Fluoride varnishes in caries prevention

Comparative Evaluation of Zwitterionic Material, Self-assembling Peptide, and Bioactive Glass Incorporated with MI Varnish for Fluoride, Calcium, and Phosphorus Ion Release, Enamel Remineralization, and Microhardness

Background

White spot lesions occur when the pathogenic bacteria have broken through the enamel layer. White spot lesions (WSLs) can be treated using a complex approach. The most crucial step is to stop demineralization and biofilm formation and use assorted strategies for remineralization of lesions, thinning, microabrasion, erosion infiltration, adhesive composite resin restorations, and the bonded facets.

Aim

To evaluate and compare the fluoride, calcium, and phosphorus ion release, remineralizing efficacy, and microhardness of zwitterionic material, self-assembling peptide, and bioactive glass (BGA) incorporated with MI Varnish.

Materials and methods

The original study was conducted on 60 extracted premolars; the sample size calculated was 10 per group. All samples were divided into four groups-group A, MI Varnish (control), group B, MI Varnish + zwitterionic material, group C, MI Varnish + self-assembling peptide, and group D, MI Varnish + BGA. All these groups were further evaluated and compared for fluoride, calcium, and phorphorus ion release, remineralizing efficacy, and surface microhardness (SMH).

Results

Zwitterionic material, when incorporated with MI Varnish showed high fluoride and calcium ion release and high remineralizing efficacy under polarized light microscopy (PLM). BGA, when incorporated with MI Varnish showed high phosphorus ion release and higher values in the evaluation of SMH, followed by zwitterionic material and self-assembling peptide.

Conclusion

MI varnish alone had remineralizing properties of WSLs, but when novel materials like zwitterionic ion, self-assembling peptide, and BGA are incorporated, its efficacy increases. Among all zwitterionic ions showed superior results for fluoride and calcium ion release and remineralization and BGA for phosphorus ion release and SMH.

How to cite this article

Patil SV, Gugwad SC, Devendrappa SN, et al. Comparative Evaluation of Zwitterionic Material, Self-assembling Peptide, and Bioactive Glass Incorporated with MI Varnish for Fluoride, Calcium, and Phosphorus Ion Release, Enamel Remineralization, and Microhardness. Int J Clin Pediatr Dent 2024;17(S-1):S37-S42.

Effect of adhesive components in experimental fluoride varnish on fluoride release within 30 days in vitro study

We aimed to determine whether adhesive components could increase the release time of effective fluoride concentration from an experimental fluoride varnish applied to bovine teeth. An experimental fluoride varnish containing 5% sodium fluoride (EX1) was prepared and combined with 35% hydroxyethyl methacrylate (HEMA) (EX2), 5% glutaraldehyde (EX3), or 35% HEMA/5% glutaraldehyde mixture (EX4). Two commercially available fluoride varnishes were used for comparison. Each group was applied to bovine incisors, and the fluoride release and pH were monitored for 30 days. Cell viability analysis, scanning electron microscopy, and energy-dispersive spectroscopy were performed. EX4 released the highest and most effective concentration of fluoride for the longest period and reached neutral pH at the earliest; the release was maintained for up to 30 days without cytotoxicity. In conclusion, EX4 is considered to be the most effective varnish to prevent dental caries.

Comparative Evaluation of Longevity of Fluoride Release from Three Different Fluoride Varnishes: An Observational Study

Introduction

The cycles of demineralization and remineralization result in a dynamic process of caries development. Caries are prevented by the shift in the balance from demineralization to remineralization at the tooth-oral fluid interface with the help of salivary fluoride levels (in parts per million). The advantages of fluoride varnish application over other substitutes like dentifrices, mouthrinses, gels, or foams are that varnishes are well tolerated by infants, young children, or children with special healthcare needs and have prolonged therapeutic effects. This study was formulated to evaluate and compare the longevity of fluoride release from different fluoride varnishes, namely Fluor Protector, Enamelast, and Enamel Pro varnish.

Aim

To evaluate and compare the longevity of fluoride release from three different fluoride varnishes.

Materials and methods

The study samples comprised 72 healthy permanent maxillary anterior teeth. The teeth were divided into four groups, with eighteen teeth in each group. The surfaces of all teeth were then covered by different colored nail varnish according to the respective group, except for a 3 × 3 mm window on the facial (labial) surface of the crown, where the test materials were applied according to their respective group. In group I, Fluor Protector varnish; in group II, Enamelast varnish; and in group III, Enamel Pro varnish was applied. Group IV was the control group; hence, no test material was applied. All specimens were then stored in plastic containers with a pH of 7.2 in artificial saliva at room temperature. The specimens were transferred into new plastic containers after 1 day, containing fresh artificial saliva, and solutions from previous plastic containers were taken for fluoride analysis. This process was repeated sequentially to analyze the amount of fluoride released in ppm from the specimens at the end of 1, 3, and 6 months.

Statistical analysis

Analysis was performed on Statistical Package for the Social Sciences (SPSS) software (Windows version 22.0).

