Antimicrobial effect of natural kinds of toothpaste on oral pathogenic bacteria.

INTRODUCTION: Because of the adverse effects on human health of some antimicrobial ingredients in traditional toothpaste, consumers are increasingly turning to toothpastes with natural ingredients. This study evaluates the antimicrobial effect of toothpastes containing different natural active agents against three oral pathogens: Streptococcus mutans, Streptococcus sanguinis, and Enterococcus faecalis. METHODOLOGY: This study tested one traditional toothpaste and seven different natural toothpastes containing theobromine, aloe vera, miswak, propolis, chitosan, enzymes and probiotics. The agar-well diffusion method was used to test the antimicrobial effect. Inhibition zones formed around toothpastes after 24 hours of incubation were measured and the data collected were statistically analyzed. RESULTS: Toothpastes containing theobromine and chitosan and the traditional toothpaste showed antimicrobial efficacy for all tested bacteria. Toothpastes containing aloe vera, miswak, and propolis were only effective on S. mutans, while toothpastes containing probiotics and enzymes did not show any antimicrobial effect on the bacteria. Among toothpastes with natural ingredients, the theobromine-containing toothpaste showed the highest efficacy on S. mutans, while the aloe vera- and propolis-containing toothpastes had the lowest efficacy (p < 0.05). CONCLUSIONS: Theobromine- and chitosan-containing toothpastes, which showed antimicrobial activity against all bacteria, can be recommended as alternatives to traditional toothpastes.

A randomised oral fluoride retention study comparing intra-oral kinetics of fluoride-containing dentifrices before and after dietary acid exposure.

OBJECTIVE: This exploratory, randomised, single-blind, crossover, study evaluated fluoride and calcium ion concentrations and pH following use of one of two 1450 ppm fluoride (NaF), 5% w/w KNO3 dentifrices: (1) test dentifrice (with cocamidopropyl betaine) with an orange juice (OJ) rinse; (2) test dentifrice with a deionized (DI) water rinse or (3) comparator dentifrice (with sodium lauryl sulphate and tetrasodium pyrophosphate) with an OJ rinse. DESIGN: Eighteen participants used their assigned dentifrice, rinsed with DI water, then expectorate was collected. Sixty min post-brushing, participants rinsed with OJ or DI water then expectorate was collected. Saliva samples were collected pre-brushing and at 1, 5, 10, 15, 30 and 60 min post-brushing and following the 60 min OJ/DI water rinse. The pH of samples was taken. RESULTS: Significant differences (p < 0.05) were found in salivary fluoride ion concentrations between test and comparator dentifrices at 30 and 60 min and following the 60 min OJ rinse, favouring the former. Significant differences were also found between test and comparator dentifrices for salivary calcium ion concentration at 1, 5 and 10 min (p < 0.0001), favouring the former, and between test or comparator + OJ rinse and test + water rinse (p < 0.005), favouring the latter. No pH differences were shown prior to OJ/water rinse. Products were generally well-tolerated. CONCLUSIONS: Results confirmed that acid-labile fluoride is released from the oral cavity following a dietary acid challenge and showed that formulation excipients may impact on retention of such.

Subgingival uptake and retention of stannous fluoride from dentifrice: Gingival crevicular fluid concentrations in sulci post-brushing.

