Mechanical Properties and Ion Release from Fibre-Reinforced Glass Ionomer Cement.

The aim of this study was to compare the mechanical properties and ion release from a commercially available resin-modified glass ionomer cement to a formulation reinforced by the addition of short glass fibres at various percentages. Methods: Three experimental groups were prepared by adding a mass ratio of 10%, 15% and 20% of short glass fibres to the powder portion of the cement from a capsule (GC Fuji II LC), while the control group contained no fibres. Microhardness (n = 12), fracture toughness, and flexural, compressive and diametral tensile strength (n = 8) were evaluated. To study ion release, readings were obtained utilising fluoro-selective and calcium-selective electrodes after 24 h, 7 days and 30 days (n = 12). The spatial distribution of fibres within the material was evaluated through scanning electron microscopy. The data were analysed using one-way ANOVA with a Bonferroni adjustment. Results: The findings suggest that elevating fibre weight ratios to 20 wt% results in improved mechanical properties (p < 0.05) in microhardness, flexural strength, diametral tensile strength and fracture toughness. In terms of ion release, a statistically significant difference (p < 0.001) was observed between the groups at the conclusion of 24 h and 7 days, when the fluoride release was much higher in the control group. However, after 30 days, no significant distinction among the groups was identified (p > 0.05). Regarding calcium release, no statistically significant differences were observed among the groups at any of the evaluated time points (p > 0.05). SEM showed the fibres were homogeneously incorporated into the cement in all experimental groups. Conclusions: Resin-modified glass ionomer enhanced with short glass fibres at a weight loading of 20% showcased the most favourable mechanical properties while concurrently maintaining the ability to release fluoride and calcium after a 30-day period.

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.

Photodegradation kinetics and halogens release of the emerging concern pollutants dexamethasone and S-metolachlor on TiO2/rGO composites.

This work studies the photocatalytic degradation of solutions containing 0.11 mM of a glucocorticoid (dexamethasone, DEX) and 0.11 mM of an herbicide (S-metolachlor, MTLC), organohalogenated compounds containing fluorine and chlorine atoms in their molecules, respectively. To treat 1 L volume, a mass of 0.5 g of TiO2/rGO composite in suspension has been used as photocatalyst, irradiated with UV-A LEDs with 200 W m-2 of irradiance. MTLC is partially adsorbed on the surface of the catalyst, while DEX is not adsorbed, showing different degradation kinetics. The halogen ions released into the solution from the breakage of the parent molecules, F- and Cl- respectively, were analysed. In the case of MTLC, the released Cl- followed two different kinetic trends, being faster, and with a rate that matched the rate of MTLC disappearance, the part corresponding to non-adsorbed MTLC. In the experiments with DEX solutions a different behaviour was observed; the released F- in the photocatalytic degradation was partially adsorbed on the catalyst surface, but the adsorption capacity decreased with the use of the photocatalyst in consecutive cycles until the solubilised F- matched the degraded concentration of DEX. Furthermore, the mass balance between the degraded contaminant and the solubilised halogen anion, for both contaminants, allowed to conclude the absence of halogenated intermediates under the final operating conditions, that is a remarkable outcome in water remediation processes.

Review on fluoride varnishes currently recommended in dental prophylaxis.

In dentistry, fluoride compounds play a very important role in the development of teeth hard tissue. They have been modifying the development of the carious process for many years in accordance with the principles of minimally invasive therapy. Studies have confirmed their effectiveness in the prevention and treatment of carious lesions and erosion of deciduous and permanent teeth, as well as in the dentin hypersensitivity treatment. Typically, each varnish consists of 3 basic components, i.e., a resin usually in the form of mastic, shellac and/or rosin, an alcohol-based organic solvent (usually ethanol) and active agents. In the first-generation varnishes, the active agent is fluorine compounds, most often in the form of 5% NaF, while in second-generation varnishes, the composition is further enriched with calcium and phosphorus compounds in the form of CPP-ACP/CPP-ACPF, ACP, TCP, fTCP, CSPS, TMP, CXP, or CaGP. This influences the bioavailability of fluoride in the oral environment by increasing both its release from the product and its subsequent accumulation in enamel and plaque, promotes more efficient closure of dentinal tubules, and facilitates pH buffering in the oral cavity.

