Visual detection of fluoride based on supramolecular aggregates of perylene diimide in 100% aqueous media

A water-soluble perylene imide derivative (PDI-Glu) was synthesized and their supramolecular aggregates composed of PDI-Glu and Al³⁺ were prepared as a "turn on" fluorometric probe to monitor F^- in a purely aqueous system. Based on an "indicator displacement assay" (IDA) approach, the sensing performance and mechanism of PDI-Glu/Al³⁺ complex toward F^- were investigated by absorption and emission spectra. It was suggested that disassembly of PDI-Glu/Al³⁺ aggregates was promoted by addition of F^- through the competitive binding between Al³⁺ and F^-. The detection limit is 240 nmol/L. This method featured simple preparation, excellent water solubility, adjustable self-assembly performance, ease of observation and operation, and high selectivity and sensitivity. It was used for monitoring F^- in toothpaste and tap water samples with excellent accuracy and recovery. To the best of our knowledge, this is the first water-soluble perylene diimide-based probe for F^- detection in 100% aqueous media. We believe this work could not only extend the sensing scope of water-soluble perylene diimide, but also bring some useful information for the rapid detection of anionic analytes  in aqueous media. The disassembly of supramolecular aggregates of PDI-Glu/Al³⁺ along with significant fluorescence recovery enable a rapid and visual detection of F^- based on an "indicator displacement assay" strategy.

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

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.

[Fluoride levels in commercial dentifrices and drinking water in Algeria]

More and more scientific evidence show that fluorides have a cariostatic action to the plaque-saliva-tooth interface during cariogenous dissolution. Fluorides slow down demineralization and enhance remineralization. Their action is optimal, in the oral environment, when used at low concentrations on a continuous basis. The use of the fluorinated toothpastes during brushing of the teeth is a simple, rational method of daily topics application of fluorine, largely used in the context of prevention of dental caries and which can even be regarded as a public health measure. The water ingestion fluorinated represents itself an excellent average of the local application of fluorine. Our work concerned a quantitative study of fluorine in toothpaste and drinking water, and comparative between the local product and the imported one for the toothpastes, and the mineral water and public supply. The standard method of fluorine based on the potentiometry and distillation has shown that 50% of the tested toothpastes contain adequate concentration so that a product of dental care fights against decay. The Tlemcen tap water contains acceptable fluorine content, but the mineral water, with an excessive contribution, can cause fluorose. Of this, we can deduce that a topical application of a suitable quantity of fluorine on a daily basis in accordance with the precautions is not only the prevention of dental caries, but also to stabilize it if it already exists.

[Dental fluorosis: an epidemiological investigation in the area of Ouardanine in Tunisia]

In this work, we carried out a transverse epidemiological investigation about the oral health state of pupils in the Ouardanine area. The investigation concerned 300 fifteen-year-old pupils. An amount of fluoride was administrated within drinking water. Further studies, within few years, will be desirableto follow the fluorosis evolution in this area.

Coupling desorption electrospray ionisation and neutral desorption/extractive electrospray ionisation with a travelling-wave based ion mobility mass spectrometer for the analysis of drugs

Desorption electrospray ionisation (DESI) and neutral desorption/extractive electrospray ionisation (EESI) have been coupled to a hybrid quadrupole travelling-wave (T-Wave)-based ion mobility time-of-flight mass spectrometer for the direct accurate mass analysis of active ingredients formulated into pharmaceutical samples. The collision cross-section measurements of polyethylene glycol (PEG) excipients detected in one formulation were estimated and compared with published data. These estimated collision cross-sections of the PEG species showed good agreement with published data.

Fluoride intake by children at risk for the development of dental fluorosis: comparison of regular dentifrices and flavoured dentifrices for children

The aim of the present study was to determine fluoride intake by children at risk of dental fluorosis according to the type of dentifrice used. Forty-two volunteers aged between 20 and 30 months, from 2 kindergartens, were supervised while brushing their teeth with regular dentifrices (nominally 1,500 ppm F) and dentifrices flavoured for children (nominally 1,100 ppm F), brushing 3 times with each type in random order to minimize bias. The amount of fluoride ingested was determined by subtracting the weight of dentifrice recovered from the weight used and calculating the mean of the 3 brushings. Fluoride was analyzed with specific electrodes. Parents were asked how often the children brushed their teeth and the daily tooth brushing frequency was used to calculate the daily fluoride intake. The average fluoride intake using regular dentifrices and those flavoured for children was 0.567 +/- 0.300 and 0.630 +/- 0.320 mg F/day, respectively, corresponding to doses of 0.046 +/- 0.023 and 0.051 +/- 0.026 mg F/kg/day (p > 0.05). Fluoride intake was slightly higher with the use of dentifrices flavoured for children. Moreover, the dose to which children were exposed with either type of dentifrice was very close to that which is considered the limit (0.05-0.07 mg F/kg/day).

Fluoride ingestion from toothpaste and diet in 1- to 3-year-old Brazilian children

OBJECTIVE

This study estimated the total daily fluoride intake of 1- to 3-year-old children from diet and dentifrice. The constituents of the diet were divided into solids, water, milk, and other beverages, which were analyzed separately. The correlation between fingernail fluoride concentrations and the total daily fluoride intake by children was also investigated.

