Ultrastructural investigation of the effect of toothpastes containing different remineralizing agents on demineralized enamel.

OBJECTIVE: The present study aimed to evaluate the effect of remineralizing agents on demineralized enamel intended for use as fluoride substitutes or supplements for oral hygiene applications. METHODOLOGY: Enamel samples were obtained from 30 bovine teeth. The enamel blocks were stored in 20 mL of demineralization solution for 72 h. They were then brushed with the following toothpaste for the remineralization protocol: NaF, NaF/SnF2 combination, NovaMin, or nano-hydroxyapatite. SEM/EDX examinations and microhardness measurements of the samples were performed to investigate the remineralization efficacy of the studied toothpaste. One-way analysis of variance (ANOVA) with post hoc Tukey's HSD test was used to analyze the change in microhardness values in different remineralization protocols (p < 0.05). RESULTS: Differences in the mean remineralization (%RP) and hardness recovery (%HR) were determined between the groups (p < 0.05). Groups 1 and 4 showed significant differences in %RP (p < 0.05). In the SEM/EDX examinations, the samples treated with n-HAp showed an accumulation of crystal deposits on the enamel surface, although at a lower density than those treated with NaF and NaF/SnF2 combination. CONCLUSION: The remineralization strategy in toothpaste plays an important role in enamel remineralization. NovaMin-containing toothpaste showed positive effects on the enamel surface with better Ca/P ratio. Toothpastes containing n-HAp triggered less change in the increase of microhardness values compared to other toothpastes. The use of SnF2 in toothpaste in combination with NaF significantly increased the binding of fluoride to demineralized enamel compared to toothpaste containing NaF alone.

Effect of polydopamine and fluoride ion coating on dental enamel remineralization: an in vitro study.

BACKGROUND: Fluoride treatment is one of the most effective dental caries prevention methods. To continuously prevent dental caries, stably immobilizing the fluoride on the tooth enamel is highly desirable. This study aimed to evaluate the remineralization of tooth enamels by one-pot coating using polydopamine and fluoride ions. METHODS: To prepare the enamel specimens for polydopamine- and fluoride ion-coating, they were treated with polydopamine- and fluoride-containing gels. The enamel specimens were collected from human molars in a blind manner (n = 100) and were randomized into five treatment groups (n = 20, each): 1) untreated, 2) polydopamine-coated, 3) fluoride-containing gel-treated, 4) F varnish-treated, and 5) polydopamine- and fluoride ion-coated enamels. Vickers hardness number (VHN), morphology, and fluoride contents of the specimens were measured before and after the pH-cycling regimen. RESULTS: Polydopamine- and fluoride ion-coated enamels showed the highest fluoride content and lowest VHN reduction among the samples. The fluoride content of the polydopamine/fluoride ion (PD/F)-coated enamel was increased to 182 ± 6.6%, which was far higher than that of the uncoated enamel (112.3 ± 32.8%, P < 0.05). The changes in the VHN values (ΔVHN) of PD/F-coated enamel substrates showed a slight reduction in the VHN (-3.6%, P < 0.05), which was far lower than that in the control group (-18.9%, P < 0.05). In addition, scanning electron microscopy clearly supported the effect of polydopamine- and fluoride ion-coatings on the remineralization of enamel specimens. CONCLUSION: Our findings suggest that one-pot treatments with polydopamine and fluoride ions could significantly enhance remineralization by inhibiting enamel demineralization through the prolonged retention of fluoride ions.

The Effect of Various Fluoride Products on Dentine Lesions during pH-Cycling.

