Fluoruro de estaño en el control de cavidades sin restauración en dientes temporales / Stannous fluoride in nonrestorative cavity control in primary teeth

Introducción: el control de cavidades sin restauración (NRCC, por sus siglas en inglés), es una opción de tratamiento conservador y no invasivo para dentina cariosa, sobre todo en dentición temporal. Una de las estrategias del NRCC es la remineralización. El fluoruro de estaño (FDE) puede considerarse, como una opción viable ya que existe evidencia de su eficacia cariostática. Objetivo: valorar al FDE como remineralizante alternativo en dentina de molares temporales, asociado al NRCC. Material y métodos: se efectuó un estudio clínico, epidemiológico, y descriptivo con preescolares voluntarios de 3 a 5 años de edad con consentimiento firmado de participación en el estudio, y que presentaron molares con ICDAS 5 y 6. La aplicación del FDE a 0.8%, la evaluación de la dureza de la dentina con los criterios de Nyvad, y el diagnóstico del estado pulpar, la efectuó un operador entrenado para esta finalidad. Se aplicó un análisis estadístico descriptivo y uno no paramétrico. Resultados: el efecto cariostático producido por el FDE a 0.8%, sobre dentina afectada de molares temporales de niños mexicanos fue estadísticamente significativo durante cinco meses. Conclusiones: la aplicación de fluoruro de estaño puede considerarse como una alternativa de tratamiento cariostático asociado al NRCC para niños de 3 a 5 años de edad (AU)

Introduction: nonrestorative cavity control (NRCC), is a conservative and non-invasive treatment option for carious dentin, especially in primary dentition. One of the NRCC strategies is remineralization. Stannous Fluoride (SDF) can be considered as a viable option since there is evidence of its cariostatic efficacy. Objective: to evaluate FDE as an alternative remineralizing agent in the dentin of primary molars, associated with NRCC. Material and methods: a clinical, epidemiological, and descriptive study was carried out with preschool volunteers aged 3 to 5 years with signed consent to participate in the study, and who presented molars with ICDAS 5 and 6. The application of FDE at 0.8%, the evaluation of dentin hardness with the Nyvad criteria, and the diagnosis of pulp status, was carried out by an operator trained for this purpose. A descriptive and non-parametric statistical analysis was applied. Results: the cariostatic effect produced by 0.8% FDE on affected dentin of primary molars of Mexican children was statistically significant for five months. Conclusions: the application of stannous fluoride can be considered as an alternative cariostatic treatment associated with NRCC for children 3 to 5 years of age (AU)

Avaliação de um gel contendo fluoreto e estanho como uma opção de tratamento profissional para o controle da erosão do esmalte e da dentina / Evaluation of a gel containing fluoride and stannous as an option for the professional treatment of enamel and dentin erosion

Este estudo teve o objetivo de desenvolver um gel experimental contendo flúor e estanho, como uma opção de tratamento profissional, para ser utilizado na prevenção da erosão dental. Foram utilizados 50 fragmentos (4mm × 4mm × 2mm) de esmalte e 50 de dentina, obtidos de incisivos bovinos. Os fragmentos foram incluídos em resina acrílica, planificados e polidos. Em seguida, uma fita adesiva foi posicionada sobre a superfície polida desses espécimes, deixando uma janela de 4mm × 1mm exposta aos testes subsequentes. Os espécimes foram previamente erodidos (10min em solução de ácido cítrico a 1%, pH~2,4) e distribuídos aleatoriamente em cinco grupos experimentais (n=10 para cada substrato), de acordo com os seguintes tratamentos: 1. F+Sn+HPMC: Gel de fluoreto de sódio e cloreto de estanho experimental (7500 ppm F- e 15000 ppm Sn2+, pH=4,5); 2. F+HPMC: Gel de fluoreto de sódio experimental (7500 ppm F-, pH=4,5); 3. Comercial: Gel de flúor fosfato acidulado comercial - APF (12300 ppm F-, pH=3,2); 4. Placebo: Gel placebo (Hidroxipropil MetilceluloseHPMC, sem componentes ativos); 5. Controle negativo: sem tratamento; aplicados por 60 s. Na sequência, os espécimes foram submetidos a uma ciclagem de erosão-re-deposição mineral, que consistia em 5 min de imersão em solução de ácido cítrico a 0,3% (pH~2,6), seguido de imersão em saliva artificial por 60min, 4x/dia, durante 5 dias. A perda de superfície dos espécimes (PS em m) foi determinada com um perfilômetro óptico após 5, 10 e 20 dias de ciclagem. Os dados obtidos foram analisados com ANOVA de dois fatores de medidas repetidas, considerando um nível de significância de 5%. Para o esmalte, o placebo não diferiu do controle em nenhum tempo experimental, e ambos apresentaram significativamente a maior PS. Após 5 e 10 dias: (F+Sn+HPMC)=(comercial)<(F+HPMC)<(placebo)=(controle). Após 20 dias: (F+Sn+HPMC)=(F+HPMC)=(comercial)<(controle)=(placebo). Para dentina, no 5º dia: (comercial)=(F+Sn+HPMC)=(F+HPMC)<(controle)=(placebo). No 10º dia, os grupos F+Sn+HMC, comercial e F+HPMC continuaram apresentando menor PS do que o controle e o placebo, porém, F+HPMC não diferiu significativamente desses dois últimos grupos. No 20º dia, somente o comercial apresentou menor PS que controle e placebo. Considerando as limitações desse estudo in vitro, pode-se concluir que o gel de F+Sn+HPMC foi capaz de controlar a progressão da erosão dental de maneira semelhante ao gel comercial, que possui 4800 ppm a mais de fluoreto em sua composição, exceto após 20 dias de desafio erosivo na dentina. Esse gel é uma alternativa clínica viável, podendo ser potencialmente utilizado em conjunto com produtos de uso diário, visando o aumento da proteção contra erosão em indivíduos com alto risco para erosão dental.