Results

Conventionally used 1.5% ammonium fluoride varnish, that is, Fluor Protector varnish, showed the least release of fluoride (0.03 ± 0.0 ppm), while resin carrier-based 5% sodium fluoride varnish, that is, Enamelast varnish showed a good amount of fluoride release for 6 months continuously, that is, (0.16 ± 0.06 ppm) at last follow-up. Enamel Pro varnish, which has 5% sodium fluoride with amorphous calcium phosphate (ACP) formula, was found to be the best varnish as it released the maximum amount of fluoride in ppm in artificial saliva for up to 3 months (0.32 ± 0.08) but less than Enamelast varnish only at 6 months follow-up that is 0.09 ± 0.03 ppm.

Conclusion

The present study concludes that based on the amount of fluoride released for 6 months duration, Enamel Pro varnish, followed by Enamelast varnish and Fluor Protector varnish, are advisable to apply for caries prevention.

How to cite this article

Singh V, Naik S, Vashisth P, et al. Comparative Evaluation of Longevity of Fluoride Release from Three Different Fluoride Varnishes: An Observational Study. Int J Clin Pediatr Dent 2024;17(3):341-345.

Role of Fluoride in Dentistry: A Narrative Review

Fluoride has performed a central role in the growth over the last fifty years. This report examines the present state of knowledge about fluoride's involvement in preventing dental caries. In recent years, our knowledge of the development of dental caries and the manner of operation of fluoride has been shifted. Dental caries is a constant procedure for enamel demineralization and remineralization, and fluoride plays an important part in this action by acting at the plaque-enamel contact. Fluoride's major method of action is now recognized as posteruptive. Fluoride's post-eruptive activity has led to the development of novel fluoride delivery systems. The importance of various fluoride delivery techniques on a population and societal level is discussed, along with suggestions.

Evaluation of the antibacterial activity of Enamelast® and Fluor defender® fluoride varnishes against Streptococcus mutans biofilm: an in vitro study in primary teeth

PURPOSE

The aim of the current work was to compare the antibacterial activity of Enamelast® and Fluor defender® fluoride varnish on biofilm generation by Streptococcus mutans on extracted primary teeth.

METHODS

Thirty-six primary molars were collected and sliced into seventy-two test model disks. All specimens were examined, and the cracked or broken ones were discarded. A total number of specimens (n = 54) were divided into two experimental analyses viz; biofilm formation (n = 27) and microscopic examination (n = 27). Specimens of each analysis were tested under different experimental conditions: a negative control group (n = 9), Fluor defender group (n = 9), and Enamelast group (n = 9). Following treatment, biofilms were generated by adherent Streptococcus mutans on the test model disks on three time intervals: 24 h (n = 3), 48 h (n = 3), and 72 h (n = 3) for each analysis. Then, for biofilm formation analysis, the biofilm was detected spectrophotometrically at 620 nm after being stained by crystal violet. For microscopical analysis, the surfaces of the test model disks were visualized by scanning electron microscopy (SEM), and each image was processed and analyzed using ImageJ software.

RESULTS

At 48 and 72 h, Enamelast® and Fluor defender®-treated group showed significantly (p < 0.001) slight adhered bacterial cells when compared with the negative control group as revealed by the absorbance and SEM. Compared with the Fluor defender®-treated group, the absorbance of the Enamelast®-treated group showed a significant (p < 0.001) increase by approximately 7- and 16.5-fold at 48 and 72 h, respectively. Similarly, SEM showed that the number of bacterial cells adhered to enamel surfaces in the Fluor defender®-treated group was significantly (p < 0.001) fewer than the Enamelast®-treated group by approximately 36.55% and 20.62% at 48 and 72 h after exposure, respectively.

CONCLUSION

We conclude that the anti-biofilm activity of Fluor defender® against Streptococcus mutans was significantly (p < 0.001) greater than Enamelast® fluoride varnish. The use of Fluor defender® is encouraged as a preventive measure in children with the high risk of developing dental caries.

Bioactive Materials for Caries Management: A Literature Review

Researchers have developed novel bioactive materials for caries management. Many clinicians also favour these materials, which fit their contemporary practice philosophy of using the medical model of caries management and minimally invasive dentistry. Although there is no consensus on the definition of bioactive materials, bioactive materials in cariology are generally considered to be those that can form hydroxyapatite crystals on the tooth surface. Common bioactive materials include fluoride-based materials, calcium- and phosphate-based materials, graphene-based materials, metal and metal-oxide nanomaterials and peptide-based materials. Silver diamine fluoride (SDF) is a fluoride-based material containing silver; silver is antibacterial and fluoride promotes remineralisation. Casein phosphopeptide-amorphous calcium phosphate is a calcium- and phosphate-based material that can be added to toothpaste and chewing gum for caries prevention. Researchers use graphene-based materials and metal or metal-oxide nanomaterials as anticaries agents. Graphene-based materials, such as graphene oxide-silver, have antibacterial and mineralising properties. Metal and metal-oxide nanomaterials, such as silver and copper oxide, are antimicrobial. Incorporating mineralising materials could introduce remineralising properties to metallic nanoparticles. Researchers have also developed antimicrobial peptides with mineralising properties for caries prevention. The purpose of this literature review is to provide an overview of current bioactive materials for caries management.