This study compared the effect of topically applied fluoride products on dentine lesions in an in vitro experiment. Demineralized bovine dentine specimens were treated once with either SDF solution (35,400 ppm F), NaF varnish (22,600 ppm F), TiF4 solution (9,200 ppm F), SnF2 gel (1,000 ppm F), no treatment (control), or preserved as baseline lesions. After the application and subsequent removal of the fluoride products, the specimens were subjected to pH-cycling. Calcium loss and uptake in the de- and remineralization buffers were assessed daily. Fluoride release into the buffers was analyzed on days 1, 2, 3, 5, 8, and 13. After the pH-cycling period, mineral distribution throughout the lesion depth was analyzed using transversal microradiography (TMR). X-ray energy-dispersive spectroscopy (EDS) examined the deposition of silver, titanium, and tin after application of SDF, TiF4, and SnF2, respectively. Overall, calcium loss and uptake analysis in the de- and remineralization buffers revealed that the SDF product was the most effective in inhibiting lesion progression, followed by the TiF4, NaF, and SnF2 products. Fluoride analysis disclosed a steep reduction of the amount of fluoride released into de- and remineralization buffers with time. The fluoride effects on de- and remineralization continued beyond the days that fluoride was released into the buffers. TMR analysis showed significant remineralization in the outer zone of the dentine lesions for all fluoride products, with SDF giving hypermineralization in this zone. In the inner zone, lesions developed in all fluoride groups, with the smallest in the SDF group. EDS showed silver and titanium deposition in depth up to 85 µm and 8 µm, respectively, while no tin deposition was observed. The silver in the dentine lesions did not contribute significantly to the density of the TMR profiles in the SDF group. In conclusion, all topical fluoride products protected the dentine lesions against lesion progression, but at different degrees. SDF showed a superior effect in protection against further demineralization and enhancement of remineralization. This was probably attributed to its fluoride concentration that was the highest among the fluoride products.

Salivary fluoride concentration following toothbrushing with and without rinsing: a randomised controlled trial.

BACKGROUND: Caries prevalence has declined significantly since the introduction of fluoridated toothpaste. There have been several developments regarding specific active fluoride ingredients but not enough evidence to support one over the other. The purpose of this double-blind randomized controlled trial was to compare salivary fluoride concentrations of different fluoride formulations in the form of toothpaste with and without post-brushing water rinsing in adults. METHODS: The study included 120 participants who were randomly assigned to one of 12 groups (10 participants/group). The toothpaste formulas investigated included (1) fluoride-free (0 ppmF); (2) sodium fluoride (1450 ppmF); (3) sodium monofluorophosphate (1450 ppmF); (4) sodium fluoride and monofluorophosphate combined (1450 ppmF); (5) stannous fluoride and sodium fluoride combined (1450 ppmF); and (6) amine fluoride (1400 ppmF). Block randomisation was used to assign each participant to one of the 12 groups. Participants brushed with 1.0 g of one of the six different toothpaste formulations either with or without post-brushing water rinsing. Saliva was collected at six different times (baseline and at 1, 15, 30, 60, and 90 min/s post-brushing). Samples were analysed using a fluoride ion-specific sensitive electrode connected to an ion analyser. RESULTS: The demographic characteristics of the participants were not significantly different among the groups (P > 0.05). Time, toothpaste formulation, and post-brushing rinsing routines had significant effects on saliva fluoride retention (P < 0.05). Amine fluoride-containing toothpaste was the only formula that showed statistically significantly higher concentrations of salivary fluoride at 90 min in both the rinsing and non-rinsing groups. Sodium monofluorophosphate toothpaste did not result in a significant difference compared to the control group at any time point, in both rinsing and non-rinsing groups. CONCLUSIONS: Based on the results from this study, no rinsing after toothbrushing in adults can be recommended when sodium monofluorophosphate containing toothpaste formula is used. It also concludes that amine fluoride resulted in a significantly higher saliva fluoride concentration at 90 min in both the rinsing and non-rinsing groups compared to other fluoride toothpaste formulations. Registry: Protocol Registration and Results System (ClinicalTrials.gov). CLINICAL TRIAL REGISTRATION NUMBER: NCT02740803 (15/04/2016).

Randomized investigation of the bioavailability of fluoride in saliva after administration of sodium fluoride, amine fluoride and fluoride containing bioactive glass dentifrices.