PURPOSE: To examine the delivery of stannous fluoride to subgingival sulci following toothpaste use in a clinical population. METHODS: This was a controlled, single-site study. 23 subjects with at least 20 dental pockets, 2-4 mm with bleeding, who had not used a stannous fluoride dentifrice in the last 3 months were enrolled. After a 2-week washout period, 20 subjects returned for a baseline visit. They were instructed to refrain from brushing the night before the baseline visit. GCF samples were taken from up to 10 sites identified as sampling sites. Subjects were then given a 0.454% stannous fluoride dentifrice and soft manual toothbrush and asked to brush for 1 minute. 30 minutes after brushing, GCF was re-sampled. Subjects continued using the stannous fluoride dentifrice and soft manual toothbrush at home, twice daily for 2 weeks, in place of their usual hygiene products. At Days 1 and 14, subjects returned to the site, and 12 hours post-brushing GCF samples were taken. The samples were analyzed by ICP-MS (inductively coupled plasma mass spectrometry). A Wilcoxon signed-rank test was performed to determine the difference between post-baseline visits and baseline. Statistical tests were 2-sided using a 5% significance level. RESULTS: 20 subjects completed the trial. Significant levels of tin, a marker for stannous fluoride, were detected 30 minutes after brushing at sampling sites of 2-4 mm. The median tin level in gingival crevicular fluid (GCF) was 24.59 ng/µl, which was highly significant versus baseline (P< 0.0001). Tin levels sampled in GCF 12 hours after brushing on Days 1 and 14 were highly significant versus Baseline (P< 0.0001), showing an increasing trend with continued use. CLINICAL SIGNIFICANCE: Stannous fluoride was found to penetrate sampling sites from 2-4 mm and was retained for 12 hours. Subgingival uptake and retention of stannous fluoride following toothbrushing may play a role in detoxification effects on microbial biofilms and may contribute to the therapeutic efficacy of stannous fluoride dentifrices in promoting gingival health.

Enhanced In Vitro Zinc Bioavailability through Rational Design of a Dual Zinc plus Arginine Dentifrice.

OBJECTIVES: To investigate bioavailability enhancement of zinc on model oral surfaces and in oral biofilms in vitro through strategic formulation with two sources of zinc and L-arginine. METHODS: To modulate the bioavailability of active zinc ions in a zinc citrate dentifrice, an additive research strategy was pursued. A series of zinc citrate dentifrice formulations were prepared with increasing replacement of zinc citrate with zinc oxide (a water insoluble source of zinc ions) to generate a Dual Zinc active system. A screening of isolated zinc and amino acid effects in simple solutions using zeta potential and uptake to model oral surfaces was performed in an effort to determine the effect of particle charge on zinc bioavailability. Zinc delivery and antibacterial efficacy of the Dual Zinc plus Arginine dentifrice formula were tested using in vitro oral epithelial tissue and saliva-derived biofilm models. Furthermore, zinc penetration and retention were determined by subjecting in vitro biofilms to dynamic flow after treatment with the Dual Zinc plus Arginine dentifrice with treated biofilms evaluated for zinc using imaging mass spectrometry (I-MS). Bacterial adhesion to gingival epithelial cells treated with the Dual Zinc plus Arginine dentifrice was imaged upon challenging with Streptococcus gordonii. RESULTS: Addition of zinc oxide into a zinc citrate dentifrice formula enhanced the efficacy of the system against anaerobic biofilms in a concentration- dependent manner. L-arginine further provided a significant positive charge (+36 mV) to the zinc oxide suspension (+16 mV) as measured by zeta potential. Simple solutions of the Dual Zinc active showed increased zinc uptake on model oral surfaces as a direct function of L-arginine concentration. Antibacterial efficacy of a Dual Zinc plus Arginine dentifrice was evaluated through multiple mechanisms. Enhanced antibacterial performance was observed through significant reductions in metabolic activity as measured through bacterial glycolytic function (p = 0.0001) and total oxygen consumption (p = 0.0001). Greater penetration and retention of zinc was observed in bacterial biofilms treated with the Dual Zinc plus Arginine dentifrice in comparison to treatment with a Dual Zinc dentifrice after twelve hours of dynamic flow (10 mL/hour) in an in vitro drip flow biofilm culture. Confocal microscopy showed adherent bacteria on cheek cells treated with the Dual Zinc plus Arginine dentifrice formula. CONCLUSIONS: The combination of zinc citrate, zinc oxide, and the amino acid L-arginine in a dentifrice formula enhances the bioavailability of zinc to model oral tissue surfaces, resulting in unique physicochemical effects. The significant antimicrobial control associated with the Dual Zinc plus Arginine dentifrice provides a unique vehicle toward achieving whole mouth health.

