Fluoride Treatment Research Articles

Fluoride Removal in Synthetic Drinking Water by Electrocoagulation Using Aluminum Electrodes

Fluoride is recognized as an essential constituent in the human diet. Low fluoride concentration could prevent dental problem while higher fluoride concentration will cause dental and skeletal fluorosis. This study aimed to remove fluoride in synthetic drinking water by electrochemical system. It had been performed at laboratory scale using fluoride synthetic water. The process consisted to optimize the fluoride removal in drinking water using the Aluminum electrodes. The effects of operating conditions such as the initial ion fluoride concentration, current density or intensity, contact time, and NaCl amount were studied. Experimental results showed that with the initial concentration of 15 mg/L using the optimal intensity (1.5 A), an admitted residual concentration (1.5 mg/L) was observed during 45 min of electrolysis while maximum fluoride removal percentage of 100 % was achieved for 60 min. The variation of energy consumption from 1.18 to 22.35 Wh showed that the electrocoagulation can be applied using photovoltaic energy for fluoride treatment in drinking water.

Fluoroacetate distribution, response to fluoridation, and synthesis in juvenile Gastrolobium bilobum plants

Like angiosperms from several other families, the leguminous shrub Gastrolobium bilobum R.Br. produces and accumulates fluoroacetate, indicating that it performs the difficult chemistry needed to make a C–F bond. Bioinformatic analyses indicate that plants lack homologs of the only enzymes known to make a C–F bond, i.e., the Actinomycete flurorinases that form 5′-fluoro-5′-deoxyadenosine from S-adenosylmethionine and fluoride ion. To probe the origin of fluoroacetate in G. bilobum we first showed that fluoroacetate accumulates to millimolar levels in young leaves but not older leaves, stems or roots, that leaf fluoroacetate levels vary >20-fold between individual plants and are not markedly raised by sodium fluoride treatment. Young leaves were fed adenosine-13C-ribose, 13C-serine, or 13C-acetate to test plausible biosynthetic routes to fluoroacetate from S-adenosylmethionine, a C3-pyridoxal phosphate complex, or acetyl-CoA, respectively. Incorporation of 13C into expected metabolites confirmed that all three precursors were taken up and metabolized. Consistent with the bioinformatic evidence against an Actinomycete-type pathway, no adenosine-13C-ribose was converted to 13C-fluoroacetate; nor was the characteristic 4-fluorothreonine product of the Actinomycete pathway detected. Similarly, no 13C from acetate or serine was incorporated into fluoroacetate. While not fully excluding the hypothetical pathways that were tested, these negative labeling data imply that G. bilobum creates the C–F bond by an unprecedented biochemical reaction. Enzyme(s) that mediate such a reaction could be of great value in pharmaceutical and agrochemical manufacturing.

3D printing of a controlled fluoride delivery device for the prevention and treatment of tooth decay.

Dental decay is a highly prevalent chronic disease affecting people from all ages. Clinically, fluoride supplementation is the primary strategy in the prevention of dental decay. However, the current existing self-application formulations such as gels or mouthwashes are rapidly cleared after administration, resulting in modest efficacy even after repeated applications. Therefore, a user-friendly formulation that can provide sustained fluoride release in the oral cavity is of great interest for dental decay prevention. Herein, we report the utilization of fused deposition modelling to fabricate personalised mouthguards, which allow local and prolonged fluoride elution. Composite filaments comprising sodium fluoride and polymers with tuneable hydrophobicity were produced using blends of poly(ε-caprolactone) (PCL) and poly(vinyl alcohol) or poly(ethylene glycol) (PEG). The materials exhibited suitable mechanical properties for dental devices as well as different release kinetics depending on their composition. Ex vivo studies were performed on decayed human teeth using the 3D printed tooth caps that precisely fit the complex geometries of each specimen. A significant elevation of fluoride content in the lesion mineral in contact with the PCL/PEG tooth caps was achieved compared to the ones in contact with solutions mimicking dental care products. In conclusion, this study suggested that a sustained localized drug release of fluoride from personalised 3D printed mouthguards at the device-enamel interface can improve the incorporation of fluoride in the tooth matrix and prevent lesion progression.

