Fluoride-containing Materials Research Articles

Comparing cytocompatibility of two fluoride-containing solutions and two resin-based restorative materials-a pilot study.

Cytocompatibility should always be considered, especially if the surface of treated carious lesions is close to soft tissue or is accidentally exposed to the oral soft tissue by the clinician. The aim of the present study was to compare the cytocompatibility of two fluoride-containing liquids and two resin-containing restorative materials with buccal mucosa fibroblasts. The fluoride-containing materials were silver diamine fluoride and water-based silver fluoride. The statistical analysis was completed by comparing the positive control growth of the buccal mucosa fibroblasts to the growth of cells exposed to various materials. The one-way ANOVA with Tukey's HSD result was completed. All the assessed materials compared to the control wells for both the 24 and 48 h time intervals indicated a significant cytocompatibility result, except for the test wells with Stela (SDI) at the 24 h time interval. There was no significant difference between the step 2 liquids and the two dental materials in cytocompatibility at the 24 h interval. All four materials indicated no significant differences between the cytocompatibility of any dental materials for 48 h. The cytocompatibility assessment for Riva Star and Riva Star Aqua with the direct method in a full dispensing drop is not viable for step 1 of the fluoride-containing liquids. The use of Stela Light Cure is a suitable material that will be in contact with buccal mucosa as it showed potential for increased cytocompatibility compared to Riva Light Cure. Riva Star Aqua is more cytocompatible than Riva Star.

Material of choice for non-invasive treatment of dentin caries: An in vitro study using natural carious lesions.

In community settings with limited dental personnel and equipment, and in an era when the aerosol transmission of infectious agents is on the rise, a non-invasive approach to caries management is critical. To provide information on non-invasive material selection, the aim of this study was to compare the remineralization effect of commonly used fluoride-containing materials, adjunctive to the everyday use of fluoride toothpaste (F-toothpaste), on primary tooth natural dentin caries. Fifty-five specimens were randomly divided into five groups: 38% silver diamine fluoride (SDF), 5% fluoride varnish (F-varnish), glass-ionomer cement (GIC), deionized water (DW) with F-toothpaste slurry, and DW as a control group (n = 11). The lesion depth and mineral density were measured before and after bacterial pH-cycling using micro-computed tomography. The percentage of mineral density change (%MDchange) was quantified. The dependent t-test, Wilcoxon-Signed-Rank Test, and one way ANOVA with Bonferroni correction were used to analyse the data. SDF application reduced lesion depth from 844.6 to 759.1 μm (p < 0.045) while increasing mineral density from 551.4 to 763.0 mgHA/cm3 (p < 0.003). Only mineral density rose from 600.2 to 678.4 mgHA/cm3 (p < 0.013) when GIC was used. The other groups showed no difference. The highest %MDchange was also found after SDF treatment (49.7%, p < 0.05), whereas GIC (17.2%, p < 0.05) presented a higher percentage than the F-varnish (2.0%), F-toothpaste (-1.1%) and no-treatment groups (-1.4%). In this in vitro study, where the pH of cycling was almost neutral, using SDF as an adjunct to F-toothpaste resulted in the highest remineralization compared with other remineralizing materials.

Inhibition of Demineralization of Dentin by Fluoride-Containing Hydrogel Desensitizers: An In Vitro Study.

Several desensitizers routinely used clinically for dentin hypersensitivity are expected to inhibit demineralization. This study aimed to evaluate the effectiveness of sealing materials in inhibiting demineralization and increasing fluorine (F) uptake by acid-treated root surfaces. Five noncarious extracted human teeth were used to produce specimens. Three different fluoride-containing materials, namely "MS Coat F" (MS), "MS Coat Hys Block Gel" (HS), and CTX2 Varnish (FV), were used herein. Each material was applied to the demineralized root surface. Single sections were obtained from each specimen. All surfaces of each specimen, except the polished surface, were covered with wax and immersed in an automatic pH cycling system for 2 weeks. Fluorine and calcium distributions in the carious lesions of each specimen were evaluated using proton-induced gamma emission (PIGE) and X-ray (PIXE) techniques, respectively. Dentin demineralization was analyzed using transverse microradiography (TMR) before and after pH cycling. µPIXE/PIGE analysis demonstrated that all sample groups showed increased fluoride uptake on the root surface. TMR analysis revealed that both HS and FV showed significantly lower integrated mineral loss values than the control group. All three samples demonstrated a tendency towards increased fluoride uptake from fluoride-containing hypersensitivity desensitizers and a demineralization inhibition effect on root dentin.

