Evaluación de fluoruro residual en saliva después de la aplicación de barnices fluorados al 2.26 por ciento: estudio comparativo / An evaluation of the residual fluoride in saliva after applying 2.26 per cent fluoride varnishes: a comparative study

El objetivo de este estudio fue comparar la cantidad de fluoruro (F) residual en saliva después de la aplicación de barniz de fluoruro desodio al 5 por ciento y de barniz fluorado con fosfato tricálcico al 5 por ciento en niños de 2 a 5 años de edad. Se recolectó la saliva no estimulada de 24 niños que tenían acceso a sal fluorada diariamente y utilizaban dentífricos infantiles conteniendo 550 ppm F. La primera toma de muestrasalival fue colectada como basal y las siguientes fueron tomadas en diferentes intervalos de tiempo luego de realizar la aplicación del barnizfluorado (15; 30; 60 minutos y 24; 48; 72; 96; 168 horas). Un total de 216 muestras fueron obtenidas, siendo 96 muestras de barniz de Duraphat®, 96 muestras de barniz de ClinproTM WV y 24 muestras muestras basales. Los análisis de laboratorio fueron realizadosen el departamento de Bioquímica de la Facultad de Odontología de Baurú (FOB), Universidad de Sao Paulo. Un electrodo Orión 9409 y un microelectrodo acoplados a un potenciómetro Orion EA 940 se utilizaron para analizar las muestras previa difusión de las muestrascon el método de Taves. La concentración de iones de flúor mostró diferencias estadísticamente significativas entre ambos productos desde las 24 horas (p<0.001), esta característica se repite a las 48 (p=0.003); 96 (p<0.001) y 168 horas (p<0.001). Se utilizó el análisisestadístico de Shapiro Wilks y T de Student. Ambos barnices mostraron un incremento de fluoruro residual en saliva durante los 15; 30 y 60 minutos, sin embargo, posteriormente a estos tiempos, ambos muestran niveles no significativamente diferentes al basal.

The aim of this study was compared the amount of residual fluoride after application of sodium fluoride varnish 5% and application offluoride varnish with phosphate tricalcium 5% in children from 2 to 5 years old. Unstimulated saliva was collected of 24 children who hadaccess to fluoridate salt daily and used children´s tooth pastes containing 550ppm F. The first salivary sample was collected as a base lineand the following were taken at different intervals after making the application of fluoride varnish (15; 30; 60 minutes; 24; 48; 72; 96;168 hours).Children were grouped in two groups according of type of varnish containing fluoride going to be applied. A total of 216samples were obtained, 96 samples from Duraphat® and 96 samples from ClinproTM WV 3M ESPE. The lab analyzes wereconducted in the Department of Biochemistry at the Faculty of Dentistry, Bauru (FOB), University of Sao Paulo. An Orion 9409electrode and a microelectrode coupled to a potentiometer Orion EA 940 analyzed the samples prior dissemination of samples with themethod of work. The fluoride concentration was statistically significant after 24 (p<0.001); 48 (p=0.003); 96 (p<0.001) y 168 hours(p<0.001) for both products. We used Shapiro Wilks and T student test for statistical analysis. Both products showed an increased inresidual fluoride in saliva during the 15; 30 and 60 minutes, however, both showed not differences that baseline levels.

Fluoride stability in dentifrices stored in schools in a town of northern Brazil.

The aim of this study was to analyze fluoride stability in dentifrices stored during nine months in schools from Careiro da Várzea, State of Amazonas, Brazil. Analysis of total fluoride concentration, total soluble fluoride, and ionic fluoride in the dentifrice samples was performed in four different time periods: at the time of purchase (baseline); after three months, after six months, and after nine months of storage. Fluoride concentration was determined using a specific electrode (Orion 96-09) connected to an ion analyzer (Orion A-720) and calibrated with fluoride standard solutions containing 2.0 to 32.0 ppm F. The results obtained during the measurements were analyzed by analysis of variance (one-way ANOVA), followed by Tukey's test for comparison of the means. After nine months of storage, total soluble fluoride, the active form of fluoride, decreased by 21.9%. As total soluble fluoride was below the minimum required for anticaries efficacy (1,000 ppm F) in the fourth analysis, it may be concluded that anticaries potential decreased with storage time.