OBJECTIVES: Bioactive glasses which degrade in aqueous solutions may release bioactive ions such as fluoride (F-) and support fluoride bioavailability in saliva. We investigated how these effects would be apparent in an in vivo experimental trial after toothbrushing in comparison with sodium fluoride and amine fluoride. MATERIAL AND METHODS: In this single-center, randomized, parallel in vivo trial with a three strata block design, where healthy subjects were randomly assigned into three groups. Each group brushed their teeth either with fluoridated bioactive glass containing dentifrice, with a sodium fluoride (NaF) containing dentifrice or with amine fluoride (AmF) containing toothpaste. Saliva was collected time intervals before, immediately after, 30, 60 and 120 min after toothbrushing. Fluoride concentration was determined in supernatant saliva and salivary sediment using a fluoride ion selective electrode. The data were evaluated statistically using non-parametric tests. RESULTS: The increase of bioactive fluoride in supernatant saliva was higher after application of NaF or AmF compared to fluoridated bioactive glass. In salivary sediment bioavailability of fluoride lasted longer after application of fluoridated bioactive glass. CONCLUSIONS: Toothbrushing with the fluoride containing bioactive glass dentifrices had positive effects on the fluoride bioavailability within two hours. Fluoride containing bioactive glass represent a new area for investigation in caries prophylaxis. The bioactive potential impact on the tooth remineralization should be examined further. TRIAL REGISTRATION: DRKS00016038 .

Fluoride content of toothpastes available in South Africa.

A high dental caries burden coupled with a lack of water or salt fluoridation make it imperative that toothpastes available to the South African consumer demonstrate adequate potential for caries control and contain between 1000ppm and 1500ppm total fluoride (TF), with at least 1000ppm F in free available/soluble form. METHODS: The objective was to determine TF, total soluble fluoride (TSF) and insoluble fluoride (IF) concentrations in 22 fluoride toothpastes commercially available in South Africa. Samples were purchased from a major pharmaceutical and food retailer located in the two metropolitan areas in South Africa. TF and TSF concentrations were determined potentiometrically, in quadruplicate, following acid hydrolysis of the samples using a calibrated Combination Fluoride Ion Selective Electrode. IF was calculated by subtracting TSF from TF. RESULTS: Although TF content was found to be statistically significantly lower than manufacturer declaration (3.2x10-7; p≤0.05), 77.3% of the samples still contained adequate free, available/soluble F levels. Relative mean TSF content for toothpastes formulated with a calcium-based abrasive was 85% (sd ±14.5; n=6) as opposed to 98.6% (sd ±2.6; n=16) for those containing silica. CONCLUSIONS: The total fluoride concentration of all the toothpastes was lower than that declared by the manufacturers, with one in four having TSF concentrations of less than 1000ppm F. The relative TSF concentrations for the calcium-containing toothpastes were lower than for the silica-based products, reducing their preventive and protective potential. The results call for strengthened regulation and quality control of fluoride toothpastes in South Africa, as well as international efforts to improve related norms.

Using High Fluoride Concentration Products in Public Policy: A Rapid Review of Current Guidelines for High Fluoride Concentration Products.

Despite improvements in dental caries levels since the widespread introduction of fluoride toothpastes, it is still a disease which is considered to be a priority in many countries around the world. Individuals at higher risk of caries can be targeted with products with a high fluoride concentration to help reduce the amount and severity of the disease. This paper compares guidance from around the world on the use of products with a high fluoride concentration and gives examples of how guidance has been translated into activity in primary care dental practice. A rapid review of electronic databases was conducted to identify the volume and variation of guidance from national or professional bodies on the use of products with a high fluoride concentration. Fifteen guidelines published within the past 10 years and in English were identified and compared. The majority of these guidelines included recommendations for fluoride varnish use as well as for fluoride gels, while a smaller number offered guidance on high fluoride strength toothpaste and other vehicles. Whilst there was good consistency in recommendations for fluoride varnish in particular, there was sometimes a lack of detail in other areas of recommendation for other vehicles with a high fluoride concentration. There are good examples within the UK, such as the Childsmile project and Delivering Better Oral Health, which highlight that the provision of evidence-based guidance can be influential in directing scarce resources towards oral health improvements. Policy can be influenced by evidence-based national recommendations and used to help encourage dental professionals and commissioners and third-party payers to adopt higher levels of practices aimed at oral health improvement.

High Fluoride Concentration Toothpastes for Children and Adolescents.