Enhancement of oil resistance of cellulose packaging paper for food application by coating with materials derived from natural polymers

Paper is widely used as food packaging because of good mechanical strength and degradability. However, the application scope of paper is limited by a relatively strong affinity for water and oil. In this study, we prepared two types of coated paper and investigated the influence of the air permeability and polarity on the oil resistance of the coated papers. Reducing the air permeability improved the grease resistance of the coated papers. High-surface-energy coatings exhibited enhanced oil resistance because of a high content of polar components that offered high resistance to grease. The mechanical properties of the paper were also improved by applying the coating. These naturally derived materials are an alternative to the fluoride-containing materials that are currently available on the market for improving the wettability of paper and the quality and safety of grease-rich foods. • The oil resistance of cellulose food packaging paper are positively related to the coating weight. • The oil resistance of cellulose food packaging paper is positively related to the polarity of the coating. • Even with relatively low coating weight, the coating with high polarity still has good oil resistance.

Effect of S-PRG particles on demineralization and remineralization of dentin: a clinical case report

It is known that the production of acid by oral bacteria dissolves mineral phases on the enamel surface, facilitating the formation of dental caries, with lactic acid being the main cause of caries, followed by acetic and propionic acids. Fluoride-containing materials play an important role in preventing demineralization and remineralization and these are widely used in dentistry. Although the benefits of fluoride in terms of reducing the incidence of dental caries are well established, fluoride cannot prevent caries in all patients; thus, the development of new anti-caries agents with remineralization properties is necessary. Thus, new products are emerging with this purpose and in this article, a material with Surface Pre Reacted Glass ionomer (S-PRG) particles will be addressed, these are produced by the acid-base reaction of fluoroboroaluminosilicate glass and polyacrylic acid and are known to have a potential to release 06 ions, such as Al, B, Na, Si, Sr and F, where these released ions played an important role in pH neutralization, leading to inhibition of enamel demineralization early point, where strontium (Sr) is becoming as a strong inducer of dentin matrix remineralization. Thus, this work aimed to demonstrate with a clinical case using S-PRG materials that can become an ally in the remineralization of the dental element. In conclusion, among the innovations that promote the concept of preventive and minimally invasive management, the bioactivity containing S-PRG can avoid invasive and definitive procedures such as tooth extraction.

High-throughput discovery of fluoride-ion conductors via a decoupled, dynamic, and iterative (DDI) framework

AbstractFluoride–ion batteries are a promising alternative to lithium–ion batteries with higher theoretical capacities and working voltages, but they have experienced limited success due to the poor ionic conductivities of known electrolytes and electrodes. Here, we report a high-throughput computational screening of 9747 fluoride-containing materials in search of fluoride-ion conductors. Via a combination of empirical, lightweight DFT, and nudged elastic band (NEB) calculations, we identified &gt;10 crystal systems with high fluoride mobility. We applied a search strategy where calculations are performed in any order (decoupled), computational resources are reassigned based on need (dynamic), and predictive models are repeatedly updated (iterative). Unlike hierarchical searches, our decoupled, dynamic, and iterative framework (DDI) began by calculating high-quality barrier heights for fluoride-ion mobility in a large and diverse group of materials. This high-quality dataset provided a benchmark against which a rapid calculation method could be refined. This accurate method was then used to measure the barrier heights for 6797 fluoride–ion pathways. The final dataset has allowed us to discover many fascinating, high-performance conductors and to derive the design rules that govern their performance. These materials will accelerate experimental research into fluoride–ion batteries, while the design rules will provide an improved foundation for understanding ionic conduction.

Management of white spot lesions induced during orthodontic treatment with multibracket appliance: a national-based survey

ObjectivesThe study aimed to survey current strategies against enamel demineralization during multibracket therapy (MBT) and guide a prevention concept based on existing scientific evidence.Materials and methodsThe survey comprised questions on the prevention and management of white spot lesions (WSL). The questionnaire was sent via email to orthodontists working in practices and universities throughout Germany. The analysis involved descriptive statistics using the chi-square test (p < 0.05).ResultsA prevention protocol was used before MBT by 80.6% of the participants. Less than a quarter of the participants regularly applied topical fluoride (gel or varnish) during MBT. According to the respondents’ assessment, the prevalence of WSL during MBT is 11.6%, mainly observed in 12- to 15-year-old male patients. Orthodontists graduating after 2000 tended to recommend and apply fluoride-containing materials more often than their senior colleagues (p = 0.039). Participants from private practices applied fluoride varnish or gel more frequently than those from university clinics (p = 0.013). Fluoridation was the most common (70.7%) treatment for WSL after MBT, followed by resin infiltration (21.2%). The majority (80.9%) of the participants favor a guideline for preventing WSL.ConclusionsWSL prevention during MBT is challenging. Males in puberty are predominantly affected. Younger orthodontists are more concerned about the prevention of WSL during MBT.Clinical relevance.The non-negligible prevalence of individuals with WSL emphasizes the need for dental education and health care reform. This would help to implement standardized procedures and establish innovative applications.