Fluoridated orthodontic adhesives: Implications of release and recharge and their impact on shear bond strength in demineralized tooth surfaces.

Background: This study measured fluoride release from a light-cured orthodontic adhesive resin (Vega type) at three time intervals (one day, one week, and one month), investigated the rechargeability of the resin, and assessed its impact on shear bond strength in demineralized tooth surfaces. Methods: This study used 30 recently extracted upper premolar teeth to explore the effects of fluoride release over specific time intervals. The teeth underwent demineralization and were categorized into groups based on time intervals: one day, one week, and one month. Subgroups within each interval underwent fluoride recharging through fluoride varnish application. Fluoride release and shear bond strength were assessed after etching with phosphoric acid gel, applying the orthodontic adhesive, and curing. The samples were stored in deionized water. Fluoride quantification used a selective electrode, while shear bond strength assessment employed a universal testing machine. Finally, statistical analysis of the data was performed using SPSS 22. Results: The study found that after one month, the adhesive had the highest fluoride release and shear bond strength mean values. There were significant differences in fluoride release and shear bond strength between the various groups studied. Conclusion: The application of fluoride varnish around the orthodontic bracket resulted in a positive effect on the shear bond strength of the bracket.

Comparative Evaluation of Fluoride Release and Compressive Strength of Biodentine Modified Using Sodium Fluorosilicate and Hydrofluoric Acid: An In-Vitro Study.

Introduction Calcium trisilicate derivatives have widely been used as dentin and enamel substitutes recently. These cements have excellent biological properties, but they do not show fluoride release. The release of fluoride from dental materials is a very important property of a material in restorative applications as fluoride confers antibacterial and anti-cariogenic properties. This study thus attempts to incorporate fluoride in the form of sodium fluorosilicate and hydrofluoric acid into Biodentine to assess its fluoride-releasing properties. Methods Biodentine was modified by adding 7% sodium fluorosilicate in the powder and 10% hydrofluoric acid to the liquid. Fluoride release was measured using a sodium 2-(parasulfophenylazo)-1,8-dihydroxy-3,6-naphthalenedisulfonate (SPADNS) spectrophotometer after 1, 3, 7, 14, 21, and 28 days. The compressive strength of the modified material was measured using a universal testing machine. Results Fluoride release was found to be higher in the group that had both powder and liquid modified than in groups in which either of the components were modified. The difference was found to be statistically significant (p<0.001). Conclusion Incorporation of fluoride in Biodentine is feasible with acceptable release of fluoride without adversely affecting the compressive strength of the Biodentine.

Fluoride Release and Rechargeability of Poly(lactic acid) Composites with Glass Ionomer Cement.

This study investigates the fluoride release, rechargeability and degradation behaviors of newly developed anticariogenic poly(lactic acid) (PLA) composites. The PLA composite with various concentrations (0%, 5%, 10%, 15% and 20% by weight) of glass ionomer cement (GIC) and sodium fluoride (NaF) were prepared using solvent casting method. The fluoride release, fluoride rechargeability and degradation behavior were evaluated. All experimental groups demonstrated fluoride-releasing ability. The highest level of fluoride ions released was found in PLA composite with sodium fluoride (PLA/NaF). Following the 28-day period, both groups showed a gradual reduction in fluoride ion released, ranging between 0.03 ± 0.01 and 0.53 ± 0.06 ppm, although remaining within the effective range for tooth remineralization. However, the rechargeability was only observed in PLA composite with GIC (PLA/GIC). Following an eight-week in vitro degradation test, all PLA/NaF groups displayed a significantly higher percentage of weight change and water absorption compared to the PLA/GIC and the control group. In SEM analysis, the formation of surface porosities was clearly noticed in all PLA/NaF. All specimens retained their structural integrity throughout the study. In conclusion, the newly developed PLA/GIC displays promising possibilities as an anticariogenic material. Furthermore, the rechargeability of these ions are repeatable, ensuring their long-term utility.