The Safety of Fluoride Compounds and Their Effect on the Human Body-A Narrative Review

Fluoride is one of the elements commonly present in the human environment. Due to its characteristics, it is very widely used in medicine, dentistry, industry or agriculture. On the other hand, its universality possesses a real threat to the human body in the form of acute and chronic poisoning. The aim of this paper is to characterize the properties of fluoride and its effects on the human body, as well as the sources of its occurrence. Particular emphasis is placed on the safety of its use and optimal dosage intake, which prevents accumulation and reduces its potential side effects. The positive effect of proper fluoride supply is widely described. In order to avoid overdose, it is best to consult a specialist to properly select the dosage.

In-vitro evaluation of the anti-cariogenic effect of a hybrid coating associated with encapsulated sodium fluoride and stannous chloride in nanoclays on enamel

OBJECTIVE

The aim of this study is to test, in vitro, the anti-cariogenic effect of experimental hybrid coatings, with nano clays of halloysite or bentonite, loaded with sodium fluoride or with a combination of sodium fluoride and stannous chloride, respectively.

METHODOLOGY

The varnish Fluor Protector (1,000 ppm of F-) was used as positive control and no treatment was the negative control. Enamel specimens (5 mm × 5 mm) were obtained from bovine teeth. The specimens (n=10) had their surfaces divided into two halves (5 mm × 2.5 mm each), in which one half received one of the treatments (Hybrid; Hybrid + NaF; Hybrid + NaF + SnCl2; Hybrid + NaF Loaded; Hybrid + NaF + SnCl2 Loaded). The specimens were submitted to a cariogenic challenge using a biofilm model (S. mutans UA159, for 5 days). Enamel surfaces both under and adjacent to the treated area were analyzed for mineral loss and lesion depth, by transverse microradiography. The pH of the medium was measured twice a day, and the fluoride release was analyzed. Additional specimens were submitted to confocal analysis.

RESULTS

Data were statistically analyzed by two-way ANOVA followed by Tukey test (α=0.05). None of hybrid groups were able to reduce the lesion depth; the Hybrid + NaF group, however, was able to reduce mineral loss differing from the negative control (p=0.008). The groups showed no significant difference in the pH measurement and fluoride release. Confocal analysis confirmed that for all groups the biofilm growth was similar.

CONCLUSION

None of the hybrid groups reduced lesion depth, but the Hybrid + NaF group was able to promote protection against mineral loss.

Regional variations in caries experience, predictors, and follow-up among children and adolescents in Western Norway

OBJECTIVE

To identify regional differences in, and determinants of dental caries among children in western Norway.

MATERIAL AND METHODS

We studied dental caries in 705 children aged 12 years and 18 years living in the southern region (n = 403) and other parts of Hordaland County (n = 302) in Norway. Information on oral hygiene, fluoride intake, and sugar consumption was collected using questionnaires. We also collected information from the Public Dental Service (PDS) on the history of decayed, missing, or filled teeth; professional fluoride application; recall and regular check-up intervals and treatment visits. Residence (southern region versus the rest of Hordaland, the reference) was the independent variable. We analysed regional differences in (i) caries prevalence and severity, (ii) potential contributors to caries, and (iii) procedures and routines in PDS.

RESULTS

Caries prevalence and severity were higher in the southern region (67% and 24%, respectively). Self-reported brushing habits, fluoride use, and sugar consumption patterns were similar between regions. We observed more frequent application of professional fluoride (incidence rate ratio [IRR] = 3.05, 95% CI: 1.99-4.66], fewer check-ups [IRR = 0.88, 95% CI: 0.81-0.95], and fewer treatment visits [IRR = 0.77, 95% CI: 0.60-0.98] among participants in the southern region, compared to the rest of Hordaland. The recall intervals in the southern region were 10% longer among 12-year-olds and 10% shorter among 18-year-olds, compared to their respective counterparts in Hordaland.

CONCLUSIONS

The observed regional gradients in caries experience mirrored regional differences in dental routines and procedures. Caries-related risk behaviours did not explain the observed differences in caries experience.

Topical fluoride varnishes promote several biological responses on human gingival cells

OBJECTIVE

To compare the in vitro cytotoxicity of four commercial topical fluoride varnishes widely used in daily dental practice for the prevention of caries on human fibroblasts: Cervitec F, Fixofluor, Fluor Protector S and Duraphat.

MATERIAL AND METHODS

Human gingival fibroblasts (hGF) were exposed to different concentrations of fluoride varnishes extracts. Biological assays, including MTT and IC50 value determination, annexin-V/7-AAD staining, cell migration and F-actin staining with phalloidin were carried out. Statistical analyses were performed using one-way ANOVA and Tukey's post hoc test.

RESULTS

At 4% concentration, all of the fluoride varnishes extracts affected fibroblasts metabolic activity, exhibiting a high degree of cytotoxicity at all measured time points. At 0.1% and 1%, Duraphat and Fixofluor or Fluor Protector S and Cervitec F exerted the lowest or highest cytotoxic effects, respectively. Similar effects were evidenced when induction of apoptosis/necrosis and cell migration assays were analyzed. Immunocytochemical assays revealed a similar number of fibroblasts, without changes in the morphology and F-actin content at 0.1% concentration of all tested materials, while at 1% concentration, Fluor Protector S and Cervitec F showed few cells with aberrant morphology or non-adhered cells, respectively.