Effect of Polyphenols on the Ultrastructure of the Dentin Pellicle and Subsequent Erosion.

INTRODUCTION: Erosive tooth wear is a highly prevalent dental condition that is modified by the ever-present salivary pellicle. The aim of the present in situ study was to investigate the effect of polyphenols on the ultrastructure of the pellicle formed on dentin in situ and a subsequent erosive challenge. METHODS: The pellicle was formed on bovine dentin specimens for 3 min or 2 h in 3 subjects. After subjects rinsed with sterile water (negative control), 1% tannic acid, 1% hop extract, or tin/fluoride solution containing 800 ppm tin and 500 ppm fluoride (positive control), specimens were removed from the oral cavity. The erosive challenge was performed on half of the specimens with 1% citric acid, and all specimens were analyzed by transmission electron microscopy. Incorporation of tannic acid in the pellicle was investigated by fluorescence spectroscopy. RESULTS: Compared to the negative control, ultrastructural analyses reveal a thicker and electron-denser pellicle after application of polyphenols, in which, according to spectroscopy, tannic acid is also incorporated. Application of citric acid resulted in demineralization of dentin, but to a lesser degree when the pellicle was pretreated with a tin/fluoride solution. The pellicle was more acid-resistant than the negative control when modified with polyphenols or tin/fluoride solution. CONCLUSION: Polyphenols can have a substantial impact on the ultrastructure and acid resistance of the dentin pellicle, while the tin/fluoride solution showed explicit protection against erosive demineralization.

Film-Forming Polymers for Inhibition of Hydroxyapatite Dissolution: A Screening Study.

The aim of this study was to evaluate the effect of film-forming polymer solutions of different concentrations and pH values, either associated or not with sodium fluoride (F; 225 ppm F-), when applied during the initial stage of salivary pellicle formation, to prevent the dissolution of hydroxyapatite (HA), which was determined by the pH-stat method. Polyacrylic acid (PA), chitosan, sodium linear polyphosphate (LPP), polyvinyl methyl ether/maleic anhydride (PVM/MA), and propylene glycol alginate (PGA) were tested in three concentrations (lower, medium, and higher), two pH values (native or adjusted), and either associated or not with F. Distilled water, F, and stannous ion+fluoride (Sn/F; 225 ppm F- and 800 ppm Sn2+, as SnCl2) solutions were the controls, totalizing 63 groups. HA crystals were pretreated with human saliva for 1 min to allow pellicle formation, then immersed in the experimental solutions (1 min), and exposed to saliva for another 28 min. Subsequently, they were added to a 0.3% citric acid solution (pH = 3.8), connected to a pH-stat system that added aliquots of 28 µL 0.1 N HCl for a total reaction time of 5 min. Data were analyzed with one-way ANOVA and Tukey's tests (α = 0.05). For PA alone, the concentrations of 0.1% (native pH), 0.06%, and 0.08% (both pH adjusted) showed significantly lower HA dissolution than the negative control. PA concentrations of 0.1% and 0.08%, of both pH values, improved the effect of F against HA dissolution to a near-identical value as Sn/F. All solutions containing chitosan and LPP significantly reduced HA dissolution in comparison with the control. For chitosan, the concentration of 0.5% (in both pH values) improved the effect of F. LPP at 0.5% (native pH) and all associations of LPP with F outperformed the effect of F. Some PVM/MA solutions significantly reduced HA dissolution but PVM/MA could not improve the protection of F. PGA was incapable of reducing HA dissolution or improving F effect. It was concluded that chitosan, LPP, and some PA and PVM/MA solutions used alone were capable of reducing HA dissolution. Only PA, chitosan, and LPP were able to enhance fluoride protection, but for PA and chitosan, this was influenced by the polymer concentration.