Use of zinc oxide nanoparticles for detection of fluoride in toothpaste gel

This study aimed to investigate the metal-binding effect of fluoride, contained in different commercial toothpaste gels; the study aimed to determine if the toothpastes contained excessive concentrations of fluoride, which result in white spot lesions. A spectrophotometric method that used spectrophotometric reagents, including zinc oxide nanoparticles and iron chloride, was used to determine fluoride distribution; the analysis was based on the selective attack of fluoride ions on metals. Fluoride concentrations between 0 and 1450 ppm were analyzed. Although the iron–fluoride complex was a more sensitive reagent, the zinc–fluoride complex could serve as a suitable alternative to it for fluoride analysis, partly because the method was less time consuming and more stable. The detection and quantification limits obtained from the linear calibration curves of the zinc–fluoride complexes, in deionized water, were 0.191:1 and 0.579:1 w/w ZnO, respectively. A model calibration curve was suggested to detect the unknown products of fluoride degradation. Dentists could use a fluoride treatment similar to the protocol used in this study, to prevent potential enamel demineralization, and exclude physical cavity preparation and restoration.

Knowledge, Practices and Attitudes towards Silver Diamine Fluoride Therapy among Dentists in Japan: A Mixed Methods Study

In 2021, the World Health Organization included silver diamine fluoride (SDF) as an essential medicine to manage caries in adults and children. SDF was developed in the 1960s, but its use for children became unpopular in Japan because of the decline and low prevalence of early childhood caries. This mixed methods study explored the knowledge, practices and attitudes towards SDF therapy among dentists promoting fluoride use in Japan. It also investigated senior dentists’ perceptions of SDF therapy in Japan. The quantitative study invited all 173 members of the largest organisation promoting fluoride use in Japan to complete a web-based questionnaire survey. Sixty (60/173; 35%) dentists promoting fluoride use in Japan completed the questionnaire survey. All dentists knew of SDF treatment, and 50 (50/60; 83%) used SDF for dental care. Fifty-nine dentists (59/60; 98%) agreed that SDF therapy was simple and quick. All 60 dentists agreed that SDF was effective to arrest caries; 51 dentists (51/60; 85%) agreed that SDF was effective to prevent caries. Most dentists (51/60; 85%) were concerned about SDF’s unaesthetic staining. Fifty-seven dentists (57/60; 95%) used SDF to arrest primary posterior teeth, and 52 dentists (52/60; 87%) used SDF to arrest root caries. However, 25 dentists (25/60; 42%) did not use SDF to prevent caries in permanent teeth. The qualitative study interviewed 12 senior dentists using snowball sampling and achieved data saturation. The dentists opined that SDF therapy was effective, simple, painless, non-invasive and inexpensive. SDF is seldom used in Japan at present because of the unaesthetic black staining and the low prevalence of early childhood caries; however, it can regain popularity by arresting root caries in the aging population.

Effects of a Two-Step Silver Diamine Fluoride Varnish on Shear Bond Strength of Restorations, Dentin and Enamel Hardness, and Biofilm Formation.