METHODS

Thirty-three children, living in a fluoridated area, participated in the study. Fluoride intake from diet was monitored by the 'duplicate plate' method, investigating the different constituents of the diet. Fluoride ingested from dentifrice was determined by subtracting the amount of fluoride recovered after brushing from the amount originally placed onto the child's toothbrush. Fingernails were clipped and collected on three occasions. Fluoride was analyzed with the ion-specific electrode, after hexamethyldisiloxane-facilitated diffusion. Data were tested by anova and Tukey's post hoc tests, Student's t-tests and linear regression (P < 0.05).

RESULTS

Mean (+/-SD) fluoride intake from diet and dentifrice was 0.025 +/- 0.013 and 0.106 +/- 0.085 mg/kg body weight/day, respectively, totaling 0.130 mg/kg body weight/day. A strong positive correlation (r = 0.971, P < 0.0001) was seen between the amount of dentifrice loaded onto the brush (0.49 +/- 0.30 g) and the amount of fluoride ingested during each tooth brushing (0.59 +/- 0.45 mg). Among the constituents of the diet, water and milk had a significantly higher contribution to the fluoride intake (0.18 +/- 0.11 mg/day, P < 0.0001), when compared with solids (0.07 +/- 0.05 mg/day) and other beverages (0.07 +/- 0.04 mg/day). Mean (+/-SD) fingernail fluoride concentration on the three dates of collection was 3.11 +/- 1.14, 2.22 +/- 1.47 and 3.53 +/- 1.40 mug F/g. There was no significant correlation between fingernail fluoride concentration and the total fluoride intake.

CONCLUSIONS

Most of the children are exposed to a daily fluoride intake above the suggested threshold for dental fluorosis. The dentifrice alone is responsible for an average of 81.5% of the daily fluoride intake, while among the constituents of the diet, water and milk are the most important contributors. In addition, small variations in daily fluoride intake cannot be detected in fingernails.

The fractional urinary fluoride excretion of adolescents and adults under customary fluoride intake conditions, in a community with 0.6-mg F/L in its drinking water

AIMS

To assess the fractional urinary fluoride excretion (FUFE) relative to the customary daily fluoride (F) ingestion in adolescents and adults aged 11-75 years, and to explore the influence that some metabolic variables, such as the F-dose (mg F/kg body weight), rate of urinary fluoride excretion, age and body weight, might have on FUFE values.

DESIGN

The fluoride ingestion and urinary excretion of 92 volunteers aged 11-75 years, resident in Santiago, Chile, were measured. In Santiago, the water is fluoridated to a concentration of between 0.5 and 0.6 mg/l. Individual FUFE values were calculated as the ratio between the total amount of F excreted with the urine and the total amount of F ingested, over a 24-hour period.

RESULTS

The average FUFE values did not differ significantly among adults (ANOVA; p > 0.31). The average 24-hour FUFE value for adults was 0.75; 95% C.I. = 0.70-0.80, while the corresponding value for adolescents was 0.35; 95% C.I. = 0.30-0.40. Individual FUFE values were fitted by a multiple regression model using the rate of F urinary excretion and the inverse of the F dose as significant predictors (R2 = 0.79).

CONCLUSIONS

Results obtained suggest that among adults residing in an area with an intermediate F-exposure, FUFE values do not depend on age. A relatively simple multiple regression model appears to explain 79% of the variability of the individually measured FUFE values. Further studies in areas with different F exposures are needed to refine the proposed model.

The effect of a dentifrice in the prevention of recurrent aphthous stomatitis

PURPOSE

A multicenter, double-blind, randomized, placebo-controlled clinical trial was conducted to determine the efficacy of an experimental dentifrice on the prevention of recurrent aphthous stomatitis (RAS).

MATERIAL AND METHODS

A 3-month pretrial period was used to self-record data pertaining to the frequency, ulcer size, duration, and pain associated with ulcers. Thirty-six participants, who reported at least 3 RAS episodes or 30 days with RAS during the pretrial period, completed the study. Following a stratified randomization for age, sex and disease severity, the participants received the experimental dentifrice (T) or the placebo (C). The test period comprised 3 months of self-evaluation of number of ulcers, size and location. Pain related to RAS was estimated by the use of a Visual Analogue Scale (VAS).

RESULTS

Symptoms were found to decrease in both groups when the pretrial and test periods were compared, although no statistical difference was reached in the C group. A statistically significant difference between the two time periods was obtained for the T group concerning the number of days with ulcers (p < 0.025) and VAS (p < 0.010). Of more clinical importance was the observation that 50% of the patients in the T group reported a more than 50% reduction in days with ulcers compared to 17% in the C group.

CONCLUSIONS

The dentifrice may be used as a treatment strategy for a subgroup of patients with RAS in view of the low adverse effects and the benefit of using a treatment modality that is a part of daily routines.

Occluding effect of dentifrices on dentinal tubules

OBJECTIVES

The objective of this study was to evaluate the tubule occluding ability of three commercial available dentifrices (Sensodyne, Emoform and Sorriso) by Scanning Electron Microscopy.