CONCLUSIONS

Different commercial topical fluoride varnishes with the same therapeutic indication may exhibit different biological effects and cytotoxicity on fibroblasts.

"It's really no more difficult than putting on fluoride varnish": a qualitative exploration of dental professionals' views of silver diamine fluoride for the management of carious lesions in children

Background

Despite evidence that Silver Diamine Fluoride (SDF) can be effective in managing carious lesions in primary teeth, the use of SDF in the UK remains limited. This study explored dental professionals’ views and experiences of using SDF for managing carious lesions in children. In addition, it explored what they perceived to be the advantages, disadvantages, barriers and enablers to the use of SDF in practice.

Methods

Fifteen semi-structured face-to-face or over-the-phone interviews were conducted with 14 dental professionals from NHS Tayside and NHS Grampian in Scotland. Interviews were transcribed verbatim, coded and analysed using a thematic approach.

Results

Thirteen of 14 dental professionals interviewed were familiar with, or had some existing knowledge of, SDF. Four had used it to treat patients. The majority of participants thought that the main advantage of SDF was that it required minimal patient cooperation. SDF was also perceived as a simple, pain-free and non-invasive treatment approach that could help acclimatise children to the dental environment. However, SDF-induced black staining of arrested carious lesions was most commonly reported as the main disadvantage and greatest barrier to using it in practice. Participants believed that this discolouration would concern some parents who may fear that the black appearance may instigate bullying at school and that others may judge parents as neglecting their child’s oral health. Participants thought that education of clinicians about SDF use and information sheets for parents would enhance the uptake of SDF in dental practice. Participants believed that younger children might not be as bothered by the discolouration as older ones and they anticipated greater acceptance of SDF for posterior primary teeth by both parents and children.

Conclusion

Dental professionals were aware that SDF can be used for arresting carious lesions. They pointed out that the staining effect of carious lesions is a major disadvantage and had preconceived ideas that this could be a barrier for many parents. Participants considered the application process to be simple and non-invasive and requires a minimum level of child cooperation. Participants appreciated the potential of SDF in paediatric dentistry and suggested actions that could help overcome the barriers they highlighted.

Inhibitory effects on Streptococcus mutans of antibacterial agents mixed with experimental fluoride varnish

We investigated the inhibitory effect of antibacterial agents mixed with experimental fluoride varnish (EFV) on Streptococcus mutans. The antibacterial agents used were (1 and 10) mM of xanthorrhizol, bakuchiol, bavachalcone, isobavachromene, and bavachromene. Agar diffusion tests were performed on S. mutans (1.1×10¹⁰ CFU/mL), using antibacterial agents without and with EFV. Bavachalcone showed the highest inhibition zone without and with EFV at both (1 and 10) mM (p<0.05). All EFV with antibacterial agents showed greater inhibition and semi-inhibition zones than EFV alone (p<0.05). The cell viability of each antibacterial agent was not significantly different from the vehicle controls (p>0.05), except xanthorrhizol and bakuchiol at 1 mM. All antibacterial agents were effective, while antibacterial agents with EFV co-formulations were more effective than EFV alone. Bavachalcone was the most effective agent against S. mutans, indicating its potential usefulness with fluoride varnish in preventing dental caries.

Surface-Specific Caries Preventive Effect of an Intervention Comprising Fissure Sealant, Povidone-Iodine and Fluoride Varnish in a Remote Indigenous Community in Australia

This study evaluates the effect of a topical intervention comprising of fissure sealant, povidone-iodine, and fluoride varnish in preventing caries on occlusal, approximal, and smooth surfaces. This three-year clinical trial was conducted in a remote Indigenous community of Australia. All schoolchildren (age range: 4–17) were invited to participate; those with parental consents to receive three-annual epidemiological examinations and interventions constituted the experimental group, while those with consents for only the epidemiological examination formed a comparison group. The intervention group received an annual application of fissure sealant, povidone–iodine and fluoride varnish for two consecutive years along with the restoration of any cavitated lesions, while the comparison group did not receive any intervention except for the usual care that included emergency treatment and restorations. Incipient and advanced caries were recorded in the permanent dentition while data on confounding variables were collected through questionnaires. Caries increment and progression were the outcome variables. A total of 408 children participated in the baseline examination, 208 finished the study. After adjusting for confounders, the prevented fraction (PF) on occlusal surfaces for advanced caries in the experimental group was 76.1% (mean difference- −0.35, 95% CI: −0.67–0.04), while the PF for progression from incipient to advanced caries was 100%(mean difference- −0.30, 95% CI: −0.52–0.09). The mean number of smooth surfaces that progressed from incipient to advanced caries in the comparison group was more than twice that of the experimental group, the mean difference was −0.25 (95% CI: −0.46–−0.03) with a PF of 61%. The intervention was only effective in preventing advanced caries on occlusal surfaces and in halting the progression of caries on occlusal and smooth surfaces but not on approximal caries.

