pellicle formation; immersion in 1% citric acid, pH 2.3, for 5 min, 4x/day; 1 h intervals of saliva exposure; and treatment with the test solutions for 1 min, 2x/day). Besides erosion, the other two specimens were also subjected to abrasion (2x/day, 15 s) with active electric toothbrush, before the treatment with the solutions. After 5 days, enamel surface loss (µm) was evaluated by profilometry. Data were analyzed by two-way RM-ANOVA and Tukey tests (5%). RESULTS: There were significant differences for both challenge and treatment factors. Erosion/abrasion challenge resulted in significantly higher enamel loss than erosion only (p < 0.05). The surface loss values for the erosion/remineralization model were (means ±â€¯SL): C = 14.7 ±â€¯5.8b; FS = 9.0 ±â€¯7.5ab; FS + Carbopol = 5.9 ±â€¯3.8a; and for erosion/abrasion: C = 26.6 ±â€¯10.1c; FS = 15.0 ±â€¯8.8b; FS + Carbopol = 12.3 ±â€¯7.9ab. CONCLUSION: The association of Carbopol to the FS solution significantly protected the enamel against erosive wear, but it was not significantly superior to FS only. CLINICAL SIGNIFICANCE: Under highly erosive and abrasive conditions, rinsing with solutions containing sodium fluoride plus stannous chloride, associated or not with the Carbopol polymer, is an effective approach to control enamel erosive wear.

Influence of Surfactants and Fluoride against Enamel Erosion.

This study investigated the effect of surfactants associated with sodium fluoride (NaF) on enamel erosion prevention, using an erosion-remineralization in vitro model. Sodium lauryl sulfate (SLS), polysorbate 20 (P20), and cocoamidopropyl betaine (CAPB) were tested, at concentrations of 1.0 and 1.5%, and associated or not with NaF (275 ppm). The control groups were distilled water and the NaF solution. Bovine enamel samples (n = 12) were prepared and submitted to a 5-day cycling model: acid challenge (0.3% citric acid, pH 2.6, 4×/day), human saliva (2 h, 4×/day), and the treatment solutions (2 min, 2×/day). The protective potential of the agents against initial erosion was assessed by microhardness and the surface loss by profilometry. Enamel surface wettability was determined by goniometry, protein adsorption was measured by spectroscopy (FTIR), and the KOH-soluble fluoride was quantified. Goniometry showed that SLS and CAPB increased enamel wettability. No differences were found among the surfactants regarding protein adsorption. Microhardness showed that SLS reduced NaF protection. P20 (1 and 1.5%) and CAPB 1.5% presented a protective effect, but lower than the NaF solution. Profilometry showed that CAPB protected enamel, but no agent associated with NaF promoted a higher protection than the NaF solution alone. KOH-soluble fluoride analysis showed that all surfactants reduced the fluoride adsorption on the enamel surface. Therefore, the surfactants tested (except for P20) changed the enamel surface energy. The SLS decreased the protective potential of NaF on initial erosion, but no tested agent interfered with the protective effect of NaF on enamel erosive wear.

Influence of bioadhesive polymers on the protective effect of fluoride against erosion.

OBJECTIVE: This study investigated if the incorporation of the bioadhesive polymers Carbopol 980, Carboxymethyl cellulose (CMC), and Aristoflex AVC in a fluoridated solution (NaF-900ppm) would increase the solution's protective effect against enamel erosion. METHODS: Enamel specimens were submitted to a 5-day de-remineralization cycling model, consisting of 2min immersions in 0.3% citric acid (6x/day), 1min treatments with the polymers (associated or not with fluoride), and 60min storage in artificial saliva. Ultrapure water was used as the negative control and a 900ppm fluoride solution as positive control. The initial Knoop microhardness (KHN1) was used to randomize the samples into groups. Another two microhardness assessments were performed after the first (KHN2) and second (KHN3) acid immersions, to determine initial erosion in the first day. The formula: %KHNalt=[(KHN3-KHN2)/KHN2]*100 was used to define the protective effect of the treatments. After the 5-day cycling, surface loss (SL, in µm) was evaluated with profilometry. Data were analyzed with 2-way ANOVA and Tukey's tests (p<0.05). RESULTS: For %KHNalt, the polymers alone did not reduce enamel demineralization when compared to the negative control, but Carbopol associated with NaF significantly improved its protective effect. The profilometric analysis showed that Carbopol, associated or not with NaF, exhibited the lowest SL, while CMC and Aristoflex did not exhibit a protective effect, nor were they able to improve the protection of NaF. CONCLUSIONS: It is concluded that Carbopol enhanced NaF's protection against initial erosion. Carbopol alone or associated with NaF was able to reduce SL after several erosive challenges. CLINICAL SIGNIFICANCE: Carbopol by itself was able to reduce the erosive wear magnitude to the same extent as the sodium fluoride, therefore, is a promising agent to prevent or control enamel erosion.