Dental caries are a limiting factor in maintaining dental and medical readiness in the military. Untreated dental caries can lead to dire health consequences. Consistent and comprehensive access to dental care is often limited due to the intensive operational demands on our nation's warfighters. The standard of care for dental caries is a surgical model where diseased tooth tissue is surgically removed and restored with appropriate restorative materials. While effective, it is not practical in the military operational environment, especially under time constraints. Dental restoratives offer military personnel a simple and preventive treatment of dental caries and are suitable as self-applied first aids. The purpose of this study was to measure the shear bond strengths of two dental restorative materials to human teeth paired with two different fluoride treatments and the hardness and biofilm formation on teeth after applying the fluoride varnishes. Specimens were made of human molar teeth treated with each of the following four materials: glass ionomer cement GC Fuji II LC Capsules, Filtek Z250, Riva Star steps 1 and 2, or Mark3 NaF varnish. Step 1 of Riva Star consists of silver diamine fluoride and step 2 contains potassium iodide. On human molar slabs, 10 circular specimens of 5 cm in diameter were prepared with restoratives according to manufacturer procedures. Etch-Rite and a proprietary aluminum chloride-based cavity conditioner were used as etchants on tooth surfaces for the Filtek Z250 and glass ionomer cement, respectively. After at least 24 hours underwater, each assembly was removed, and the shear bond strength of the adhesive was measured according to International Organization for Standardization (ISO) 29022.The hardness was measured according to ISO 14233. Hardness measurements were performed before varnish application, then after storage in an incubator at 37 °C for 4 hours in a demineralization solution (pH = 4.5), and after 1 day in a mineralization solution (pH = 7). A crystal violet staining assay was used to measure biofilm formation of Streptococcus mutans bacteria on human molar teeth after the application of fluoride varnish. We report a 16% increase in shear bond strength of the Filtek Z250/Riva Star coupled treatment compared to the Filtek Z250/Mark3 NaF coupled treatment. We also demonstrate a significant 84% decrease in bond strength with a GC Fuji II LC/Mark3 NaF treatment compared to control (P = .0002), while Riva Star remains statistically unchanged. Enamel and dentinal hardness are significantly improved when Riva Star is applied compared to NaF varnish. A 25%-35% (P < .0001) decrease in oral biofilm formation was observed on samples where a Riva Star or NaF varnish was applied. Mechanical and antimicrobial testing indicated Riva Star, compared favorably with and in some cases, performed better in the laboratory than a Mark3 NaF varnish. Hardness measurements indicated Riva Star is more effective in dentin tubule occlusion compared to NaF varnish. Our findings help provide practical suggestions to dental treatment, particularly to the unique dental environments seen in the military. Riva Star may be used as an adjunctive treatment prior to placing a final restoration. This study supports the use of Riva Star in conjunction with GC Fuji II LC or Filtek Z250 restorative materials, making it a promising treatment in military dental applications.

Potential of chitosan nanoparticle/fluoride nanocomposite for reducing the toxicity of fluoride an in-vivo study on the rat heart functions: Hematopoietic and immune systems

The present work-study the decreasing fluoride ions toxicity on the rat heart via loading them on the chitosan nanoparticles (Cs NPs) surface to form the biologically compatible composite (Cs@NaF). The obtained nanocomposite was characterized by different techniques such as field emission scanning electron microscopy (FEG-SEM), zeta potential, and x-ray diffraction (XRD). The biochemical parameters in the albino rats perform, where twenty-eight male adult Sprague Dawley rats (average body weight of 150 ± 10 g) were obtained from the Faculty of Agriculture, Alexandria University, then acclimatized for two weeks before the experiment and divided into four groups in galvanized wire cages at room temperature (22–25 °C) with a 12-h photoperiod and fed a well-balanced commercial diet. The blood samples were obtained from the vena cava of the rat heart via estimation of the troponin T, Lactate dehydrogenase, and creatine phosphokinase. Also, immunoglobulins (IgA, IgM, and IgG) and hematological measurements have been performed on the rat heart. To express all of the data, the mean and standard error of the mean are utilized by (ANOVA), followed by Tukey's multiple comparison test. The modified chitosan with fluoride decreases the toxicity of fluoride via improving the rat heart function due to the presence of Cs NPs helped to mitigate some of the negative effects of fluoride therapy.