Comparative Evaluation of Fluoride Release from Four Commercially Available Pediatric Dental Restorative Materials.

Objectives: The aim of this study was to evaluate the fluoride-releasing abilities of commercially available restorative materials such as-Activa™ BioActive-restorative™ material, Zirconomer (Shofu Inc), Beautifil® II (Shofu Inc), GC Gold Label 9 high strength posterior restorative glass ionomer cement (GIC Corp). Materials and methods: A total of 40 disk specimens (10 of each material) were placed into distilled/deionized (DI) water and the fluoride release was measured for 30 days. Fluoride ion measurement was performed at the end of the 1st, 3rd, 7th, 15th, and 30th day under normal atmospheric conditions by fluoride ion selective electrode (F-ISE) (Orion 9609 BNWP, Ionplus SureFlow fluoride electrode, Thermo Scientific, United States of America) coupled to a benchtop analyzer (Hachsen Ion+). Results: All the materials included in the study exhibited fluoride release. Although there were differences in the amounts of fluoride released between Activa™, Zirconomer, and GC Gold Label 9 the mean difference between these three groups was not found to be statistically significant. Beautifil® II showed low amounts of fluoride released at all time intervals. Conclusion: Among the above-compared materials Activa™ and Zirconomer exhibit both improved mechanical properties as well as they have fluoride-releasing ability so can be preferred over conventional glass ionomer restorations. How to cite this article: Dhumal RS, Chauhan RS, Patil V, et al. Comparative Evaluation of Fluoride Release from Four Commercially Available Pediatric Dental Restorative Materials. Int J Clin Pediatr Dent 2023;16(S-1):S6-S12.

Pruned litter decomposition primes fluorine bioavailability in soils planted with different tea varieties.

Tea (Camellia sinensis L.) plant is fluoride (F) hyperaccumulator. The decomposition of pruned litter in tea plantations releases a large amount of F back into the soil. However, the effect of pruned litter return on soil F bioavailability has remained unclear. We investigated the decomposition dynamics of pruned litter from four tea varieties (Chuannong Huangyazao, Chuancha No. 3, Chuanmu No. 217 and C. sinensis 'Fuding Dabaicha') and its effect on soil F bioavailability. The decomposition of pruned litter occurred in two distinct periods, with an early period of rapid decomposition during the first 120 days, releasing 26-33 % of F, followed by a late period of slow decomposition during 120-360 days, releasing 2-9 % of F. The decomposition of pruned litter enhanced soil F bioavailability by increasing the concentrations of soil water-soluble F (WS-F), exchangeable F (EX-F), and organic matter-bound F (OR-F). The increase in WS-F, EX-F, and OR-F concentrations was higher than the amount of F released from pruned litter, suggesting that the increases in soil F availability did not solely originate from the release of F from pruned litter. The findings reveal the pathway of pruned litter decomposition priming soil F bioavailability through both the direct release of F and transformation from other fractions. Furthermore, the traits (C, N, lignin, and cellulose) of pruned litter from different tea varieties were the dominant factors controlling F release and soil F bioavailability. Compared with other tea varieties, the pruned litter of Chuanmu No. 217 with low lignin and cellulose content promoted higher mass loss and F release, resulting in the highest soil F bioavailability. These findings provide new insights into the mechanisms underlying the accumulation of bioavailable F in soil. These insights offer valuable support for devising effective management strategies for the incorporation of pruned litter into soil.

Shear Bond Strength and Fluoride Release of a Universal Adhesive: An In-Vitro Study on Primary Teeth.