Study protocol of the cost-effectiveness comparison of two preventive methods in the incidence of caries: A randomized, controlled clinical trial

INTRODUCTION

Dental caries is the most frequent oral disease worldwide and the main cause of tooth loss in children and young adults. One of the most frequently affected areas is the occlusal surfaces of the first permanent molars (FPM) due to their morphological complexity. At present, several preventive treatments can reduce the incidence of this disease in school populations. In Mexico, the most commonly used technologies are those derived from some presentation of fluoride; on the other hand, research on this topic has been limited.

OBJECTIVE

To determine the cost-effectiveness of two different methods for preventing the incidence of caries on the FPM of schoolchildren (6-8 years of age) from public primary schools.

MATERIAL AND METHODS

This is a randomized experimental design. Participants will be assigned to two treatment groups of 114 each. In the first group, pit and fissure sealants will be applied, whereas the second group will receive a fluoride varnish. The work will be carried out in schoolchildren that attend public elementary schools in the state of Hidalgo, Mexico. The result variable will be the incidence of caries and the total cost of each of the interventions will be calculated in order to calculate the intervention's cost-effectiveness.

CONCLUSION

This work will allow us to compare the cost-effectiveness of the pit and fissure sealants and the fluoride varnish in order to determine which offers the best results.

Oral health knowledge in pre-school children: A survey among parents in central Italy

Background

The aim of this survey was to evaluate the knowledge and awareness of parents about potential oral health risk factors and correct management of oral hygiene of their preschool children.

Material and Methods

The participation to the survey was proposed to all parents of 3-5 year aged children attending a kindergarten in Campobasso. A self-administered questionnaire was completed to obtain information regarding demographic and education variables, knowledge about caries and its transmission, infant feeding practice, maternal oral health during pregnancy, parents and children’s oral hygiene habits and risk behaviors (e.g., sharing cutlery, tasting of baby food, nightly using of baby bottles or pacifier), oral health prevention and role of school.

Results

Overall, the parents of 101 children consented to fill the questionnaire. Data analysis showed that only 24% of respondents was aware of the potential vertical transmissibility of cariogenic bacteria through contaminated saliva. It is still a common trend from 61% of parents tasting food of their child. On 101 children, 30% used pacifier and 17% used baby bottle with milk during night and among these children 41% for more than 2 years. Parents reported no toothbrushing for 57% of the children in their first 3 years of life.

Conclusions

From this survey, independently on parents education, it emerges as still nowadays parents are not fully trained and informed about the management of their child’s oral hygiene and as it’s necessary a parental oral health promoting program to control children oral health risk status, starting from school.

Key words:Oral health, pre-school children, dental caries, oral prevention.

Effect of Fluoride Varnish and Dentifrices and Its Combination on Deciduous Enamel Demineralization: An In vitro Study

Introduction:

Dental caries remains the most important dental health problem in developing countries. Application of varnish on tooth surfaces is shown to promote the uptake of firmly bound fluoride by enamel, which is considered important. Along with the incorporation of fluoride into the crystalline lattice, there is formation of calcium fluoride compounds on enamel.

Methodology:

Seventy deciduous canines were covered with nail polish. A window measuring 4 mm × 4 mm was left on their buccal surface, These were randomly assigned to seven groups (n = 6): S: sound enamel not subjected to any regimen or treatment; N: negative control, subjected to the pH-cycling regimen without any treatment; D1 and D2: subjected to the pH-cycling regimen and treated two times daily with 1100 and 500 ppm F dentifrice, respectively; VF: fluoride varnish (subjected to F-varnish before and in the middle of the pH-cycling regimen); and VF + D1 and VF + D2. After a period of 10 days, sectioning of teeth was done, and enamel demineralization was measured.

Results:

The combination of dentifrice and varnish (groups VF + D1 and VF + D2) significantly reduced demineralization compared with the N group at all distances evaluated (P < 0.05), but the combination did not differ from the dentifrice groups at most distances from the surface (P > 0.05).

Conclusion:

The results of this study suggest that the combination of F-varnish with dentifrices containing 500 or 1100 ppm F is not more effective in reducing demineralization in primary teeth than the isolated effect of dentifrice containing 1100 ppm.

Mechanism of Action of TiF4 on Dental Enamel Surface: SEM/EDX, KOH-Soluble F, and X-Ray Diffraction Analysis

This in vitro study aimed to evaluate the action of TiF4 on sound and carious bovine and human enamel. Sound (S) and pre-demineralised (DE) bovine and human (primary and permanent) enamel samples were treated with TiF4 (pH 1.0) or NaF varnishes (pH 5.0), containing 0.95, 1.95, or 2.45% F for 12 h. The enamel surfaces were analysed using SEM-EDX (scanning electron microscopy/energy-dispersive X-ray spectroscopy) (n = 10, 5 S and 5 DE) and KOH-soluble fluoride was quantified (n = 20, 10 S and 10 DE). Hydroxyapatite powder produced by precipitation method was treated with the corresponding fluoride solutions for 1 min (n = 2). The formed compounds were detected using X-ray diffraction (XRD). All TiF4 varnishes produced a coating layer rich in Ti and F on all types of enamel surface, with micro-cracks in its extension. TiF4 (1.95 and 2.45% F) provided higher fluoride deposition than NaF, especially for bovine enamel (p < 0.0001). It also induced a higher fluoride deposition on DE samples compared to S samples (p < 0.0001), except for primary enamel. The Ti content was higher for bovine and human primary enamel than human permanent enamel, with some differences between S and DE. The XRD analysis showed that TiF4 induced the formation of new compounds such as CaF2, TiO2, and Ti(HPO4)2·H2O. In conclusion, TiF4 (>0.95% F) interacts better, when compared to NaF, with bovine and human primary enamel than with human permanent enamel. TiF4 provoked higher F deposition compared to NaF. Carious enamel showed higher F uptake than sound enamel by TiF4 application, while Ti uptake was dependent on the enamel condition and origin.