Iron oxide nanozymes stabilize stannous fluoride for targeted biofilm killing and synergistic oral disease prevention.

Dental caries is the most common human disease caused by oral biofilms despite the widespread use of fluoride as the primary anticaries agent. Recently, an FDA-approved iron oxide nanoparticle (ferumoxytol, Fer) has shown to kill and degrade caries-causing biofilms through catalytic activation of hydrogen peroxide. However, Fer cannot interfere with enamel acid demineralization. Here, we show notable synergy when Fer is combined with stannous fluoride (SnF2), markedly inhibiting both biofilm accumulation and enamel damage more effectively than either alone. Unexpectedly, we discover that the stability of SnF2 is enhanced when mixed with Fer in aqueous solutions while increasing catalytic activity of Fer without any additives. Notably, Fer in combination with SnF2 is exceptionally effective in controlling dental caries in vivo, even at four times lower concentrations, without adverse effects on host tissues or oral microbiome. Our results reveal a potent therapeutic synergism using approved agents while providing facile SnF2 stabilization, to prevent a widespread oral disease with reduced fluoride exposure.

Avaliação de um gel contendo fluoreto e estanho como uma opção de tratamento profissional para o controle da erosão do esmalte e da dentina / Evaluation of a gel containing fluoride and stannous as an option for the professional treatment of enamel and dentin erosion

Este estudo teve o objetivo de desenvolver um gel experimental contendo flúor e estanho, como uma opção de tratamento profissional, para ser utilizado na prevenção da erosão dental. Foram utilizados 50 fragmentos (4mm × 4mm × 2mm) de esmalte e 50 de dentina, obtidos de incisivos bovinos. Os fragmentos foram incluídos em resina acrílica, planificados e polidos. Em seguida, uma fita adesiva foi posicionada sobre a superfície polida desses espécimes, deixando uma janela de 4mm × 1mm exposta aos testes subsequentes. Os espécimes foram previamente erodidos (10min em solução de ácido cítrico a 1%, pH~2,4) e distribuídos aleatoriamente em cinco grupos experimentais (n=10 para cada substrato), de acordo com os seguintes tratamentos: 1. F+Sn+HPMC: Gel de fluoreto de sódio e cloreto de estanho experimental (7500 ppm F- e 15000 ppm Sn2+, pH=4,5); 2. F+HPMC: Gel de fluoreto de sódio experimental (7500 ppm F-, pH=4,5); 3. Comercial: Gel de flúor fosfato acidulado comercial - APF (12300 ppm F-, pH=3,2); 4. Placebo: Gel placebo (Hidroxipropil MetilceluloseHPMC, sem componentes ativos); 5. Controle negativo: sem tratamento; aplicados por 60 s. Na sequência, os espécimes foram submetidos a uma ciclagem de erosão-re-deposição mineral, que consistia em 5 min de imersão em solução de ácido cítrico a 0,3% (pH~2,6), seguido de imersão em saliva artificial por 60min, 4x/dia, durante 5 dias. A perda de superfície dos espécimes (PS em m) foi determinada com um perfilômetro óptico após 5, 10 e 20 dias de ciclagem. Os dados obtidos foram analisados com ANOVA de dois fatores de medidas repetidas, considerando um nível de significância de 5%. Para o esmalte, o placebo não diferiu do controle em nenhum tempo experimental, e ambos apresentaram significativamente a maior PS. Após 5 e 10 dias: (F+Sn+HPMC)=(comercial)<(F+HPMC)<(placebo)=(controle). Após 20 dias: (F+Sn+HPMC)=(F+HPMC)=(comercial)<(controle)=(placebo). Para dentina, no 5º dia: (comercial)=(F+Sn+HPMC)=(F+HPMC)<(controle)=(placebo). No 10º dia, os grupos F+Sn+HMC, comercial e F+HPMC continuaram apresentando menor PS do que o controle e o placebo, porém, F+HPMC não diferiu significativamente desses dois últimos grupos. No 20º dia, somente o comercial apresentou menor PS que controle e placebo. Considerando as limitações desse estudo in vitro, pode-se concluir que o gel de F+Sn+HPMC foi capaz de controlar a progressão da erosão dental de maneira semelhante ao gel comercial, que possui 4800 ppm a mais de fluoreto em sua composição, exceto após 20 dias de desafio erosivo na dentina. Esse gel é uma alternativa clínica viável, podendo ser potencialmente utilizado em conjunto com produtos de uso diário, visando o aumento da proteção contra erosão em indivíduos com alto risco para erosão dental.

