Fluoride-releasing capacity and cariostatic effect provided by sealants

Effect of a bioactive pit and fissure sealant on demineralized human enamel: in vitro study

BACKGROUND

Incorporation of bioactive agent into pit and fissure sealant would halt demineralization and promote further remineralization. The aim was to assess the effect of bioactive and fluoride fissure sealants on calcium and phosphate content and surface topography of artificially demineralized enamel in young permanent teeth.

METHODS

30 sound extracted premolars free from cracks or any developmental anomalies were used. They were divided into group I bioactive fissure sealant, group II fluoride fissure sealant and group III no material applied. Each tooth was divided into halves in a buccolingual direction and evaluated by energy dispersive X-ray spectrometer (EDX) at baseline, demineralization and after applying the material. Another set of 7 sound extracted premolars was evaluated by scanning electron microscopy (SEM) at the same phases.

RESULTS

EDX showed that regaining calcium to demineralized enamel was significantly higher with bioactive sealant than either fluoride or the control group. SEM revealed minerals deposits with formation of distinct white zone at tooth/sealant interface for both pit and fissure sealant groups. Whereas no white zone formation was detected in control group.

CONCLUSIONS

Incorporating bioactive material into pit and fissure sealant through microcapsules provided better results than incorporating fluoride by enhancing the biological process of remineralization.

CLINICAL RELEVANCE

The more use of bioactive pit and fissure sealant would maintain the occlusal surfaces as sound structures and decrease the need for operative procedures to restore teeth cavitation.

Comparative Evaluation of Fluoride Release from Glass Ionomer, Compomer, and Giomer Sealants Following Exposure to Fluoride Toothpaste and Fluoride Varnish: An In Vitro Study

Introduction

Applying sealants to the deep pit and fissure area will be an excellent way to stop and slow down tooth caries from developing. Dental sealants that include fluoride are more successful at lowering dental cavities. It is anticipated that exposure to fluoride from dental sealants of various origins may enhance the fluoride release from dental sealants. Therefore, this study's objective was to investigate the amount of fluoride released after using fluoride toothpaste and fluoride varnish from different sealants.

Materials and methods

Using only a fluoride ion selective electrode, the initial release of fluoride was detected every 24 hours for 15 days. After every measurement, the saliva was refreshed. The samples were split into three identical subgroups and given the respective regimes on the 15th day-subgroup A was given fluoride toothpaste every morning and evening, subgroup B was provided fluoride varnish once, and subgroup C was not given any fluoride regime at all. After another 15 days of fluoride exposure, the fluoride release was monitored.

Results

With notable variations across groups over the initial 15 days, glass ionomer sealants (GIS) released more amount of fluoride, second by giomer sealant, and third by resin sealant (p = 0.00). All dental sealants that have been tested released more fluoride when using fluoride toothpaste, with giomer sealants surpassing GIS, followed by resin sealants (p = 0.00). Giomer and resin sealants, fluoride varnish treatment dramatically improves fluoride release in GIS (p = 0.00).

Conclusion

The release of fluoride among all dental sealants is improved by using fluoride toothpaste daily and fluoride varnish just once.

How to cite this article

Senthilkumar A, Chhabra C, Trehan M, et al. Comparative Evaluation of Fluoride Release from Glass Ionomer, Compomer, and Giomer Sealants Following Exposure to Fluoride Toothpaste and Fluoride Varnish: An In Vitro Study. Int J Clin Pediatr Dent 2022;15(6):736-738.

Effect of nano-hydroxyapatite incorporation on fluoride-releasing ability, penetration, and adaptation of a pit and fissure sealant

BACKGROUND

Dental caries is one of the most common multifactorial oral diseases and can be prevented using pit and fissure sealants.

AIM

To evaluate the effect of nano-hydroxyapatite (nanoHAP) incorporation on fluoride-releasing ability, penetration, and adaptation of a pit and fissure sealant.