Bifunctional Passivation through Fluoride Treatment for Highly Efficient and Stable Perovskite Solar Cells

AbstractDue to the low formation energy, surface defects are more likely to form on the surface of TiO2 films, resulting in a decline in the efficiency and stability of perovskite solar cells (PSCs). Additionally, defects on the bottom surface of the perovskite layer in contact with TiO2 play a key role in Voc (open circuit voltage) loss and the PSC degradation process. Therefore, to improve the efficiency and stability of PSCs, it is critical to develop a reproducible and low‐cost method for passivating the defects on both the TiO2 surface and on the bottom surface of the perovskite layer. In this work, fluoride is utilized as a bifacial contact passivation agent for decreasing the number of defects on the TiO2 surface and the bottom surface of the perovskite layer. PSC efficiency can be significantly increased from 21.3% to 23.7% with fluoride passivation. In addition, the long‐term stability of PSCs, especially light irradiation stability, can be markedly improved. The passivation effects of fluoride treatment on TiO2 films are studied by theoretical calculation and experimental characterization. This work provides a thorough understanding of the TiO2/perovskite interface and demonstrates an approach for improving the efficiency and stability of PSCs.

Wearable battery-free theranostic dental patch for wireless intraoral sensing and drug delivery

Dental caries caused by oral microbiome dysbiosis with the elevation of acidogenic bacteria is the most prevalent non-communicable disease worldwide. Early prevention and timely fluoride treatment are crucial for caries lesion management. Herein, to address the challenges of in situ sensing and topical drug delivery within the oral cavity, a miniaturized, battery-free, and wearable dental patch system was developed for microenvironment monitoring and controlled fluoride treatment. With the integration of near-field communication, the dental patch realizes wireless energy harvesting and data transmission with mobile terminals like smartphones when attached conformally to the tooth surface. The acidic microenvironment caused by bacterial metabolism are electrochemically detected, while fluorides can be delivered locally from the electric-responsive drug delivery electrode for on-demand treatment. As flexible electronics armed to the teeth, this intraoral theranostic wearable system provides an inspiring platform for point-of-care monitoring and treatment of dental caries and oral diseases.

Fluoride Concentration in Tap Water from Different Regions in Thailand

Fluoride supplementation in drinking tap water is one of the well-known effective methods for dental caries prevention. However, overexposure to fluoride following excessive fluoride intake from drinking water leads to dental fluorosis. Therefore, the assessment of daily fluoride consumption is required to calculate the optimal fluoride intake. The present study investigated the fluoride concentration in tap water collected from different areas in Thailand. A total of 27 locations were selected. Three samples of tap water (500 mL each) were independently collected from one location. Each sample in the same location was collected from the same faucet of tap water and stored in different containers. The samples were collected by dental students or dentists who worked in the selected areas from March 2020 to June 2020. Briefly, the faucet was cleaned with the tap water and the water was run from the faucet for 1-2 mins. Then, water was collected in 500 mL bottles and immediately capped. Samples were then stored at room temperature in tightly sealed bottles until analysis. Findings showed that most samples contained fluoride at a concentration lower than 0.7 mg/mL. Further, the water pH was in the range of 6.81-8.37. These levels were lower than the cut-offs established by the World Health Organization (WHO) for maximum levels of fluoride and pH in drinking water. In conclusion, the present study demonstrated that fluoride levels in tap water from different regions in Thailand are lower than those recommended by WHO for fluoride levels in drinking water.

Zero-valent iron coupled calcium hydroxide: A highly efficient strategy for removal and magnetic separation of concentrated fluoride from acidic wastewater

