Excess dietary fluoride affects laying performance, egg quality, tissue retention, serum biochemical indices, and reproductive hormones of laying hens.

The present study aimed to evaluate the effects of excess dietary fluoride (F) on laying performance, egg quality, tissue retention, serum biochemical indices, and serum reproductive hormones of laying hens. A total of 384 Hy-Line Gray hens, 37 wk old, were treated with sodium fluoride added to a corn-soybean meal basal diet at 0, 400, 800, and 1200 mg fluorine/kg feed. The results showed that dietary F levels at 800 and 1200 mg/kg markedly decreased ADFI, laying rate, average egg weight, and increased feed conversion ratio (FCR) (P < 0.05). Dietary F levels at 800 and 1200 mg/kg dramatically decreased the egg quality of albumen height, yolk color, eggshell strength, and eggshell thickness, and on the 49th D, 400 mg/kg F group significantly decreased the eggshell strength, compared to those of control group. Fluoride residues in tissues of hens were increased significantly with the increase of dietary F supplemental levels (P < 0.05). Fluoride concentrations were generally high in feces, eggshell, tibia, kidney, and ovary, and the highest in feces, following with eggshell and tibia, lower in kidney and ovary, and the lowest in serum. Serum uric acid levels and alanine aminotransferase activity increased significantly (P < 0.05), and glucose, triglycerides, and phosphorus decreased significantly (P < 0.05) in response to dietary F concentration, compared to those of the control group, respectively. Dietary F supplementation at 1200 mg/kg significantly decreased (P < 0.05) the estrogen concentrations in serum, compared to those of the control group. Concentrations of progesterone in the fluoride-treated groups were significantly (P < 0.05) decreased relative to those of the control group. In conclusion, these results indicated that the excessive ingestion of F has had a detrimental effect on egg laying rate and quality of eggs by damaging the function of the liver, kidney, and ovary of laying hens.

A comparative evaluation of the anticaries efficacy of herbal extracts (Tulsi and Black myrobalans) and sodium fluoride as mouthrinses in children: A randomized controlled trial.

BACKGROUND: Dental caries is a multifactorial disease in which microorganisms play an important role. Recently, herbs have been tried as mouthrinses to combat the side effects of chemical mouthrinses. The anticaries efficacy of Sodium fluoride, Tulsi leaf, and Black myrobalans fruit extracts on Streptococcus mutans (S. mutans) have been reported in the literature, but no comparative study has been done yet. AIM: This study aims to observe the change in the pH of saliva and to assess the efficacy of the herbal rinses-Tulsi and Black myrobalans on S. mutans count while comparing it with Sodium fluoride mouthrinse. METHODS: Herbal ethanolic extracts of Tulsi (4%) and Black myrobalans (2.5%) were prepared as mouthrinses and compared with sodium fluoride mouthrinse (0.05%). Sixty high caries risk patients were selected and allocated randomly into three groups [n = 20], categorized as Group A-Sodium fluoride mouthrinse, Group B-Tulsi mouthrinse, and Group C-Black myrobalans mouthrinse. They were instructed to rinse their mouth with their assigned mouthrinses for 7 days. Salivary samples were collected and sent to the laboratory at baseline, 1 h postrinsing and after 7th day of rinsing for determining the salivary pH and S. mutans count. The increase in pH and reduction of S. mutans were determined. The values obtained were tabulated and statistically analyzed. RESULTS: There was a significant increase in the salivary pH and reduction in S. mutans count after rinsing in all the three groups. Increase in salivary pH was more in the Sodium fluoride mouthrinse when compared to the experimental herbal groups (Group B and Group C). While S. mutans counts reduced more with Tulsi mouthrinse at 1 h postrinsing and after the 7th day of rinsing more reduction was seen in Black myrobalans mouthrinse group. CONCLUSION: The results of the study suggest that herbal mouthrinses could be tried as an adjunctive anticaries agent against dental caries causing microorganisms.

Bicuspid Aortic Valve Stenosis and the Effect of Vitamin K2 on Calcification Using 18F-Sodium Fluoride Positron Emission Tomography/Magnetic Resonance: The BASIK2 Rationale and Trial Design.