An in vitro assessment of fluoride uptake by tooth enamel from four different fluoride dentifrices.

AIM: The aim of this study was to evaluate fluoride uptake by tooth enamel with four different fluoride dentifrices. STUDY DESIGN: Sixty human premolars extracted for orthodontic purpose were selected for the study. The teeth were covered with nail varnish leaving a window of 4 × 4 mm on the enamel surface of the buccal and lingual sides. The teeth were demineralised and were divided into four groups with 15 teeth in each group. The buccal window served as experimental and the lingual as control. The teeth were immersed in toothpaste slurry containing: sodium fluoride (Group A); sodium monofluorophosphate (Group B); stannous fluoride (Group C) and amine fluoride (Group D). The fluoride content in the etched superficial enamel layer in the windows was analysed using a fluoride ion-specific electrode. RESULTS: Within the parameters of this study, the uptake of fluoride was statistically significant in Group D (p < 0.05). The uptake of fluoride by tooth enamel in an increasing order was Group A < Group B < Group C < Group D. CONCLUSION: The study showed that enamel treated with amine fluoride had the highest fluoride uptake.

Protective effects of SnF2 - Part II. Deposition and retention on pellicle-coated enamel.

UNLABELLED: Deposition of an acid-resistant barrier onto enamel represents a potentially superior means for delivering protection against dietary, erosive acid challenges. PURPOSE: The purpose of this study was to demonstrate the ability of a stabilised stannous fluoride (SnF2 ) dentifrice to: (1) deposit a SnF2 barrier layer onto pellicle-coated enamel surfaces; (2) increase the intensity of the barrier layer over time; and (3) be retained on the enamel surface for hours after product use. METHODS: Squares of human enamel were exposed to pooled saliva for 1 hour (pellicle formation) and separated into six sets. Set 1 was treated with the supernatant of a 1:3 slurry of the test dentifrice (Crest(®) Pro-Health(®) : water for 2 minutes), then rinsed. Set 2 was treated in the same manner and then placed into saliva (6 hours). Set 3 was cycled through seven repeated treatments. Set 4 was treated for seven cycles and then placed into saliva (6 hours). Set 5 was a water control, and set 6 was a water control that remained in saliva for 6 hours. Surface analysis of specimens was done using laser ablation Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). RESULTS: Deposition of a barrier layer was demonstrated, beginning with the initial treatment, with Sn (using isotopes (117) Sn + (120) Sn) measured on the enamel surface as the reference marker. Deposition of the barrier layer was greater after seven cycles, and the retention of this layer was highly significant (P = 0.05, anova: 6 hours). CONCLUSIONS: This study confirms that: (1) the stabilised SnF2 dentifrice deposits a barrier layer onto the enamel surface, beginning with the first use of the product; (2) this barrier is enhanced following multiple treatments; and (3) the barrier layer is retained on the enamel surface for hours after product use.

In Vivo Antiplaque Effect of Three Edible Toothpastes

OBJECTIVES: The objective of this study was to analyse the antibacterial and antiplaque activity of three edible toothpastes with the widest worldwide distribution: KidScents(TM), which contains essential oils; Browning B&B(TM), with medicinal plants; and Wysong Probiodent(TM), which contains probiotics. Study DESIGN: The study group was formed of twenty healthy volunteers (dental students) with a good oral health status. Using a balanced randomisation system, all volunteers performed toothbrushing with four products (the three edible toothpastes and water) at intervals of one week. Bacterial vitality in the saliva was analysed by epifluorescence microscopy and plaque regrowth was evaluated using the Turesky-Quigley-Hein plaque index.RESULTS: Bacterial vitality in the saliva was significantly higher after toothbrushing with water (positive control) than with the three toothpastes (P=0.002, P=0.003 and P<0.001, respectively). The plaque index was significantly higher after using these three toothpastes than after toothbrushing with water (P=0.047, P=0.032 and P<0.001, respectively).CONCLUSIONS: The three edible toothpastes analysed have some antimicrobial activity but favour plaque regrowth

No disponible

Fluoride bioavailability in saliva and plaque.