The cytotoxic effect of TiF4 and NaF on fibroblasts is influenced by the experimental model, fluoride concentration and exposure time

Objective

Titanium tetrafluoride (TiF₄) has shown promising effect in preventing tooth lesions. Therefore, we compared the cytotoxicity of TiF₄ with sodium fluoride (NaF) (already applied in Dentistry) considering different fluoride concentrations, pH values and experimental models.

Materials and methods

Step 1) NIH/3T3 fibroblasts were exposed to mediums containing NaF or TiF₄ (from 0.15 to 2.45% F), both at native and adjusted pH, for 6 h. Step 2) NIH/3T3 were exposed to NaF or TiF₄ varnishes with 0.95, 1.95 or 2.45% F (native pH), for 6, 12 or 24 h. We applied MTT (1^st and 2^nd steps) and Hoescht/PI stain (2^nd step) assays. Step 3) NIH/3T3 were exposed to NaF or TiF₄ varnish (2.45% F), at native pH, for 6 or 12 h. The cell stiffness was measured by atomic force microscopy (AFM).

Results

Step 1) All cells exposed to NaF or TiF₄ mediums died, regardless of the F concentration and pH. Step 2) Both varnishes, at 1.90 and 2.45% F, reduced cell viability by similar extents (33–86% at 6 h, 35–93% at 12 h, and 87–98% at 24 h) compared with control, regardless of the type of fluoride. Varnishes with 0.95% F did not differ from control. Step 3) TiF₄ and NaF reduced cell stiffness to a similar extent, but only TiF₄ differed from control at 6 h.

Conclusions

Based on the results of the 3 experimental steps, we conclude that TiF₄ and NaF have similar cytotoxicity. The cytotoxicity was dependent on F concentration and exposure time. This result gives support for testing the effect of TiF₄ varnish in vivo.

Absence of Fluoride Varnish-Related Adverse Events in Caries Prevention Trials in Young Children, United States

Introduction

Fluoride varnish is an effective prevention intervention for caries in young children. Its routine use in clinical care is supported by meta-analyses and recommended by clinical guidelines, including the US Preventive Services Task Force (B rating). This report is the first prospective systematic assessment of adverse events related to fluoride varnish treatment in young children.

Methods

We determined the incidence of adverse events related to fluoride varnish treatment in 3 clinical trials on the prevention of early childhood caries, conducted under the auspices of the Early Childhood Caries Collaborating Centers, an initiative sponsored by the National Institute of Dental and Craniofacial Research. Each trial incorporated use of fluoride varnish in its protocol and systematically queried all children’s parents or legal guardians about the occurrence of acute adverse events after each fluoride varnish treatment.

Results

A total of 2,424 community-dwelling, dentate children aged 0 to 5 years were enrolled and followed for up to 3 years. These children received a cumulative total of 10,249 fluoride varnish treatments. On average, each child received 4.2 fluoride varnish treatments. We found zero fluoride varnish–related adverse events.

Conclusion

Fluoride varnish was not associated with treatment-related adverse events in young children. Our findings support its safety as an effective prevention intervention for caries in young children.

The effect of different fluoride application methods on the remineralization of initial carious lesions

Objectives

The purpose of this study was to assess the effect of single and combined applications of fluoride on the amount of fluoride release, and the remineralization and physical properties of enamel.

Materials and Methods

Each of four fluoride varnish and gel products (Fluor Protector, FP, Ivoclar Vivadent; Tooth Mousse Plus, TM, GC; 60 Second Gel, A, Germiphene; CavityShield, CS, 3M ESPE) and two fluoride solutions (2% sodium fluoride, N; 8% tin(ii) fluoride, S) were applied on bovine teeth using single and combined methods (10 per group), and then the amount of fluoride release was measured for 4 wk. The electron probe microanalysis and the Vickers microhardness measurements were conducted to assess the effect of fluoride application on the surface properties of bovine teeth.

Results

The amount of fluoride release was higher in combined applications than in single application (p < 0.05). Microhardness values were higher after combined applications of N with FP, TM, and CS than single application of them, and these values were also higher after combined applications of S than single application of A (p < 0.05). Ca and P values were higher in combined applications of N with TM and CS than single application of them (p < 0.05). They were also increased after combined applications of the S with A than after single application (p < 0.05).

Conclusions

Combined applications of fluoride could be used as a basis to design more effective methods of fluoride application to provide enhanced remineralization.