BASIK2 is a prospective, double-blind, randomized placebo-controlled trial investigating the effect of vitamin K2 (menaquinone-7;MK7) on imaging measurements of calcification in the bicuspid aortic valve (BAV) and calcific aortic valve stenosis (CAVS). BAV is associated with early development of CAVS. Pathophysiologic mechanisms are incompletely defined, and the only treatment available is valve replacement upon progression to severe symptomatic stenosis. Matrix Gla protein (MGP) inactivity is suggested to be involved in progression. Being a vitamin K dependent protein, supplementation with MK7 is a pharmacological option for activating MGP and intervening in the progression of CAVS. Forty-four subjects with BAV and mild-moderate CAVS will be included in the study, and baseline 18F-sodiumfluoride (18F-NaF) positron emission tomography (PET)/ magnetic resonance (MR) and computed tomography (CT) assessments will be performed. Thereafter, subjects will be randomized (1:1) to MK7 (360 mcg/day) or placebo. During an 18-month follow-up period, subjects will visit the hospital every 6 months, undergoing a second 18F-NaF PET/MR after 6 months and CT after 6 and 18 months. The primary endpoint is the change in PET/MR 18F-NaF uptake (6 months minus baseline) compared to this delta change in the placebo arm. The main secondary endpoints are changes in calcium score (CT), progression of the left ventricularremodeling response and CAVS severity (echocardiography). We will also examine the association between early calcification activity (PET) and later changes in calcium score (CT).

Tratamento da hipersensibilidade dentinária com verniz de fluoreto de sódio a 5%, terapia com laser de baixa intensidade e aplicação associada: estudo clínico, controlado, randomizado, duplo cego, boca dividida / Treatment of dentin hypersensitivity with 5% sodium fluoride varnish, low level laser therapy and associated application: a clinical, controlled, randomized, double-blind and split-mouth study

A hipersensibilidade dentinária é uma das complicações mais comuns entre os pacientes após o tratamento periodontal. Recentemente a terapia com o uso de laser de baixa intensidade foi introduzida como uma nova modalidade de tratamento e tem proporcionado resultados benéficos. Foi realizado um estudo clínico controlado, randômico, duplo-cego, de boca dividida com o objetivo de comparar a efetividade do uso do verniz tópico Fluoreto de sódio 5%, do Laser GaA1As 780 nm e da combinação do Fluoreto de sódio 5% e o Laser GaA1As 780 nm para o tratamento de hipersensibilidade dentinária. Os Grupos foram divididos em Grupo Controle (C), Grupo Fluoreto de sódio 5% (F), Grupo Laser GaA1As 780 nm (LLLT), e o Grupo Fluoreto de sódio 5% + Laser GaA1As 780 nm (F+LLLT). A aplicação do verniz foi realizada com pinceis do tipo "microbrush", e para cada elemento dental cinco pontos receberam a LLLT, com dose de 52,5 J/cm2 (70mW e 30 segundos) ou 2,1 J por ponto; 6 segundos por ponto. A hipersensibilidade primária foi registrada pela escala analógica visual (VAS: 0-10) para quantificar a dor subjetiva após estímulo com "spray de gelo" no baseline, e após o tratamento nos intervalos de 24 horas e 30 dias. Todos os dados foram analisados estatisticamente pela análise de variância ANOVA. Para cada um dos três tempos de avaliação foi efetuada uma comparação entre os 4 grupos (por meio da ANOVA oneway) com complementação pelos testes de Tukey e Bartlett a fim de verificar as diferenças estatísticas entre grupos. O nível de significância foi de 5%. Após análises estatísticas os resultados mostraram que o verniz de flúor, a terapia com laser de baixa potência e a associação de ambos é eficaz para a dessensibilização dentinária, necessitando de uma amostra e um período maior de observação para verificar diferenças entre os três tratamentos(AU)