BACKGROUND: Different fluoride formulations may have different effects on caries prevention. It was the aim of this clinical study to assess the fluoride content, provided by NaF compared to amine fluoride, in saliva and plaque. METHODS: Eight trained volunteers brushed their teeth in the morning for 3 minutes with either NaF or amine fluoride, and saliva and 3-day-plaque-regrowth was collected at 5 time intervals during 6 hours after tooth brushing. The amount of collected saliva and plaque was measured, and the fluoride content was analysed using a fluoride sensitive electrode. All subjects repeated all study cycles 5 times, and 3 cycles per subject underwent statistical analysis using the Wilcoxon-Mann-Whitney test. RESULTS: Immediately after brushing the fluoride concentration in saliva increased rapidly and dropped to the baseline level after 360 minutes. No difference was found between NaF and amine fluoride. All plaque fluoride levels were elevated after 30 minutes until 120 minutes after tooth brushing, and decreasing after 360 minutes to baseline. According to the highly individual profile of fluoride in saliva and plaque, both levels of bioavailability correlated for the first 30 minutes, and the fluoride content of saliva and plaque was back to baseline after 6 hours. CONCLUSIONS: Fluoride levels in saliva and plaque are interindividually highly variable. However, no significant difference in bioavailability between NaF and amine fluoride, in saliva, or in plaque was found.

Ultramorphology and dentine permeability changes induced by prophylacticprocedures on exposed dentinal tubules in middle dentine

Objectives: The purpose of this study was to evaluate the changes in dentinal permeability (i.e. hydraulic conductance)after prophylactic treatments performed using prophy-powders with air-polishing system or prophy-pasteson exposed middle dentine. The changes in dentine morphology were evaluated by SEM.Study design: Commercial prophylactic pastes and air-polishing powders were tested in this study. Dentine discs from human third molars were used to study the quantitative reduction of the dentine permeability under simulated pulpal pressure (20 cm H2O). Further specimens were gold-coated and analysed using observed a SEM.Results: The results of this study showed different dentine permeability redaction based on the type of productemployed (i.e. prophylactic paste or air-polishing powders). The use of Sylc bioactive glass and sodium bicarbonate were the most effective in reducing dentine permeability of the specimens. However, the air-polishing procedures performed with Sylc bioactive glass created a dentine surface devoid of exposed dentinal tubules due to the presence of a compact multilayered smear layer. Colgate Sensitive Pro-Relief and Nupro NU-Solution reduced thedentine permeability up to 69.8% and 66.9% respectively.Conclusion: Although all the tested products are able to statistically reduce dentine permeability, Sylc bioactiveglass is an innovative and effective product which completely occludes the dentinal tubules during prophylactic procedures of air-polishing (AU)

Diffusion of peroxides through dentine in vitro with and without prior use of a desensitizing varnish.

Different bleaching regimens are used in dentistry possibly penetrating the dentine and affecting the pulp. The aim of the present study was to investigate peroxide diffusion through dentine pre-treated with a desensitizing varnish (Vivasens®) in a standardized in vitro setup during application of different bleaching materials. The penetration was tested using 1.3-mm-thick bovine dentine slabs. The following bleaching materials were tested with and without prior application of the desensitizing varnish on the external side of the dentine slabs: Vivastyle, Whitestrips, Simply White, Opalescence (external bleaching), and sodium perborate (internal bleaching, only tested without varnish; n = 8 samples per subgroup). The penetration of peroxides was measured photometrically using 4-aminoantipyrin as a substrate, the penetration of peroxides was monitored over 240 min. All bleaching agents yielded a diffusion of peroxides through the dentine, the kinetics of penetration were approximately linear for all materials tested. The significantly highest diffusion of peroxides was observed with Opalescence, the lowest with sodium perborate. The adoption of the desensitizing varnish reduced the diffusion of peroxides significantly for all external bleaching materials. Peroxides penetrated the dentine during application of bleaching materials; the penetration of peroxides can be reduced by application of a desensitizing agent.