METHODS

Fifty cervical areas from buccal and lingual surfaces of sound third human molars were used. Cervical enamel was wet abraded to expose flat dentin surfaces and further polished with diamond pastes. Specimens were randomly divided into five groups (n=10): G1-no brushing; G2-brushing without dentifrice; G3-brushing with Sensodyne; G4-brushing with Emoform; G5-brushing with Sorriso. Brushed specimens were treated for 4 min per day, for 7 days in a toothbrushing machine. Specimens were prepared and observed under SEM for calculation of the percentage of occluded tubules. In addition, slurries of toothpastes were analyzed by X-ray microanalysis. Data were statistically analyzed by ANOVA and Tukey test (p<0.05).

RESULTS

Means of occluded tubules in descending order were: G5-98.83+/-3.31% (a), G4-96.02+/-5.24% (a), G3-80.12+/-24.65% (a), G1-37.31+/-24.22% (b); G2-22.92+/-15.19% (b). The three tested dentifrices produced increased dentinal occlusion as compared to controls (p<0.05) but equivalent occlusion among each other. Calcium from calcium-carbonate abrasive was identified in all dentifrices.

CONCLUSIONS

Results indicated that the use of all dentifrices occluded tubules more than no brushing and brushing without dentifrices groups. Thus, the tested dentifrices seem effective for desensitization by tubule occlusion.

Fluoride intake by Brazilian children from two communities with fluoridated water

OBJECTIVES

To determine total daily fluoride intake by young children from two communities in a developing country.

METHODS

Fluoride intake from diet and dentifrice was determined for 71 Brazilian children, aged 19-38 months, living in two communities with fluoridated water (0.6-0.8 ppm). The children from Piracicaba attended a full-time day care centre but those from Ibiá did not. Fluoride ingested during tooth brushing was determined, and 'duplicate-plate' samples of all foods and beverages ingested during a 2-day period were collected from which fluoride for analysis was extracted by hexamethyldisiloxane (HMDS) microdiffusion. The amount of fluoride ingested (mg F/kg body weight/day) from the diet and dentifrice and the combined fluoride intake were calculated. A limit of 0.05-0.07 mg F/kg body weight/day was considered as the safe threshold for fluoride exposure.

RESULTS

The children from Ibiá had lower amounts of fluoride in their diets than those from Piracicaba (P < 0.05); no differences in the amount of fluoride ingested from dentifrice were found between the communities. In both communities, the daily fluoride intake from dentifrice was higher than that from the diet (P < 0.05). Most of the children from both communities were exposed to a combined dose (diet + dentifrice) of fluoride above the risk threshold for dental fluorosis.

CONCLUSION

The data suggest that fluoride intake from diet depends on living conditions, and measures should be implemented to reduce the fluoride intake of these Brazilian children.

Fluoride intake from foods, beverages and dentifrice by children in Mexico

OBJECTIVES

This investigation monitored fluoride ingestion in Mexican children who were susceptible to developing dental fluorosis.

METHODS

Total fluoride intake, from dietary and toothpaste samples, was determined in 15-36-month-old children from Mexico City and Veracruz, Mexico. A duplicate plate technique was used. Plasma fluoride levels were also determined in this group of children.

RESULTS

The children ingested a mean (+/-SD) of 0.20 +/- 0.08 and 0.18 +/- 0.07 mg fluoride/kg/day, in Mexico City and Veracruz, respectively. There was no statistically significant difference between the fluoride ingested by children in the two cities (P > 0.9). Plasma from children in Mexico City and Veracruz contained a mean of 1.30 +/- 0.81 and 0.87 +/- 0.72 micro mol fluoride/l, respectively, and these values were not significantly different.

CONCLUSIONS

Our results lead to the conclusion that mean fluoride ingested from the combination of foods and beverages was within the proposed safe threshold for fluoride intake of 0.05-0.07 mg F/kg/day. Most of the fluoride intake by these children was derived from the ingestion of fluoridated toothpaste. When all sources of ingested fluoride were added and total fluoride intake was calculated, the children, both in Mexico City and Veracruz, were ingesting amounts of fluoride well above the upper limits of the proposed safe threshold for fluoride intake.

Evaluation of total pH and soluble and ionic fluoride concentrations in dentifrices commercially available in Brazil

PURPOSE

To verify the total (TF), soluble (SF) and ionic (IF) fluoride concentrations in the main Brazilian dentifrices for comparison and quality control according to the current Brazilian Ministry of Health Regulations, 2000.

MATERIALS AND METHODS

Nineteen brands, from 2 batches, fresh or aged at 45 degrees C/48 h, had their F concentrations and pH analyzed with a specific electrode and pHmeter. To analyze the TF, 0.25 ml of 2M HCL was added to 0.25 ml of the suspension of each dentifrice. This was kept at 45 degrees C/1 h and 0.50 ml of M NaOH and 1.0 ml of TISAB II was added. To assay SF and IF, after centrifugation, the supernatant was used and the same steps described above were followed for SF. The analysis of IF was made by adding 0.25 ml of the supernatant to 1.0 ml of TISAB II, 0.5 ml of M NaOH and 0.25 ml of 2M HCL. Paired t tests were used for statistical analysis.