This investigation aimed to assess the shear bond strength and fluoride-releasing capabilities of Clearfil Universal Bond Quick (Kuraray Noritake Dental Inc., Tokyo, Japan). Forty-four extracted primary molars were divided into two groups, and the enamel substrate was prepared for evaluating shear bond strength. Scotchbond (3M ESPE) and Clearfil UBQ were used to bond composite-to-enamel substrates in each group (n = 22). Shear bond strength was measured using a universal testing device and compared. Sixteen discs (6 mm diameter and 3 mm thickness) were fabricated from each Clearfil UBQ, Fuji IX, and Fuji II LC. Over the course of 30 days, each materials' fluoride release was examined and compared using ion analysis. Results revealed that Clearfil UBQ had statistically similar shear bond strength to Scotchbond. Between the three materials, Clearfil UBQ had the lowest fluoride release at baseline (0.11 ± 0.25) and the lowest cumulative fluoride release (0.12-0.27 ppm) over 30 days. Fuji IX had the highest fluoride release at baseline (19.38 ± 2.50) and cumulatively (40.87 ± 4.03 ppm), followed by Fuji II LC. We conclude that Clearfil UBQ and Scotchbond showed comparable bond strengths to the enamel. Fluoride release was seen in Clearfil UBQ in the initial two days of the 30-day period. The amount of fluoride release was significantly less than with glass ionomer cements.

Nanofluorapatite Hydrogels in the Treatment of Dentin Hypersensitivity: A Study of Physiochemical Properties and Fluoride Release.

The aim of this work was to prepare a new hydrogel based on nanohydroxyapatite (nFAP, 10% w/w) and fluorides (4% w/w), both of which are used as sources of fluoride ions in the treatment of dentin hypersensitivity, and to characterize its physicochemical properties. The release of fluoride ions from 3 gels (G-F, G-F-nFAP, and G-nFAP gel) was controlled in Fusayama-Meyer artificial saliva at pH 4.5, 6.6, and 8.0. The properties of the formulations were determined by an analysis of viscosity, a shear rate test, a swelling study, and gel aging. Various methods, i.e., FT-IR spectroscopy, UV-VIS spectroscopy, and thermogravimetric, electrochemical, and rheological analysis, were used for the experiment. The profiles of fluoride release indicate that the amount of fluoride ions released increases with a decrease in the pH value. The low pH value facilitated water absorption by the hydrogel, which was also confirmed by the swelling test, and it promoted the exchange of ions with the surrounding environment. Under conditions similar to physiological conditions (at pH 6.6), the amounts of fluorides released into artificial saliva were approximately 250 µg/cm2 and 300 µg/cm2 for the G-F-nFAP hydrogel and G-F hydrogel, respectively. The aging study and properties of the gels showed a loosening of the gel network structure. The Casson rheological model was used to assess the rheological properties of the non-Newtonian fluids. Hydrogels consisting of nanohydroxyapatite and sodium fluoride are promising biomaterials in the prevention and management of the dentin hypersensitivity.

Evaluation of Mechanical Properties of Glass Ionomer Cements Reinforced with Synthesized Diopside Produced via Sol-Gel Method.

This study aimed to fabricate a glass ionomer cement/diopside (GIC/DIO) nanocomposite to improve its mechanical properties for biomaterials applications. For this purpose, diopside was synthesized using a sol-gel method. Then, for preparing the nanocomposite, 2, 4, and 6 wt% diopside were added to a glass ionomer cement (GIC). Subsequently, X-ray diffraction (XRD), differential thermal analysis (DTA), scanning electron microscopy (SEM), and Fourier transform infrared spectrophotometry (FTIR) analyses were used to characterize the synthesized diopside. Furthermore, the compressive strength, microhardness, and fracture toughness of the fabricated nanocomposite were evaluated, and a fluoride-releasing test in artificial saliva was also applied. The highest concurrent enhancements of compressive strength (1155.7 MPa), microhardness (148 HV), and fracture toughness (5.189 MPa·m1/2) were observed for the glass ionomer cement (GIC) with 4 wt% diopside nanocomposite. In addition, the results of the fluoride-releasing test showed that the amount of released fluoride from the prepared nanocomposite was slightly lower than the glass ionomer cement (GIC). Overall, the improvement in mechanical properties and optimal fluoride release of prepared nanocomposites can introduce suitable options for dental restorations under load and orthopedic implants.

Modification of glass-ionomer cement properties by quaternized chitosan-coated nanoparticles.