The effect of brushing time and dentifrice quantity on fluoride delivery in vivo and enamel surface microhardness in situ.

While the clinical anticaries efficacy of fluoride toothpaste is now without question, our understanding of the relation of fluoride efficacy to brushing time and dentifrice quantity is limited. The aim of this in situ study was to determine how differences in brushing time and dentifrice quantity influence (i) fluoride distribution immediately after brushing, (ii) clearance of fluoride in saliva, (iii) enamel fluoride uptake (EFU) and (iv) enamel strengthening, via the increase in surface microhardness. The study compared brushing times of 30, 45, 60, 120 and 180 s with 1.5 g of dentifrice containing 1,100 microg/g fluoride as sodium fluoride. In addition, 60 s of brushing with 0.5 g dentifrice was evaluated. A longer brushing time progressively reduced retention of dentifrice in the brush, thereby increasing the amount delivered into the mouth. A longer brushing time also increased fluoride concentrations in saliva for at least 2 h after the conclusion of brushing, showing that increased contact time promoted fluoride retention in the oral cavity. There was a statistically significant positive linear relationship between brushing time and both enamel strengthening and EFU. Compared to 0.5 g dentifrice, brushing with 1.5 g dentifrice more than doubled the fluoride recovered in saliva after brushing and increased EFU. In conclusion, the results of this preliminary, short-term usage study suggest for the first time that both brushing time and dentifrice quantity may be important determinants both of fluoride retention in the oral cavity and consequent enamel remineralization.

The role of ionic release from NovaMin (calcium sodium phosphosilicate) in tubule occlusion: an exploratory in vitro study using radio-labeled isotopes.

OBJECTIVE: The primary objective of this work was to develop a method of quantifying the levels and source of calcium and phosphate deposited on dental hard tissue from a novel calcium phosphosilicate (NovaMin) material using neutron activation analysis (NAA). A second objective was to explore the utility of radiotracing to determine dentin porosity following exposure to calcium phosphosilicate. METHODS: Neutron activation was used to create isotopes of Ca and P in the calcium phosphosilicate particles. Gamma radiation emitted from these isotopes was used to identify and measure their uptake (concentration) onto dental hard tissue. Three experiments were conducted to explore calcium and phosphate uptake to dental hard tissue: 1) a dose response to quantify the relative levels of calcium and phosphate deposited on dental hard tissue as a function of calcium phosphosilicate dose; 2) the effect of calcium phosphosilicate particle size on the relative levels of calcium and phosphate uptake; and 3) the permeability of calcium phosphosilicate-treated dentin by employing the radiotracer technetium. For all experiments, extracted bovine incisors were employed as the test substrate. RESULTS: The results indicate there is a strong dose relationship between the wt% and particle size of calcium phosphosilicate in the dentifrice formulation and new Ca and P deposition. At above 5.0 wt% calcium phosphosilicate, there appears to be an exponential increase in the number of counts from the tooth surface. Finer particle size calcium phosphosilicate appears to deposit much higher levels of Ca and P than the larger range of particle sizes. The results from the technetium study show that when treated with the dentifrice slurry containing calcium phosphosilicate, dentin shows only a slight amount of technetium infiltration, indicating a lowering of dentin permeability. CONCLUSION: This exploratory study has demonstrated that NAA and the use of radio isotopes have utility in monitoring the uptake of Ca and P into both dentin and enamel tooth structure. The data generated from these studies have shown that there is a dose dependence and particle size effect for calcium phosphosilicate on the deposition of calcium and phosphate to dental hard tissue.

In vitro remineralization efficacy of NaF systems containing unique forms of calcium.