Efeitos de diferentes dentifrícios na permeabilidade e rugosidade de dentina erodida / Effect of different toothpastes on permeability and roughness of eroded dentin

O objetivo deste estudo foi avaliar a rugosidade, a obliteração dos túbulos dentinários e a permeabilidade da dentina erodida e escovada com diferentes dentifrícios. Noventa dentes bovinos foram seccionadas em blocos, sendo que em trinta a hemiface foi protegida com verniz ácido resistente e sessenta foram submetidos ao teste de permeabilidade. Os espécimes foram divididos de acordo com os dentifrícios: sem flúor (SF), com fluoreto de sódio (NaF) e com fluoreto de estanho (SnF2). Em seguida, os blocos foram submetidos a um protocolo erosivo-abrasivo por 5 dias. As análises de rugosidade superficial e obliteração dos túbulos dentinários (n=10) foram realizadas nas hemifaces controle e teste do mesmo espécime e a análise da permeabilidade (n=20) foi realizada novamente. Os dados foram submetidos aos testes de ANOVA a dois critérios medidas repetidas e pós teste de Tukey (p≤0,05). Os grupos NaF e SnF2 apresentaram maior rugosidade comparando-se ao SF. O grupo SF apresentou a maior quantidade de túbulos abertos quanto comparado aos demais. Não houve diferença significativa na permeabilidade pós-ciclagem entre os dentifrícios SF e NaF, contudo o dentifrício SnF2 apresentou maior permeabilidade comparando-se aos demais. Ambos os dentifrícios contendo flúor tiveram oclusão efetiva dos túbulos dentinários; contudo, os efeitos da presença de fluoreto de estanho na permeabilidade podem ser neutralizados pela abrasão deste dentifrício(AU)

The aim of this study was to evaluate the roughness, dentin tubule occlusion and permeability of eroded dentin brushed with different toothpastes. Ninety bovine teeth were sectioned in blocks. The hemiface of thirty specimens was protect with acid resistant varnish and sixty were submitted to permeability test. The specimens were divided according to the dentifrices: without fluoride (WF), sodium fluoride (NaF) and stannous fluoride (SnF2). Then, the blocks were submitted to erosive-abrasive protocol for 5 days. The analysis of surface roughness and dentin tubule occlusion (n=10) were performed on control and test hemifaces of the same sample and permeability analysis (n=20) was again performed. Data were analyzed by two-way RM ANOVA and Tukey tests (p≤0.05). NaF and SnF2 groups presented higher roughness when compared with WF. WF group presented larger number of opened tubules compared to the others. No significant differences were found between WF and NaF for permeability; however, SnF2 presented higher hydraulic conductance compared to other dentifrices. In conclusion, both fluoride-containing toothpastes had promising tubule occlusion; however, the effects on permeability of stannous formulation may be counteracted by the effects of abrasion from this dentifrice(AU)

Influence of cigarette smoke combined with different toothpastes on enamel erosion.

This in vitro study aimed to evaluate the effect of different toothpastes on dental enamel subjected to an erosive cycle with and without exposure to cigarette smoke. Bovine enamel specimens were randomly allocated into 12 groups (n = 12). For the in vitro simulation of smoking, half the groups underwent an exposure cycle of 20 cigarettes per day for 5 days. Subsequently, all groups were subjected to a 5-day erosion cycle intercalating demineralization (1 min; 1% citric acid; pH = 3.5) and treatment with toothpaste slurries (2 min) of NaF, SnF2, F/Sn/Chitosan, F/CaSiO3/Na3PO4, and F/bioactive glass. The control group was immersed in distilled water. Surface microhardness (SMH) was measured initially, after exposure to smoke, and after the erosive cycle, and %SMH was calculated. At the end of the experimental cycle, surface roughness, profilometry, and atomic force microscopy (AFM) were performed. SMH increased after exposure to cigarette smoke (p < 0.05). After the erosive cycle, there were no differences between the presence and absence of cigarette smoke exposure in SMH and roughness (p > 0.05). Besides increasing enamel SMH, cigarette smoke did not prevent enamel loss after the erosion cycle (p < 0.05). In profilometry, roughness and surface loss had the lowest values in the groups treated with SnF2 and F/Sn/Chitosan (p < 0.05). AFM showed lower mineral loss with F/CaSiO3/Na3PO4 and F/Sn/Chitosan. For all groups, except F/CaSiO3/Na3PO4, cigarette smoke resulted in higher enamel wear. F/Sn/Chitosan showed the best results against erosion.

Solving the problem with stannous fluoride: Formulation, stabilization, and antimicrobial action.