RESULTS

The concentration of TF, SF and IF ranged from 555.7 - 1835.1; 449.3 - 1619.3 and 96.9 - 1534.6 ppm respectively. After aging, a significant reduction in the SF concentration (p = 0.00002) was observed, which did not occur for TF and IF (p > 0.05). Only the brand Colgate Baby presented pH 6.8. The other dentifrices had an alkaline pH, ranging from 7.1 - 9.9.

CONCLUSION

Although the term 'soluble' was suppressed by the new regulation, the dentifrices analyzed were in accordance to the Brazilian Ministry of Health Regulations, 1989.

Safety profile of a new liquid whitening gel

Colgate Simply White Clear Whitening Gel, an at-home tooth-whitening product purchased over the counter, contains 18% carbamide peroxide (equivalent to 6.5% hydrogen peroxide) as the active ingredient in a brush-applied liquid gel. The excipients include ingredients commonly used in dentifrices. The potential for effects on the tooth pulp, oral soft tissue irritation, enamel damage, and tooth sensitivity with this peroxide-containing product have been evaluated. An in vitro study demonstrated that pulpal chamber hydrogen peroxide levels are well below those considered to cause an effect on pulpal tissue. An exaggerated-use (4 applications per day for 3 weeks) clinical study showed that no oral irritation occurred during 3 weeks of use. A study measuring peroxide salivary concentration after use of Colgate Simply White Clear Whitening Gel showed that the concentration of peroxide in the saliva after use of the product was extremely low, further supporting the position that this product has a low potential for causing oral irritation. Additional studies demonstrate that Colgate Simply White Clear Whitening Gel does not harm the enamel surface or produce demineralization after exposure equivalent to 3 weeks of normal use and over 6 weeks of exaggerated use. Colgate Simply White Clear Whitening Gel has not produced oral irritation (hard and soft tissues) or tooth hypersensitivity in a clinical subject population of 141 individuals using varying treatment regimens. These studies prove that Colgate Simply White Clear Whitening Gel is safe for daily use as directed.

Influence of socioeconomic level and dentifrice brand on the oral hygiene habits and the fluoride dentifrice ingestion

The aim of this study was to evaluate the influence of socioeconomic level and dentifrice brand on the brushing habits and the fluoride ingestion. The sample was composed of 124 Brazilian children aged 3-9 years, from different socioeconomic levels (SEL). It was used a crossover study with the children using two dentifrice brands: Tandy Uva/T (1,100 ppm NaF) and Super Branco/SB (1,500 ppm MFP). Each child brushed his/her teeth with both dentifrice brands with weekly intervals between the brushes. The oral hygiene habits considered in this study were the Dentifrice Amount Placed on toothbrush (ADP), Dentifrice Amount Ingested (ADI), Fluoride Amount Ingested (FAI) and Brushing Time (TB). The data obtained were submitted to ANOVA test. It was observed that there was influence of SEL on the ADP and TB. The high SEL children showed a higher ADP and TB. The dentifrice brand influenced significantly the ADP, ADI, AFI and TB; the dentifrice T showed a higher ADP, ADI, but a lower AFI and TB. The results showed a significant interaction between SEL and dentifrice brand as ADI, AFI and TB. Although the children ingested a higher amount of T dentifrice they ingested a higher amount of fluoride from the SB dentifrice.

Reversal of primary root caries using a dentifrice with a high fluoride content

Root caries is a widespread problem and can be quite serious in older populations. The restoration of root carious lesions is often difficult. Compared to enamel caries, there has been limited research into the pharmaceutical management of primary root caries lesions (PRCLs), and many of these studies have been carried out in vitro, with limited numbers of clinical trials. Fluoride is presently a cornerstone in dentifrice formulations for cost-effective and anticaries therapy. It is generally accepted that fluoride ions promote remineralization of tooth substances and reduce the rate of demineralization. The use of a dentifrice with a high fluoride content may be considered to reverse PRCLs, since more fluoride is required for the remineralization of roots than for enamel. This paper reviews the effects of dentifrices with high fluoride contents on the management of root caries.

Fluoride intake from foods, beverages and dentifrice by young children in communities with negligibly and optimally fluoridated water: a pilot study

While the level of fluoride intake that affords optimal cariostatic efficacy without causing dental fluorosis is not precisely known, it has been suggested that the threshold of fluoride exposure above which fluorosis may occur is between 0.05 and 0.07 mg/kg/day.

OBJECTIVE

To monitor and compare fluoride intake from diet and dentifrice use (theoretical F: 0.10-0.11%) by three groups of 16- to 40-month-old children: two groups living in the negligibly water-fluoridated communities of San Juan, Puerto Rico, and Connersville, Indiana, and the third group residing in the optimally water-fluoridated region of Indianapolis, Indiana.

METHODS

Fluoride intake from diet was monitored by the "duplicate plate" method, and fluoride ingested from dentifrice was determined by subtracting the amount of fluoride recovered after brushing from the amount originally placed on the child's toothbrush.

RESULTS

The mean combined amount of fluoride ingested daily by children living in the negligibly fluoridated communities was not significantly different from that ingested by children in the fluoridated community. The major component of fluoride ingested by children in the negligibly fluoridated communities came from fluoridated dentifrice, and in the fluoridated area children ingested as much fluoride from toothpaste as they did from beverages. In San Juan mean daily fluoride intake was within the estimated range for safe fluoride exposure; however, in the "halo" community of Connersville and in Indianapolis, daily fluoride ingested by many of the children may have exceeded this level.