Dentin hypersensitivity is one of the most common complications among patients after periodontal treatment. Recently the low level laser therapy has been introduced as a new treatment modality and has provided beneficial results. A split-mout, double-blind, randomized, controlled clinical trial was conducted with the aim of compare the effectiveness of the topical varnish 5% Sodium Fluoride, Laser GaA1As 780 nm and the combination of 5% Sodium Fluoride and the Laser GaA1As 780 nm for the treatment of dentin hipersensitivity. The groups were divided in Control Group (C), Sodium Fluoride at 5% Group (F), Laser Group GaAlAs 780 nm (LLLT), and Sodium Fluoride at 5% Group + GaAlAs Laser 780 nm (F + LLLT). The application of the varnish was realized with "microbrush", and for each dental element, five points was received LLLT. The dose was 52.5 J / cm2 (70mW and 30 seconds) or 2.1 J per point, 6 seconds per point. Primary hypersensitivity was be recorded by visual analogue scale (VAS: 0-10) to quantify subjective pain after the stimulus with "ice spray" at baseline, and after treatment at 24-hour and 30-day intervals. All data was analyzed statistically by analysis of variance ANOVA. For each of the three evaluation times a comparison was made between the 4 groups (through the oneway ANOVA) with complementation by the Tukey's and Bartlett's tests in order to verify the statistical differences between groups. The level of significance will be 5%. After statistical analysis the results showed that fluoride varnish, low level laser therapy and the combination of both are effective for dentin desensitization, requiring a sample and a longer evaluation period to verify differences between the three treatment(AU)

Sodium fluoride adversely affects ovarian development and reproduction in Drosophila melanogaster.

The study demonstrates the effects of chronic sub-lethal exposure of sodium fluoride (NaF) on reproductive structure and function of female Drosophila melanogaster. As a part of treatment, flies were maintained in food supplemented with sub-lethal concentrations of NaF (10-100 µg/mL). Fecundity, ovarian morphology, presence and profusion of viable cells from ovary and fat body were taken into consideration for evaluating changes in reproductive homeostasis. Wing length (a factor demonstrating body size and reproductive fitness) was also monitored after NaF exposure. Significant reduction in fecundity, alteration in ovarian morphology along with an increase in apoptosis was observed in treated females. Simultaneous decline in viable cell number and larval weight validates the result of MTT assay. Furthermore, altered ovarian Glucose-6-phosphate dehydrogenase and catalase activities together with increased rate of lipid peroxidation after 20 and 40 µg/mL NaF exposure confirmed the changes in reproduction related metabolism. Enhanced lipid peroxidation known for ROS generation might have induced genotoxicity which is confirmed through Comet assay. The enzyme activities were not dose dependent, rather manifested a bimodal response, which suggests a well-knit interaction among the players inducing stress and the ones that help establish physiological homeostasis.

Genotoxic effect and rat hepatocyte death occurred after oxidative stress induction and antioxidant gene downregulation caused by long term fluoride exposure.

Studies focusing on possible genotoxic effects of excess fluoride are contradictory and inconclusive. Currently, studies have reported a probable link to oxidative stress, DNA damage and apoptosis induced by fluoride in rat hepatocytes. We developed an in vivo study administering three doses of fluoride by gavage given to rats for 60 day. Micronucleus test was applied to investigate genotoxic potential of fluoride. The TUNEL method determined DNA fragmentation and apoptosis. Biochemical parameters to investigate mitochondrial swelling and oxidative stress. Semi-quantitative RT-PCR and immunostaining to determine mRNA and protein expression of antioxidant enzymes. Analyses of the hepatic function and morphology were performed. Our results revealed the genotoxic potential of fluoride but did not confirm mitochondrial swelling nor an increase of positive TUNEL labelling induced by fluoride, indicating absence of apoptosis. Oxidative stress induction was confirmed and is probably associated to DNA damage. Cell death events such as empty nuclear spaces, cytoplasm degeneration, nuclear pyknosis, karyorrhexis and karyorrhexis followed by karyolysis were observed. Hepatic function did not appear to be significantly modified makes no evidence of necrosis and suggesting other cell death pathway, the autophagic. In conclusion, prolonged fluoride intake at chosen concentrations caused imbalance of the cellular oxidative state, affected DNA and disrupted cellular homeostasis. It is recommended that fluoride supplementation requires a fresh consideration in light of the current study.

Fluoride varnish or fluoride mouth rinse? A comparative study of two school-based programs.