BACKGROUND: Stannous fluoride (SnF2) is a compound present in many commercially available dentifrices; however, oxidative decomposition negatively impacts its efficacy. Stannous oxidation is often mitigated through the addition of complexing agents or sources of sacrificial stannous compounds. The authors have found that the addition of zinc phosphate significantly improved stannous stability more effectively than other stabilization methods. The authors evaluated the chemical speciation of stannous compounds within a variety of formulations using x-ray absorption near edge spectroscopy (XANES), a technique never used before in this manner. These data were compared and correlated with several antimicrobial experiments. METHODS: XANES data of various commercially available compounds and Colgate TotalSF were performed and analyzed against a library of reference compounds to determine the tin chemical speciation. The antibacterial assays used were salivary adenosine triphosphate, short-interval kill test, plaque glycolysis, and anaerobic biofilm models. RESULTS: XANES spectra showed a diverse distribution of tin species and varying degrees of SnF2 oxidation. In vitro antimicrobial assessment indicated significant differences in performance, which may be correlated to the differences in tin speciation and oxidation state. CONCLUSIONS: Driven by the excipient ingredients, SnF2 dentifrices contain a distribution of tin species in either the SnF2 or Sn(IV) oxidation state. The addition of zinc phosphate provided significant robustness against oxidation, which directly translated to greater efficacy against bacteria. PRACTICAL IMPLICATIONS: The choice of inactive ingredients in a dentifrice with active SnF2 can dramatically impact product stability.

Randomized in situ clinical trial evaluating erosion protection efficacy of a 0.454% stannous fluoride dentifrice.

OBJECTIVES: To assess the protective effects of a 0.454% stabilized stannous fluoride dentifrice and a marketed triclosan dentifrice against enamel erosion in a 10-day in situ model. METHODS: This was a double-blind, randomized, 2-treatment, 4-period, crossover in situ trial involving healthy adult participants. Participants were randomized to a treatment sequence involving the following products: a highly bioavailable 0.454% stannous fluoride dentifrice (Procter & Gamble) and a marketed dentifrice control containing 0.24% sodium fluoride and 0.3% triclosan (Colgate-Palmolive). Each study period took place over 10 days. Participants wore an intra-oral appliance retaining two polished human enamel samples for 6 hours per day. Two times per day they swished with the assigned dentifrice slurry and four times per day they swished with 250 mL of orange juice (25 mL per minute) over a 10-minute period. Contact profilometry measurements were made for each sample at baseline and day 10 to determine surface change. RESULTS: Thirty-six participants were enrolled and 33 completed the study (mean age = 40.5 years). The stannous fluoride dentifrice demonstrated 93.5% less enamel loss than the NaF/triclosan dentifrice (P < 0.001) at Day 10, with median enamel loss of 0.097 µm and 1.495 µm, respectively. Both products were well tolerated. CONCLUSION: The stannous fluoride dentifrice demonstrated significantly greater erosion protection efficacy relative to the NaF/triclosan dentifrice in this randomized in situ clinical trial.

Anti-Erosive Effect of Solutions Containing Sodium Fluoride, Stannous Chloride, and Selected Film-Forming Polymers.

The aim of this study was to evaluate the anti-erosive effect of solutions containing sodium fluoride (F: 225 ppm F-), stannous chloride (Sn: 800 ppm Sn2+), and some film-forming polymers (Gantrez: Poly [methylvinylether-alt-maleic anhydride]; PGA: propylene glycol alginate; Plasdone: poly[vinylpyrrolidone]; and CMC: carboxymethylcellulose). Solutions were tested in an erosion-remineralization cycling model, using enamel and dentin specimens (n = 10, for each substrate). Distilled water was the negative control. Cycling consisted of 120 min immersion in human saliva, 5 min in 0.3% citric acid solution, and 120 min of exposure to human saliva, 4×/day, for 5 days. Treatment with solutions (pH = 4.5) was carried out 2×/day, for 2 min. Surface loss (SL) was evaluated with optical profilometry. Zeta potential of hydroxyapatite crystals was determined after treatment with the solutions. Data were statistically analyzed (α = 0.05). For enamel, all polymers showed significantly lower SL (in µm) than the control (11.09 ± 0.94), except PGA (10.15 ± 1.25). PGA significantly improved the protective effect of F (4.24 ± 0.97 vs. 5.64 ± 1.60, respectively). None of the polymers increased the protection of F+Sn (5.13 ± 0.78). For dentin, only Gantrez (11.40 ± 0.97) significantly reduced SL when compared with the negative control (12.76 ± 0.75). No polymer was able to enhance the effect of F (6.28 ± 1.90) or F+Sn (7.21 ± 1.13). All fluoridated solutions demonstrated significantly lower SL values than the control for both substrates. Treatment of hydroxyapatite nanoparticles with all solutions resulted in more negative zeta potentials than those of the control, except Plasdone, PGA, and F+Sn+PGA, the latter two presenting the opposite effect. In conclusion, Gantrez, Plasdone, and CMC exhibited an anti-erosive effect on enamel. PGA increased the protection of F. For dentin, only Gantrez reduced erosion.