Glass ionomers (GICs), because of their qualities, are in a good position to be modified to resist masticatory stresses as permanent posterior restoration and prevent recurrent caries. The purpose of the present study was to evaluate the effect of adding quaternized chitosan-coated mesoporous silica nanoparticles (HTCC@MSNs) to conventional GIC on its mechanical properties, antimicrobial activity and fluoride release and the effect of 1- and 3-month water aging on the studied properties. HTCC@MSNs was synthesized, added to commercially available conventional GIC at 1%, 3%, and 5% by weight forming three experimental groups and compared with plain GIC as a control group. Flexural strength, modulus, Vickers microhardness and wear volumes were evaluated. Antibacterial activity was tested against Streptococcus mutans and fluoride release in de-ionized water was measured. All properties were evaluated before and after one- and three-month aging (n = 10 specimens per test/per time). Two-way ANOVA was used for statistical analysis. Characterization confirmed successful preparation of HTCC@MSNs. The flexural strength, modulus, hardness and wear resistance of the GICs improved significantly by adding 1-3% HTCC@MSNs, while 5% HTCC@MSNs group showed no significant difference compared to control group. Bacterial inhibition zones and fluoride release increased proportionally to the amount of filler added. Mechanical properties were improved by artificial aging. Fluoride release values, and bacterial inhibition zones decreased with aging for all groups. HTCC@MSNs as a filler with the optimized proportion provides strengthening and antibacterial effect. In addition, aging is an important factor to be considered in evaluating experimental fillers.

Effects of Protective Surface Coating on Fluoride Release and Recharge of Recent Uncoated High-Viscosity Glass Ionomer Cement.

The ability to release and recharge fluoride is a property of glass ionomer cement materials, which is an advantage for patients with a high caries risk. The purpose of this study was to evaluate the amount of released and recharged fluoride in recent uncoated high-viscosity glass ionomer cement (KetacTM Universal AplicapTM) with different surface coatings and at different time points. In total, 135 cylindrical-shaped specimens were equally divided into the following three groups: KetacTM Universal AplicapTM, KetacTM Molar AplicapTM, and KetacTM Fil Plus AplicapTM. The different coatings performed on each group were as follows: uncoated, coated with KetacTM Glaze, and coated with G-Coat PlusTM. The amounts of released and recharged fluoride were measured at 24 h and at weeks 1, 2, 3, and 4. The recharging agent was a 1.23% APF gel. KetacTM Universal AplicapTM showed the highest released fluoride at all time points and the highest recharged fluoride at weeks 1, 2, and 3. Both the KetacTM Glaze- and G-Coat PlusTM-coated specimens presented significantly lower released and recharged fluoride ions than the uncoated group at all time points (p < 0.001). Coating with G-Coat PlusTM significantly decreased the released and recharged fluoride compared to the coating with KetacTM Glaze at almost all time points (p < 0.05), except for weeks 1 and 2. The application of coating agents reduced the amount of released and recharged fluoride by the KetacTM Universal AplicapTM.

Biocompatible carboxymethyl chitosan-modified glass ionomer cement with enhanced mechanical and anti-bacterial properties.

Due to the potential adverse effects of conventional dental cements, the demand for biocompatible cements have grown tremendously in the field of dentistry. In this respect, Glass ionomer cements (GICs) are being developed by different researchers. However, low mechanical strength of GIC make them unsuitable for application in high-stress areas. Thus, numerous initiatives to improve mechanical performance have been attempted till date including incorporation of reinforcing fillers. Novelty of the study lies in using carboxymethyl chitosan (CMC) to develop a biocompatible dental cement (DC/CMC-m-GP), which would have enhanced mechanical strength due to greater interaction of CMC with the particles of GIC and better cyto-compatibility due to its cell-proliferation activity. The mechanical strength, acid erosion and fluoride release of DC/CMC-m-GP were studied and compared with control dental cement (DC/Control). DC/CMC-m-GP shows compressive strength of 157.45 M Pa and flexural strength of 18.76 M Pa which was higher as compared to DC/Control. The morphology of the GICs were studied through FESEM. Anti-microbial activity of DC/CMC-m-GP was studied by Agar disc-diffusion method and biofilm assay against S. mutans, which shows that DC/CMC-m-GP inhibits bacterial adhesion on its surface. MTT assay infers that DC/CMC-m-GP was non-cytotoxic and did not affect the cell viability significantly.

