Biphasic Functions of Sodium Fluoride (NaF) in Soft and in Hard Periodontal Tissues

Sodium fluoride (NaF) is widely used in clinical dentistry. However, the administration of high or low concentrations of NaF has various functions in different tissues. Understanding the mechanisms of the different effects of NaF will help to optimize its use in clinical applications. Studies of NaF and epithelial cells, osteoblasts, osteoclasts, and periodontal cells have suggested the significant roles of fluoride treatment. In this review, we summarize recent studies on the biphasic functions of NaF that are related to both soft and hard periodontal tissues, multiple diseases, and clinical dentistry.

Fluoride Treatment and In Vitro Corrosion Behavior of Mg-Nd-Y-Zn-Zr Alloys Type

Fluoride conversion coatings on Mg present many advantages, among which one can find the reduction of the corrosion rate under “in vivo” or “in vitro” conditions and the promotion of the calcium phosphate deposition. Moreover, the fluoride ions released from MgF2 do not present cytotoxic effects and inhibit the biofilm formation, and thus these treated alloys are very suitable for cardiovascular stents and biodegradable orthopedic implants. In this paper, the biodegradation behavior of four new magnesium biodegradable alloys that have been developed in the laboratory conditions, before and after surface modifications by fluoride conversion (and sandblasting) coatings, are analyzed. We performed structural and surface analysis (XRD, SEM, contact angle) before and after applying different surface treatments. Furthermore, we studied the electrochemical behavior and biodegradation of all experimental samples after immersion test performed in NaCl solution. For a better evaluation, we also used LM and SEM for evaluation of the corroded samples after immersion test. The results showed an improved corrosion resistance for HF treated alloy in the NaCl solution. The chemical composition, uniformity, thickness and stability of the layers generated on the surface of the alloys significantly influence their corrosion behavior. Our study reveals that HF treatment is a beneficial way to improve the biofunctional properties required for the studied magnesium alloys to be used as biomaterials for manufacturing the orthopedic implants.

Effects of brief sodium fluoride treatments on the growth of early and mature cariogenic biofilms

Although fluoride has been widely used as a preventive agent for dental caries, the effects of fluoride on the activities of biofilms in different stages of cariogenic biofilm formation are less studied. This study was designed to investigate the antibiofilm activity of sodium fluoride during the early and mature stages of Streptococcus mutans (S. mutans) biofilm formation. S. mutans biofilms were formed on saliva-coated hydroxyapatite disks. In the early (0–46 h) and mature (46–94 h) biofilm stages, the biofilms were treated with different concentrations of fluoride (250, 500, 1000, 2000 ppm; 5 times in total, 1 min/treatment). Acidogenicity, dry weight, colony-forming units (CFUs), water-soluble/insoluble extracellular polysaccharides (EPSs), and intracellular polysaccharides were analysed, and confocal laser scanning microscopy images were obtained of the two stages of biofilms to determine antibiofilm activities of fluoride at varying concentrations during the formation of early and mature biofilms. In the early stages of cariogenic biofilm formation, test groups with all fluoride concentrations significantly inhibited the growth of S. mutans biofilms. The antibiofilm and anti-EPS formation activities of the brief fluoride treatments increased with a concentration-dependent pattern. At the mature biofilm stage, only the 2000 ppm fluoride treatment group significantly inhibited biofilm accumulation, activity, and intracellular/extracellular polysaccharide content compared with those of the control and other fluoride treatment groups. The antimicrobial effect of fluoride treatment on the growth of S. mutans biofilms was linked with the stage of cariogenic biofilm formation. The inhibition of S. mutans biofilm growth by fluoride treatment was easier in the early formation stage than in the mature stage. Fluoride treatment in the early stage of cariogenic biofilm formation may be an effective approach to controlling cariogenic biofilm development and preventing dental caries.

Aloe Vera Protects Fluoride Induced Teratogenic Effects During Pre- and Postnatal Development in Mice

Pregnancy and feto-gestational toxicities on exposure to fluoride (F) and its possible amelioration on co-administration with Aloe-vera were studied in pregnant Swiss albino mice. Once the confirmed pregnancy was tested, animals were equally divided into four groups and were given following treatment. Group I was given no treatment and served as Control, Group II and III were administered sodium fluoride, 100 and 300 ppm respectively while group IV was co-administered with sodium fluoride, 300 ppm and Aloe-vera (300mg/kg) daily for 14 days prior to gestation and continued till the 18th day of gestation. Animals were sacrificed `on the 19th day of gestation for prenatal observations. Maternal body weight, the gravid uterine weight, number of corpora lutea in both the ovaries, number of implantations and resorptions, number of live (mature and immature ) male and female fetuses as well as number of dead fetuses were examined in each dam. The treatment continued in another set of animals till the completion of weaning period to observe postnatal changes due to test substances on the mother and pups. Sodium fluoride treated animals showed morphometric and skeletal changes which were more pronounced in the high dose group showing significantly decreased body weight gain in pregnant mothers; and dead/immature fetuses. Morphometric changes included open eyelids, limb defects, wrinkles on whole body, anophthalmias, pulmonary edema, enlarged esophagus and decreased body weight of fetuses and pups. Alizarin prepared skeletal structures of fetuses of such female mice showed delayed ossification or bending in number of bones of skull, thoracic and limb regions. However, concomitant exposure to Sodium Fluoride and Aloe-vera treated animals, there was a marked improvement in all the prenatal and postnatal variables. The study suggests that Sodium fluoride at the high concentrations may be teratogenic while co-administration of Aloe-vera during fluoride exposure might be beneficial in reducing these toxic effects. We thus recommend use of aloe vera as preventive agent or as a complimentary agent during fluoride treatment.