Effect of palm oil alone or associated to stannous solution on enamel erosive-abrasive wear: A randomized in situ/ex vivo study.

OBJECTIVE: Palm oil has demonstrated preventive potential against initial erosive demineralization in vitro. This in situ study evaluated the effect of palm oil alone or associated with stannous-containing (Sn) solution on preventing enamel loss from an erosive/abrasive challenge. DESIGN: This single-blind, randomized, crossover in situ/ex vivo study was developed in four phases (one per group of five days) with sixteen volunteers. Enamel blocks (n = 256) were allocated to groups according to the treatment: Palm oil; Palm oil plus Sn solution; Sn solution - positive control; and Deionized water - negative control. Half of the enamel blocks of each group was subjected to erosion and the other half to erosion + abrasion. The daily ex vivo protocol consisted of four citric acid immersions (2 min). Before the first and third acid exposure, the blocks were treated with the test solutions (1 drop/block) for 1 min followed by acid immersion and abrasive challenge (toothpaste was applied on all blocks and half were brushed for 15 s/block). Enamel loss was quantified profilometrically and data were analyzed by two-way ANOVA and Tukey's test (p < 0.05). RESULTS: A significant difference was found for type of treatment (p < 0.001); wear condition (p = 0.38) and the treatment x condition interaction (p = 0.33) was non-significant. Palm oil associated or not to Sn solution significantly reduced enamel wear in comparison with the negative control but did not differ from the positive control (p > 0.05). CONCLUSIONS: Palm oil was able to prevent enamel loss under erosive and erosive + abrasive challenges in a similar extend to stannous-containing commercial solution.

In vitro efficacy of essential oil mouthrinse versus dentifrices.

OBJECTIVES: To compare the antimicrobial efficacy and kill penetration of essential oils (EO) mouthrinse versus stannous fluoride, and triclosan dentifrice slurries on saliva-derived biofilms using confocal laser scanning microscopy (CLSM). METHODS: Saliva-derived biofilms were grown for 48h on hydroxyapatite discs using pooled, homogenized saliva from 8 healthy volunteers as the inoculum. The mean thickness of these biofilms was 84µm (range, 23-241µm). CLSM with viability mapping was used to visualize the antimicrobial kill penetration of each treatment regime within a biofilm. RESULTS: At 30s treatment durations, CLSM imaging revealed greater antimicrobial activity and kill penetration of EO mouthrinse compared to sodium fluoride-, stannous fluoride-, and triclosan-containing dentifrice slurries. Quantification of biovolume revealed that EO mouthrinse treatment at 30s resulted in a greater non-viable biovolume proportion (84.6%±15.0%) than other treatment groups. Increasing the treatment duration of the triclosan dentifrice (to 60 and 120s) resulted in better penetration and an increased reduction of viable cells, comparable to EO mouthrinse treatment at 30s duration. Further, CLSM imaging showed that the combined treatment of a non-antimicrobial dentifrice (45s) with EO mouthrinse (30s) showed superior antimicrobial activity (96.2%±3.7%) compared to the antimicrobial triclosan-containing dentifrice used without a mouthrinse step (26.0%±32.0%). CONCLUSIONS: Within typical exposure times, the EO-containing mouthrinse can penetrate deep into the accumulating plaque biofilm compared to the chemotherapeutic dentifrice slurries, and may provide an efficacious alternative to triclosan, when used as an adjunct with a mechanical oral care regimen. CLINICAL SIGNIFICANCE: Using viability mapping and CLSM, this study demonstrated that EO-containing mouthrinse penetrates and kills microorganisms deeper and more effectively in plaque biofilm in typical exposure times when compared to dentifrice chemotherapeutic agents, providing an efficacious alternative to triclosan or stannous fluoride when used as an adjunct to mechanical oral care.

In situ evaluation of fluoride-, stannous- and polyphosphate-containing solutions against enamel erosion.

