Fluorides

The purpose of this study was to investigate the effect of radiant heat, ultrasonic treatment, and 42.7 wt% CaCl 2 solution on fluoride release and surface hardness in three conventional glass-ionomer cements (GICs). The fluoride release patterns of each GIC were evaluated during a 28-day period using a fluoride ion-selective electrode. The surface hardness of the tested GICs was evaluated 24 hours after preparation of the specimens using Vickers hardness test. Statistical analysis of the data was made using analysis of variance and Bonferroni post hoc test (α = .05). Radiant heat, ultrasonic, and CaCl 2 solution treatments reduced fluoride release and increased the surface hardness of the tested GICs (P < .05). Among the tested GICs, differences in fluoride release and surface hardness were observed (P < .05). The clinical treatments investigated may be effective methods for improving the setting reaction of GICs and may achieve sufficient initial mechanical properties earlier. Although a reduction in fluoride release occurs after the treatments, anticariogenic properties of the GICs may not be significantly affected. Int J

A two-photon excitable molecular probe for fluoride, developed based on a fluoride-specific desilylation reaction, is demonstrated to be useful for fluorescent imaging of fluoride ions in live zebrafish by one-photon as well as two-photon microscopy for the first time.

Le but de notre travail a été de doser les Fluorures (F-) dans les eaux de puits consommées comme eau potable dans certaines zones rurales au Maroc. Tous les prélèvements ont été faits entre avril et octobre 2011. Les mesures ont été réalisées par une électrode spécifique à l'ion F-. Trente puits répartis de façon à couvrir la majorité du pays et choisis localement en fonction du nombre d'habitant qui consomment cette eau. La valeur moyenne de F-était 1,84 ± 1,6 mg/L avec des extrêmes entre 0,42 et 8,95 mg/l. Les concentrations dans les régions phosphatières ont été plus élevées comparées à d'autres régions. Plus de la moitié des échantillons dépassaient la norme en vigueur. Notre étude a montré que certaines régions marocaines ont des eaux naturelles riches en F-ce qui expose la population qui les consomme à un risque élevé de la fluorose.

To document the oral health status, to study oral health determinants and oral health-related quality of life among 12-year-olds from the Barents Euro-Arctic Region. The study was conducted in Severodvinsk (North-West Russia) and Tromsø (Northern Norway). Two schools representing each region were selected and all 12-year-old pupils having obtained their parents&#39; written consent were included (Severodvinsk n=48, Tromsø n=36). Background factors were collected by questionnaires. Oral health conditions, i.e. caries (DMFT/S), oral hygiene (OHI-S) and satisfaction with their own dental appearance were recorded under field conditions and possible associations between background factors and the children&#39;s oral health status were studied. Oral health was better among Norwegian than Russian participants. The most important factors explaining variation in oral health were country of origin and treatment (filling/no filling) received at the last dental visit. Among parental factors, ed...

O sealant, UltraSeal XT ® hydro™ (Ultradent Products, USA), and to investigate its in vitro resistance to microleakage after placement on conventionally acid etched and sequentially lased and acid etched molars. Material and Methods: The sealant was characterised by Fourier transform infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and Vickers indentation test. Occlusal surfaces of extracted human molars were either conventionally acid etched (n=10), or sequentially acid etched and laser irradiated (n=10). UltraSeal XT ® hydro™ was applied to both groups of teeth which were then subjected to 2,500 thermocycles between 5 and 55°C prior to microleakage assessment by fuchsin dye penetration. Results: UltraSeal XT ® hydro™ is an acrylate-based sealant that achieved a degree of conversion of 50.6±2.2% and a Vickers microhardness of 24.2±1.5 under standard light curing (1,000 mWcm-2 for 20 s). Fluoride ion release is negligible within a 14-day period. SEM and EDX analyses indicated that the sealant comprises irregular submicron and nano-sized silicon-, barium-, and aluminium-bearing reduce microleakage (Mann-Whitney U test, p<0.001). The lased teeth presented enhanced