DESIGN

This was an in vitro study with two groups: conventional sealant and nanoHAP-incorporated sealant. Sealant penetration and adaptation were assessed using stereomicroscope and scanning electron microscope (SEM) (15 and 10 samples per group, respectively). Fluoride release was analyzed using ion-selective electrode (15 samples per group). The chi-square test was used to compare penetration and adaptation between the 2 groups, and an independent Student t test was used to compare fluoride release.

RESULTS

The nanoHAP group showed significantly more samples with no bubbles (P = .001) and no debris (P < .001). SEM analysis showed a significantly greater percentage of adequate fissures in the test group (P = .007). The fluoride release was significantly higher in test samples with p values of .001 and .016 on day 1 and day 60, respectively.

CONCLUSION

The incorporation of nanoHAP into the conventional pit and fissure sealant improved its penetration and adaptation properties along with fluoride release.

Remineralizing Effects of Resin-Based Dental Sealants: A Systematic Review of In Vitro Studies

The incorporation of remineralizing additives into sealants has been considered as a feasible way to prevent caries by potential remineralization through ions release. Thus, this systematic review aimed to identify the remineralizing additives in resin-based sealants (RBS) and assess their performance. Search strategies were built to search four databases (PubMed, MEDLINE, Web of Science and Scopus). The last search was conducted in June 2020. The screening, data extraction and quality assessment were completed by two independent reviewers. From the 8052 screened studies, 275 full-text articles were assessed for eligibility. A total of 39 laboratory studies matched the inclusion criteria. The methodologies used to assess the remineralizing effect included microhardness tests, micro-computed tomography, polarized-light microscopy, ions analysis and pH measurements. Calcium phosphate (CaP), fluoride (F), boron nitride nanotubes (BNN), calcium silicate (CS) and hydroxyapatite (HAP) were incorporated into resin-based sealants in order to improve their remineralizing abilities. Out of the 39 studies, 32 studies focused on F as a remineralizing agent. Most of the studies confirmed the effectiveness of F and CaP on enamel remineralization. On the other hand, BNN and CS showed a small or insignificant effect on remineralization. However, most of the included studies focused on the short-term effects of these additives, as the peak of the ions release and concentration of these additives was seen during the first 24 h. Due to the lack of a standardized in vitro study protocol, a meta-analysis was not conducted. In conclusion, studies have confirmed the effectiveness of the incorporation of remineralizing agents into RBSs. However, the careful interpretation of these results is recommended due to the variations in the studies’ settings and assessments.

Evaluating fluoride uptake of dentin from different restorative materials at various time intervals - In vitro study

Background

Glass ionomer cement is very popular in clinical practice due to their antibacterial and cariostatic properties, which is totally dependant on the amount of fluoride release and uptake by dentine. The short-term and long-term fluoride uptake by dentine from commercially available restorative materials like nano-ionomer, zirconia reinforced glass ionomer cement and flowable composite is of clinical interest.

Objective

To evaluate and compare Nano-ionomer, Zirconia reinforced glass ionomer, and flowable composite resin for the fluoride uptake by dentin at different time intervals.

Results

One-way ANOVA (Tukey-Kramer Multiple Comparison Test) was applied to test the comparison of mean values of all parameters compared together. The student's paired 't' test was applied to compare groups. The fluoride uptake was evaluated at 3 days and 42 days. At 3 days dentin showed higher fluoride uptake with Zirconomer (Group Z) as compared to Ketac N100 and SDR Composite which was statistically significant. At 42 days higher fluoride uptake was seen in Ketac N100 (Group K) as compared to Zirconomer and SDR composite which was also statistically significant.

Conclusion

Fluoride uptake by dentine was seen in all study materials. Fluoride uptake by dentine at 3 days was seen maximum in Zirconomer, whereas fluoride uptake at 42 days was more in Ketac N100.