The removal of concentrated fluoride in acidic wastewater by the conventional Ca(OH)2 method is challenged by the insufficient efficiency and difficult separation of fine CaF2 precipitate. Herein, we construct a strategy to tackle these challenges by coupling zero-valent iron (ZVI) with Ca(OH)2. ZVI reduces fluoride concentration from 12,000 to 3980 mg L−1 under optimal conditions primarily through the in-situ growth of porous FeF2·4H2O shell on its surface, which simultaneously assists fluoride removal via adsorption. The residual fluoride after ZVI treatment then decreases to 6.74 mg L−1 via precipitation with Ca(OH)2. Interestingly, the iron ions dissolved from ZVI also participate in the precipitation to form magnetite. This co-precipitation reinforces the fluoride removal and meanwhile endows the resulted precipitates with magnetism, thus enabling the perfect solid-liquid separation by the magnetic field before discharge. The application prospect of this coupling strategy is further verified by its ability in decreasing the concentrations of fluoride and other coexisting heavy metals (Zn2+, Cd2+ and Pb2+) in real smeltery wastewater below their discharge limitations. This study provides a promising strategy for the treatment of concentrated fluoride in acidic wastewater and also highlights ZVI as a good candidate to couple with conventional methods for enhanced pollution control.

Impact of Silver Diamine Fluoride Therapy on the Oral Health-Related Quality of Life of Preschool Children with Behavioral Problems after Three Months: A Pilot Study.

Background: In Austria, almost every second child has caries. The consequences of untreated carious lesions are infections, pain, and limitations in everyday life. The aim of this study was to evaluate the influence of silver diamine fluoride (SDF) treatment on the oral health-related quality of life (OHRQoL) of uncooperative children aged 0–5 years using the German version of the Early Childhood Oral Health Impact Scale (ECOHIS-G). Methods: This prospective study was conducted at the Department of Paediatric Dentistry at the Medical University of Vienna. Preschool children with behavioral problems and carious lesions that required SDF application were included. The ECOHIS-G questionnaire was given to the caregiver before (T0) and three months (T1) after treatment. Using descriptive analysis and the Wilcoxon Signed-Rank test, changes in the ECOHIS scores were evaluated and tested for significance. Results: A total of 30 children aged 0–5 years were enrolled and received SDF treatment. At baseline, the total ECOHIS score was 21.4 (±8.5). Three months after therapy, a significant improvement was achieved (16.3 [±5.6], p < 0.05). Significantly better scores were observed in six subdomains, especially in “child function” (3.9 [±2.0]) and “child symptoms” (2.0 [±1.3]) (p < 0.05). Conclusions: Treatment of carious lesions with SDF in the primary dentition resulted in an improvement in the OHRqoL of children with behavioral problems.

The acid resistance, roughness, and microhardness of deciduous enamel induced by Er:YAG laser, fluoride, and combined treatment: an in vitro study

Erbium-doped yttrium aluminium garnet (Er:YAG) lasers and fluoride have been used as preventive treatments to combat permanent tooth decay; however, little is known about deciduous teeth, which are more prone to caries. The purpose of this study was to assess acid resistance, roughness, and microhardness induced by an Er:YAG laser, fluoride application and a combined treatment on deciduous enamel. Seventy samples of deciduous enamel were randomly assigned to seven groups (n = 10): a negative control group [G1_C (−)], a positive control group [G2_C (+)], a group treated with acidulated phosphate fluoride (G3_F), a group treated with an Er:YAG laser (G4_L7.5 and G5_L12.7) and one tretated with an Er:YAG laser plus fluoride (G6_L7.5+F and G7_L12.7+F). The samples were then placed in a lactic acid solution for 24 h; the calcium and phosphate release was measured by atomic absorption spectroscopy and ultraviolet-visible spectroscopy (UV–vis). The surface roughness and microhardness were then analysed using a stylus profilometer and a static microhardness tester, respectively. In relation to the calcium release, G3_F presented values statistically lower than all others groups (p < 0.05). Group G7_L12.7+F had lower phosphorus release values than all other groups (p < 0.05). Group G3_F (0.24 ± 0.14 µm) had lower roughness values than groups G6_L7.5+F and G7_L12.7+F. Group G1_C(−) presented statistically significant differences in comparison to the rest of the groups (p < 0.05). The laser treatment and the combined treatment (laser plus fluoride) were not more effective than the fluoride treatment alone at improving acid resistance of deciduous enamel. However, the combined treatment diminished phosphorous release and increased the surface roughness of deciduous enamel. Finally, the acid dissolution decreased the microhardness of deciduous enamel regardless of the preventive protocol (fluoride, laser, or laser plus fluoride treatment).