In order to understand the common features of tetrahedral liquids with water-like anomalies, the relationship between local order and anomalies has been studied using molecular dynamics simulations for three categories of such liquids: (a) atomistic rigid-body models for water (TIP4P, TIP4P/2005, mTIP3P, SPC/E), (b) ionic melts, BeF 2 (TRIM model) and SiO 2 (BKS potential) and (c) Stillinger-Weber liquids parametrized to model water (mW) and silicon. Rigid-body, atomistic models for water and the Stillinger-Weber liquids show a strong correlation between tetrahedral and pair correlation order and the temperature for the onset of the density anomaly is close to the melting temperature. In contrast, the ionic melts show weaker and more variable degrees of correlation between tetrahedral and pair correlation metrics, and the onset temperature for the density anomaly is more than twice the melting temperature. In the case of water, the relationship between water-like anomalies and solvation is studied by examining the hydration of spherical solutes (Na + , Cl − , Ar) in water models with different temperature regimes of anomalies (SPC/E, TIP4P and mTIP3P). For both ionic and nonpolar solutes, the local structure and energy of water molecules is essentially the same as in bulk water beyond the second-neighbour shell. The local order and binding energy of water molecules are not perturbed by the presence of a hydrophobic solute. In the case of ionic solutes, the perturbation is largely localized within the first hydration shell. The binding energies for the ions are strongly dependent on the water models and clearly indicate that the geometry of the partial charge distributions, and the associated multipole moments, play an important role. However the anomalous behaviour of the water network has been found to be unimportant for polar solvation.

aIm: This was to evaluate the retention of fissure sealants (FS) and their effectiveness after resealing on caries reduction applied to first permanent molars, in a sample of children stratified according to their caries risk status in a private practice setting. mETHODs: The sample was 1,274 FS applied on first permanent molars (FPM) of 380 children (6 to 8 years old). Follow-up and monitoring for resealing was 3 years after FS placement, having at least one recall visit per year. Caries risk was based on baseline dmft index: low (dmft=0), moderate (dmft=1-4), high (dmft >4), with almost half of the teeth belonging to the high-risk group. All sealed teeth were evaluated and recorded for FS failure and resealing in case of partial/total loss, as well as caries development. Survival analysis using the Cox Proportional Hazards regression model was used for data evaluation. REsulTs: Of the 1,274 sealed surfaces, 927 (72.8%) needed no intervention 185 (14.5%) needed only resealing and 162 (12.7%) developed caries during the study. Of 162 carious surfaces, 107/ 675 (15.9 %) were from the high caries risk children, compared with 17/144 (11.8 %) and 38/455 (8.3 %) from the moderate and low caries risk group respectively. The highest number of failures, 4.9% and resealing were found at first recall, declining to 1.4% at the end of the study. Development of caries followed a steady rate of 6-8% per year. Cox proportional hazards model indicated, regardless if resealing or caries development was considered a failure or resealing was a success and caries development a failure, only the high dmft index appeared in both cases to significantly increase the chance (158% and 173% respectively) of FS failure and caries development compared with moderate and low dmft index. Other variables when inserted into the hazard model, such as age, sex and number of visits, either did not show a significant effect or only marginally affected FS retention, without modifying the association between caries risk and sealant failure. CONClusIONs: Children of a high baseline caries risk status showed lower FS retention rates and higher occlusal caries prevalence following FS loss compared with those of moderate and low risk status. Resealing does not seem to dramatically change the final outcome of the higher risk group to develop more caries, necessitating other more effective measures to increase the retention of FS on these highly vulnerable areas.

Twenty-two adults, considered to have high caries activity, rinsed for one yr with either SnF2 or acidulated NaF mouthrinses. Total colony-forming units and numbers of S. mutans and lactobacilli were estimated from saliva samples. Large reductions were found in the number of recoverable S. mutans in subjects rinsing with SnF2 but not in the NaFgroup. J Dent Res 62(8):907-91 1

To compare the survival and peri-implant bone loss of implants with a fluoride-modified surface in smokers and nonsmokers. Patient files of all patients referred for implant treatment from November 2004 to 2007 were scrutinized. All implants were placed by the same experienced surgeon (B. C.). The only inclusion criterion was a follow-up time of at least 2 years. Implant survival and bone loss were assessed by an external calibrated examiner (S. V.) comparing digital peri-apical radiographs taken during recall visits with the post-operative ones. Implant success was determined according to the international success criteria (Albrektsson et al. 1986). Survival of implants installed in smokers and nonsmokers was compared using the log-rank test. Both nonparametric tests and fixed model analysis were adopted to evaluate bone loss in smokers and nonsmokers. One-thousand one-hundred and six implants in 300 patients (186 females; 114 males) with a mean follow-up of 31 months (SD 7.15; range 24-58) were included. Nineteen implants in 17 patients failed, resulting in an overall survival rate of 98.3% at the implant level and 94.6% at the patient level. After a follow-up period of 2 years, the cumulative survival rates was 96.7% and 99.1% with the patient and implant as the statistical unit, respectively. Implant survival was significantly higher for nonsmokers compared with smokers (implant level P=0.025; patient level P=0.017). The overall mean bone loss was 0.34 mm (n=1076; SD 0.65; range 0-7.1). Smokers lost significantly more bone compared with nonsmokers in the maxilla (0.74 mm; SD 1.07 vs. 0.33 mm; SD 0.65; P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001), but not in the mandible (0.25 mm; SD 0.65 vs. 0.22 mm; SD 0.5; P=0.298). The present study is the first to compare peri-implant bone loss in smokers and nonsmokers from the time of implant insertion (baseline) to at least 2 years of follow-up. Implants with a fluoride-modified surface demonstrated a high survival rate and limited bone loss. However, smokers are at a higher risk of experiencing implant failure and more prone to show peri-implant bone loss in the maxilla. Whether this bone loss is predicting future biological complications remains to be evaluated.