The purpose of this review is to present the available evidence to support the use of dentifrices with high (>1,500 ppm) concentrations of fluoride to help in the prevention and treatment of caries in high-risk children and adolescents. Recent evidence from high-quality systematic reviews supports the dose-response relationship between caries prevention and fluoride levels, and there is good evidence from randomised clinical trials to support the use of high fluoride dentifrices. Such products are typically prescribed oral pharmaceuticals that require thorough risk assessment by the clinician and restricting use in those less than 6 years old to cases where the risk of severe morbidity caused by caries is greater than that of aesthetically objectionable fluorosis and which should mitigate the risk of fluorosis. Further research is required on the use of population- or community-based interventions using such products and currently, the evidence for dentifrices containing more than 2,900 ppm is weaker than for those containing 2,800 ppm or less.

Effective Fluoride Mouthwash Delivery Methods as an Alternative to Rinsing.

BACKGROUND: Special-needs patients with high caries risk cannot benefit from the proven caries-reducing effect of fluoride mouthrinse because of poor rinsing compliance and a lack of home-use fluoride application recommendations. OBJECTIVES: This study aimed to evaluate whether two modified delivery methods-spray or swab application-could raise the salivary fluoride to levels similar to that of rinsing. METHODS: Five healthy men and 16 healthy women, ages 18-22 years, participated in this crossover study. The subjects performed a standardized brushing routine twice a day with 1,000-ppm fluoride dentifrice 1 week before and during the experimental period. The three fluoride mouthwash (0.05% NaF; 226-ppm fluoride) administration methods consisted of rinsing, spray, and cotton swab application. Each application was separated by at least 1 week. Unstimulated whole saliva was sampled for 2 minutes at baseline and at 0, 5, 10, 20, 30, 60, and 120 minutes after each fluoride mouthwash application. Salivary fluoride level (ppm) was measured by a blinded investigator using an ion-specific electrode (ORION EA940). The differences in salivary fluoride concentration for each application method were analyzed by repeated measures ANOVA at a nominal significance level of .05. RESULTS: The newly designed fluoride mouthwash delivery methods yielded a similar fluoride level in whole saliva compared to that of rinsing at all time points (p > .05). The t half-life of fluoride concentration ranged from 1.62 minutes (SD = 0.53) in the spray group to 2.08 minutes (SD = 0.87) in the cotton swab group; the values were not significantly different. DISCUSSION: Our results indicate that the spray and cotton swab fluoride delivery methods were effective alternatives to conventional mouth rinsing. Caregivers of individuals with acute and chronic illness, including developmental disabilities affecting cognitive or physical abilities, may consider using these alternative fluoride delivery methods to help promote dental hygiene.

Prevalence, risk surfaces and inter-municipality variations in caries experience in Danish children and adolescents in 2012.

OBJECTIVE: The aim of this study was to describe the caries experience, prevalence and distribution related to tooth type and surfaces in the primary and permanent dentition in children and adolescents in Denmark in 2012. In addition, to examine if explanatory factors influence the inter-municipality variation in caries experience. MATERIALS AND METHODS: Data was collected in the public Child Dental Health Service. In total, 5636 caries registrations on 3-, 9-, 15- and 18-year-olds were collected in 35 of the 98 Danish municipalities. Caries experience was expressed by mean def-s/DMF-S and caries prevalence by def-s = 0/DMF-S = 0. Inter-municipality variations were illustrated. Multivariate regression analyses were applied to assess the influence of fluoride concentration in drinking water, proportion of immigrants and personal income on the inter-municipality variation in mean def-s/DMF-S. RESULTS: Only 4.6% of 3-year-olds had def-s (mean = 0.25), compared to 44.9% of 9-year-olds (mean = 3.07), primarily located occlusally and interproximally on the primary molars. Mean DMF-S for the 9-, 15- and 18-year-olds were 0.27, 1.97 and 4.40, respectively. Caries were primarily located occlusally and in pits on the permanent molars, which also showed high frequencies of sealings. Mean def-s/DMF-S showed substantial inter-municipality variations, while the caries location in both dentitions was rather stable. The three background factors explained less than 25% of the variation in mean def-s/DMF. CONCLUSIONS: The caries distribution within the primary and permanent dentition among 3-, 9-, 15- and 18-year-olds followed definite patterns concerning location on teeth and surfaces. Background factors only explained a minor part of the variation.