OBJECTIVE: In many Danish communities, school-based fluoride programs are offered to children with high caries risk in adjunct to tooth brushing. The purpose of this field trial was to compare the caries-preventive effectiveness of two different fluoride programs in 6-12 year olds. BASIC RESEARCH DESIGN: Clinical controlled trial. CLINICAL SETTING: The 2-year study was conducted in Public Dental Clinics in a multicultural low-socioeconomic suburban area of Odense, Denmark with an elevated prevalence of caries compared to the city average. PARTICIPANTS: 1,018 children (aged 6-12 years) from 9 different schools were enrolled after informed consent and their class unit was randomly allocated to one of two fluoride programs. INTERVENTIONS: One group received a semi-annual fluoride varnish applications (FV) and the other group continued with an existing program with fluoride mouth rinses once per week (FMR). All children received oral hygiene instructions and comprehensive dental care at the local Public Dental Clinics throughout the study period. MAIN OUTCOME MEASURES: Increment of caries lesions in permanent teeth at both cavitated and initial caries levels. RESULTS: The groups were balanced at baseline. After two years, 961 children (94.4%) were reexamined. The FV group showed a mean DMFS increment of 0.36 compared to 0.41 in the FMR group. The corresponding values for initial caries lesions were 0.83 and 0.91 respectively. CONCLUSION: There were no statistically significant differences in caries development over two years among children participating in a school-based fluoride varnish or mouth rinse program.

Galla chinensis Compounds Remineralize Enamel Caries Lesions in a Rat Model.

OBJECTIVES: To investigate the effect of Galla chinensis chemical compounds on enamel caries remineralization in rats. METHODS: A total of 40 rats were inoculated with Streptococcus sobrinus 6715 and fed a cariogenic diet (Keyes 2000). The rats were randomly divided into 4 groups and treated topically twice a day with each of the following extracts (or control) for 5 weeks: distilled and deionized water (DDW, negative control); 1,000 ppm NaF (positive control); 4,000 ppm G. chinensis crude aqueous extract (GCE), or 4,000 ppm gallic acid (GA). After the experimental period, Keyes' caries diagnosis and scoring technique was applied as a preliminary evaluation on the molar teeth. For more accurate remineralization data, the residual enamel volume of the first molar and the mineral density (MD) of the enamel were further analyzed by micro-CT. RESULTS: The severity of molar enamel caries decreased in the following order of treatment groups: DDW > GA > GCE > NaF (p < 0.05). In addition, the residual first molar enamel volume and MD values increased in the order of DDW, GA, GCE and NaF treatment groups (p < 0.05). In most molars, remineralization layers were observed on the surface of lesions. CONCLUSION: G. chinensis compounds remineralize enamel caries lesions in a rat model.

Effect of high-dose fluoride on antioxidant enzyme activities of amniotic Fluid in rats.

OBJECTIVE: To investigate the effect of high-dose fluoride on antioxidant enzyme activities of amniotic fluid and fluoride of serum in rats. METHODS: The experimental study was conducted from January 8, 2008, to December 14, 2010, at the Suleyman Demirel University Experimental Animals Laboratory and the Medical Biochemistry Department Research Laboratory, Isparta, Turkey. Impregnated Wistar albino rats were divided into two equal groups. Group I had controls, while Group II rats were exposed to high-dose fluoride. Group I was given drinking water mixed with 0.1 mg/kg/b.w./day of natrium fluoride, while group II was given drinking water mixed with 10 mg/kg/b.w./day of natrium fluoride for 18 days. At the end of 18 days, amniotic fluid and blood samples were collected from control and experimental groups of pregnancy. Superoxide dismutase, glutathione peroxidase, catalase activities and thiobarbituric acid reactive substances as antioxidant enzymes in amniotic fluid and levels of fluoride in serum samples were investigated. RESULTS: There were 14 rats, with 7(50%) in each group. Foetal weight in group II significantly decreased compared to the control group (p< 0.05). Antioxidant enzyme activities in amniotic fluid were significantly higher in group II than group I (p< 0.05) although thiobarbituric acid reactive substances in amniotic fluid and serum fluoride levels were significantly lower in group II than group I (p< 0.05). CONCLUSIONS: Fluoride that created oxidative stress inhibited lipid peroxidation and apparently increased the antioxidant defence system.