PURPOSE: To determine the in vitro remineralization potential of a new calcium phosphate technology in a 1000 ppm F system. METHODS: 3 mm diameter bovine enamel specimens were mounted, ground and polished, and softened in a carbopol-lactic acid solution (pH = 5.0) for 36 hours at 37 degrees C. Specimens were then measured for baseline Vickers microhardness and stratified (N = 10, mean VHN = 35) into the following groups: Group A: distilled water (negative control); Group B: MI Paste Plus (900 ppm F); Group C: Theramed SOS (1450 ppm F); Group D: "control" dentifrice (1000 ppm F); and, Group E: "test" dentifrice (1000 ppm F) admixed with a new functionalized calcium phosphate system. The groups were then cycled for 10 days in a pH cycling model consisting of four 2-minute treatment periods (diluted 1:3 with distilled water) and one 4-hour acid challenge (carbopol-lactic acid, pH = 5.0) per day. Between these events, specimens were immersed in artificial saliva (pH = 7.0). After 10 days of cycling, the specimens were measured for Vickers surface microhardness and were subsequently microdrilled, with the powder measured for fluoride content using a calibrated fluoride-sensitive electrode. RESULTS: Significant differences resulted between the distilled water and fluoride-containing groups. Among the fluoride-containing groups, Group B demonstrated statistically low levels of enamel fluoride deposition and deltaVHN, while Group E statistically outperformed Group D. Among the groups with different calcium systems (Groups B, C, and E), Groups C and E were found to be statistically equivalent and superior to Group B with respect to both bioavailable fluoride and deltaVHN. Based on our results, these data demonstrated the combination of a new calcium phosphate technology plus 1000 ppm F, produced significantly greater remineralization relative to both the 1000 ppm F test dentifrice and MI Paste Plus, and was statistically equivalent to Theramed SOS.

Laboratory assessment of the anticaries potential of a new dentifrice.

OBJECTIVE: The aim of the present study was to investigate the anticaries potential of a new sodium fluoride dentifrice in comparison to two commercial dentifrices containing different fluoride compounds by determining enamel fluoride uptake (EFU) and early caries lesion remineralization (REM) in an established in vitro caries remineralization/demineralization pH cycling model. METHODS: Test products were: new dentifrice formulation in a fluoride dose-response (0; 675; 1426 ppm F as sodium fluoride [NaF-0; NaF-675; NaF]); Elmex Kariesschutz (1400 ppm F as amine fluoride [AmF]); and Oral-B Pro-Expert (1450 ppm F-1100 ppm F as stannous fluoride and 350 ppm F as sodium fluoride [SnNaF]). Artificial caries-like lesions were formed in human enamel specimens by immersion in lactic acid buffer (LA). Specimens were then subjected to a daily cycling regime for 20 days comprising four one-minute dentifrice slurry treatments (prepared in pooled human saliva), and one four-hour LA challenge and remineralization in pooled human saliva. After 20 days, REM was evaluated as the change in surface Vickers microhardness from lesion baseline and EFU using the microdrill technique. The data were analyzed using ANOVA. RESULTS: A good fluoride dose-response was established for EFU and REM, with NaF delivering greater EFU and REM than NaF-675, which was superior to NaF-0 (p < 0.05). The new dentifrice NaF also showed greater EFU and REM than AmF and SnNaF (p < 0.05). In EFU, AmF and SnNaF were as efficacious as NaF-675 and superior to NaF-0 (p < 0.05). AmF and NaF-675 were also comparable in REM, whereas both products exhibited superior REM vs. SnNaF (p < 0.05), which was superior to NaF-0 (p < 0.05). CONCLUSION: The present study has demonstrated that fluoride dentifrices vary in their capability of enhancing anticaries potential as determined using an established in vitro caries cycling model. The new dentifrice NaF showed superior predicted anticaries potential compared to the two commercial dentifrices AmF and SnNaF in this model, which demonstrates the importance of fluoride compound and formulation excipients on driving anticaries potential in vitro.

Mechanism of fluoride dentifrice effect on enamel demineralization.