The influence of lifestyle on the incidence of dental caries among 3-year-old Japanese children

The present cohort study examined how lifestyle, household environment, and caries activity test score of Japanese children at age 1.5 years affected their dental caries incidence at age 3. Inclusion criteria were 1.5-year-old children with no dental caries. Dental examinations were performed for 33,655 children who participated in routine dental examinations at 1.5 years of age, and the exam was repeated approximately 21 months later (at age 3) at the Kobe City Public Health Center in Japan. After excluding 622 children who had caries at age 1.5 and 1831 children with missing lifestyle and household environment data in the questionnaires, the final data analysis was performed on a total of 31,202 children (16,052 boys, 15,150 girls).The multivariate logistic regression analysis indicated a strong association of the consumption of sugar-sweetened beverages/snacks, less frequent tooth brushing by the parents, lack of fluoride varnish, family history of smoking, with the risk of developing dental caries. A child’s late bedtime is also one of the major risk factors for dental caries development. Further investigation is needed to examine whether the short duration or the irregularity of the sleep-wake cycle would affect early childhood oral health and whether there is a relationship between late bedtime and late night snack intake.

Virtual screening as a strategy for the identification of xenobiotics disrupting corticosteroid action

BACKGROUND

Impaired corticosteroid action caused by genetic and environmental influence, including exposure to hazardous xenobiotics, contributes to the development and progression of metabolic diseases, cardiovascular complications and immune disorders. Novel strategies are thus needed for identifying xenobiotics that interfere with corticosteroid homeostasis. 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2) and mineralocorticoid receptors (MR) are major regulators of corticosteroid action. 11β-HSD2 converts the active glucocorticoid cortisol to the inactive cortisone and protects MR from activation by glucocorticoids. 11β-HSD2 has also an essential role in the placenta to protect the fetus from high maternal cortisol concentrations.

METHODS AND PRINCIPAL FINDINGS

We employed a previously constructed 3D-structural library of chemicals with proven and suspected endocrine disrupting effects for virtual screening using a chemical feature-based 11β-HSD pharmacophore. We tested several in silico predicted chemicals in a 11β-HSD2 bioassay. The identified antibiotic lasalocid and the silane-coupling agent AB110873 were found to concentration-dependently inhibit 11β-HSD2. Moreover, the silane AB110873 was shown to activate MR and stimulate mitochondrial ROS generation and the production of the proinflammatory cytokine interleukin-6 (IL-6). Finally, we constructed a MR pharmacophore, which successfully identified the silane AB110873.

CONCLUSIONS

Screening of virtual chemical structure libraries can facilitate the identification of xenobiotics inhibiting 11β-HSD2 and/or activating MR. Lasalocid and AB110873 belong to new classes of 11β-HSD2 inhibitors. The silane AB110873 represents to the best of our knowledge the first industrial chemical shown to activate MR. Furthermore, the MR pharmacophore can now be used for future screening purposes.

In vitro study of the effects of fluoride-releasing dental materials on remineralization in an enamel erosion model

OBJECTIVES

This study was conducted to compare the remineralization effects of five regimens on the loss of fluorescence intensity, surface microhardness, roughness and microstructure of bovine enamel after remineralization. We hope that these results can provide some basis for the clinical application of these materials.

METHODS

One hundred bovine incisors were prepared and divided into the following five groups, which were treated with distinct dental materials: (1) Clinpro™ XT varnish (CV), (2) F-varnish (FV), (3) Tooth Mousse (TM), (4) Fuji III LC(®) light-cured glass ionomer pit and fissure sealant (FJ) and (5) Base Cement(®) glass polyalkenoate cement (BC). Subsequently, they were detected using four different methods: quantitative light-induced fluorescence, microhardness, surface 3D topography and scanning electron microscopy (SEM).

RESULTS

The loss of fluorescence intensity of CV, BC and FJ groups showed significant decreases after remineralization (p<0.05). The microhardness values of the BC group were significantly higher than those of the other groups (p<0.05) after 6 weeks of remineralization. The CV group's surface roughness was significantly lower than those of the other groups after 6 weeks of remineralization (p<0.05). Regarding microstructure values, the FV group showed many round particles deposited in the bovine enamel after remineralization. However, the other four groups mainly showed needle-like crystals.

CONCLUSIONS

Glass ionomer cement (GIC)-based dental materials can promote more remineralization of the artificial enamel lesions than can NaF-based dental materials. Resin-modified GIC materials (e.g., CV and FJ) have the potential for more controlled and sustained release of remineralized agents. The effect of TM requires further study.

Asthma and caries: a systematic review and meta-analysis

There is inconclusive evidence suggesting a possible association of asthma with increased risk of caries. The authors conducted a systematic review and meta-analysis to synthesize the evidence on the relation between asthma and caries. They performed an Ovid Medline (US National Library of Medicine) database search of literature published from 1950 through May 2010 using the Medical Subject Headings "asthma" and "caries." Summary effect estimates were calculated with fixed- and random-effects models, and determinants of heterogeneity were studied in meta-regression analysis. The meta-analysis was based on 11 articles providing estimates of the effect of asthma on primary dentition and 14 articles on permanent dentition. Summary effect estimates for the relation between asthma and caries from the random-effects models were 2.73 (95% confidence interval: 1.61, 4.64) and 2.04 (95% confidence interval: 1.44, 2.89), respectively. Factors identified as determinants of heterogeneity were geographic region for primary dentition and publication year, sample size, asthma definition, and information on the use of asthma medication for permanent dentition. Evidence from this analysis suggests that asthma doubles the risk of caries in both primary and permanent dentition. Publication bias diagnostics and simulation suggested possible overestimation of the summary odds ratio for permanent dentition but not for primary dentition. Physicians and dentists should recommend preventive measures against caries for persons with asthma.