Anti-plaque and antimicrobial efficiency of different oral rinses in a 3-day plaque accumulation model.

The idea of incorporating a mouthrinse with normal tooth brushing could be a useful adjunct to oral hygiene. Despite the principle nature of the toothpaste vehicle, most alcohol-based chemical plaque-control agents have been evaluated and later formulated in the mouthrinse vehicle. The current study was aimed to investigate the persistence of antimicrobial action and plaque inhibitory properties of a new alcohol-free mouthrinse when compared with positive control, chlorhexidine 0.12% and placebo control, physiologic saline solution mouthrinses. The evaluation of the antimicrobial activity was performed by saliva samples collected during the 3 days of usage. The results of this study indicate that this new oral rinse has an equivalent plaque inhibitory action to chlorhexidine, and the plaque inhibitory action of the rinse appears to be derived from a persistence of antimicrobial action in the mouth. Furthermore, no side effects were reported during the study, and the additional benefit of no alcohol presence in the rinse solution.

Fluoride Modulates Parathyroid Hormone Secretion in vivo and in vitro.

The study objective was to investigate the effects of fluoride on intact parathyroid hormone (iPTH) secretion. Thyro-parathyroid complexes (TPC) from C3H (n = 18) and B6 (n = 18) mice were cultured in Ca²âº-optimized medium. TPC were treated with 0, 250, or 500 µM NaF for 24 h and secreted iPTH assayed by ELISA. C3H (n = 78) and B6 (n = 78) mice were gavaged once with distilled or fluoride (0.001 mg [F⁻]/g of body weight) water. At serial time points (0.5-96 h) serum iPTH, fluoride, total calcium, phosphorus, and magnesium levels were determined. Expression of genes involved in mineral regulation via the bone-parathyroid-kidney (BPK) axis, such as parathyroid hormone (Pth), calcium-sensing receptor (Casr), vitamin D receptor (Vdr), parathyroid hormone-like hormone (Pthlh), fibroblast growth factor 23 (Fgf23), α-Klotho (αKlotho), fibroblast growth factor receptor 1c (Fgf1rc), tumor necrosis factor 11 (Tnfs11), parathyroid hormone receptor 1 (Pth1r), solute carrier family 34 member 1 (Slc34a1), solute carrier 9 member 3 regulator 1 (Slc9a3r1), chloride channel 5 (Clcn5), and PDZ domain-containing 1 (Pdzk1), was determined in TPC, humeri, and kidneys at 24 h. An in vitro decrease in iPTH was seen in C3H and B6 TPC at 500 µM (p < 0.001). In vivo levels of serum fluoride peaked at 0.5 h in both C3H (p = 0.002) and B6 (p = 0.01). In C3H, iPTH decreased at 24 h (p < 0.0001), returning to baseline at 48 h. In B6, iPTH increased at 12 h (p < 0.001), returning to baseline at 24 h. Serum total calcium, phosphorus, and magnesium levels did not change significantly. Pth, Casr,αKlotho,Fgf1rc,Vdr, and Pthlh were significantly upregulated in C3H TPC compared to B6. In conclusion, the effects of fluoride on TPC in vitro were equivalent between the 2 mouse strains. However, fluoride demonstrated an early strain-dependent effect on iPTH secretion in vivo. Both strains demonstrated differences in the expression of genes involved in the BPK axis, suggesting a possible role in the physiologic handling of fluoride.

In situ evaluation of low-fluoride toothpastes associated to calcium glycerophosphate on enamel remineralization.