Although the anticaries effect of fluoride (F) dentifrices is clearly established, the relative importance of F taken up by dental plaque not removed by brushing and of F products (CaF(2)-like) formed on totally cleaned enamel for the subsequent inhibition of demineralization is not known. Both effects were evaluated using conventional (1,100 microg F/g) and low-F concentration (500 microg F/g) dentifrices in a randomized, crossover, double-blind in situ study. Enamel blocks not treated or pretreated with the dentifrices to form CaF(2)-like deposits were mounted in palatal appliances in contact with a Streptococcus mutans test plaque. Volunteers brushed with non-F (negative control), low-F or conventional dentifrices and inserted the appliance in the mouth. F concentration in the fluid and solid phases of the test plaque was determined after 30 min, and a rinse with 20% sucrose solution was performed. After additional 45 min, plaque was collected and the loss of surface hardness at different test-plaque depths was measured. CaF(2)-like deposition on enamel and F taken up by plaque due to the use of F dentifrices were able to significantly increase F concentration in the fluid phase of the test plaque, but only the latter significantly reduced the loss of hardness because of the 20-30 times higher F concentration. Also, significant differences between the low-F and conventional dentifrices were observed for F on enamel, in plaque and on the subsequent loss of hardness. The results suggest that uptake of F by dental plaque not removed by brushing may be the main cause of the anticaries effect of F dentifrices.

Topical oral cavity pharmacokinetic modeling of a stannous fluoride dentifrice: an unusual two compartment model.

A pharmacokinetic model was developed describing the pharmacokinetics of stannous fluoride in human subjects after oral topical application of a stannous fluoride dentifrice. Twenty subjects participated in an investigation of an experimental dentifrice. Subjects rinsed their mouths with the experimental dentifrice slurry. Saliva and plaque samples were obtained from the subjects at various times up to 6 h after administration. Samples were analyzed for total tin content, used as an analytical marker for the active stannous fluoride ingredient, using a graphite furnace atomic absorption spectrometer. The modeling indicates that there is an obvious kinetic relationship between saliva and plaque compartments and that stannous fluoride is very well retained in and slowly released from plaque (and oral surfaces) into saliva. Additionally, both compartments are simultaneously loaded during administration unlike typical systemic drug behavior, and the elimination rate "constant" from the central compartment (saliva) changes due to changes in salivary flow. Stannous fluoride is cleared from saliva rapidly but very well retained in gingival plaque. The model with simultaneous loading of plaque and saliva describes these observations and may account for the prolonged antiplaque and antigingivitis benefits of stannous fluoride.

Fluoride uptake by plaque from water and from dentifrice.

It has been suggested that fluoride retention in plaque is limited by available binding sites. We determined the effects of fluoridated or placebo dentifrices on plaque and salivary fluoride concentrations [F]s in communities with different water fluoride concentrations (0.04, 0.85, 3.5 ppm). After one week of dentifrice use, samples were collected 1.0 and 12 hrs after the last use of dentifrices. After the use of fluoridated dentifrice, plaque fluoride concentrations were higher at both times, except at 12 hrs in the 3.5-ppm community. Plaque concentrations at 1.0 hr after the use of fluoridated dentifrice increased almost constantly (6.5 mmol/kg), but then decreased approximately 50% at 12 hrs in each community. Unlike previous studies, the present findings suggest that the use of fluoridated dentifrice is likely to increase plaque fluoride concentrations significantly for up to 12 hrs in areas where the water contains fluoride close to 1.0 ppm. As previously reported, plaque fluoride concentrations were directly related to calcium concentrations.

[Enamel fluoride uptake following fluoride application and fluoride precipitation]. / Schmelz-fluoridaufnahme nach Fluoridierung und Fluoridfällung.