Mode of drinking fluoridated milk: effect on intraoral fluoride concentrations.

OBJECTIVE: To determine the effect of the mode of drinking fluoridated milk on salivary and plaque fluoride concentrations. METHODS: Fluoridated milk was ingested by 32 children in three ways: (a) directly from the container (1.0 and 5.0 mg F/litre), (b) through a straw with the tip between the lips (5.0 mg F/litre), and (c) with the tip deep in the oral cavity (5.0 mg F/litre). Saliva was collected at baseline and 2, 15, and 40 min and plaque at baseline and 20 min after drinking. Fluoride concentrations were determined using the electrode after HMDS-facilitated diffusion. RESULTS: The mode of drinking did not affect fluoride concentrations in saliva or plaque. The average 2-min salivary concentrations were 65 ng F/mL for the 1.0 mg F/litre group and 276 ng F/mL for the three 5.0 mg F/litre groups (P < 0.01). The average of the 15- and 40-min salivary concentrations was 22 ng F/mL for the 1.0 mg F/litre group and 41 ng F/mL for the 5.0 mg F/litre groups (P < 0.01). Plaque concentrations showed the same patterns as in saliva, that is, they were higher in the three 5.0 mg F/litre groups than in the 1.0 mg F/litre group and the differences among the 5.0 mg F/litre groups were not statistically significant. CONCLUSION: Salivary and plaque fluoride concentrations were independent of the mode of drinking but directly related to milk fluoride concentrations.

Oral fluoride levels 1 h after use of a sodium fluoride rinse: effect of sodium lauryl sulfate.

Increasing the concentration of free fluoride in oral fluids is an important goal in the use of topical fluoride agents. Although sodium lauryl sulfate (SLS) is a common dentifrice ingredient, the influence of this ion on plaque fluid and salivary fluid fluoride has not been examined. The purpose of this study was to investigate the effect of SLS on these parameters and to examine the effect of this ion on total (or whole) plaque fluoride, an important source of plaque fluid fluoride after a sufficient interval following fluoride administration, and on total salivary fluoride, a parameter often used as a surrogate measure of salivary fluid fluoride. Ten subjects accumulated plaque for 48 h before rinsing with a 12 mmol/l NaF (228 µg/g F) rinse containing or not containing 0.5% (w/w) SLS. SLS had no statistically significant effect on total plaque and total saliva fluoride but significantly increased salivary fluid and plaque fluid fluoride (by 147 and 205%, respectively). These results suggest that the nonfluoride components of topical agents can be manipulated to improve the fluoride release characteristics from oral fluoride reservoirs and that statistically significant change may be observed in plaque fluid and salivary fluid fluoride concentrations that may not be observed in total plaque and total saliva fluoride concentrations.

On the relationship between the rate of salivary flow and salivary fluoride clearance.

The amount of fluoride retained in the mouth following the application of dentifrices, mouthwashes, etc. may be important in determining their anticaries efficacy. In this study we investigated the relationship between the salivary flow rate and salivary fluoride clearance. Ten adults tested six mouthrinses, consisting of aqueous sodium fluoride solutions (0.013, 0.026 mol/l) with and without added sodium chloride (1.28 mol/l) or sucrose (0.44 mol/l), in a randomised order. Prior to each test, subjects swallowed, rinsed for 2 min with 2 ml water and then expectorated into a preweighed container to obtain a measure of initial saliva flow rate. Next, the procedure was repeated using one of the test rinses. Finally, samples of unstimulated whole saliva were collected for up to 3 h after each mouthrinse application and analysed for fluoride. Salivary fluoride concentrations were significantly lower after application of mouthrinses that contained either sucrose or NaCl, both of which compounds markedly enhanced salivary flow, than after the use of corresponding mouthrinses without any additive. Area under the salivary fluoride clearance curve (AUC) values were inversely correlated with salivary flow rate on an individual basis (p < 0.01). The observed behaviour could not be completely attributed to treatment dilution by saliva at the time of application.

Fluoride content and labelling of toothpastes marketed in India.