OBJECTIVES: This study aimed to evaluate the effect of low-fluoride toothpastes with calcium glycerophosphate (CaGP) on enamel remineralization in situ. METHODS: Volunteers (n=10) wore palatal devices holding four bovine enamel blocks. The treatments involved 5 experimental phases of 3 days each according to the following toothpastes: placebo, 500 ppm F (500 NaF), 500 ppm F with 0.25% CaGP (500 NaF CaGP), 500 ppm F with 0.25% CaGP (500 MFP CaGP) and 1100 ppm F (1100; positive control). After this experimental period, the fluoride, calcium, and phosphorus ion concentrations from enamel were determined. Surface and cross-sectional hardness were also performed. Data were analysed by 1-way ANOVA, Student-Newman-Keuls' test and by Pearson's correlation. RESULTS: The addition of 0.25% CaGP improved the remineralization potential of low-fluoride toothpastes and the NaF as source of fluoride yielded the best results (p<0.001) as evidenced by the hardness analysis. The 1100 ppm F toothpaste provided higher presence of fluoride in the enamel after remineralization (p<0.001). The addition of CaGP to the NaF and MFP toothpastes led to similar calcium concentration in the enamel as the observed with the positive control (p=0.054). CONCLUSIONS: Toothpastes with 500 ppm F (NaF or MFP) and CaGP showed similar remineralization potential than 1100 ppm F toothpaste. CLINICAL SIGNIFICANCE: Toothpastes containing 500 ppm F associated to CaGP, with both fluoride source (NaF or MFP), showed a potential of remineralization similar to commercial toothpaste. Although there is a need for confirmation in the clinical setting, these results point to an alternative for improving the risk-benefit relationship between fluorosis and dental caries in small children.

Erosion protection by calcium lactate/sodium fluoride rinses under different salivary flows in vitro.

This study investigated the effect of a calcium lactate prerinse on sodium fluoride protection in an in vitro erosion-remineralization model simulating two different salivary flow rates. Enamel and dentin specimens were randomly assigned to 6 groups (n = 8), according to the combination between rinse treatments - deionized water (DIW), 12 mM NaF (NaF) or 150 mM calcium lactate followed by NaF (CaL + NaF) - and unstimulated salivary flow rates - 0.5 or 0.05 ml/min - simulating normal and low salivary flow rates, respectively. The specimens were placed into custom-made devices, creating a sealed chamber on the specimen surface connected to a peristaltic pump. Citric acid was injected into the chamber for 2 min, followed by artificial saliva (0.5 or 0.05 ml/min) for 60 min. This cycle was repeated 4×/day for 3 days. Rinse treatments were performed daily 30 min after the 1st and 4th erosive challenges, for 1 min each time. Surface loss was determined by optical profilometry. KOH-soluble fluoride and structurally bound fluoride were determined in specimens at the end of the experiment. Data were analyzed by 2-way ANOVA and Tukey tests (α = 0.05). NaF and CaL + NaF exhibited significantly lower enamel and dentin loss than DIW, with no difference between them for normal flow conditions. The low salivary flow rate increased enamel and dentin loss, except for CaL + NaF, which presented overall higher KOH-soluble and structurally bound fluoride levels. The results suggest that the NaF rinse was able to reduce erosion progression. Although the CaL prerinse considerably increased F availability, it enhanced NaF protection against dentin erosion only under hyposalivatory conditions.

Differential influence of fluoride concentration on the synthesis of bone matrix glycoproteins within mineralizing bone cells in vitro.

OBJECTIVE: This study investigated the influence of fluoride levels on the temporal synthesis of bone-associated glycoproteins, which have been assigned prominent roles in regulating crystal growth, size and shape during the mineralization process. MATERIALS AND METHODS: Bone marrow stromal cells were isolated from male Wistar rats and cultured under mineralizing conditions, supplemented with 0 M, 10(-7) M or 10(-5) M sodium fluoride. The presence of bone-associated glycoproteins was examined 2-13 days post-reseeding by immunocytochemical localization. Results: All bone-associated glycoproteins increased in 10(-7) M fluoride, compared to untreated controls, particularly at days 6 and 13 in culture. Conversely, higher 10(-5) M fluoride concentrations decreased glycoprotein levels, compared to controls. CONCLUSIONS: Results highlight a differential effect of fluoride concentration on glycoprotein synthesis by osteoblasts.

Decreased IgA+ B cells population and IgA, IgG, IgM contents of the cecal tonsil induced by dietary high fluorine in broilers.