CONCLUSION

Attention needs to be given, in negligibly water-fluoridated as well as in optimally water-fluoridated communities, to reducing the daily intake of fluoride by young children in order to avoid putting them at risk of developing dental fluorosis.

Factors influencing the amount of fluoride toothpaste applied by the mothers of young children

OBJECTIVE

To determine the weight of dentifrice and consequent amount of fluoride placed on a toothbrush by the mothers of young children when instructed to apply a pea-sized quantity or smear of two dentifrices containing different fluoride concentrations from tubes with round or star-shaped nozzles.

SUBJECTS AND METHODS

53 mothers participated in the study and each applied the eight possible combinations of dentifrice in a random order.

RESULTS

The mean weight of dentifrice, and therefore fluoride, applied was statistically less for the smear instruction than the pea but the difference was small. Significantly less weight of Colgate 0-6 gel was applied when compared with Colgate Great Regular Flavour (GRF) but the nozzle shape had no significant effect on the weight of dentifrice applied.

CONCLUSIONS

The difference in fluoride concentration between GRF (1450 ppm F) and Colgate 0-6 gel (400 ppm F) was the most important determinant of the amount of fluoride applied.

Analysis of fluoride ion concentrations and in vitro fluoride uptake from different commercial dentifrices

The effectiveness of fluoride (F) dentifrices in reducing dental caries is well documented. However, not all F dentifrices are equally effective. The objective of this study was to compare fluoride uptake from Thai, Chinese and Indian dentifrices which are widely used in these respective countries. A non-fluoride dentifrice was included as a control. Dentifrices were analysed for fluoride concentrations using the 'acid-etch biopsy technique'. This study suggests that, when compared to 'multinational dentifrices', the Thai, Chinese and Indian dentifrices manufactured locally failed to show the F availability and/or F uptake efficacy even though they claimed to contain varying levels of F.

Fluorimetric determination of tin and organotin compounds in hydroorganic and micellar media in the presence of 8-hydroxyquinoline-5-sulfonic acid

The fluorescence of tin(IV) complexed by 8-hydroxyquinoline-5-sulfonic acid (8-HQSA) has been studied in both aqueous and hydroorganic (acetate buffer and dimethylsulfoxide) media. Several experimental parameters such as pH, DMSO/water ratio and reactant concentration have been investigated to increase the fluorescence of the tin(IV)-8-HQSA complex. A linear relationship between tin(IV) concentration and fluorescence intensity was observed between 1.7 and 20 microM). Mechanistic and quantitative studies in the presence of surfactants have been performed. Judiciously selected micellar media permitted solubilisation and quantitation of tin(IV) as well as dibutyltin compounds. A linear relationship between concentration and fluorescence intensity was found for mono-, di- and tributyltin with detection limits of 0.1 microM, 0.7 microM and 1 microM, respectively.

Spectrophotometric determination of fluoride in dosage forms and dental preparations

The method is based upon the reaction between fluoride ions and the coloured complex of Fe(III) with methyl salicylate to form the stable, colourless hexaflouride complex of iron. The conditions of the method (pH, time and combination ratio) were studied and a standard curve was obtained for 0.01-0.08 mg NaF ml-1, at 525 nm. A study was conducted on interference with complexing anions of Fe(III), cations that react with fluoride ions and with common ingredients of dosage forms and dental preparations. The method was validated and the results showed good precision (100.16 +/- = 2.33%) comparable with that of other analytical methods. Good results were obtained in the spectrophotometric determination of fluoride ions in a stomatological gel and in a toothpaste.

Effects of sodium bicarbonate dentifrices on the levels of cariogenic bacteria in human saliva

This investigation evaluated the efficacy of two bicarbonate-containing dentifrices (one with fluoride and one without) against one placebo dentifrice (containing neither fluoride nor bicarbonate) in vivo in a panel of human volunteers to determine whether or not sodium bicarbonate would affect salivary mutans streptococci and lactobacilli. Ten caries-inactive adults were divided randomly into three groups, each of which was exposed to all three dentifrices, in a crossover manner, during three 4-week test periods. Saliva samples were taken at 1-week intervals. Samples were stored on ice, and microbiological analyses were conducted. The statistical analyses showed that, over a 4-week period, there was a statistically significant (p < 0.05) reduction in numbers of mutans streptococci with the two bicarbonate dentifrices as compared with the placebo dentifrice. Although not statistically significant, a similar trend was observed with lactobacilli. Longer-term, large-scale studies need to be conducted to investigate the possible mechanisms of action of sodium bicarbonate on these organisms and to relate the results to possible cariostatic effects in humans.