OBJECTIVE: To enumerate the fluoride content and labelling practices of toothpastes marketed in India and to determine if the content is in accordance with the information provided on the packaging. METHOD: In vitro analysis of total and free available fluoride in 5 adult and 5 children's fluoride toothpastes in India using fluoride ion electrode. Information on the tube and carton was checked to assess the labelling. RESULTS: The mean Total Fluoride concentrations (TF) in the toothpastes labelled 1,000 ppm, 500ppm and 458 ppm were 1,000, 500 and 449mg/L (sd values 3, 5 and 4mg/L) respectively. The toothpastes' Total Soluble Fluoride (TSF) concentration was generally slightly less than the TF concentration. Overall mean percentage of TSF concentration was 94% sd 9%. The mean percentage of TSF concentration in SMFP (sodium monofluorophosphate)/CaCO3 (calcium carbonate) containing toothpastes was 86% sd 16% while that in NaF (sodium fluoride)/Si (silica) based toothpastes was 98% sd 1% and 95% sd 1% in the remaining toothpastes with unknown abrasive. NaF/Si based toothpastes had more TSF concentration than the others (p<0.05). All the information required by the Indian regulations was shown on all 10 toothpastes. CONCLUSION: The available fluoride content of one of the ten toothpastes was substantially less than the total fluoride content. Although the toothpastes were labelled following the guidelines of the regulatory body of India, 3 of the 10 failed to mention the abrasive present.

Fractional Urinary Fluoride Excretion (FUFE) of 3-4 year children in the Gaza Strip.

UNLABELLED: A positive association between dental fluorosis prevalence and fluoride (F) concentration in drinking waters has been detected in Gaza Strip. Total Daily Fluoride Retention (TDFR), and Fractional Urinary Fluoride Excretion (FUFE) indicate F body burden; important in assessing fluorosis risk in susceptible age groups. OBJECTIVE: 1, To determine and compare Daily Urinary Fluoride Excretion (DUFE) and FUFE of 3-4-year-olds living in lower (< 0.7), moderate (0.7-1.2) or higher (> 1.2 ) ppm F tap water areas; 2, To determine any relationship between i, DUFE and tap water F; ii, DUFE and Total Daily Fluoride Intake (TDFI); iii, TDFI and TDFR. METHODS: 24-hour urine and tap water samples were collected from 216 children exposed to lower (n = 81), moderate (n = 72), or higher (n = 63) tap water F. ANOVA with Tukey's Test and Pearson's correlation were used to examine differences in mean DUFE and FUFE and relationships between variables. RESULTS: Mean drinking water F was 0.11(sd 0.17), 0.14 (sd 0.28) and 0.38 (sd 0.63) ppmF respectively. Differences (p < 0.0001) in mean DUFEs (0.17 (sd 0.13), 0.25 (sd 0.15) and 0.38 (sd 0.23) mg/day respectively) and mean FUFEs (48 (sd 39)%, 47 (sd 31)% and 63(sd 76)%) were found (p < 0.05). Significant (p < 0.0001) positive correlations were found between DUFE and tap water F; DUFE and TDFI, and; TDFI and TDFR. CONCLUSION: DUFEs of children drinking waters with 0.11 and 0.14ppm F, represented low F usage. The group drinking 0.38ppm F water represented optimal F usage. The weak significant positive association of DUFE with home tap water F suggests low validity for tap water F in estimating F exposure.

Salivary fluoride levels after use of high-fluoride dentifrice.

The aim of the study was to evaluate salivary fluoride (F) availability after toothbrushing with a high-F dentifrice. Twelve adult volunteers took part in this crossover and blind study. F concentration in saliva was determined after brushing with a high-F dentifrice (5000 µg F/g) or with a conventional F concentration dentifrice (1100 µg F/g) followed by a 15 mL distilled water rinse. Samples of nonstimulated saliva were collected on the following times: before (baseline), and immediately after spit (time = 0) and after 1, 2, 3, 4, 5, 10, 15, 20, 30, 45, 60, 90, and 120 min. F analysis was performed with a fluoride-sensitive electrode and the area under curve of F salivary concentration × time (µg F/mL × min(-1)) was calculated. At baseline, no significant difference was found among dentifrices (P > 0.05). After brushing, both dentifrices caused an elevated fluoride level in saliva; however salivary F concentration was significantly higher at all times, when high-F dentifrice was used (P < 0.01). Even after 120 min, salivary F concentration was still higher than the baseline values for both dentifrices (P < 0.001). High-F dentifrice enhanced the bioavailability of salivary F, being an option for caries management in patients with high caries risk.