Fluoride stability in dentifrices stored in schools in a town of northern Brazil

The aim of this study was to analyze fluoride stability in dentifrices stored during nine months in schools from Careiro da Várzea, State of Amazonas, Brazil. Analysis of total fluoride concentration, total soluble fluoride, and ionic fluoride in the dentifrice samples was performed in four different time periods: at the time of purchase (baseline); after three months, after six months, and after nine months of storage. Fluoride concentration was determined using a specific electrode (Orion 96-09) connected to an ion analyzer (Orion A-720) and calibrated with fluoride standard solutions containing 2.0 to 32.0 ppm F. The results obtained during the measurements were analyzed by analysis of variance (one-way ANOVA), followed by Tukey’s test for comparison of the means. After nine months of storage, total soluble fluoride, the active form of fluoride, decreased by 21.9%. As total soluble fluoride was below the minimum required for anticaries efficacy (1,000 ppm F) in the fourth analysis, it may be concluded that anticaries potential decreased with storage time.

Assessment of fluoride concentrations in commercially available mouthrinses in central Saudi Arabia.

OBJECTIVES: To assess the fluoride concentration of different commercially available mouthrinses in central Saudi Arabia, and compare the obtained measurements with label values. METHODS: This cross-sectional study identified 25 brands of mouthrinses in the markets of Riyadh city  between August and September 2013. Nineteen brands of mouthrinses whose labels indicate the percentage of sodium fluoride (NaF) and 6 brands not indicating the fluoride percentage were included in the study. Three bottles of 2 manufacturing batches of each brand were acquired, coded, and analyzed after dilution using specific electrodes for fluoride and an ion analyzer at the College of Science, King Saud University, Riyadh, Saudi Arabia.   RESULTS: The average fluoride concentrations in the tested mouthrinses ranged from 8.4 ppm (Voza) to 448.7 ppm (Sensodyne `Pronamel`). Analysis of variance showed a statistically significant difference (p<0.05) in the fluoride concentration between the studied 25 brands. Almost 60% of the brands' fluoride concentrations were significantly different (mainly lower) from the label value. However, only 5 brands contain fluoride at a concentration not significantly different from the recommended fluoride concentration in daily mouthrinses 0.05% (225 ppm). CONCLUSION: Most of the studied commercially available mouthrinses contain topical fluoride at concentrations below the manufacturers' label value, but above the recommended 0.05%. 

Method for the analysis of total fluoride in fluoride-releasing dental varnishes.

Today's fluoride-releasing varnishes (F-varnish) contain a wide variety of ingredients which present analytical challenges for measuring their total fluoride content. This study reports improved methods to measure fluoride content in F-varnishes. Six different commercially available F-varnishes that contain difluorosilane (0.1% F) or NaF (2.26% F) alone or in combination with calcium-phosphates were analyzed. In a vial, 1-3 drops (0.05-0.15 g) of varnish product was dispensed, dissolved in chloroform, equilibrated in TISAB and analyzed via fluoride ion-selective electrode. The average weight percentage of fluoride for all F-varnishes containing NaF ranged from 2.03 to 2.24% F, which is within 90% of the declared label concentration of 2.26% F. Analysis of the difluorosilane-containing product required an additional hydrolysis step. ANOVA found no significant difference between the 5% NaF varnishes at p < 0.05. This method for fluoride analysis yields reliable and reproducible results and can be used for a wide variety of F-varnishes. The standard uncertainty for this method is ±4%. This method may become the basis for national and international standards that ensure the F-varnish products used in clinical practice have the fluoride content declared in the product literature.

The in vivo efficacy of Fluorinex topical fluoridation treatment.