Sources of fluoride intake in children

Wide variations in fluoride intake among children make estimating fluoride intake difficult. This paper discusses the various sources of fluoride intake among children, beginning with a review of the fluoride concentrations of water and other beverages, foods, and therapeutic fluoride products. A review of previous studies' estimates of fluoride intake from diet, dentifrice, fluoride supplements, fluoride mouthrinses, and gels, as well as total fluoride intake also is presented. Then, estimates of fluoride intake among young children of different age groups are summarized, and examples demonstrating the high level of variability of fluoride intake, both from individual sources and in total, are presented. Lastly, this paper discusses the implications of our current level of knowledge of children's fluoride intake, and presents recommendations for the use of fluoride for children in light of this current knowledge. The major recommendations are that: (1) the fluoride content of foods and beverages, particularly infant formulas and water used in their reconstitution, should continue to be monitored closely in an effort to limit excessive fluoride intake; (2) ingestion of fluoride from dentifrice by young children should be controlled, and the use of only small quantities of dentifrice by young children should be emphasized; and (3) dietary fluoride supplements should be considered a targeted preventive regimen only for those children at higher risk for dental caries and with low levels of ingested fluoride from other sources.

Sodium lauryl sulfate and recurrent aphthous ulcers. A preliminary study

Sodium lauryl sulfate (SLS), a synthetic detergent commonly used in dentifrices, is an effective denaturant. The aim of the present study was to investigate the effect of SLS in patients with recurrent aphthous ulcers (RAU). Ten patients with multiple minor RAU participated in the study. The mean incidence of RAU was 17.8 during a 3-month period before the study. The patients used a dentifrice containing 1.2% SLS for a test period of 3 months followed by a dentifrice without SLS for the same time period. The results showed a statistically significant decrease in the number of aphthous ulcers from 14.3 after using the SLS-containing dentifrice to 5.1 ulcers after brushing with the SLS-free dentifrice (p < 0.05). It is suggested that the denaturing effect of SLS on the oral mucin layer, with exposure of the underlying epithelium, induces an increased incidence of RAU.

Desquamative effect of sodium lauryl sulfate on oral mucosa. A preliminary study

Sodium lauryl sulfate (SLS) is the most commonly used detergent in dentifrices. The present study was concerned with the effect of SLS content of toothpastes on oral epithelial desquamation in an experimental model. Ten dental hygiene students participated in this double-blind cross-over study. Five dentifrices with different concentrations of SLS (ranging from 0.0% to 1.5%) were used in randomized order in the study. One centimeter of each test dentifrice was applied in a cap-splint, which covered both attached and non-attached oral mucosa of the upper jaw for 2 min twice daily. The test period for each experimental dentifrice was 4 days, followed by a 10-day rest period. The dentifrice without SLS did not result in any onward reaction, whereas the dentifrice containing 1.5% SLS provoked desquamation in 60% of the subjects.

Factors affecting the ingestion of fluoride dentifrice by children

Several factors affecting the amount of fluoride ingested during toothbrushing by 2- to 7-year-old children were investigated. The specific purpose of this study was to determine the contribution of age, the amount of dentifrice used, and rinsing after brushing to the variation in the ingestion of fluoride dentifrice. Four hundred and five children brushed their teeth in front of a portable sink. The tubes of dentifrice in gel (0.24% NaF) were weighed before and after use to determine the amount of toothpaste used. The fluoride content of the collected liquids was determined with a fluoride-ion-specific electrode. The amount of fluoride ingested was derived by determining the difference between the amounts used and recovered. The amount of dentifrice used, the age, and the rinsing habits, entered in a multiple regression model, explained up to 66 percent of the total variation in the amount of fluoride ingested. The amount of dentifrice used accounted by itself for 60 percent of the total variation. Therefore, these results indicate that the quantity of dentifrice used was the most important factor affecting the ingestion of fluoride through toothbrushing by young children.

Oral fluoride measurements for estimation of the anti-caries efficacy of fluoride treatments

The aims of this work were (a) to assess the oral bioavailability of fluoride delivered from dentifrices and (b) to test for a possible link between the results and clinical data obtained with the same dentifrices. Oral fluoride concentrations were measured in samples of saliva and plaque taken from seven subjects, after use of dentifrices which contained 0, 1000, 1500, and 2500 micrograms F/g as sodium monofluorophosphate. Salivary fluoride in samples obtained within the first few hours after a single dentifrice application, or up to 20 h after four weeks' daily use, increased with increasing F content of the dentifrice. For example, the mean zero-time intercepts of the second phase of salivary fluoride clearance curves for the above dentifrices were 0.46, 1.48, 1.88, and 3.03 mumol F/L, respectively. Plaque fluoride measured after four weeks' daily use of the dentifrices exhibited similar dose-response behavior. Linear regression analysis showed these trends to be statistically significant for both saliva (p less than 0.001) and plaque (p less than 0.025). Mean saliva and plaque fluoride concentrations were inversely associated with mean three-year caries increments for the three fluoride-containing dentifrices obtained in a recent clinical trial: DMFS scores 6.80, 6.33, and 5.71, respectively (Stephen et al., 1988). This suggests that oral fluoride measurements are a valuable in vivo method for the evaluation of the potential anti-caries efficacy of fluoride-containing dental products.

Dentifrice abrasivity and cervical dentinal hypersensitivity. Results 12 weeks following cessation of 8 weeks' supervised use

Following an 8-week controlled investigation of 2 strontium chloride hexahydrate dentifrices (SCH) of differing abrasivity, 2 groups of 20 subjects each, with cervical dentinal hypersensitivity, were re-examined at 20 weeks; that is, 12 weeks after the active period. The examination procedures were conducted in the same manner as in the main clinical trial. Sensitivity levels were assessed by 2 instrument methods: tactile (Yeaple probe), and cold air (dental air syringe), and by subjective perception of pain by means of a Visual Analogue Scale. The results from these methods of assessment demonstrated that 12 weeks following the cessation of 8 weeks' controlled use of standard and low abrasive SCH dentifrices, sensitivity levels reversed on slightly in both groups and, overall, sensitivity remained significantly lower than at baseline. The abrasivity of the dentifrice did not affect the desensitivity activity.