Comparison Adhesive strength of Resin Composite between Total-etch and Self-etch Techniques on Enamel After Fluoride Application

Background : White Spot Lesion (WSL) is caused by Streptococcus Mutan which causes demineralization of teeth. One of the treatments of WSL is topical application of fluoride which aims to remineralize the teeth. However, if topical fluoride treatment does not give satisfactory results, alternative treatments can be made using restorative treatments, one of which is veneers. The procedure for applying veneers requires the application of an adhesive system. The adhesive system used to apply veneers is self-etch and total-etch. Several references state that the application of fluoride which aims to remineralize teeth can influence the adhesiv strength of the restorative material using self etch and total-etch techniques. Purpose : To determine the effect of composite resin adhesion strength between total-etch and self etch techniques on enamel after fluoride application. Review : Literature sources used in the preparation of the article through several databases with descriptions of the effects of fluoride application before total-etch and/or self etch administration. From the existing references, it was found that the application of fluoride before the total-etch system had a less significant effect on the adhesiv strength. Whereas in the self etch system, fluoride application has a significant effect on the adhesiv strength. Conclusion : More references say that the application of fluoride before the total-etch system has a better adhesive strength than the application of fluoride before the self etch system

QPCR Screening of Pediatric Saliva Samples to Evaluate Effects of Dental Sealants on Cariogenic Bacteria Streptococcus Mutans and Scardovia Wiggsiae

Dental caries is an alarmingly prevalent multifactorial disease worldwide but is most common as a chronic disease among children and adolescents. Within the oral cavity there are hundreds bacterial species, including specific cariogenic pathogens such as Streptococcus mutans and Scardoviawiggsiae. Although dental caries are highly prevalent, it may also be preventable using methods such as dental sealants or fluoride treatment, which have proven to be highly effective in reducing caries risk – although there is limited evidence on the exact effect of these treatments on S. wiggsiaeinparticular. Due to the lack of conclusive evidence, this study is aimed to evaluate the microbial burden of S. mutans and S. wiggsiae among pediatric saliva samples to analyze the effects dental sealants have on these oral microbiota. Saliva samples derived from pediatric patients pre- and post-sealant were obtained from an existing repository. DNA was extracted and screened using qPCR and primers specific for the cariogenic organisms, S. mutans (SM) and S. wiggsiae (SW). These data demonstrated an overall reduction in SW among Post-sealant samples (11.14 U/uL) compared with Pre-sealant samples (11.68 U/uL), as well as a reduction in the overall number of samples harboring S. wiggsiae (n=8). The Pre-sealant average amount of SM (14.54 U/uL) was slightly increased among the Post-sealant samples (15.67 U/uL) with half of the samples analyzed (n=13) exhibiting slight increases in SM levels, and nearly one-third (n=8) exhibiting slight decreases in SM levels. The data from this study may suggest that dental sealants have an impact on certain cariogenic pathogens in the oral microbiota. Whether or not the impact is positive or not in light of the increase in S. mutans remains an observation that should be further analyzed. More research is required to address the limitations found in this study in order to localize the exact effect on the teeth with dental sealants.

Оral hygiene and fluoride influence on dental health in early childhood

Early childhood caries occurs immediately after the eruption of deciduous teeth. During this period, children are too young to be able to properly implement oral hygiene. Consequently, it is at a negligible level, with plenty of soft plaque on the deciduous tooth surfaces. The objective of this investigation was to determine the correlation between oral hygiene (shown with the OHI index) and the initial stages of early childhood caries: initial lesion (white spot) and superficial form, before and after local fluoride treatment. Material and methods: For determining the OHI index among our examinees we used the method of Green-Vermillion. It was determined in 117 examinees twice, during the first visit and immediately before physiological replacement of deciduous teeth. Patients were two to three years of age, diagnosed with initial stages of early childhood caries and fluoride preparate (amino fluoride solution) was applied once a week, for 6 months. Results: In 30 subjects treated with local fluoride treatment from both basic groups (with initial and superficial lesions), just before the physiological change of the teeth, we received a statistically significant improvement in the OHI index (p = 0.000038; p = 0.00006) at the end from the examination. Conclusion: From the conducted analysis of the obtained results, we can conclude that the level of oral hygiene is correlated with the progression of changes in the enamel. Oral hygiene and fluoride treatment significantly reduce soft tissue levels and improve the OHI index.