OBJECTIVE: This randomized, single-controlled study was performed to validate in vivo the efficacy of single Fluorinex treatment by examining fluoride incorporation into enamel using electron microscopy. METHOD AND MATERIALS: Twenty healthy participants referred for routine dental treatment which also required extractions of at least two teeth as part of their treatment plan were included in this study. For each participant, one randomly selected tooth was extracted and sent for blind electron microscopic fluoride assay (control, C). Next, following a single Fluorinex treatment, the second (test, T) tooth was extracted and sent for the same assay. Intra-individual and intergroup fluoride content comparisons were performed, between control and test teeth. RESULTS: Highly significant intra-individual and intergroup differences were found between the treated and untreated teeth. Fluoride atomic percent (at%) and weight percent (wt%) estimated least squares means of untreated group were found to be 0.56 and 0.48, and in the treated group 17.35 and 14.35. This increase in fluoride at% [16.78 ± 2.3 (SE)], was also significant statistically (P < .0001); likewise, the increase in fluoride wt % [13.86 ± 1.97 (SE)] was similarly significant (P < .0001). The system was well tolerated by the participants with minimal transitional mild side effects. CONCLUSION: In vivo fluoride application using the active Fluorinex system resulted in a significant increase of fluoride content in the enamel of adult permanent teeth compared to untreated internal controls.

Salivary retention after application of fluoride gel using toothbrush or tray: a crossover trial

Currently, there are no studies in the literature evaluating salivary fluoride retention after small amounts of fluoride gel are applied to children's teeth. Therefore, the objective of the present study was to compare salivary retention after gel application using a toothbrush or by traditional application with trays. In this crossover study, children with active caries (n = 10) were randomized into one of the following treatment groups: a) application of fluoride gel using a tray (control), or b) application of fluoride gel with a toothbrush (treatment). After a 7-day washout period, the treatments were inverted. Unstimulated saliva samples were collected at baseline and 0.5, 5, 15, 30, 60 and 120 minutes after acidulated phosphate fluoride (APF) gel application in order to analyze fluoride retention in saliva. The area under the curve (AUC) was also calculated. There were no differences in fluoride retention after application of small amounts of APF with a toothbrush compared to traditional gel application using trays at all time points studied, and no differences in AUC were observed (Student t-test, p > 0.05). These results suggest that application of fluoride gel in children using a toothbrush can be utilized as an option rather than traditional trays, since the same salivary retention of fluoride is obtained using a lower dose.

Salivary retention after application of fluoride gel using toothbrush or tray: a crossover trial.

Currently, there are no studies in the literature evaluating salivary fluoride retention after small amounts of fluoride gel are applied to children's teeth. Therefore, the objective of the present study was to compare salivary retention after gel application using a toothbrush or by traditional application with trays. In this crossover study, children with active caries (n = 10) were randomized into one of the following treatment groups: a) application of fluoride gel using a tray (control), or b) application of fluoride gel with a toothbrush (treatment). After a 7-day washout period, the treatments were inverted. Unstimulated saliva samples were collected at baseline and 0.5, 5, 15, 30, 60 and 120 minutes after acidulated phosphate fluoride (APF) gel application in order to analyze fluoride retention in saliva. The area under the curve (AUC) was also calculated. There were no differences in fluoride retention after application of small amounts of APF with a toothbrush compared to traditional gel application using trays at all time points studied, and no differences in AUC were observed (Student t-test, p > 0.05). These results suggest that application of fluoride gel in children using a toothbrush can be utilized as an option rather than traditional trays, since the same salivary retention of fluoride is obtained using a lower dose.

Total and free available fluoride in toothpastes in Brunei, Cambodia, Laos, the Netherlands and Suriname.