Flexural Strength, Elastic Modulus and Remineralizing Abilities of Bioactive Resin-Based Dental Sealants

Objective: To assess the remineralizing abilities and compare the flexural strength and elastic modulus of different bioactive pit and fissure sealants. Materials and Methods: Human enamel samples were randomly and blindly sealed with one of the following bioactive materials: BioCoat (Bc), ACTIVA KIDS (Av) and BeautiSealant (Bu). Seal-it (Si) was used as a non-bioactive sealant beside a control blank (B) group with no sealant. The sealed samples were subjected to a pH-cycling model (7 days of demineralization–remineralization cycles). The enamel surface hardness change (SHC), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) and polarized light microscopy were used to assess the remineralizing abilities of the studied sealants. Flexural strength and elastic modulus were also assessed following the ISO 4049 protocols. One-way analysis of variance (ANOVA) was used to analyze the results. Results: Bc sealant showed the highest FS and EM (p < 0.05). The contact with Bc and Bu sealants showed significantly lower %SHL (p < 0.05) in comparison to the other. These findings were supported by the results of SEM-EDX and polarized imaging by showing higher percentages of calcium and phosphate ions with the former sealants and thinner demineralized enamel bands. Conclusion: In this study, Bc showed the highest flexural strength. Bc and Bu sealants outperformed the other studied sealants in terms of their remineralization abilities.

Anti-bacterial and anti-microbial aging effects of resin-based sealant modified by quaternary ammonium monomers

OBJECTIVES

Pit and fissure sealant is used in the prevention of dental caries. However, commercial pit and fissure sealant lacks persistent antibacterial properties. Dimethylaminododecyl methacrylate (DMADDM) was added to pit and fissure sealants to give it sustainable antibacterial properties and anti-microbial aging properties.

METHODS

Resin-based sealant was used as a control. Novel sealants were made with DMADDM. Atomic force microscope observation, curing depth, cytotoxicity, lactic acid measurement, hardness and microleakage were measured. Saliva-derived biofilms were grown on sealants. Biofilm metabolic activity, lactic acid production and biomass accumulation were measured.

RESULTS

Incorporating DMADDM did not increase the cytotoxicity or change the physical properties when the mass fraction of the DMADDM was 2.5-10%. The modification decreased the amount of bacterial biofilm, metabolic activity, lactic acid production and exopolysaccharide (EPS) in the saliva biofilms. It also provided anti-microbial aging properties.

CONCLUSION

The incorporation of DMADDM improved the antibacterial and anti-microbial aging effects of the material. It demonstrated a sustained antibacterial effect. The antibacterial and anti-microbial aging modification might be a potential choice for future clinical applications to inhibit dental caries, especially for children at high caries risk.

CLINICAL SIGNIFICANCE

The antibacterial and anti-microbial aging modification might be a potential choice for future clinical applications to prevent dental caries, especially for individuals at high caries risk.

Comparison of resin-based and glass ionomer sealants with regard to fluoride-release and anti-demineralization efficacy on adjacent unsealed enamel

This study compared resin-based and glass ionomer sealants with regard to their fluoride-release behavior and anti-demineralization potential on adjacent unsealed enamel surfaces. Sealant cavities prepared on bovine enamel blocks were filled with fluoride-containing resin sealants [TeethmateF-1 (TF), Clinpro^TM (CP)], and glass ionomer sealant [Fuji VII (FVII)]. Specimens were then incubated in artificial saliva for 14 days to measure fluoride. Thereafter, demineralization was performed for 10 days, and the anti-demineralization efficacy was assessed by Swept Source Optical Coherence Tomography (SS-OCT), and cross-sectional nanohardness. All data were statistically analyzed by using ANOVA. FVII exhibited the highest fluoride release. SS-OCT and nanohardness findings indicated that anti-demineralization efficacy of TF was the greatest, whereas FVII was not significantly different from that of CP. Resin sealants released a lower amount of fluoride but exhibited anti-demineralization effects on the adjacent unsealed enamel surfaces that were comparable to that of a glass ionomer sealant.