This study is on fluoride uptake into enamel following fluoride precipitation with calcium hydroxide. Five specimens each from 12 bovine incisors were polished, covered with a salivary pellicle, and distributed into five groups (n=12). A fluoride solution (43,500 ppm F from magnesiumfluorosilicate, copper-(II)-fluorosilicate and sodium-fluoride, pH 2; Tiefenfluorid Touchierlösung, Humanchemie) and Ca(OH)2-solution (Tiefenfluorid Nachtouchierlösung) were applied subsequently in group TN. "Touchierlosung" only was used in group T, sodium-fluoride (43,500 ppm F, pH 2) in group NaF, and aminefluoride (Elmex fluid, 10,000 ppm F, pH 4) in group EF. No fluoride was used in group NK (negative control). Following rinsing and 24 h storage in artificial saliva surface KOH-soluble fluoride content (KOHF), and structurally bound fluoride content (SBF) from three layers (0-33, 33-66 and 66-99 pm) was determined by fluoride electrode procedures. KOHF (median in microg/cm2) of NK was below the lower limit of quantification of the fluoride electrode. The other group values were significantly higher (Mann-Whitney test, p < or = 0.05). TN (1.6), T (1.4) and NaF (1.1) did not differ significantly. EF (0.6) was significantly smaller than TN and T but not smaller than NaF. SBF (0-33, 33-66, 66-99 pm; median in microg/cm3) of TN (445, 341, 275), T (644, 481, 360), NaF (804, 480, 307) and EF (449, 346, 280) did not differ significantly but, with the exception of TN, were significantly higher as compared to NK. A precipitation reaction with Ca(OH)2 following fluoridation did not increase enamel fluoride uptake.

Determinación de la substantividad de un dentífrico con flúor de aminas y xilitoly de un dentífrico con flúor de sodio / No disponible

Los agentes químicos utilizados para el control y eliminación de la placa bacteriana deben reunir unas características específicas para ser utilizados como medio de prevención de la caries y la enfermedad periodontal. Todas estas características son de gran interés, sin embargo, debemos destacar tres condiciones sine qua non a la horade seleccionar el agente químico a utilizar: la toxicidad, la potencia y la substantividad. Un factor determinante en la acción antiplaca de un agente químico parece estar relacionado con la capacidad de ser retenido en la cavidad oral durante largos períodos de tiempo, es la propiedad conocida con el nombre de substantividad. En el presente trabajo se realiza un estudio comparativo para determinar el contenido de flúor en saliva después del cepillado dental con un dentífrico que contiene flúor de aminas y con un dentífrico que contiene flúor de sodio; comparando la substantividad de cada uno de ellos en el medio oral (AU)

The chemical agents used for the control and elimination of the bacterial plaque must have especial and determinant characteristics to be used by a prevention method of caries and periodontal disease. All of these characteristics are very interesting; however, we must insist on three essential conditions in the time of choose the chemist agent for use: the toxicity, the potency and the substantivity. A determinant factor in the antiplaque action of our chemical agent seem to be related with the capacity for are retained in the oral cavityduring long periods of time; is the property known as substantivity. In the present study it is been compared three different dentifrices in order to determine the quantity of fluorine in saliva after a tooth brushing with amina fluorine dentifrice and with sodium fluorine dentifrice; comparing the substantively of each in the oral medium (AU)

Effect of a combination of fluoride dentifrice and varnish on enamel surface rehardening and fluoride uptake in vitro.

The purpose of this study was to evaluate the effect of combining fluoride dentifrice (FD) and varnish (FV) on in vitro enamel surface rehardening and on fluoride uptake under a pH-cycling regimen. Seventy-eight bovine enamel blocks with early lesions were used and 52 were divided into four treatment groups: (a) placebo non-fluoridated dentifrice (PD); (b); FD (1100 p.p.m. F as NaF); (c); FV (Duraphat) + PD; and (d) FV + FD. The FV was applied to enamel blocks of groups FV + PD and FV + FD before the pH-cycling regimen, and all of them were submitted to dentifrice during cycling. Surface enamel microhardness was determined on the dental blocks before and after demineralization, and after the pH-cycling regimen. The percentage of surface microhardness recovery (%SMHR) was calculated. Fluoride in the blocks was also determined, after removing three layers of enamel. The highest values of percentage SMHR were observed for the FD group. The greatest fluoride uptake was found in the FD and FV + FD groups, but the difference between them was not statistically significant. It was found that the frequent use of fluoride dentifrice resulted in greater benefit in enamel surface rehardening, with a similar effect on fluoride uptake, when compared with its combination with a single fluoride varnish application.