OBJECTIVES: This study assessed total and free fluoride concentrations in samples of toothpaste from Brunei, Cambodia, Laos, the Netherlands and Suriname, and investigated the labelling practices of the respective manufacturers. MATERIALS AND METHODS: Convenience samples were bought in the five countries and sent for analysis to the Netherlands. Levels of total and free available fluoride were measured. Details of the information declared on the packaging about type of fluoride and abrasives were recorded, and manufacturing and expiry dates were noted. RESULTS: A total of 119 samples of toothpaste were analysed. With one exception, all samples from the Netherlands complied with ISO (International Organisation for Standardisation) labelling requirements and there were no differences between the fluoride content declared and that found to be present on analysis. In samples purchased in the other countries, sodium monofluorophosphate (SMFP) toothpastes predominantly showed a low percentage of free available fluoride and the majority of toothpastes did not follow standard labelling guidelines. DISCUSSION: This study is not representative of any of the brands analysed, yet it highlights problematic discrepancies in products across countries. These may be related to the lack of a generally accepted methodology for analysing total and free fluoride content, absence of an agreement on the minimum concentration of fluoride required to ensure efficacy, weak regulating institutions that are unable to control labelling and consumer information, as well as a possible influx of counterfeit low-quality toothpaste. CONCLUSIONS: Renewed international focus should be directed towards closing gaps in guidelines and standards. Consumers should use only non-expired toothpaste, which should preferably be silica-based fluoride toothpaste that does not include abrasives containing calcium and that is properly labelled.

Avaliação do teor de fluoretos em géis neutros e acidulados de uso tópico profissional / Evaluation of fluoride content in neutral and acidic gels for topical professional use

Os géis fluoretados para aplicação tópica pelo profissional têm sido empregados comoagentes de prevenção da cárie dental, no tratamento da hipersensibilidade dentinária ecomo remineralizadores do esmalte dental. Neste estudo foi analisado in vitro, por meiodo método do fluorímetro com eletrodo específico termo-plus®, o teor de flúor de 10 produtosbrasileiros de gel fluoretados, ( 5 de fluoreto de sódio a 2% em concentração, e 5 deflúor fosfato acidulado a 1,23% em concentração). Os resultados indicaram que todos osprodutos avaliados nesse estudo apresentaram irregularidades no teor de fluoreto, sendoque nove destes apresentavam uma concentração menor que a indicada na embalageme uma apresentou uma concentração maior que o declarado. Com base nessas análises,conclui-se que os produtos avaliados neste trabalho não apresentam a concentração indicadaem suas embalagens.

Fluoride gels for topical application by the professional staff have been employed as preventionof dental caries, in dentin hypersensitivity treatment and as mineralizing enamelagents. The aim of this study was to evaluate in vitro by the method of the fluorometer witha specific electrode termo-plus®, the fluoride concentration of 10 Brazilian products offluoride gel, (5 sodium fluoride at 2% concentration of fluoride and 5 acidulated phosphateto 1.23% in concentration). The results indicated that all the products evaluated in thisstudy showed irregularities in the fluoride content, nine of them had a lower concentrationthan indicated on the package and one of them had a higher concentration than stated.Based on this analysis, we conclude that the products evaluated in this study do not showthe concentration indicated on their packaging.

Diode laser irradiation and fluoride uptake in human teeth.

AIM: To evaluate chemically the effects of diode laser on fluoride uptake before and after laser irradiation of enamel surfaces. METHODS: Crowns of 20 sound human teeth were halved and a 3 x 3 mm acid-resistant varnish uncovered window left for: A) no treatment; B) fluoride (Elmex gel); C) diode (fluoride + diode laser); D) diode (diode laser + fluoride). The dental surfaces were analysed using a fluoride ion-selective electrode, in order to evaluate the fluoride treatment in combination with a diode laser. Also, to investigate laser-induced compositional changes (contents in F(-)) in enamel before/after laser irradiation and topical fluoride application. RESULTS: The mean ± SD of fluoride uptake of teeth of group A was 1.55 ± 0.89 mg/l. Mean fluoride uptake increased sevenfold after fluoride gel treatment: 10.51 ± 3.38 mg/l for group B, up to 15 times after gel and laser treatment: 23.62 ± 3.58 mg/l for group C and was 22.7 ± 4.60 mg/l for group D (diode laser before fluoride application). The Kruskal Wallis test indicated a statistically significant effect of fluoride uptake for all three treatments (p<0.001). The Student-Newman-Keuls multiple comparison test indicated a statistically significant increase of fluoride uptake before and after all treatments, and also a statistically significant difference for laser treatment versus fluoride gel. However, there was no statistically significance difference between laser groups. CONCLUSIONS: There is an enhanced capability of lasers to increase fluoride uptake of enamel and providing protection to enamel surface from acid attack.