Gestational exposure to fluoride impairs cognition in C57 BL/6 J male offspring mice via the p-Creb1-BDNF-TrkB signaling pathway

Fluoride exposure has a detrimental effect on neurodevelopment, while the underlying processes remain unknown. The goal of this study was to investigate how fluoride impacts synaptogenesis, with a focus on the phosphorylation of Creb1 (p-Creb1)-brain-derived neurotrophic factor (BDNF)-tyrosine kinase B (TrkB) pathway. We generated a sodium fluoride (NaF) model using C57 BL/6 J mice exposed to 100 mg/L NaF from gestation day 1 (GD1) to GD20. It was identified that NaF treatment impaired the learning and memory abilities of the male offspring, reduced dendritic spine density, lowered postsynaptic density protein-95 (PSD95) and synaptophysin (SYN) expression in the male offspring's hippocampus, indicating that synaptic dysfunction may contribute to the cognitive impairment in the NaF model. In addition, in vivo experiment demonstrated that the protein abundance of BDNF and the ratio of p-Creb1 to Creb1 were increased in the hippocampus of NaF offspring, while the level of TrkB was reduced. Similarly, PC12 cells treated with NaF also showed increased expression of BDNF and decreased levels of TrkB. Notably, fluoride treatment increased p-Creb1 in vitro, while inhibiting p-Creb1 by 66615 significantly alleviated the effects of NaF exposure, indicating that p-Creb1 exerts a regulatory function in the BDNF-TrkB pathway. Altogether, these results demonstrated prenatal fluoride exposure triggered neurotoxicity in the male offspring hippocampus was linked to synaptogenesis damage caused by activating p-Creb1, which disrupted the BDNF-TrkB pathway.

Um guia rápido sobre o desgaste dentário erosivo

Erosive tooth wear (ETW) is considered an oral health problem, caused by chemical-physical processes resulting from repetitive exposure to acids (dental erosion) and physical forces (abrasion and attrition), which causes the loss of its mineral structure. This problem occurs in a multifactorial condition, and there may be an interaction between biological, dietary, behavioral and environmental factors. In recent years its prevalence has increased, making it a challenge for dentists, especially when it reaches more advanced stages where it can cause pain, hypersensitivity, problems with function and aesthetics. Through a literature review, the present study aims to present a brief guide on the etiology, diagnosis, prevention and treatments of ETW, helping the dentist in his clinical decision making. The dentist must carry out an early diagnosis and perform the appropriate treatment of this problem, being mainly dietary and oral hygiene guidelines in addition to fluoride therapies.

Effect of &lt;i&gt;Ginkgo biloba&lt;/i&gt; extract on Histomorphometric changes of Hippocampus against Fluoride Toxicity in Wistar Rats

Prolonged ingestion of fluoride leads to the pathogenesis known as fluorosis. Fluoride exposure leads to neuro degenerative changes such as reduction in the neuronal cell size and number. Exposure to fluoride showed neurodegenerative changes like shrunken neurons, increased in folding of the nuclear membrane, mitochondrial alterations, and dilated rough endoplasmic reticulum cisternae and clusters of vesicles near the Golgi bodies. Present study is to explore the histomorphometric changes of the hippocampus of fluoride induced brain and treated with Ginkgo biloba Extract (GBE). Thirty number (30) adult male Wistar rats were randomly separated into 5 Groups (n=6). Group1 (Control) supplemented with water, 2 to 5 Groups were supplemented with 100ppm of sodium fluoride for 30 days, while the Groups 3, 4, and 5 were Ginkgo biloba extract treated at 50mg/ kg, 100mg/kg and 200mg/kg body weight for 15 days, after sodium fluoride treatment, results showed that, 200mg/kg GBE provided effective and complete protection against fluoride toxicity. From the present study concluded that 50, 100 and 200 mg/kg GBE was significantly attenuated the fluoride induced toxicity in a dose depending manner. Present histomorphometrical study showed delayed neuronal death in the CA1 and CA3 regions of hippocampus of fluoride group that was significantly attenuated by GBE (50,100 and 200 mg/kg) in a dose dependant manner.