Three outstanding effects of ionisation density on the thermoluminescence (TL) mechanisms giving rise to the glow peaks of LiF:Mg,Ti (TLD-100) are currently under investigation: (1) the dependence of the heavy charged particle (HCP) relative efficiency with increasing ionisation density and the effectiveness of its modelling by track structure theory (TST), (2) the behaviour of the TL efficiency, f (D), as a function of photon energy and dose. These studies are intended to promote the development of a firm theoretical basis for the evaluation of relative TL efficiencies to assist in their application in mixed radiation fields. And (3) the shape of composite peak 5 in the glow curve for various HCP types and energies and following highdose electron irradiation, i.e. the ratio of the intensity of peak 5a to peak 5. Peak 5a is a low-temperature satellite of peak 5 arising from electron-hole capture in a spatially correlated trapping centre/luminescent centre (TC/LC) complex that has been suggested to possess a potential as a solid-state nanodosemeter due to the preferential electron/hole population of the TC/LC at high ionisation density. It is concluded that (1) the predictions of TST are very strongly dependent on the choice of photon energy used in the determination of f (D); (2) modified TST employing calculated values of f (D) at 2 keV is in agreement with 5-MeV alpha particle experimental results for composite peak 5 but underestimates the 1.5-MeV proton relative efficiencies. Both the proton and alpha particle relative TL efficiencies of the high-temperature TL (HTTL) peaks 7 and 8 are underestimated by an order of magnitude suggesting that the HTTL efficiencies are affected by other factors in addition to radial electron dose; (3) the dose-response supralinearity of peaks 7 and 8 change rapidly with photon energy: this behaviour is explained in the framework of the unified interaction model as due to a very strong dependence on photon energy of the relative intensity of localised recombination and (4) the increased width and decrease in T max of composite peak 5 as a function of ionisation density is due to the greater relative intensity of peak 5a (a low-temperature component of peak 5 arising from two-energy transfer events, which leads to localised recombination).

Objectives: This field demonstration trial evaluates the long-term effects of introducing daily toothbrushing with fluoride toothpaste in a Chinese kindergarten (test group) compared to caries development in children who had no organized preventive program (control group). Methods: In the test group teacher-supervised toothbrushing was initiated with 1,000 ppm MFP toothpaste in addition to oral health education activities. Test and control children were examined at baseline (n=289, aged 3 years) and annually thereafter. Results: After three years, 251 children (87%) were still in the trial. Caries development (dmfs) calculation included only those children who were present at both baseline and subsequent annual examinations. At baseline the mean dmfs was 4.8 in the test group and 6.5 in the control group (NS). After three years the caries increment was 6.2 and 8.4 in the test group and the control group, respectively Pc.05).

In this paper a new and simple defluoridation method is presented using local Kenyan soil derived from volcanic ash (e.g. Ando soils or soils with 'andic' properties) as a fluoride sorbent. The ability of Kenyan Ando soil to adsorb fluoride was determined experimentally. These results were extended to possible technical application using a one dimensional solute transport model. Based on the results it is concluded that the use of Ando soils appears to be an economical and efficient method for defluoridation of drinking water on a small scale in rural areas of Kenya and other regions along the Rift Zone. Further research is warranted to evaluate its practical applications and social acceptance.

This study was conducted to determine the efflux of specific ions, including fluoride, from a deionization (DI) water purification system (WPS) when the WPS was operated beyond exhaustion of the DI resin. Effluent from the DI WPS was monitored for resistivity, total dissolved solids, pH, and concentrations of silica, fluoride, potassium, and sodium. After 16,000 L of water was purified, the resistivity declined to 0.492 n Ohm-cm, and silica was released from the DI WPS. Fluoride ions were released after an additional 8,000 L water was treated, and the resistivity fell t o 0.07 0 Ohm-cm. The fluoride efflux reached a peak of 32 mglL, 28 times greater than the original fluoride concentration in the city water. So-dium and potassium ions were released after approximately 26,000 and 32,000 L of water had been treated and reached peaks of 76 and 47 mg/L, respectively. This study confirms that the minimum resistivity standard of 1 R Ohm-cm for DI water used for hemodialysis should provide an adequate safety margin. Once resistivity fell to I R Ohm-cm, more than 8,000 L of water was treated before fluoride efflux occurred. Accordingly, heniodialysis centers should be attentive to the calculated capacity of their DI WPS and reliably monitor the resistivity to prevent patient illness related to exhaustion of IX resins.