The roughness, microhardness, and surface analysis of nanocomposites after application of topical fluoride gels.

OBJECTIVES: Application of acidulated phosphate fluoride (APF) gels has long been considered to cause deterioration of composite surfaces. The aims of this study were to demonstrate that nanocomposite surfaces were not affected by some APF gels and to investigate the possible underlying mechanisms. METHODS: The elemental composition and viscosity of 3 acidulated phosphate fluoride (APF) agents (60 Second Taste Gel, Topex, and Zap) and 1 neutral fluoride agent (pH7 Gel) were analyzed. Subsequently, 320 specimens of 3 nanocomposites (Premisa, Filtek Z350, and Grandio) and a microhybrid composite (Estelite Sigma) with 80 specimens for each composite were randomly divided into 5 groups (n=16) and treated with 4 fluoride gels as well as distilled water which served as the control. Fluoride gels were applied on composite resin surfaces 4 times, 30 min each time. The roughness and microhardness were measured after treatments. Qualitative examination of the surface degradation of the composites was carried out with Fourier transforming infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). RESULTS: Topex and Zap did not cause surface changes of composite resins, the possible reason being ascribed to the presence of magnesium aluminum silicate (MAS) clays. In contrast, 60 Second Taste Gel treatments caused significant roughness increase, microhardness decrease, more prominent filler dissolution, and IR spectral changes of Premisa, Filtek Z350, and Grandio. Estelite Sigma was less affected by the 4 fluoride gels. SIGNIFICANCE: The composite surfaces were not affected by Topex or Zap even after extended treatments. These two APF gels may be more suitable for clinical applications.

Fingernail may not be a reliable biomarker of fluoride body burden from dentifrice.

Fingernail has been suggested as a biomarker of fluoride (F) body burden, but there is no consensus if it would be a reliable indicator of F exposure from dentifrice. Therefore, the present study was conducted to investigate if fingernails would have sensitivity to detect F exposure from dentifrice in young children. Twenty-three 1-3-year-old children living in the city of Piracicaba (0.72 ppm F in water), Brazil, were enrolled in two phases of different F exposure: in phase A (1st to 11th week), they were exposed to the combination of F from diet (solids and liquids) and dentifrice (1,500 microg F/g as MFP), and in phase B (12th to 29th week), only to F from diet (the use of F dentifrice was interrupted). Fingernails were weekly clipped during 35 weeks for F determination. F intake from diet and dentifrice in each phase was also determined. Both analyses were made with ion-specific electrode. F intake (Mean +/- SD) was significantly higher (p<0.01) when the children were exposed to F from diet+dentifrice than only to F from diet (0.086 +/- 0.032 and 0.040 +/- 0.009 mg F/day/kg body weight, respectively). However, F concentrations in nails collected during the whole experimental period of 35 weeks presented great variation with no trend of decreasing after F dentifrice intake interruption. The findings suggest that fingernail may not be a reliable F biomarker of body burden from dentifrice.

Long-term fluoride release from resin-reinforced orthodontic cements following recharge with fluoride solution.

The aim of this study was to test the hypothesis that there is no difference in the fluoride release behavior of resin-reinforced glass ionomer cements before or after fluoride recharge. The materials were divided into 5 groups: 2 resin-reinforced glass ionomer cements used for attaching orthodontic bands, that is, group FOB (Fuji Ortho Band) and group MCB (Multi-Cure Glass Ionomer Orthodontic Band Cement); 2 resin-reinforced glass ionomer cements and a composite used for bonding orthodontic brackets, that is, group OGLC (Ortho Glass LC), group FOLC (Fuji Ortho LC), and group TXT (Transbond XT), respectively. Fluoride release was measured during a 60-day period by using selective ion electrodes connected to an ionic analyser. After 4 weeks, the samples were exposed to 0.221% sodium fluoride solution. The results showed that cements achieved a maximum fluoride release 24 h after initial setting. No statistically significant differences were observed between groups FOB and OGLC regarding the amount of released fluoride following fluoride recharge from day 31 to day 36 (p>0.05). In conclusion, FOB and OGLC cements showed a higher capacity of capturing and releasing fluoride compared to the other cements studied.