Fluoride is an environmental and industrial pollutant that affects various organs in humans and animals. The cecal tonsil is an important component of the mucosal immune system and performs important and unique immune functions. In the present study, we investigated the effects of dietary high fluorine on the quantities of IgA+ B cells in the cecal tonsil by immunohistochemistry, and the immunoglobulin A (IgA), immunoglobulin G (IgG) and immunoglobulin M (IgM) contents in the cecal tonsil by ELISA. A total of 280 one-day-old avian broilers were divided into four groups and fed on a corn-soybean basal diet as control diet (fluorine 22.6 mg/kg) or the same diet supplemented with 400, 800 and 1,200 mg/kg fluorine (high fluorine groups I, II and III) in the form of sodium fluoride, respectively, throughout a 42-day experimental period. The results showed that the quantities of IgA+ B cells were lower (p < 0.05 or p < 0.01) and the IgA, IgG, and IgM contents were decreased (p < 0.05 or p < 0.01) in high fluorine groups II and III in comparison with those of control group. It was concluded that dietary fluorine, in the 800-1,200 mg/kg range, could reduce the numbers of the IgA+ B cells and immunoglobulin contents in the cecal tonsil, implying the local mucosal immune function was ultimately impacted in broilers.

The color change in artificial white spot lesions measured using a spectroradiometer.

OBJECTIVES: The purpose of this study was to determine the color of white spot lesions. MATERIALS AND METHODS: Human premolars were subjected to a pH cycling to produce artificial caries lesions and classified into groups (n = 10/group): group 1, immersion in deionized water; group 2, pH cycling without fluoride (F) application; group 3, pH cycling with immersion in 1,000 ppm NaF solution; and group 4, pH cycling with immersion in 5,000 ppm NaF solution. CIE L*a*b* color parameters of the tooth were determined using a spectroradiometer at baseline, after demineralization and after pH cycling. The extent of demineralization was evaluated by scanning electron microscopy (SEM) and electron microprobe analysis (EPMA). RESULTS: Significant degrees of color change (ΔE*) were observed after demineralization (p < 0.05). The changes were mainly due to an increase in lightness (L*) and a decrease in yellowness (b*). F application induced a significantly large ΔE* in group 4 (p < 0.05). The color reversal after remineralization was mostly due to the recovery of L*. SEM and EPMA verified that net mineral gains occurred in the subsurface lesions. CONCLUSIONS: The initially white appearance of enamel caries was a result of changes of L* and b*. F treatment partially restored the color of white spot lesions. CLINICAL RELEVANCE: F-driven remineralization induced both mineral gains and esthetic enhancement of artificially produced enamel white spot lesions. The increase of L* and the decrease of b* contributed to the color changes.

Effect of a third application of toothpastes (1450 and 5000 ppm F), including a 'massage' method on fluoride retention and pH drop in plaque.

OBJECTIVE: The aim was to investigate fluoride (F) retention in plaque, saliva and pH drop in plaque using high-F toothpaste (5000 ppm F) or standard toothpaste (1450 ppm F) twice a day or 3-times a day. A method using the toothpaste as a 'lotion' and massaging the buccal surfaces with the fingertip was also evaluated. MATERIALS AND METHODS: The investigation had a randomized, single-blinded, cross-over design and 16 subjects participated in six brushing regimes: (1) 5000 ppm F; twice a day, (2) 5000 ppm; 3-times/day, (3) 5000 ppm; twice a day, plus the 'massage' method once a day, (4) 1450 ppm F; twice a day, (5) 1450 ppm; 3-times/day and (6) 1450 ppm; twice a day, plus the 'massage' method once a day. The outcome measure was F retention in plaque, saliva and the plaque-pH change after a sucrose rinse. RESULTS: The highest F concentration was found using high-F toothpaste (No 1-3) and differed significantly from those with 1450 ppm (No 4-6). Brushing with high-F toothpaste 3-times a day (No 2) resulted in a 3.6-times higher F saliva value compared with standard toothpaste twice a day (No 4) (p < 0.001). Increasing the frequency of application, from twice to 3-times a day, increased the F retention in plaque significantly when the two methods for application 3-times a day were pooled (p < 0.05). Brushing with 5000 and 1450 ppm toothpastes twice a day plus the 'massage' once a day resulted in the same F concentration in saliva and plaque as brushing 3-times a day with the same paste. CONCLUSION: A third application of toothpaste is increasing the F retention and toothpaste as a 'lotion' and massaging the buccal surfaces with the fingertip may be a simple and inexpensive way of delivering F a third time during the day.