Tamarind seed, a household waste from the kitchen is used for the sorptive removal of fluoride from synthetic aqueous solution as well as from field water samples. Batch sorptive defluoridation was conducted under variable experimental conditions such as pH, agitation time, initial fluoride concentration, particle size and sorbent dose. Maximum defluoridation was achieved at pH 7.0. Defluoridation capacity decreases with increase in temperature and particle size. Further, defluoridation follows first order kinetics and Langmuir adsorption isotherm. Desorption was carried out with 0.1 N HCl and is 90 per cent. The surface and sorption characteristics were analysed using FTIR and SEM techniques. All these results indicate the involvement of energetic forces such as coulombic interaction in sorption. For domestic and industrial applications, defluoridation with 100% achievement and subsequent regeneration of adsorbent was performed with a household water filter and fixed bed column respectively.

To ascertain the mode of action of a new Pro-Argin formula desensitizing dentifrice with a gentle whitening benefit containing 8.0% arginine, a high cleaning calcium carbonate system and sodium monofluorophosphate, utilizing a range of state-of-the-art surface techniques. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were used to assess tubule occlusion. Electron spectroscopy for chemical analysis (ESCA) was used to identify the composition of the occlusive material. CLSM was also used to identify the location of the arginine within the occluded dentin tubule and to demonstrate the resistance of the occlusion to an acid challenge. The CLSM and SEM studies demonstrated that the arginine-calcium carbonate technology in this new Pro-Argin formula sensitivity dentifrice was highly effective in occluding dentin tubules. ESCA showed that the dentin surface deposit contained high levels of calcium, phosphorous, oxygen and carbonate. CLSM also confirmed th...

In order to investigate the molecular mechanism(s) underlying brain dysfunction caused by chronic fluorosis, neuronal nicotinic acetylcholine receptors (nAChRs) in the brain of rats receiving either 30 or 100 ppm fluoride in their drinking water for 7 months were analyzed in the present study employing ligand binding and Western blotting. There was a significant reduction in the number of [ 3 H]epibatidine binding sites in the brain of rats exposed 100 ppm of fluoride, but no alteration after exposed to 30 ppm. On the other hand, the number of [ 125 I]a-BTX binding sites was significantly decreased in the brains of rats exposed to both levels of fluoride. Western blotting revealed that the level of the nAChR a4 subunit protein in the brains of rats was significantly lowered by exposure to 100 ppm, but not 30 ppm fluoride; whereas the expression of the a7 subunit protein was significantly decreased by both levels of exposure. In contrast, there was no significant change in the level of the b2 subunit protein in the brains of rats administered fluoride. Since nAChRs play major roles in cognitive processes such as learning and memory, the decrease in the number of nAChRs caused by fluoride toxicity may be an important factor in the mechanism of brain dysfunction in the disorder. D

O tratamento ortodôntico envolve procedimentos, geralmente, realizados durante um longo período. No ato da remoção do aparelho, freqüentemente, são encontradas áreas de desmineralização sob braquetes e bandas, quando já não há cavitações e, na maioria das vezes, inflamações dos tecidos periodontais. Para evitar estas iatrogenias, o clínico geral ou o especialista e toda sua equipe devem estar realmente motivados e envolvidos na aplicação dos conceitos de Odontologia Preventiva em seus pacientes ou, pelo menos, dispostos a delegar esta tarefa a alguém capacitado para fazê-la. Existem métodos relativamente simples para se avaliar o potencial de colaboração do paciente com o tratamento proposto, antes mesmo de seu início, e de se manter este paciente em níveis aceitáveis de saúde bucal. A utilização de recursos áudiovisuais para motivar os pacientes, os reforços positivos, a realização de escovação supervisionada e da limpeza interdentária, orientação sobre higiene, manutenção de saúde bucal e dieta, utilização de diferentes tipos de acessórios ortodônticos e de agentes cimentantes, além do uso, quando necessário, de diversos métodos químicos, são importantes instrumentos a serem utilizados durante o tratamento ortodôntico. Tomando-se as devidas precauções, é possível alcançar uma oclusão funcional e esteticamente aceitável sem deixar que a doença tenha um papel coadjuvante no transcorrer e após o término do tratamento ortodôntico.

Abstract. Spatial distribution of pH, electrical conductivity (EC), total dissolved solids (TDS), fluoride and total iron content of ground water samples collected from the muvattupuzha river basin, Kerala, India, has been studied for pre monsoon and post monsoon periods of year 2001. ...