An in vitro evaluation of a novel high fluoride daily mouthrinse using a combination of microindentation, 3D profilometry and DSIMS.

OBJECTIVES: Firstly, to evaluate the in vitro anti-erosion efficacy of a new mouthrinse formulation containing 450 ppm fluoride using profilometry and microindentation. Secondly, to compare fluoride uptake by erosive lesions from two mouthrinses containing different fluoride sources using dynamic secondary ion mass spectrometry (DSIMS). METHODS: Sound human enamel was treated (60s) with mouthrinses containing different fluoride concentrations, then immersed in 1.0% citric acid pH 3.8 for either 300 s or 30 min (Studies 1 & 2 respectively). Surface roughness and erosion depth were determined profilometrically in Study 1, and surface microhardness monitored as a function of time in Study 2. Lesion rehardening was monitored following a 60 s rinse and immersion in artificial saliva for 48 h (Study 3), whilst Study 4 employed DSIMS to quantify fluoride uptake by lesions treated (60s) with rinses containing either sodium fluoride (NaF) or a NaF/Olaflur/stannous chloride combination. RESULTS: The test rinse (450 ppm fluoride) suppressed surface roughening and bulk tissue loss versus all comparators (p< 0.0001), except in the latter measure for the rinse containing 112 ppm fluoride. The test rinse significantly inhibited enamel surface softening versus the three rinses containing ≤112 ppm fluoride (as NaF) at 30 min (p<0.05), but was not statistically significantly different from the 225 ppm fluoride rinse. The test rinse conferred statistically superior lesion rehardening versus all comparators at both 24 and 48 h (p< 0.0001). DSIMS demonstrated statistically significantly higher fluoride uptake by incipient erosive lesions treated with the test rinse versus the NaF/Olaflur/stannous rinse. CONCLUSIONS: Anti-erosion efficacy was positively correlated with fluoride concentration. DSIMS showed significantly higher levels of fluoride uptake by incipient erosive lesions treated with the 450 ppm fluoride rinse versus the NaF/Olaflur/stannous rinse.

Evaluation of salivary fluoride retention from a new high fluoride mouthrinse.

OBJECTIVES: To evaluate salivary fluoride retention from a new high fluoride daily use mouthrinse over a 120 min period. METHODS: Sixteen subjects completed a randomised single-blind, four-treatment cross-over trial. Sensodyne® Pronamel® mouthrinse (A) contained 450 ppm fluoride; reference products were Colgate® Fluorigard® (B), Listerine® Total Care (C) and Listerine Softmint Sensation (D) containing 225, 100 and 0 ppm fluoride respectively. Salivary fluoride retention was monitored ex vivo after a single supervised use of test product (10 mL, 60 s). Samples were collected at 0, 1, 3, 5, 15, 30, 60 and 120 min post-rinse, generating fluoride clearance curves from which the area under the curve (AUC) was calculated. Differences in salivary fluoride concentrations for each product were analysed using ANCOVA at each time point using a 5% significance level, as well as lnAUC for the periods 0-120, 0-1, 1-15, 15-60 and 60-120 min. Pairwise comparisons between all treatment groups were performed. RESULTS: Salivary fluoride levels for A-C peaked immediately following use. Fluoride levels were statistically significantly higher for A versus B-D (p≤ 0.004), linear dose responses were apparent. AUC(0-120) was statistically significantly greater for A than for B (p = 0.035), C (p< 0.0001) and D (p< 0.0001). Post-hoc comparisons of lnAUC for the remaining time domains showed fluoride retention from A was statistically significantly greater versus B-D (p< 0.0001). CONCLUSIONS: Single-use treatment with the new mouthrinse containing 450 ppm fluoride resulted in statistically significantly higher salivary fluoride levels throughout the 120 min test period. Total fluoride retention (AUC(0-120)) was also statistically significantly greater versus comparator rinse treatments.