Testicular histopathological changes following sodium fluoride administration in mice.

It has been revealed that excessive fluoride intake on long-term is associated with toxic effects and can damage a variety of organs and tissues in the human body, including the male reproductive system. However, the molecular mechanisms of fluoride-induced male reproductive toxicity are not well understood. The study wants to get news concerning the effects of natrium fluoride on testicular tissues when this substance is administrated to a population of mice. The study was conducted on NMRI mice descending from the pregnant females treated with 0.25 mg and 0.5 mg natrium fluoride by daily gavage, from the beginning of pregnancy until the lactation is ceased. Then, the mice, males and females, were divided in six groups, three groups descending from the pregnant females treated with 0.5 mg natrium fluoride (Groups A, B and C) and three groups from the pregnant females with 0.25 mg natrium fluoride (Groups D, E and F). From the moment when the lactation is finished until the adulthood, the animals received the following treatments: homeopathic (a CH7 solution of natrium fluoride - Groups A and D), allopathic-homeopathic (0.25 mg‰ natrium fluoride administered like drinking water ad libitum and CH7 solution of natrium fluoride - Group E; 0.5 mg‰ natrium fluoride administered like drinking water ad libitum and CH7 solution of natrium fluoride - Group B), and allopathic administration of natrium fluoride (0.25 mg‰ natrium fluoride like drinking water ad libitum - Group F; 0.5 mg‰ natrium fluoride like drinking water ad libitum - Group C). When the males reached the adulthood, the administration of natrium fluoride was stopped and, by randomization, they where selected for euthanasia. The euthanasia was realized by cervical dislocation. The testes for the histopathological examination were preserved in a 10% formalin solution. The preparation of samples for optical microscopy was realized with Hematoxylin-Eosin staining. The results indicate that natrium fluoride administered in different doses, even at homeopathic dose or at allopathic-homeopathic dose, determined vacuolar dystrophy of epididymal epithelial cells, vacuolar dystrophy of linear seminal cells and necrosis.

Fluoride-supplemented milk inhibits acid tolerance in root caries biofilms.

In this study we investigated the effect of fluoride on plaque acid tolerance. The test group consumed 200 ml of milk supplemented with 5 mg F/l as NaF once a day, the milk control group drank 200 ml of unsupplemented milk, and the no-milk control group did not consume milk in this manner. Plaque samples were taken at baseline and after 15 months. The proportion of acid-tolerant bacteria in plaque was estimated using LIVE/DEAD® BacLight™ staining after exposure to pH 3.5 for 2 h. The fluoride group showed a statistically significant decrease in plaque acid tolerance compared to baseline. This study shows that daily intake of fluoride in milk reduces plaque acid tolerance.

Fluoride modulates preosteoblasts viability and matrix metalloproteinases-2 and -9 activities.

This study evaluated the influence of fluoride on cell viability and activity of matrix metalloproteinases (MMP) -2 and -9 secreted by preosteoblasts. Preosteoblasts (MC3T3-E1 murine cell line) were cultured in MEM medium supplement with 10% Fetal Bovine Serum (FBS) and nucleosides/ribonucleosides without ascorbic acid. Adherent cells were treated with different concentrations of F (as sodium fluoride-NaF) in medium (5 x 10(-6) M, 10(-5) M, 10(-4) M and 10(-3) M) for 24, 48, 72 and 96 h at 37ºC, 5% CO(2). Control cells were cultivated in MEM only. After each period, preosteoblast viability was assessed by MTT assay. MMP-2 and -9 activities were performed by gel zymography. Also, alkaline phosphatase (ALP) activity was quantified by colorimetry in all experimental groups. It was shown that cultured cells with the highest dose of F (10(-3) M) for 96 h decreased preosteoblast viability while lower doses of F did not alter it, when compared to untreated cells. No differences were observed in ALP activity among groups. Moreover, compared to control, the treatment of cells with F at low dose slightly increased MMP-2 and -9 activities after 24 h. It was concluded that F modulates preosteoblast viability in a dose-dependent manner and also may regulate extracellular matrix remodeling.