Assessment of the inhibitory effects of fissure sealants on the demineralization of primary teeth using an automatic pH-cycling system

In this study, we examined the effects of fissure sealants on inhibition of demineralization of primary teeth using an automatic pHcycling system. Three fissure sealants were used: Teethmate F-1 2.0 (TM), BeautiSealant (BS), and Fuji III LC (IIILC). Using an automatic pH-cycling system, the specimens (n=12) were repeatedly demineralized and remineralized. Specimens were subjected to transverse microradiography (TMR), and changes in integrated mineral loss (IML) and lesion depth (Ld), indicated as ΔIML and ΔLd, respectively, were calculated. In addition, fluoride levels in the enamel were assessed using microparticle-induced gamma-ray emission/particle-induced X-ray emission (n=3). IIILC showed the lowest values for ΔIML and ΔLd, followed by BS and then TM. The highest amount of fluorine in the enamel was observed for IIILC, followed by TM and BS. All fissure sealants inhibited demineralization in primary teeth.

Comparative Evaluation of Longevity of Fluoride Release From three Different Fluoride Varnishes - An Invitro Study

INTRODUCTION

Fluoride varnishes play a pivotal role in inhibition of dental caries by increasing remineralization.

AIM

To determine the longevity of fluoride release from 3 different fluoride varnishes over a period of time through salivary fluoride estimation.

MATERIALS AND METHODS

Twenty four extracted human deciduous anterior teeth were divided into four groups, i.e., ClinproTM XT, Flouritop SR, Flourprotector and Control group. Fluoride varnishes were applied on 3mm x 3mm window on labial surface of the teeth and then the teeth were immersed and stored in artificial saliva. The concentration of fluoride in ppm was measured after 1 week, 1 month, 3 months and 6 months. Fluoride release at each time interval for different groups was statistically analyzed using ANOVA and Post Hoc Tukey's test.

RESULTS

Although all the fluoride varnishes released fluoride, with greatest release observed during 1(st) week by Fluoritop SR (66.92±16.30ppm), ClinproTM XT Varnish released consistently and substantially more fluoride than Fluoritop SR and Fluorprotector during 6 months analysis (p<0.05). Fluorprotector showed the lowest rate of F release among all the groups compared.

CONCLUSION

Over a period of 6 months ClinproTM XT Varnish released consistently and substantially more fluoride than other tested products.

Fissure sealants: Knowledge and practice of Yemeni dental practitioners

OBJECTIVES

This study was conducted to evaluate Yemeni dental practitioners' knowledge and practices concerning fissure sealants.

MATERIALS AND METHODS

A modified questionnaire consisted of 25-items was distributed to 500 dentists working in Sana'a City. Descriptive statistics and Chi-square/Fisher's exact tests were used for statistical analyses.

RESULTS

The response rate was 74%. Most of the respondents were male (61.3%), general practitioners (84.2%), and had <5 years of clinical experience (48.3%). The respondents showed a reasonable level of knowledge about sealants, with the majority (88%) believed that there is strong scientific evidence about fissure sealants effectiveness and around 90% showed a good understanding of sealant placement instructions. On the other hand, respondents showed insufficient knowledge about sealants clinical practice.

CONCLUSION

Although a high proportion of dental practitioners showed adequate knowledge about dental sealant, following guidelines and standardized procedures in clinical practice is lacking. These emphasize the need for regular continuing education courses for dental professional.