Salivary fluoride concentrations and fluoride ingestion following application of preparations containing high concentration of fluoride.

The aim of the study was to assess salivary fluoride concentrations and ingestion of fluorides after five different techniques of topical fluoride treatment. Ten volunteers received applications of fluoride gel, toothpaste, and foam. Fluoride concentrations were determined using ion-selective fluoride electrode in the samples of unstimulated saliva before and after procedures. The amounts of fluoride applied, recovered from the mouth, and retained in the mouth were calculated for each treatment. It was proved that fluoride ingestion following tray application of fluoride foam was significantly lower than ingestion following tray applications of fluoride gel (p < 0.01). The use of limited amounts of fluorides on a tray resulted in similar fluoride retention and lower ingestion comparing to the method which involves a large portion of fluorides followed by rinsing. Tooth brushing resulted in high salivary retention rates per amount of fluorides used in the procedure. These data provide initial concept about the possible advantages of some methods of topical fluoride application over others.

Fingernail may not be a reliable biomarker of fluoride body burden from dentifrice

Fingernail has been suggested as a biomarker of fluoride (F) body burden, but there is no consensus if it would be a reliable indicator of F exposure from dentifrice. Therefore, the present study was conducted to investigate if fingernails would have sensitivity to detect F exposure from dentifrice in young children. Twenty-three 1-3-year-old children living in the city of Piracicaba (0.72 ppm F in water), Brazil, were enrolled in two phases of different F exposure: in phase A (1st to 11th week), they were exposed to the combination of F from diet (solids and liquids) and dentifrice (1,500 µg F/g as MFP), and in phase B (12th to 29th week), only to F from diet (the use of F dentifrice was interrupted). Fingernails were weekly clipped during 35 weeks for F determination. F intake from diet and dentifrice in each phase was also determined. Both analyses were made with ion-specific electrode. F intake (Mean ± SD) was significantly higher (p<0.01) when the children were exposed to F from diet+dentifrice than only to F from diet (0.086 ± 0.032 and 0.040 ± 0.009 mg F/day/kg body weight, respectively). However, F concentrations in nails collected during the whole experimental period of 35 weeks presented great variation with no trend of decreasing after F dentifrice intake interruption. The findings suggest that fingernail may not be a reliable F biomarker of body burden from dentifrice.

As unhas têm sido consideradas um biomarcador para a exposição ao flúor (F), mas não há consenso se é um indicador confiável para exposição ao F a partir do dentifrício. Vinte e três crianças, com idade entre 1 a 3 anos, moradoras de Piracicaba (0,72 ppm F na água), Brasil, foram submetidas a duas fases de diferentes exposição ao F: fase A (1a a 11a semanas), as crianças foram expostas à combinação de F a partir da dieta (sólidos e líquidos) e dentifrício (1500 µg F/g como MFP); e na fase B (12ª a 29ª semanas), apenas ao F da dieta, uma vez que usaram dentifrício não fluoretado. As unhas das mãos foram coletadas semanalmente durante 35 semanas para determinação de F. A exposição ao F a partir da dieta e dentifrício foi também determinada. Ambas análises foram feitas com eletrodo específico para F. A exposição ao F foi significativamente maior (p<0,001) quando as crianças foram expostas ao F da dieta + dentifrício que ao F da dieta (0,086 ± 0,032 e 0,040 ± 0,009 mg F/kg corpóreo/dia, respectivamente). Entretanto, a concentração de F nas unhas coletadas durante todo o período experimental não diminuiu após a interrupção da ingestão do F a partir do dentifrício. Os resultados sugerem que as unhas das mãos não são um biomarcador confiável para refletir a exposição ao F pelo dentifrício.