Dentifrices containing new agents for the control of plaque and gingivitis: microbiological aspects

Antimicrobial agents have been proposed as playing an important role in controlling plaque and gingivitis. Unfortunately, a large number of potential compounds are unsuitable for use in dentifrices because they lack "substantivity", produce undesirable side-effects, or are incompatible with toothpaste ingredients. New agents that have been successfully incorporated into dentifrices include plant extracts, phenolic compounds and metal salts. Several products are currently being based on the phenol, Triclosan. Triclosan has a broad spectrum of antimicrobial activity against yeasts and oral bacteria. To enhance its clinical efficacy, Triclosan has been combined either with a co-polymer or with another compatible antimicrobial agent, zinc citrate. The co-polymer acts to increase the oral retention of Triclosan, and has resulted in further reductions in salivary bacterial counts in vivo. Zinc salts also have antimicrobial activity, and at low concentrations, can inhibit glycolysis and bacterial proteases. In mixed culture chemostat studies, Triclosan selectively inhibited Gram-negative periodontopathic bacteria; additive effects were obtained when zinc citrate and Triclosan were combined. In an experimental human gingivitis study, a zinc citrate/Triclosan dentifrice reduced plaque accumulation and gingivitis compared to a placebo paste; the ratio of anaerobic/aerobic bacteria and the proportions of Actinomyces species in plaque were also reduced. The prolonged use of a zinc citrate/Triclosan dentifrice neither significantly altered the ecology of supragingival plaque nor led to the selection of Triclosan-resistant bacteria. The data suggest that dentifrices containing new antimicrobial agents could be of clinical relevance in the prevention and control of plaque and gingivitis.

Fluoride dentifrices: current status and prospects

Toothpastes have developed from the poorly effective formulations using incompatible abrasive systems to the highly effective products now being given credit for the decline in dental caries in most developed countries. The earliest toothpastes used sodium fluoride but this was soon replaced by stannous fluoride, sodium monofluorophosphate and amine fluoride. Monofluorophosphate has the advantage that it is compatible with a wide variety of abrasive systems. Although most toothpastes world-wide currently contain monofluorophosphate, sodium fluoride formulations are growing in availability because of the development of compatible abrasives. Clinical caries trials have indicated that, with proper formulation, there is little or no difference in effectiveness among toothpastes prepared with different fluoride agents, but that increasing the fluoride concentration will enhance the anti-caries effect. The addition of other active agents to fluoride toothpaste has been a relatively recent occurrence, and it is important to be assured that they do not interfere with the anti-caries activity of fluoride. Pyrophosphate, a calculus control agent, is one additive that was considered to be a potential problem; however, human and animal tests have shown that both caries and calculus inhibiting effects can be obtained from a single formulation. With the use of modern methodology to evaluate toothpaste formulations before clinical trials, many new products containing anti-calculus and other agents will probably become available in the coming years.

Effect of dentifrices containing either xylitol and glycerol or sorbitol on mutans streptococci in saliva

In 76 adults, randomly distributed between two groups, a comparison was made of the effect on the level of mutans streptococci in saliva between two dentifrices containing: (1) xylitol (9.9%) and glycerol (20%) or (2) sorbitol (28%) as humectants. After the use of the dentifrices twice daily for 3 months, the levels of mutans streptococci had not changed significantly in the sorbitol-treated group, whereas a significant reduction (p less than 0.0005) was found in subjects using the xylitol/glycerol dentifrice. The difference between the two dentifrice groups based on the changes observed during the 3-month period was also significant (p less than 0.02).

Analytical methods for the determination of various forms of fluoride in toothpastes

Fluoride (F) toothpastes, properly formulated and tested to show chemical activity, stability and clinical efficacy, are the most important components of caries prevention programmes. Analytical methods, based on the use of a F- -specific electrode, for the determination of various F species (ionic, soluble and total F) in toothpastes were investigated. The methods involved analysis of F species in the supernatants, suspensions and precipitates (residues) of 20 per cent aqueous slurry of toothpastes as well as in the pastes themselves. The ionic F (F-) concentration was determined by the addition of acetate buffer (7.5 M, pH 5.2; containing a metal-chelating agent) to the supernatant of slurried toothpastes. The soluble F (F- plus F of hydrolysed PO3F2-) in the supernatants was determined by direct acid hydrolysis in 0.8 M HCl, at room temperature (23 + 1 degree C), for 3, 12 or 24 h and in 2.3 M HCl, at 50 degrees, for 10, 20 or 40 min. The total F concentration in the suspensions (slurries) and in the pastes was determined using acid-hexamethyldisiloxane (HMDS) diffusion; a method which hydrolysed PO3F2- and separated F as well. Inaccuracy was encountered in the determination of ionic and soluble F in the suspensions of slurried toothpastes. There was a good agreement (r = 0.997) between the soluble and total F concentrations in the supernatants of monofluorophosphate (Na2PO3F; MFP) toothpastes, suggesting that the two methods, i.e. direct acid hydrolysis and acid-HMDS diffusion, can interchangeably be used.(ABSTRACT TRUNCATED AT 250 WORDS)