Five-year clinical performance of two fluoride-releasing giomer resin materials in occlusal restorations.

OBJECTIVE: To evaluate and compare the clinical performance of two nano-hybrid giomer restorative composite materials after 5 years. MATERIALS AND METHODS: Forty-four pairs of restorations (total n = 88) of a flowable giomer (Beautifil Flow Plus F00; Shofu Inc., Kyoto, Japan) and a conventional nano-hybrid giomer restorative material (Beautifil II; Shofu Inc.) were placed in Class I cavities after the application of a dentin adhesive (FL-Bond II; Shofu Inc.) and a flowable liner (Beautifil Flow Plus F03; Shofu Inc). After 5 years, 32 pairs of restorations were assessed using the modified United States Public Health Service criteria. Both tested materials were compared using Fisher's exact test and each tested clinical criterion for each material was analyzed separately with respect to different follow-up periods using Friedman's test (a = 0.05). RESULTS: None of the restorations showed complete retention loss, post-operative sensitivity, secondary caries or color change. There were no significant changes to any of the clinical criteria for each material during the 5-year evaluation period (p > 0.05) and no significant differences between the two materials in all clinical parameters after 5 years (p > 0.05). CONCLUSIONS: Five-year clinical performance of both two nano-hybrid giomer restorative materials was comparably acceptable and not significantly different for any of the parameters evaluated. CLINICAL SIGNIFICANCE: Nano-hybrid giomer-based materials are clinically acceptable for the restoration of occlusal cavities as they demonstrate excellent performance after 5 years.

The fluoride release, abrasion resistance, and cytotoxicity to hGFs of a novel cyanoacrylate-based fluoride varnish compared with conventional fluoride varnish.

The important factors contributing to the effectiveness of fluoride varnish are the amount of fluoride ion release and the retention time of the varnish on the tooth surface. Commercial fluoride varnishes are susceptible to mechanical removal; therefore, patients are informed to avoid eating or performing oral hygiene for at least 12-24 h, which results in patient inconvenience. However, cyanoacrylate-based fluoride varnish would not have these disadvantages. This study compared the daily fluoride ion release, abrasion resistance to brushing, and toxicity to human gingival fibroblasts (hGFs) between a newly-developed cyanoacrylate-based fluoride varnish and conventional fluoride varnish (Duraphat varnish). The results demonstrated that the cyanoacrylate varnish had a significantly higher fluoride release for 9 days after application, higher abrasion resistance to brushing, and slightly less toxicity to hGFs compared with Duraphat varnish. This novel cyanoacrylate varnish could be an alternative fluoride varnish for preventing dental caries.

Evaluation of Fluoride Release in Chitosan-Modified Glass Ionomer Cements.

OBJECTIVE: This study assessed the influence of chitosan nanoparticles on the fluoride-releasing ability of 4 glass ionomer cement (GIC) through an in vitro analysis. METHODS: Four types of GIC (type II light cure universal restorative, type II universal restorative, GC Fuji VII, and type IX) were modified with nanochitosan particles; 10% chitosan was added to the glass ionomer liquid. Six specimens for each of the 4 groups were created, using expendable Teflon moulds. Discs of each type of GIC (n = 6) were immersed in deionised water at various time intervals. Electrodes selective for fluoride ions were employed to analyse the amount of released fluoride at 1, 7, 14, 21, and 28 days. RESULTS: Chitosan-modified GICs showed greater fluoride release than conventional GICs at all time points. All samples showed an initial high release of fluoride that tapered off with time. The total amount of fluoride released increased from the 1st day to the 28th day on adding chitosan to all the 4 types of GIC. Amongst those, type IX high-strength posterior extra with chitosan released a considerably higher quantity of fluoride at all time intervals. CONCLUSIONS: In all the experimental groups, adding chitosan to the glass ionomer liquid had an accelerating effect on its fluoride-releasing property.