Layered double hydroxides (LDH) calcined at different temperatures (denoted as CLDH) have been demonstrated to recover their original layered structure in the presence of appropriate anions. In the light of this so-called "memory effect", a study of removal of fluoride from aqueous solution by calcined Mg-Al-CO 3 -LDH has been carried out. The LDH calcined at 500 • C had the highest capacity of removal of fluoride ion, because of retention of its intrinsic structure. The CLDH with an Mg/Al ratio of 2 has a remarkable ability to adsorb anions. The adsorption loading is higher for the calcined Mg-Al-LDH than for calcined Zn-Al and Ni-Al-LDH. The influence of varying the conditions for removal of fluoride, such as the pH of aqueous solution, the initial fluoride concentration, the dosage of adsorbent, and temperature on removal of fluoride have been investigated. The influence of co-existing anions in fluoride aqueous solution indicates that the percentage of removal of fluoride increased in order PO 4 3− < Cl − ≈ SO 4 2− < Br − NO 3 − . It was found that maximum removal of fluoride from aqueous solutions was obtained in 6 h at pH 6.0 with an initial concentration of 50 mg/L, and that the retention of fluoride ions by the CLDH material was 98% or higher. The residual fluoride concentration was found to be 0.4 mg/L with an initial concentration of 20 mg/L, which meets the national standard for drinking water quality. The Freundlich isotherm and Langmuir isotherm were used to fit the data of equilibrium experiments. The results of X-ray diffraction, FT-IR and TG-MS demonstrate that the adsorption phenomenon is accompanied by rehydration with concomitant uptake of fluoride ions to rebuild the initial layered structure. .cn (X. Duan).

Objective: This article models the cost-effectiveness, from a societal viewpoint, of a dental caries prevention program using salt fluoridation for children 12 years of age, compared with non-intervention (or status quo) in Arequipa, Peru. Methods: Standard cost-effectiveness analysis methods were used. The costs associated with implementing and operating the salt-fluoridation program were identified and measured using 2009 prices. Health outcomes were measured as dental caries averted over a 6-year period. Clinical effectiveness data was taken from published data. Costs were measured as direct treatment costs, programs costs and costs of productivity losses as a result of dental treatments. The incremental costeffectiveness ratio was calculated. A hypothetical population of 25,000 12-year-olds living in Arequipa, Peru was used in this analysis. Two-way sensitivity analyses were conducted over a range of values for key parameters. Results: Our primary analysis estimated that if a dental caries prevention program using salt-fluoridation was available for 25,000 6-year-old children for 6 years, the net saving from a societal perspective would total S/. 11.95 [1 US$ = S/. (2009) 3.01] per diseased tooth averted when compared with the status quo group. That is, after 6 years, an investment of S/.0.32 per annum per child would result in a net saving of S/.11.95 per decayed/missing/filled teeth prevented. Conclusions: While the analysis has inherent limitations as a result of its reliance on a range of assumptions, the findings indicate that for the situations prevailing in Peru, there are significant health and economic benefits to be gained from the use of salt fluoridation.

Glass ionomer cement systems have become important dental restorative and luting materials for use in preschoolers, children and teenagers. These materials form chemical bonds to tooth structure, are biocompatible, release fluoride ions for uptake by enamel and dentin, and are able to take up fluoride ions from dentifrices, mouthwashes, and topically applied solutions. Unlike early glass ionomers, the new cement systems are easy and practical to use. Resin-modified glass ionomer cements not only have improved physical characteristics, but the photopolymerizable resin component reduces initial hardening time substantially. This article reviews the development and history of glass polyalkenoate cement systems and their ongoing role in dentistry for children.

Objectives. To describe CO 2 laser characteristics and to review the literature regarding its effects on caries inhibition in enamel and dentin. Another aim of this review is to discuss the effects of CO 2 laser in combination with fluoride.

The objective of this study was to determine the fluoride content in drinking water and urine samples of adolescent males aged 11-16 years living in Southern Haryana, India. A total of 30 drinking water sources in the studied habitations were assessed for fluoride contamination. Fluoride was estimated in the urine of 400 male children randomly selected from these habitations. The fluoride concentration in drinking water and urine samples was determined using USEPA fluoride ion selective electrode method. The mean fluoride concentration in drinking water samples of Pataudi, Haily Mandi and Harsaru villages was 1.68 ± 0.35, 3.22 ± 1.18 and 1.78 ± 0.12 mg/l, respectively. The mean urinary fluoride concentration was 2.26 ± 0.024 mg/l at Pataudi, 2.48 ± 0.77 mg/l at Haily Mandi and 2.43 ± 0.84 mg/l at Harsaru village. The higher fluoride levels in the urine of children may be associated to higher fluoride levels in drinking water. The accuracy of measurements was assessed with known addition method in water and urine. Mean fluoride recovery was 98.0 and 99.1% in water and urine. The levels obtained were reproducible with in ±3% error limit.