Effect of Fluoridated Sealants on Adjacent Tooth Surfaces: A 30-mo Randomized Clinical Trial

A double-blind randomized clinical trial was performed in 6- to 7-yr-old schoolchildren to evaluate, in a 30-mo period, whether the caries increment on the distal surface of the second primary molars adjacent to permanent first molars sealed with fluoride release compounds would be lower with respect to those adjacent to permanent first molars sealed with a nonfluoridated sealant. In sum, 2,776 subjects were enrolled and randomly divided into 3 groups receiving sealants on sound first molars: high-viscosity glass ionomer cement (GIC group); resin-based sealant with fluoride (fluoride-RB group); and a resin-based sealant without fluoride (RB group). Caries (D1 - D3 level) was recorded on the distal surface of the second primary molar, considered the unit of analysis including only sound surfaces at the baseline. At baseline, no differences in caries prevalence were recorded in the 3 groups regarding the considered surfaces. At follow-up, the prevalence of an affected unit of analysis was statistically lower (p = .03) in the GIC and fluoride-RB groups (p = .04). In the GIC group, fewer new caries were observed in the unit of analysis respect to the other 2 groups. Incidence rate ratios (IRRs) were 0.70 (95% confidence interval: 0.50, 0.86; p < .01) for GIC vs. RB and 0.79 (95% confidence interval: 0.67, 0.89; p = .005) for fluoride-RB vs. RB [Corrected]. Caries incidence was significantly associated with low socioeconomic status (IRR = 1.18; 95% confidence interval: 1.10, 1.42; p = .05). Dental sealant high-viscosity GIC and fluoride-RB demonstrated protection against dental caries, and there was evidence that these materials afforded additional protection for the tooth nearest to the sealed tooth (clinical trial registration NCT01588210).

In situ evaluation of the remineralizing capacity of pit and fissure sealants containing amorphous calcium phosphate and/or fluoride

OBJECTIVE

This in situ study evaluated the remineralizing potential of pit and fissure sealants containing amorphous calcium phosphate (ACP) and/or fluoride in artificially induced carious lesions on smooth enamel surfaces.

MATERIAL AND METHODS

Ten volunteers who wore acrylic palatal devices were enrolled in this 5-day double-blind study and assigned to one of the following five groups: (I) demineralized enamel slab+Fluroshield (sealant with fluoride); (II) demineralized enamel slab+Aegis (sealant with ACP); (III) demineralized enamel slab+experimental sealant with fluoride (ESF); (IV) demineralized enamel slab+experimental sealant with fluoride/ACP (ACP-F); and (V) demineralized enamel slab (control). After the experimental period, the percentage of surface microhardness recovery (%SMHR) and the integrated loss of subsurface hardness (DeltaKHN) were evaluated. The concentrations of fluoride, calcium and phosphorus in enamel were also determined.

RESULTS

The sealants containing ACP and/or fluoride presented a higher remineralizing capacity (%SMHR and DeltaKHN) than that of the control group. Aegis provided either more efficient or similar remineralization than the other sealants. The association between ACP and fluoride did not show a greater efficacy in the remineralization. F, Ca and P concentrations in enamel varied according to the group.

CONCLUSION

The pit and fissure sealants containing ACP were able to promote remineralization of artificially induced carious lesions on smooth enamel surfaces.

Influence of environmental conditions on properties of ionomeric and resin sealant materials

Objectives:

The aim of this study was to determine the effect of environmental conditions on the degradation of ionomeric and resin sealant materials.

Material and Methods:

FluroShield, Vitremer, and Ketac Molar disc-shaped specimens (n=18/material) were prepared, polished, subjected to initial hardness and roughness readings. Six discs of each material were randomly assigned to one of three different storage solutions: 0.3% citric acid (CA), demineralization solution (DE), and remineralization solution (RE). The specimens were individually immersed in 3 mL of the test solutions, which were daily changed. After 15 days of storage, new surface roughness and hardness readings were done. Fluoride release in the solutions was measured within 15 days. Data were analyzed by ANOVA and Tukey's and Contrast tests (α=0.05).