OBJECTIVE: To evaluate the anti-erosive effect of solutions containing sodium fluoride (F: 225ppm of fluoride), sodium fluoride+stannous chloride (F+Sn: 225ppm of fluoride+800ppm of stannous), sodium fluoride+stannous chloride+sodium linear polyphosphate (F+Sn+LPP: 225ppm of fluoride+800ppm of stannous+2% of sodium linear polyphosphate), and deionized water (C: control), using a four-phase, single-blind, crossover in situ clinical trial. METHODS: In each phase, 12 volunteers wore appliances containing 4 enamel specimens, which were submitted to a 5-day erosion-remineralization phase that consisted of 2h of salivary pellicle formation with the appliance in situ, followed by 2min extra-oral immersion in 1% citric acid (pH 2.4), 6x/day, with 90min of exposure to saliva in situ between the challenges. Treatment with the test solutions was performed extra-orally for 2 min, 2x/day. At the end of the experiment, surface loss (SL, in µm) was evaluated by optical profilometry. Data were analyzed using ANOVA and Tukey tests (α=0.05). The surface of additional specimens was evaluated by x-ray diffraction after treatments (n=3). RESULTS: C (mean SL±standard-deviation: 5.97±1.70) and F (5.36±1.59) showed the highest SL, with no significant difference between them (p>0.05). F+Sn (2.68±1.62) and F+Sn+LPP (2.10±0.95) did not differ from each other (p>0.05), but presented lower SL than the other groups (P<0.05). Apatite and stannous deposits on specimen surfaces were identified in the x-ray analysis for F+Sn and F+Sn+LPP. CONCLUSIONS: Sodium fluoride solution exhibited no significant anti-erosive effect. The combination between sodium fluoride and stannous chloride reduced enamel erosion, irrespective of the presence of linear sodium polyphosphate. CLINICAL SIGNIFICANCE: Under highly erosive conditions, sodium fluoride rinse may not be a suitable alternative to prevent enamel erosion. A rinse containing sodium fluoride and stannous chloride was shown to be a better treatment option, which was not further improved by addition of the sodium linear polyphosphate.

Comparative effect of a stannous fluoride toothpaste and a sodium fluoride toothpaste on a multispecies biofilm.

OBJECTIVES: This paper aimed to compare the mode of action of a stannous fluoride-containing toothpaste with a conventional sodium fluoride-containing toothpaste on anti-biofilm properties. METHODS: A three-species biofilm model that consists of Streptococcus mutans, Streptococcus sanguinis and Porphyromonas gingivalis was established to compare the anti-biofilm properties of a stannous fluoride-containing toothpaste (CPH), a conventional sodium fluoride-containing toothpaste (CCP) and a negative control (PBS). The 48h biofilms were subjected to two-minute episodes of treatment with test agents twice a day for 5 consecutive days. Crystal violet staining and XTT assays were used to evaluate the biomass and viability of the treated biofilm. Live/dead staining and bacteria/extracellular polysaccharides (EPS) double-staining were used to visualize the biofilm structure and to quantify microbial/extracellular components of the treated biofilms. Species-specific fluorescent in situ hybridization and quantitative polymerase chain reaction (qPCR) were used to analyze microbial composition of the biofilms after treatment. RESULTS: The biomass and viability of the biofilms were significantly reduced after CPH toothpaste treatment. The inhibitory effect was further confirmed by the live/dead staining. The EPS amounts of the three-species biofilm were significantly reduced by CCP and CPH treatments, and CPH toothpaste demonstrated significant inhibition on EPS production. More importantly, CPH toothpaste significantly suppressed S. mutans and P. gingvalis, and enriched S. sanguinis in the three-species biofilm. In all experiments CPH had a significantly greater effect than CCP (p<0.05) and CCP had a greater effect than PBS (p<0.05). CONCLUSIONS: Stannous fluoride-containing toothpaste not only showed better inhibitory effect against oral microbial biofilm, but was also able to modulate microbial composition within multi-species biofilm compared with conventional sodium fluoride-containing toothpaste.

A clinical study to measure anti-erosion properties of a stabilized stannous fluoride dentifrice relative to a sodium fluoride/triclosan dentifrice.

OBJECTIVE: To compare the enamel protection efficacy of a stabilized stannous fluoride (SnF2 ) dentifrice to a sodium fluoride (NaF)/triclosan dentifrice following acidic erosive challenge. METHODS: In this in situ, randomized, controlled, double-blind, two-treatment, four-period crossover clinical trial, subjects wore an appliance fitted with human enamel samples 6 h day-1 during each 15-day treatment period. Twice each treatment day they swished with their assigned dentifrice slurry: 0.454% SnF2 /0.077% NaF or 0.32% NaF/0.3% triclosan. After each treatment and two other times daily, subjects swished with 250 ml of orange juice over a 10-min period (acidic erosive challenge). Enamel samples were measured for tooth surface loss using contact profilometry at baseline and days 10 and 15. RESULTS: Thirty-six subjects (mean age 44.8 years, range 23-65 years) were randomized to treatment; 33 subjects completed the final study visit. There were no statistically significant baseline differences (P > 0.44) in the specimen surfaces of the two dentifrice treatment groups via profilometry. At day 10, the SnF2 dentifrice provided a statistically significant (P < 0.0001) reduction in enamel loss by 67% versus the NaF/triclosan dentifrice with estimated medians of 1.22 and 3.68 µm, respectively. At day 15, the SnF2 dentifrice again provided a significantly greater benefit (P < 0.0001) against tooth surface loss versus the NaF/triclosan dentifrice, with 68% less erosion, and estimated medians of 1.60 and 5.03 µm, respectively. Both dentifrices were well tolerated. CONCLUSION: A stabilized SnF2 dentifrice provided superior protection against the initiation and progression of tooth enamel surface loss in situ after erosive challenge compared to a NaF/triclosan dentifrice.