Combined Effects of Topical Fluorides and Semiconductor Lasers on Prevention of Enamel Caries: A Systematic Review and Meta-Analysis.

Objective: To compare the effects of combined treatment of topical fluoride and semiconductor laser (F&L) with topically using fluoride (F) on remineralization and prevention of enamel caries. Background: There is no agreement on whether semiconductor lasers can promote the effect of topical fluoride on the remineralization and prevention of dental caries. This study is the first systematic review and meta-analysis to investigate the pooled effect of data from studies that compared the combined use of semiconductor lasers and topical fluorides with the single use of fluoride on remineralization and prevention of caries. Methods: We performed literature search on Scopus, Web of Science, and PubMed. The keywords were as follows: ((diode lasers) OR (diode laser) OR (quantum cascade laser) OR (quantum cascade lasers) OR (Gallium Aluminum Arsenide lasers) OR (Gallium Aluminum Arsenide laser) OR (GaAlAs lasers) OR (GaAlAs Laser) OR (semiconductor laser) OR (semiconductor lasers)) AND ((caries) OR (dental caries) OR (remineralisation) OR (remineralization) OR (demineralization) OR (demineralisation)) AND fluoride. We carried out meta-analysis to compare the microhardness of demineralized enamel, lesion depth (LD), and percent reduction of calcium (Ca%) of sound enamel receiving F&L with F. Results: The search identified nine laboratory studies, which used 445 to 980 nm semiconductor lasers with various fluorides. The standard mean difference of microhardness of demineralized enamel between F&L and F was 1.06 [95% confidence interval (CI): 0.12 to 2.00, p = 0.03]. No difference was found in LD (95% CI: -1.63 to 0.10, p = 0.08) and Ca% (95% CI: -0.52 to 1.28, p = 0.40) on sound enamel between the two groups. Conclusions: Semiconductor lasers enhance the effect of fluoride on remineralizing but not on preventing enamel caries. Moreover, substantial heterogeneity was found among the studies, and the results should be interpreted cautiously.

Remineralizing Effect from Topical Fluoride Treatment on Inicial Lesion of Early Childhood Caries

The starting phase on early childhood caries or circular caries is an initial lesion, known as macula Alba or white spot, which is reversible, stops or reverses (perform biological repairs). In the initial lesion stage (macula alba) with the removal of caries the causative agent (dental plaque) on the one hand, and taking maximum preventive measures on the other hand: proper nutrition of the young child, salivation with normal pH and saliva composition, adequate mechanical and chemical control of dental plaque, by maintaining proper oral hygiene and topical application of fluoride preparations in various forms, conditions are created for the predominance of remineralization processes in relation to demineralization, which compensates for the insufficiency of minerals and may lead to the disappearance of the initial lesion (restutio ad integrum). Purpose of the Study investigation: Evaluation of ultra-structural enamel changes in the enamel in the starting phase on initial lesion of circular caries - Early childhood caries. It is done with Scanning Electronic Microscope (SEM) evaluation of remineralizing effects in enamel ultrastructure at the stage of initial lesion and superficial form, after topical application of fluoride-based preparation (p-p amino fluoride). Material and method: The investigation was done on laboratory tests on extracted 20 healthy lower incisions and two more groups with 10 upper incisions, where some have topical fluoride compression treatment with SEM (Scanning Electron Microscope), and the others did not have the treatment. After that, we have analysis of the remineralizing effect of fluorides with SEM photo attachments. Results: In some dental samples we managed to get almost healthy enamel, i.e. complete remineralization process of the inicial lesion. Conclusion: Once again, we have confirmation of one of the many benefits of fluoride in dentistry which is long been known.