Results:

The storage in CA increased the roughness of Vitremer and Ketac Molar. A significant reduction in hardness was observed for all materials after storage in all solutions. For all materials, the greatest amounts of fluoride release occurred during the 1^st day. FluroShield presented the same patterns of fluoride release in all solutions. Ketac Molar and Vitremer released the highest amounts of fluoride in the CA solution.

Conclusions:

Ionomeric materials are more susceptible to degradation than resin-based materials under acidic conditions. Acidic conditions lead to a higher fluoride release from ionomeric materials.

PH-cycling model to verify the efficacy of fluoride-releasing materials in enamel demineralization

The current study proposes a pH-cycling model to verify the dose-response relationship of fluoride-releasing materials in their ability to reduce in vitro demineralization. Sixty bovine enamel blocks (4 x 3 x 3 mm) were selected, using baseline surface microhardness (SMH1) evaluations at different distances from the enamel sectioned border (150, 300, 450 and 600 microm). Specimens (n=48) were prepared with Z100, Fluroshield and Vitremer at the standard powder/liquid ratio and at a 1/4 diluted-powder/liquid ratio. The 12 remaining specimens were used as a control group. The specimens were submitted to a pH-cycling model with high cariogenic challenge. After pH-cycling, final surface microhardness (SMH2) was assessed to calculate the percentage change of surface microhardness (%SMHc). Next, the fluoride present in enamel (microg F/mm3) and in pH-cycling solutions (microg F) was measured. Cross-sectional microhardness was done to calculate the mineral content (deltaZ). Data from %SMHc, deltaZ and microg F were analyzed by analysis of variance (p < 0.05), while microg F/mm3 analysis was done using the Kruskal-Wallis test. The results showed a correlation between %SMHc and microg F/mm3 (r3 = 0.4129; p < 0.0001), %SMHc and microg F (r2 = 0.4932; p < 0.0001), deltaZ and microg F/mm3 (r3 = 0.4573; p < 0.0001), micorg F/mm3 and microg F (r2 = 0.3029; p < 0.0001) and between deltaZ and microg F (r2 = 0.5276; p < 0.0001). The pH-cycling model allowed the in vitro verification of the dose-response relationship of fluoride-releasing materials in the demineralization of enamel.

Inhibition of mineral loss at the enamel/sealant interface of fissures sealed with fluoride- and non-fluoride containing dental materials in vitro

OBJECTIVE

In this in vitro study we evaluated the enamel mineral loss effect of fluoride-containing and non-fluoride-containing materials at different distances from the sealant margin, and verified the fluoride-releasing capability of these materials.

MATERIAL AND METHODS

Extracted molars were randomly assigned into nine groups (n = 12): Concise (C), FluroShield (F), Helioseal Clear Chroma (H), Vitremer (V), Fuji II-LC (FII), Ketac Molar (KM), Fuji IX (FIX), Single Bond (SB), and Clearfil Protect Bond (CF). All groups were subjected to thermo and pH cycling. Enamel mineral loss was evaluated by cross-section micro-hardness analysis at distances: -100 microm, 0 microm, 100 microm, 200 microm. The mineral loss data were analyzed using a multi-factor ANOVA with split-plot design, and fluoride-released data were submitted to ANOVA and Tukey tests.

RESULTS

FIX demonstrated a lower mineral loss than C, F, and H, but did not differ from the SB, CF, V, FII, and KM groups, which also demonstrated no difference among them. C, F, H, and V presented the highest mineral loss, with no difference among them. V did not differ from the other groups (p > 0.05). Regarding the different distances from the sealant margin, -100 microm presented the lowest mineral loss. FIX showed the highest fluoride release on the 7th and 14th days of evaluation, while CF showed high fluoride release only on the 7th day.

CONCLUSION

Resin sealant did not prevent enamel mineral loss, contrary to glass-ionomer cement, which showed the highest capacity for fluoride release. It is not exclusively the presence of fluoride in a material's composition that indicates its capability to interfere with the development of enamel caries-like lesions.