To compare the prevalence and severity of developmental defects of enamel (DDE) among subjects whose maxillary incisors developed during periods with different concentrations of fluoride in the public water supply. Standardized intra-oral photographs of random samples of 12-year-old children were collected in 1983, 1991 and 2001 (n = 1,990) in Hong Kong and assessed for DDE by a trained masked examiner. The fluoride concentrations in the public water supply at the times when the enamel on their maxillary incisors developed were 1.0, 0.7 and 0.5 ppm, respectively. The mouth prevalence of DDE for these children (based on the maxillary incisors) were 92.1, 55.8 and 35.2% in the years 1983, 1991 and 2001, respectively (p &amp;amp;amp;lt; 0.001). Most of these children were affected by diffuse opacities (89.3% in 1983, 48.5% in 1991 and 32.4% in 2001, p &amp;amp;amp;lt; 0.001). Marked differences in the mean number of teeth affected by DDE (p &amp;amp;amp;lt; 0.001) and in the maximum extent of DDE (p &amp;amp;amp;lt;or= 0.002) between 1983, 1991 and 2001 were also observed. A decrease in the prevalence and severity of DDE among the maxillary incisor teeth of the children corresponded to the reductions in the concentration of fluoride in the water during the time of enamel development.

A number of factors should be taken into account when designing toothpaste formulations for use by children at the different stages of their development. While adult toothpaste formulations may provide caries prevention benefits for children at risk of caries, these formulations may also contain higher levels of abrasive in order to address the staining needs of the adult population owing to smoking and the consumption of dietary chromogens such as coffee and tea, which are not normally found in the diet of children. While toothpastes formulated for adults are also likely to contain higher concentrations of surfactant and flavour, many children prefer toothpastes with mild flavours and modest foaming characteristics. An ideal children's toothpaste formulation should therefore aim to maximise fluoride availability, with appropriate abrasivity, while still delivering effective cleaning, as well as levels and types of flavour and surfactant to provide an acceptable brushing experience. Selection of toothpaste flavour types for children of different ages should ideally be based directly upon preference data from children. Flavours perceived as pleasant during brushing studies have been linked to increased brushing time, which, in turn, can increase the delivery and efficacy of fluoride from toothpastes. Therefore, manufacturers select tested, child-friendly flavours to maximise compliance, providing a more pleasurable brushing experience and oral health benefits.

A new, highly filled primer is currently marketed as a fluoride delivery system effective in reducing white spot lesions in orthodontic patients. However, no studies in the literature support this claim. The purpose of this in-vivo study was to investigate the retention and the efficacy of this primer in reducing the formation of white spot lesions. In each patient for whom premolar extractions were planned (n = 22), 1 premolar was randomly chosen as the experimental tooth for the application of the fluoride delivery system (Opal Seal; Ultradent Products, South Jordan, Utah), and the contralateral tooth was assigned as the control to receive the standard treatment (Transbond XT; 3M Unitek, Monrovia, Calif). After the bonding procedures, separators were placed around the premolar brackets to encourage plaque retention over 8 weeks. After the extractions, the tooth surfaces were evaluated visually and with microhardness techniques for demineralization. Primer retention was also invest...

The ADA recommends the use of fluoridated dentifrices as soon as the primary teeth erupt, so as to reduce the incidence of dental caries. However young children can ingest a significant amount of dentifrice during normal toothbrushing; this is a potential problem because the permanent teeth are at risk from fluorosis for the first seven years of life. the objective of this paper was to review the literature on the role of fluoride dentifrices in causing dental fluorosis. a search for literature was performed using MEDLINE, OVID with the key words fluorosis, dentifrice, ingestion, and children. The search was limited to English language publications. Subsequently, 31 articles were retrieved, additional relevant articles were collected from the references cited in the initially identified papers. Ultimately, 96 articles were retrieved for review. Fluoride, should be used with caution so that the benefits out-way the adverse affects. Oral health care providers need to systematically as...

This issue of Special Care in Dentistry presents protocols that were designed during a conference, Practical Protocols for the Prevention of Dental Disease in Community Settings for People with Special Needs, which was held at the University of the Pacific School of Dentistry on February 1, 2002. After each expert reviewed and reported on one area of the literature, which included risk assessment; chlorhexidine mouth rinses; xylitol chewing gum; topical fluoride and fluoride varnish applications; and methods to control or treat periodontal disease, practical protocols were developed. Next, a strategy of implementation and dissemination will be designed using nurses, case managers, social workers, caregivers, and others to encourage people with special needs to use these protocols. A plan will also be implemented to increase social and health care provider awareness about these interventions through professional publications and educational opportunities. The goal is to reduce dental disease in special needs populations and thereby decrease the need for difficult and costly treatment.