Microhardness and SEM after CO(2) laser irradiation or fluoride treatment in human and bovine enamel

BACKGROUND

It remains uncertain as to whether or not CO(2) laser is able to hinder demineralization of enamel. The possibility to use bovine instead of human teeth on anticariogenic studies with laser has not yet been determined.

PURPOSE

To compare the ability of CO(2) laser and fluoride to inhibit caries-like lesions in human enamel and to test whether a similar pattern of response would hold for bovine enamel.

STUDY DESIGN

Ninety-six enamel slabs (2 × 2 × 4 mm) (48 from bovine and 48 from human teeth) were randomly distributed according to surface treatment (n = 12): CO(2) laser, 5% sodium fluoride varnish (FV), 1.23% acidulated phosphate fluoride (APF) gel, or no treatment (control). Specimens were subjected to a 14-day in vitro cariogenic challenge. Microhardness (SMH) was measured at 30 μm from the surface. For ultrastructural analysis, additional 20 slabs of each substrate (n = 5) received the same treatment described earlier and were analyzed by SEM.

RESULTS

ANOVA and Tukey test ascertained that CO(2) laser promoted the least mineral loss (SMH = 252(a)). Treatment with FV resulted in the second highest values (207(b)), which was followed by APF (172(c)). Untreated specimens performed the worst (154(d)). SEM showed no qualitative difference between human and bovine teeth. APF and control groups exhibited surfaces covered by the smear layer. A granulate precipitate were verified on FV group and fusion of enamel crystals were observed on lased-specimens.

CONCLUSIONS

CO(2) laser may control caries progression more efficiently than fluoride sources and bovine teeth may be a suitable substitute for human teeth in studies of this nature.

Dental providers' attitudes regarding the application of fluoride varnish by pediatric health care providers

OBJECTIVES

To ascertain what proportion of dental hygienists and dentists in Indiana, United States, support the application of fluoride varnish in medical offices, and to determine if support differed by dental provider characteristics, practice characteristics, a limited assessment of knowledge about fluoride, or use of fluoride.

METHODS

Practicing dental hygienists and dentists in 2005 were asked to fill out a mail questionnaire. Logistic regression models tested the association of independent variables with support for medical providers applying varnish.

RESULTS

Response rates were 36% (dental hygienists) and 37% (dentists); median year of graduation was 1988 and 1981. Sixty-six percent of respondents were in solo practices, 82% of dentists in general practice, 5% in dental pediatrics, and 13% were other specialists. While 51.2% of dental professionals agreed that medical practices could apply fluoride varnish, 29% responded "none" should be allowed, and 19% were undecided. In the multivariable logistic regression for support of medical practices applying fluoride versus not supporting it, three practice characteristics and two measures of fluoride use were significant. Provider characteristics and a limited assessment about knowledge about fluoride were not significant.

CONCLUSIONS

Half of dental professionals felt that it was appropriate for medical providers to apply fluoride varnish; pediatric dental professionals were less supportive. A few dental practice characteristics were associated with acceptance of the use of fluoride varnish by medical care providers: targeting messages to dental hygienists and those with practices in mixed rural-urban areas may be a useful approach to garner greater support for this medical/dental partnership.

Effect of an experimental 4% titanium tetrafluoride varnish on dental erosion by a soft drink

OBJECTIVES

This in vitro study assessed the effect of an experimental 4%TiF(4) varnish on enamel erosion.

METHODS

Sixty bovine enamel blocks were randomly allocated to each type of varnish: Duraphat-D (NaF, 2.26%F), Duofluorid-F (NaF, 2.71% F), TiF(4)-T (2.45%F) and no-fluoride-P. After application of the varnishes, the blocks were subjected to six sequential pH cycles (cola drink for 10 min and artificial saliva for 50 min, each) per day, during 4 days. After the pH cycles, the blocks were maintained in artificial saliva for 18 h. Enamel alterations were determined in the 2nd and 4th days, using profilometry (wear) and microhardness (%SMHC) tests. Data were tested using ANOVA and Tukey's tests (p<0.05).

RESULTS

The mean %SMHC (+/-S.D.) at the 2nd and 4th day was, respectively, D (-77.26+/-5.04a and -88.59+/-5.11A), F (-76.79+/-7.82a and -88.78+/-6.10A), T (-88.28+/-3.19b and -92.04+/-2.54A,B) and P (-87.96+/-2.23b and -94.15+/-1.14B). The mean wear (microm+/-S.D.) at the 2nd and 4th day was, respectively, D (3.16+/-0.32a and 7.56+/-0.90A), F (3.35+/-0.78a,b and 7.92+/-0.98A), T (3.81+/-0.43b and 7.69+/-0.76A) and P (3.43+/-1.13a,b and 7.31+/-0.53A).

CONCLUSIONS

The NaF varnishes reduced the softening, but had no effect on the reduction of the wear. The TiF4 varnish was not able to reduce the softening and wear.