An In Vitro Study to Compare the Release of Fluoride from Glass Ionomer Cement (Fuji IX) and Zirconomer.

Mercury toxicity from amalgam dental fillings and their potential for creating problems in the environment and for human health have prompted the development of new restorative materials. The leading alternatives among these are glass ionomer cements. According to current understanding, restorative materials that slowly release fluoride exert a local cariostatic effect. For this purpose, glass ionomer cements have desirable properties in that they help prevent recurrence of caries by releasing fluoride over a long period. Thus, they function in accord with the major cariostatic mechanism of fluoride, which is believed to be its action to promote remineralization and to influence the morphology of teeth by reducing enamel solubility and by suppressing oral cariogenic bacteria. Although the minimum local concentration of fluoride release required to inhibit demineralization has not been determined, it is reported that the cariostatic ability of fluoride releasing restorative materials is significant. Zirconomer defines a new class of restorative that promises the strength and durability of amalgam with the protective benefits of glass ionomer while completely eliminating the hazards of mercury. The inclusion of specially micronized zirconia fillers in the glass component of zirconomer reinforces the structural integrity of the restoration and imparts superior mechanical properties for the restoration of load-bearing permanent teeth. Combination of outstanding strength, durability, and sustained fluoride protection deems it ideal for multiple applications. The aim of the present study was to determine the fluoride release from glass ionomer cements and compare it with new material zirconomer. Materials and methods: Sample preparation: Tablets of glass-ionomer cements and zirconomer were prepared. A dental floss was incorporated into the tablets during fabrication to allow suspension into the test medium. Each disk specimen was immersed in airtight polyethylene bottle containing 20 mL of deionized water and incubated at 37°C and stored for 24 hours. Determination of fluoride ion release: Fluoride ion measurement was performed after 6 hours, 24 hours, 48 hours, 7 days, and 14 days under normal atmospheric conditions by fluoride ion selective electrode connected to an ion selective electrode meter. Result and conclusion: Both the material tested in the study had the ability to release fluoride but higher fluoride release was observed by zirconomer as compared to GIC at all time intervals. Clinical significance: From a clinical point of view, both the restorative materials release fluoride at all time intervals; however, addition of zirconia particles in zirconomer increases its strength and provides superior mechanical properties. Therefore, due to the combination of both good structural integrity and fluoride releasing properties, zirconomer can be used for restoration of load bearing teeth. How to cite this article: Kukreja R, Singla S, Bhadoria N, et al. An In Vitro Study to Compare the Release of Fluoride from Glass Ionomer Cement (Fuji IX) and Zirconomer. Int J Clin Pediatr Dent 2022;15(1):35-37.

Development of New Experimental Dental Enamel Resin Infiltrants-Synthesis and Characterization.

The aim of the present study was to obtain experimental infiltration materials, intended for the treatment of dental white spots, and to investigate them. Two series of infiltrants (P1-P6)/(P1F-P6F) were obtained, based on different monomer mixtures, without/with glass filler (with fluoride release ability). Each infiltrant from the second series contained the same amount of glass powder, and each infiltrant from the (P-PF) group contained the same resin composition. The characteristics of the experimental infiltrants were investigated by degree of conversion (DC), mechanical strength, water sorption (WS), and fluoride release, in addition to residual monomer for (P1F-P6F) infiltrants. The results were compared with those obtained for commercial Icon infiltrant. For the experimental infiltrants, without/with filler, the recorded DC was in the range of 58.27-89.70%/60.62-89.99%, compared with Icon (46.94%) 24 h after polymerization. The release of fluoride depends on the permeability of the polymer matrix, with respect to the water sorption, which may help to diffuse ions in the storage medium but which can also influence the release of residual monomers. The highest flexural strengths were recorded for the (TEGDMA/HEMA/Bis-GMA) infiltrants (133.94 ± 16.389 MPa/146.31 ± 7.032 MPa). The best experimental infiltrants were P2 and P2F (Bis-GMA/HEMA/TEGDMA).