[Fluoride content of bottled natural mineral waters in Spain and prevention of dental caries]. / Fluoruro en aguas minerales naturales envasadas en España y prevención de la caries dental.

AIM: The aim of the study was to determine the concentration of fluoride in natural mineral waters marketed in Spain in order to prevent tooth decay without the risk of causing dental fluorosis DESIGN: Descriptive and cross-sectional study during 2012. LOCATION: Natural mineral waters marketed in Spain. PARTICIPANTS: Three bottles with different bottling dates of 109 natural mineral waters (97 Spanish and 12 imported brands). MAIN MEASURES: Determination of fluoride by ion chromatography RESULTS: Median fluoride concentrations of the natural mineral waters bottled in Spain was 0.22 (range 0.00-4.16; interquartile range:0.37). Most samples (61 brands, 62%) contained less than 0.3mg/L. There are 19 Spanish brands with more than 0.6 mg/L. The median level in imported brands was 0.35 (range 0.10-1.21; interquartile range: 0.23). Only 28 of the 109 brands examined (25.6%) specified the fluoride content on the label. Good correlation was observed between the concentrations indicated and those determined. CONCLUSIONS: Fluoride concentrations in natural mineral waters showed high variation. Given the growing consumption of natural mineral waters in Spain, this type of information is important to make proper use of fluoride in the primary prevention of dental caries.

Energy dispersive x-ray spectroscopy evaluation of demineralized human enamel after titanium tetrafluoride application.

OBJECTIVE: Evaluate the presence of a titanium dioxide layer after application of titanium tetrafluoride on human permanent tooth enamel. STUDY DESIGN: The sample consisted of unerupted third molars. After the removal of the roots, each tooth was mesiodistally divided into 2 fragments, one reserved for the experimental group and the other for the control group. Before the treatments the fragments were artificially demineralized. The experimental group (n=5) received an application of 4% titanium tetrafluoride, for one minute and the control group (n=5) did not receive any treatment. The samples were sputter-coated with a 20-30nm gold layer as the energy dispersive x-ray spectrometer analysis was carried out in a scanning electron microscope and the results were descriptively analyzed. RESULTS: The titanium dioxide layer was present on all experimental samples with a titanium peak varying between 6.82 and 26.37%. This layer was not found in the control group. Fluoride and calcium fluoride precipitates were present in the samples treated with titanium tetrafluoride. CONCLUSION: Titanium dioxide layer was formed after one titanium tetrafluoride application, but it was not uniform. Further studies should be carried out so that both the morphology and thickness of such layers can be better understood.

A spectroscopic and surface microhardness study on enamel exposed to beverages supplemented with lower iron concentrations.

OBJECTIVES: This study aimed to compare the in vitro mineral loss and surface microhardness (SMH) changes in human enamel specimens following supplementation of acidic carbonated beverages with low iron concentrations than when treated without. STUDY DESIGN: 180 enamel blocks each from primary and permanent teeth were prepared and equally subdivided (n=10) for their respective treatments in Group 1 (Coca Cola and Sprite without iron supplementation) and Group 2 (beverages supplemented with 2/5 mmol/L FeSO4.7H2O). Following initial SMH estimation, the blocks were subjected to 3 treatment cycles of 5/20 minute incubation periods, equally interspaced by a 5-min treatment in artificial saliva. The calcium and phosphate released after each cycle were analyzed spectrophotometrically and the final SMH was recorded. The results were tested using student's T test, One-way ANOVA and Kruskal Walli's test (p<0.05). RESULTS: Two and five mmol/L FeSO4.7H2O supplementation produced a highly significant SMH change and calcium and phosphate reduction than when treated without (p<.0005). Both the enamel specimens showed similar patterns of mineral loss and SMH reduction, with pronounced effects in the twenty minute incubation cycles. CONCLUSION: Our results suggest that 2 mmol/L FeSO4.7H2O supplementation to acidic beverages is beneficial in reducing mineral loss and preserving surface microhardness of human enamel.

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.