Defluoridation of groundwater using brick powder as an adsorbent was studied in batch process. Different parameters of adsorption, viz. effect of pH, effect of dose and contact time were selected and optimized for the study. Feasible optimum conditions were applied to two groundwater samples of high fluoride concentration to study the suitability of adsorbent in field conditions. Comparison of adsorption by brick powder was made with adsorption by commercially available activated charcoal. In the optimum condition of pH and dose of adsorbents, the percentage defluoridation from synthetic sample, increased from 29.8 to 54.4% for brick powder and from 47.6 to 80.4% for commercially available activated charcoal with increasing the contact time starting from 15 to 120 min. Fluoride removal was found to be 48.73 and 56.4% from groundwater samples having 3.14 and 1.21 mg l −1 fluoride, respectively, under the optimized conditions. Presence of other ions in samples did not significantly affect the deflouridation efficiency of brick powder. The optimum pH range for brick powder was found to be 6.0-8.0 and adsorption equilibrium was found to be 60 min. These conditions make it very suitable for use in drinking water treatment. Deflouridation capacity of brick powder can be explained on the basis of the chemical interaction of fluoride with the metal oxides under suitable pH conditions. The adsorption process was found to follow first order rate mechanism as well as Freundlich isotherm.

The seriousness and societal costs of dental caries in preschool children are enormous. National data shows that caries is highly prevalent in poor and near poor US preschool children, yet this disease is infrequently treated. The etiology includes elevated colonization levels of mutans streptococci, high frequency sugar consumption, and developmental defects on primary teeth. A necessary first step in preventing dental caries in preschool children is evaluating the child's caries risk factors that include socioeconomic status, previous carious experience, presence of white spot lesions, presence of visible plaque, perceived risk by dental professionals, and microbiologic testing for the presence or quantity of mutans streptococci. Based on this knowledge, different preventive strategies, as well as different intensities of preventive therapies, can be employed. Caries preventive strategies in preschool children include diet modifications to reduce high frequency sugar consumption, supervised tooth brushing with fluoridated dentifrice, systemic fluoride supplements to children living in a nonfluoridated area that are at risk for caries, professional topical fluoride with fluoride varnish, and sealants for primary molars. (Pediatr Dent. 2002;24:543-551)

PURPOSE: As a requirement of the Food & Drug Administration's final monograph on "Anticaries drug products for over-the-counter human use", the toothpaste industry has been conducting animal caries tests on every fluoride-containing toothpaste introduced into the U.S. market since 1996. The practice of testing in animals, although required by law, is in stark conflict with the corporate policy of many U.S. and global toothpaste manufacturers, in which, if possible, alternatives to animal testing are utilized. A provision does exist within the regulation which allows the use of an alternative method to demonstrate efficacy. However, to take advantage of this provision, a petition must be submitted to the FDA and in this petition data demonstrating the alternative provides results of "equivalent accuracy" must be included. After many years of research, model development and model comparisons, we have identified one particular laboratory model that demonstrated excellent correlation with the currently accepted animal caries models. This model, known as the Featherstone pH cycling model, is discussed in this paper.METHODS: The Featherstone pH cycling model has been shown to produce results of equivalent accuracy to the animal caries model by: (1) demonstrating a clinically relevant fluoride dose response similar to that shown in the animal caries model (including 1100 ppm F, 250 ppm F and placebo); (2) demonstrating similar results to the animal caries model for clinically proven dentifrice formulations relative to positive and negative controls; (3) demonstrating discriminating ability in strong agreement with the animal caries model for differentiating between a dentifrice formulation with attenuated fluoride activity and a USP standard; and (4) providing a clinically relevant representation of the caries process, as demonstrated by orthodontic banding studies. In addition, the model sufficiently addresses both salivary and abrasive/anticalculus agent interference concerns.RESULTS: For more than 50 years, fluoride has been the first defense in the fight against dental caries. The clinical effectiveness of fluoride is well accepted and documented extensively in the literature. The mechanism through which fluoride provides its benefit is very straightforward and well understood. The proposed laboratory model effectively simulates the effect of the caries process and has been shown to demonstrate equivalent accuracy to animal caries. This indicates that there are strong scientific grounds for the use of this model as an alternative to the animal caries test. Based on the strength of the data and the correlations noted between the two models, we recommend that the scientific community and the toothpaste industry broadly accept the Featherstone laboratory pH cycling model as an appropriate alternative to animal testing, particularly for ionic fluoride based dentifrices.