Upregulation of protein N-glycosylation plays crucial roles in the response of Camellia sinensis leaves to fluoride

The tea plant (Camellia sinensis) is one of the three major beverage crops in the world with its leaves consumption as tea. However, it can hyperaccumulate fluoride with about 98% fluoride deposition in the leaves. Our previously studies found that cell wall proteins (CWPs) might play a central role in fluoride accumulation/detoxification in C. sinensis. CWP is known to be glycosylated, however the response of CWP N-glycosylation to fluoride remains unknown in C. sinensis. In this study, a comparative N-glycoproteomic analysis was performed through HILIC enrichment coupled with UPLC-MS/MS based on TMT-labeling approach in C. sinensis leaves. Totally, 237 N-glycoproteins containing 326 unique N-glycosites were identified. 73.4%, 18.6%, 6.3% and 1.7% of these proteins possess 1, 2, 3, and ≥4 modification site, respectively. 93.2% of these proteins were predicted to be localized in the secretory pathway and 78.9% of them were targeted to the cell wall and the plasma membrane. 133 differentially accumulated N-glycosites (DNGSs) on 100 N-glycoproteins (DNGPs) were detected and 85.0% of them exhibited upregulated expression after fluoride treatment. 78.0% DNGPs were extracellular DNGPs, which belonged to CWPs, and 53.0% of them were grouped into protein acting on cell wall polysaccharides, proteases and oxido-reductases, whereas the majority of the remaining DNGPs were mainly related to N-glycoprotein biosynthesis, trafficking and quality control. Our study shed new light on the N-glycoproteome study, and revealed that increased N-glycosylation abundance of CWPs might contribute to fluoride accumulation/detoxification in C. sinensis leave.

Comparing the prevalence of Helicobacter pylori and virulence factors cagA, vacA, and dupA in supra-gingival dental plaques of children with and without dental caries: a case–control study

BackgroundHelicobacter pylori infection is one of the most common infectious diseases in humans. Dental plaque is considered as a reservoir of this bacterium, which could play an important role in the development of gastrointestinal problems. Our aim was to investigate the prevalence of H. pylori and its virulence factors in dental plaques in children with and without dental caries.MethodsAmong children aged 6 to 12 years, a total of 72 children were enrolled in the study, including 36 cases with total DMFT/dmft > 3 (case group) and 36 participants with total DMFT/dmft < 1 (control group). After removing supra-gingival plaques from the lower first permanent molar teeth, the samples were examined using PCR method for the presence of H. pylori and some of its virulence factors. Statistical analysis was performed using chi-square, Fisher' exact test, t-tests, and logistic regression.ResultsOf 72 participants, 40 cases were male, and 32 cases were female. The minimum and maximum values of total DMFT/dmft indices were zero and ten, respectively, and the mean ± SD value of total DMFT/dmft was 2.78 ± 3.22. Except for vegetable consumption (p = 0.045), there was no significant difference between the two groups regarding gastrointestinal disorders, feeding methods in infancy (p = 0.058), frequency of daily brushing (p = 0.808), frequency of dental visits (p = 0.101), and history of dental scaling (p = 0.246) and professional topical fluoride therapy (p = 0.5). Out of 72 samples, 15 cases were positive for H. pylori DNA (20.8%), and there was no significant association between the presence of this bacterium in dental plaque and dental caries (p = 0.281). The frequency of virulence factors detected in 15 H. pylori cases was as follows: cagA in six cases (40.0%), vacAm1 in three cases (20.0%), and vacAs1 in one case (6.7%). There was no significant difference between the groups regarding the prevalence of virulence factors.ConclusionOur results indicate the presence of H. pylori along with some virulence factors in dental plaques as a reservoir of this bacterium in children in Iran. Although there was no significant association between this bacterium and the incidence of dental caries, dental health in children needs to be seriously taken into consideration.