Influência de polímeros bioadesivos sobre o efeito protetor do flúor no desenvolvimento da erosão dental / Influence of polymers bioadhesive on the protective effect of fluoride over enamel erosion development

A erosão é um processo multifatorial que envolve a desmineralização dental pela ação química de ácidos extrínsecos ou intrínsecos. Visto que o efeito protetor do flúor contra erosão tem sido relacionado principalmente à formação de depósitos de fluoreto de cálcio e à adsorção de íons flúor na superfície dental, hipotetizou-se que a incorporação de agentes bioadesivos nas soluções fluoretadas poderia aumentar a interação de flúor aos tecidos e, consequentemente, potencializar seu efeito protetor. Neste estudo foram testados três polímeros (Carbopol 980, Carboximetil Celulose e Aristoflex AVC), em concentrações pré-determinadas com base na viscosidade da solução a ser utilizada, que simularam um enxaguatório bucal. Amostras de esmalte bovino foram confeccionadas e submetidas a um modelo de desmineralização e remineralização com imersão em ácido cítrico a 0,3%, pH 2,6, tratamentos com as soluções contendo os polímeros associados ou não ao fluoreto de sódio (900 ppm) e imersão em saliva artificial. Foram realizadas medidas de microdureza Knoop (KHN1) e análise perfilométrica inicial de todos os espécimes. Após o primeiro desafio ácido, foi realizada novamente leitura da microdureza dos espécimes (KHN2), bem como após a primeira imersão nas soluções de tratamento (KHN3) e o segundo desafio ácido (KHN4), caracterizando a avaliação da erosão inicial. A alteração de percentual de remineralização (% rem = (KHN3-KHN2/KHN2)*100) e de proteção (% prot = (KHN4-KHN2/KHN2)*100) foram determinadas. A ciclagem des-re foi repetida por cinco dias, 6x/dia, com imersão nas soluções de tratamento após a primeira e última imersão diária em ácido. Ao final do experimento, a análise perfilométrica final foi realizada para mensurar a perda de estrutura de esmalte, comparando-se a altura dos perfis inicial e final. Os dados foram analisados com o teste estatístico ANOVA e teste de Tukey (p < 0,05). Nenhum polímero isolado apresentou propriedades de remineralização, apenas o Carbopol, ...

Dental erosion is a multifactorial process involving tooth demineralization by the chemical action of intrinsic and extrinsic acids. Since the protective effect of fluoride against erosion has been mainly related to fluoride adsorption and calcium fluoride deposits on tooth surface, it was hypothesized that the incorporation of bioadhesive polymers in fluoridated solutions would increase fluoride interaction with the enamel surface, and consequently, enhance its protective effect. In this study, three polymers were tested (Carbopol 980, Carboxymethyl Cellulose and Aristoflex AVC), in pretested concentrations based on the viscosity of the solutions to be used, which simulated a mouthrinse. Bovine enamel specimens were prepared and submitted to a demineralization-remineralization model with immersion in 0.3% citric acid, treatment with polymers solution associated or not to sodium fluoride (900 ppm), and storage in artificial saliva. Initial Knoop hardness (KHN1) and profilometry of all specimens were measured. After the first acid challenge, microhardness were measured again (KHN2), as well as after the first immersion in treatment solutions (KHN3) and after the second acid challenge (KHN4), characterizing the initial erosion analysis. Percentage of remineralization (%rem=KHN3-KHN2/KHN2*100) and of protection (%prot=(KHN4-KHN2/KHN2*100) was determined. The demineralization-remineralization cycling was repeated for five days, 6x/day, with immersion in treatment solutions after the first and last acid immersion of the day. At the end of the experiment, enamel loss was assessed with profilometry, by comparison of the initial and final profiles. Data were analyzed with ANOVA an Tukey´s tests (p < 0.05). Regarding rehardening properties, no polymer isolated differed from control. When associated to NaF, Carbopol presented similar %rem compared to NaF control. For initial erosion protection, the polymers isolated did not significantly reduce ...