The water from lakes and reservoirs are collected, treated and supplied for public distribution by Government agencies in India. Water from open dug wells (Groundwater) is one of the major resources for individual residents. Studies on physicochemical parameters of groundwater of open dug wells and surface water of Waddepally Lake in Warangal district of Andhra Pradesh State are carried out and the results are presented in this paper. The groundwater samples were collected from 15 open dug wells in an area of 4 km from the lake. The lake water samples from 4 different locations were taken from top surface, 1m and 2m depth wise. Laboratory tests were conducted for determining (i) physical

Nano-filled fissure sealant Conversion degree Microhardness Microleakage Fluoride release A B S T R A C T The purpose of this study was to determine the degree of conversion (DC), microhardness, microleakage and fluoride release of a nano-filled resin based fissure sealant (Grandio Seal, GS) and compare it with an un-filled resin based fissure sealant (Clinpro, CL) and a glassionomer based fissure sealant (Fuji Triage, FT). Disk shaped specimens were prepared from tested fissure sealants to determine the DC, Vicker hardness (VHN) and fluoride release (FR). The DC and VHN of each material was evaluated after 24 h. The cumulative fluoride concentrations were evaluated at 1 h, 6 h, 12 h, 1, 7, 15 and 30 days. For microleakage evaluation, fissure sealants were applied to the etched and dried enamel surfaces of sound third molar teeth according to the manufacturer's instructions (n = 10). After the thermocycling and mechanical loading procedures, microleakage assessments were carried out. Data were analyzed using oneway ANOVA followed by a post hoc Tukey test, the Kruskal Wallis and Mann-Whitney U test (p < 0.05).

A review and mapping of fluoride test data for 270 water sources in 126 communities and examination of the literature of fluorosis distribution in Ethiopia show that this health problem extends beyond the Rift Valley into some highland communities. Fluoride concentrations above 5.0 mg/l in the Rift Valley were found mostly in hot springs (100% of all sources), lakes (78%), shallow wells (54%) and boreholes (35%) and the lowest concentrations (below 1.5 mg/l) in springs and rivers. Analysis of hydrochemical, economic and demographic factors in the spatial distribution of high-fluoride domestic water sources indicates that the fluorosis problem has become more serious in the Rift Valley in recent decades. Considerable spatial variation in the occurrence of fluoride, even within the same communities, and the presence of some low-fluoride water sources in the Rift Valley offer possibilities for geochemical exploration for acceptable domestic sources. The defluoridation programme in the Wonji irrigation scheme illustrates the problems faced by a large rural community in a developing country. Possibilities for control are examined and recommendations made for the development of alternative water sources and promising defluoridation methods using locally available materials and technologies.

Purpose: To test the hypotheses that microtensile bond strengths of single-step, self-etch adhesives to hydrated dentin are adversely affected by delayed-activation of a light-cured composite, as well as the use of a chemical-cured composite. Methods: Seven commercially available and one experimental single-step, self-etch adhesives were bonded to hydrated human dentin. A dual-cured composite was used and activated using: [1] the lightcured mode (base paste only -control), [2] the chemical-cured mode (base and catalyst pastes, in the dark); and [3] delayed light-activation (base syringe only, left on top of cured adhesives in the dark for 20 minutes before activation). After microtensile bond strength evaluation, fractured samples were examined using SEM. Intact, unstressed interfaces of [1] and [3] were examined with TEM. Microtensile bond strengths were also evaluated for selected adhesives bonded to dehydrated dentin and coupled with the composite activated by or . Results: For all adhesives, bond strengths decreased significantly to bonded hydrated dentin when the composites were activated with [2] or [3] (P< 0.001). Whereas the hybrid layer-adhesive interface was intact, water-blisters that developed along the adhesive-composite interface in these two modes were responsible for the decline in bond strength. When bonded to dehydrated dentin, delayed light-activation of the light-cured composite did not result in compromised bond strength. The results of chemical-cured composites improved but were more variable and system-dependent. (Am J Dent 2004;17;000-000).

The studies described in this paper aimed to assess the stain removal efficacy, fluoride efficacy and abrasivity to enamel and dentine of a new whitening toothpaste containing calcium carbonate and perlite, using appropriate in vitro models. Stain removal efficacy was assessed using the pellicle cleaning ratio (PCR) method. Fluoride efficacy was assessed using remineralisation, demineralisation and fluoride-uptake methods. Abrasivity was assessed using an enamel and dentine wear method. The results showed that the new whitening toothpaste was able to remove extrinsic tooth stain more effectively than three commercially available toothpaste formulations. The fluoride efficacy was superior to a non-fluoridated control and was not significantly different to a clinically tested fluoride-containing toothpaste. The abrasivity data showed that the calcium carbonate/perlite toothpaste is no more abrasive to enamel or dentine than two other commercially available whitening toothpastes. The s...