The state of fluorides in toothpastes

Formulating an effective toothpaste formula requires that fluoride (F) in toothpaste must be made available to the enamel microenvironment in reactive form (bioactive). The aims of this study were to evaluate the compatibility of F with the abrasives (cleaning and polishing agents) used in toothpaste formulations and to monitor the effect of ageing on availability of F in NaF/abrasive mixtures as well as in toothpaste formulations. There was a great variation in the rate and extent of loss of F in the NaF/abrasive mixtures and in the toothpaste formulas. Addition of NaF solution to aluminium- and calcium-containing abrasives resulted in losses of 60-90 per cent of the added F after 1 week's storage at room temperature. At 1 month of age, calcium phosphate dihydrate and aluminium silicate adsorb about four times more F than calcium carbonate. On the other hand, sodium bicarbonate and sodium metaphosphate inactivated 20-25 per cent of the added F after 9 months' storage. Silica was inert in binding and inactivating F of NaF and Na2PO3F (MFP). Calcium-containing abrasives were markedly more compatible with MFP than with NaF. After 12 months of storing the toothpastes, the soluble F (initial F- plus F of hydrolysed PO3F2-) in MFP-calcium carbonate/sodium silicate toothpaste was twice as much as MFP-calcium carbonate/aluminium silicate toothpaste.(ABSTRACT TRUNCATED AT 250 WORDS)

Dentine hypersensitivity. II. Effects produced by the uptake in vitro of toothpastes onto dentine

Toothpastes arguably are the most common preparations used in the treatment of dentine hypersensitivity. Evidence for efficacy largely comes from clinical trials, and supports the role of the contained so-called "active" ingredient. How such compounds produce therapeutic benefit has received limited attention. This study measured the availability and uptake onto dentine of fluoride and metal ions contained in commercial and test toothpastes. The effects of exposure of dentine sections to these toothpastes, and abrasive only pastes in particular, was investigated by scanning electron microscopy and X-ray microanalysis. Aqueous extracts of the different toothpastes contained measurable concentrations of the incorporated metal and or fluoride, but usually considerably below that incorporated by the manufacturer. Extraction of dentine sections exposed to toothpaste slurries revealed levels of fluoride and metal ions, although post-treatment washing in water reduced these levels. Surface changes at 1 and 10 h were not consistent with the uptake of fluoride or metals. These changes were almost certainly produced by the contained abrasives, including calcium carbonate, dicalcium phosphate, alumina and silica. In particular fume silica progressively accumulated on the dentine surface to narrow and occlude dentinal tubules. Unlike other abrasives fume silica was resistant to removal by washing. It would appear that insufficient attention has been given to the therapeutic potential of toothpaste ingredients, particularly abrasives, to produce benefit by occlusion of dentinal tubules.

[Fluoride content of Spanish dentifrices and recommendations for its use in pediatrics]

A study about ion "F" concentrations in 48 different Spanish market dentifrices is presented. The author makes advice and recommendations about the use of dentifrices in children taken in account of on age.

Radon estimation in some Indian tobacco, tea and tooth powder using CR-39 nuclear track detector

Radon contents in some samples of tobacco, tea and tooth powder have been estimated using CR-39 solid state nuclear track detectors. The Radon content in tobacco has been found to vary from 14.06 +/- 1.4 to 89.91 +/- 3.3 mBq/l. The Radon content in tea and tooth powder has been found to vary from 27.38 +/- 1.8 to 41.81 +/- 2.2 mBq/l and 26.27 +/- 1.4 to 413 +/- 6.0 mBq/l respectively. The present investigations are useful from the health hazards point of view.

Amounts of fluoride in self-administered dental products: safety considerations for children

With the increased use of various fluoride preparations for caries prevention, all dental personnel should know their potential toxicity and the margins of safety associated with their use. An understanding of the body's mechanisms for handling fluoride provides a rational basis for assessing the possible risks of excessive fluoride ingestion. Five to 10 g of sodium fluoride is considered a certainly lethal dose for a 70-kg adult. One quarter of the certainly lethal dose can be ingested without producing serious acute toxicity and is known as the safely tolerated dose. Comparisons of certainly lethal and safely tolerated doses for commonly used fluoride agents and procedures show that they can be applied with little or no risk of adverse acute effects, as long as they are used judiciously. If their use is abused, there is a risk of illness or even death. If amounts of fluoride close to the certainly lethal dose are ingested, the speed of initiating proper treatment is critical for survival. Vomiting should be induced, if it is not spontaneous; fluoride-binding liquids, such as milk or liquid or gel antacids, administered; and the patient taken to the nearest hospital for emergency care. Frequent ingestion of low but excessive quantities of fluoride during the period of tooth formation can lead to dental fluorosis. Particular concern is warranted for the ingestion of fluoride-containing toothpastes by young children and the inappropriate use of dietary fluoride supplements in communities with sufficient fluoride already present in drinking water.(ABSTRACT TRUNCATED AT 250 WORDS)