Long-term fluoride release from resin-reinforced orthodontic cements following recharge with fluoride solution

The aim of this study was to test the hypothesis that there is no difference in the fluoride release behavior of resin-reinforced glass ionomer cements before or after fluoride recharge. The materials were divided into 5 groups: 2 resin-reinforced glass ionomer cements used for attaching orthodontic bands, that is, group FOB (Fuji Ortho Band) and group MCB (Multi-Cure Glass Ionomer Orthodontic Band Cement); 2 resin-reinforced glass ionomer cements and a composite used for bonding orthodontic brackets, that is, group OGLC (Ortho Glass LC), group FOLC (Fuji Ortho LC), and group TXT (Transbond XT), respectively. Fluoride release was measured during a 60-day period by using selective ion electrodes connected to an ionic analyser. After 4 weeks, the samples were exposed to 0.221 percent sodium fluoride solution. The results showed that cements achieved a maximum fluoride release 24 h after initial setting. No statistically significant differences were observed between groups FOB and OGLC regarding the amount of released fluoride following fluoride recharge from day 31 to day 36 (p>0.05). In conclusion, FOB and OGLC cements showed a higher capacity of capturing and releasing fluoride compared to the other cements studied.

O objetivo deste estudo foi testar a hipótese que não há diferença no desempenho dos cimentos de ionômero de vidro reforçados com resina entre si quanto à liberação de flúor antes e após recarga com flúor. Os materiais foram divididos em 5 grupos: 2 cimentos de ionômero de vidro reforçados com resina utilizados para cimentação de bandas ortodônticas: Grupo FOB (Fuji Ortho Band) e Grupo MCB (Multi-Cure Glass Ionomer Orthodontic Band Cement); 2 cimentos de ionômero de vidro reforçados com resina e 1 compósito utilizados para colagem de bráquetes ortodônticos: Grupo OGLC (Ortho Glass LC), Grupo FOLC (Fuji Ortho LC); e Grupo TXT (Transbond XT), respectivamente. A liberação de flúor foi medida durante 60 dias, através de eletrodo íon seletivo conectado a um analisador de íons. Após 4 semanas, os corpos de prova foram expostos a solução de fluoreto de sódio à 0,221 por cento. Os resultados evidenciaram que os cimentos atingiram o pico máximo de liberação de flúor com 24 h após presa inicial. Não houve diferença estatisticamente significante entre a quantidade de flúor liberado após as recargas de fluoreto de sódio entre os grupos FOB e OGLC do 31° ao 36° dia (p>0.05). Concluindo os cimentos FOB e OGLC apresentaram maior capacidade de captação e liberação de flúor comparada aos outros CIVRRs.

In vitro fluoride release and the antibacterial effect of glass ionomers containing chlorhexidine gluconate.

Fluoride release from glass-ionomers (GI) may be important for the prevention of secondary caries. The addition of chlorhexidine gluconate (CHX) to glass-ionomer cement (3%) adds an effect that enables it to be used as a varnish for the temporary coating of surfaces at risk for caries. This study investigated the fluoride release pattern and antibacterial effect of such a material. Glassionomer luting cement powder (Aqua-Cem) was mixed with water, 10% CHX or 10% CHX with 11% tartaric acid (TA), respectively, to test specimens (6 X 1.5 mm). After setting, the specimens were immersed in 10 ml deionized water and transferred to new vials after various intervals over a period of two months. The antibacterial effect towards mutans streptococci was assessed using agar diffusion. The fluoride release was measured after two hours and after shifting the specimens to new vials 10 times during the two-month period. The mean total fluoride release was 69.02, 50.64 and 48.56 microg/cm2 from each specimen in the GI, GI-CHX and the GI-CHX-TA groups, respectively. For two-hour old specimens, the mean inhibition zone was 0, 50, 36 mm2 in the GI, GI-CHX and GI-CHX-TA groups, respectively, and, after two months, 45 mm2 in the GI-CHX group and 19 mm2 in the GI-CHX-TA group. It can be concluded that the addition of CHX and CHX-TA adds antibacterial properties to GI and the release of fluoride is decreased.