AmF/NaF/SnCl2 solution reduces in situ enamel erosion - profilometry and cross-sectional nanoindentation analysis

Abstract This in situ study aimed to investigate the effect of a tin-containing fluoride solution in preventing enamel erosion. Also, its effects on the partly demineralized zone were assessed for the first time. Thirteen volunteers participated in this 2-phase study, wearing removable intra-oral appliances containing four sterilized bovine enamel slabs, for 8 days, where 2 treatment protocols were tested using samples in replicas (n = 13): CO - no treatment (negative control) and FL - AmF/NaF/SnCl2 solution (500 ppm F-, 800 ppm Sn2+, pH = 4.5). Samples were daily exposed to an erosive challenge (0.65% citric acid, pH 3.6, 4 min, 2x/day). In the 2nd phase, volunteers switched to the other treatment protocol. Samples were evaluated for surface loss using a profilometer (n = 13) and a cross-sectional nanohardness (CSNH) test (n = 13) was carried out in order to determine how deep the partly demineralized zone reaches below the erosive lesion. The data were statistically analyzed by two-way ANOVA. Erosive challenges lead to smaller enamel surface loss (p < 0.001) in the FL group when compared to group CO. Data from CSNH showed that there was no significant difference in demineralized enamel zone underneath erosion lesions between the groups. An amorphous layer could be observed on the surface of enamel treated with tin-containing solution alone. Under the experimental conditions of this in situ study, it can be concluded that AmF/NaF/SnCl2 solution prevents enamel surface loss but does not change the hardness of the partly demineralized zone near-surface enamel.

Impact of CO2 laser and stannous fluoride on primary tooth erosion.

This study evaluated in vitro the effect of input power of CO2 laser, either associated or not to stannous fluoride (SnF2) gel, for the control of intrinsic erosion in primary teeth. One hundred four enamel slabs (3 × 3 × 2 mm) from human primary molars were flattened and polished. Adhesive tapes were placed on their surface leaving a window of 3 × 1 mm. Slabs were then cycled four times in 0.01 M hydrochloric acid (pH 2, 2 min) and in artificial saliva (2 h) for creation of erosive lesions. Specimens were randomly assigned into eight groups (n = 13) according to fluoride application [absent (control) or 0.4% stannous fluoride gel (SnF2)] and input power of CO2 laser [unlased (control), 0.5, 1.0 or 1.5 W]. The CO2 laser irradiation was performed in an ultra-pulse mode (100 µs of pulse duration), 4-mm working distance, for 10 s. Specimens were then submitted to further erosive episodes for 5 days and evaluated for enamel relative permeability. Fluoride did not show any protective effect for any of the laser-treated groups or control (p = 0.185). However, a significant effect was detected for input power of CO2 laser (p = 0.037). Tukey's test showed that there was a significant statistically difference between specimens irradiated with 0.5 and 1.5 W (p = 0.028). The input power of 0.5 W showed lower permeability. Variation of input power CO2 laser can influence enamel permeability, at the power of 1.5 W which promoted greater permeability.

An alternate technique of care using silver fluoride followed by stannous fluoride in the management of root caries in aged care.

An alternate technique of care to prevent, arrest and manage root caries using aqueous silver fluoride followed by stannous fluoride (AgF+SnF2) in aged care is demonstrated by three case studies. With increasing age, the inability to maintain ones own oral care from dementia, illness or frailty and polypharmacy induced salivary gland hypofunction will result in dental caries becoming a progessively greater burden for the elderly. Future generations of elders will live longer and need to maintain many more teeth longer than earlier generations. Both silver diamine fluoride (SDF)and AgF+SnF2 arrest and prevent caries and are easy to use in residential aged care facilities. Clinical differences between SDF and AgF+SnF2 are discussed. However, in aged care, AgF+SnF2 may offer advantages over SDF. AgF+SnF2 used to arrest and prevent caries in children can be modified to provide effective but minimally invasive care for an ageing and frail population. These techniques are rapid, inexpensive and nonthreatening suited to treat frail elders, dementia patients exhibiting challenging behaviours and patients with multiple rapidly progressing decay. Silver fluoride, applied before placing glass-ionomer cement (GIC) restorations is an important adjunct to the atraumatic restorative technique and may retard caries reactivation more than GIC used alone.