Novel rechargeable calcium fluoride dental nanocomposites

ObjectivesComposite restorations with calcium fluoride nanoparticles (nCaF2) can remineralize tooth structure through F and Ca ion release. However, the persistence of ion release is limited. The objectives for this study were to achieve long-term remineralization by developing a rechargeable nCaF2 nanocomposite and investigating the F and Ca recharge and re-release capabilities. MethodsThree nCaF2 nanocomposites were formulated: (1) BT-nCaF2:Bisphenol A glycidyl dimethacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA); (2) PE-nCaF2:Pyromellitic glycerol dimethacrylate (PMGDM) and ethoxylated bisphenol A dimethacrylate (EBPADMA); (3) BTM-nCaF2:BisGMA, TEGDMA, and Bis[2-(methacryloyloxy)ethyl] phosphate (Bis-MEP). All formulations contained 15% nCaF2 and 55% glass particles. Initial flexural strength and elastic modulus, F and Ca ion release, recharge and re-release were tested and compared to three commercial fluoride-containing materials. ResultsBT and BTM nCaF2 composites were 3–4 times stronger and had elastic modulus 2 times that of resin-modified glass ionomer controls. PE-nCaF2 had comparable strength to RMGIs. All nCaF2 composites had significant F and Ca ion release and ion rechargeability. In F and Ca recharging cycles, PE-nCaF2 had the highest ion recharging capability among nCaF2 groups, followed by BT-nCaF2 and BTM-nCaF2 (p < 0.05). For all recharge cycles, ion release maintained similar levels, demonstrating long-term ion release was possible. Furthermore, after the final recharge cycle, nCaF2 nanocomposites provided continuous ion release for 42 days without further recharge. SignificanceNovel nCaF2 rechargeable nanocomposites exhibited significant F and Ca ion release over multiple recharge cycles, demonstrating continuous long-term ion release. These nanocomposites are promising restorations with lasting remineralization potential.

Clinical Evaluation of Glass-Lonomer Cement and Giomer for the Management of Cervical Caries

Background: Giomer is a unique class of restorative material has been introduced as the true hybridization of Glass Ionomer (GI) and composite resin and has the distinguishing feature of a stable surface pre-reacted glass ionomer. Glass Ionomer Cements (GIC) are also unique restorative materials with many uses in clinical practice and provide for caries-protective fluoride releasing at the margins of restorations, as well as their ability to have the fluoride within their chemical matrix recharged by outside exposure to other fluoride-containing materials. The present study aim at clinically evaluate the comparison between the glass Ionomer cement and Giomer for the management of cervical caries.&#x0D; Materials and methods: The study was a cross sectional comparative study which was carried out from 01 December 2018 to 31 November 2019 in the Department of Conservative Dentistry and Endodontics, Bangladesh Dental College, Dhanmondi, Dhaka. Total number of cases was 80. The patients were divided into two groups, half of the patient (Group-1) was treated with Glass Ionomer cement and half of the patient (Group-2) was treated with Giomer restoration. The post-operative sensitivity discoloration, dislodgement of filling material and secondary caries formation were recorded. All the patients were assigned and the data were analyzed statistically by SPSS version 21. p-value &lt; 0.05 was taken as significant.&#x0D; Results: The study reveals 60% of the study population was within 41 to 50 years of age group (Group-1) and 62.5% were 51 to 60 years (Group-2) 45% in (Group-1) and 10% in (Group-2) had history of post filling sensitivity, 12% in (Group-1) and 5% in (Group-2) had discoloration after restoration, 2.5% had history of dislodgement of the filling in (Group-1), no history of dislodgement of the filling in (Group-2), 2.5% had history of secondary caries formation in (Group-1) and no history of Secondary caries formation in (Group-2).&#x0D; Conclusion: Patients were more approachable for Giomer restoration than Glass ionomer for the management of cervical caries over a period of 12 month.&#x0D; Chatt Maa Shi Hosp Med Coll J; Vol.20 (2); July 2021; Page 60-64

Orthodontic materials with fluoride have an antimicrobial ability for the prevention of white spot lesions

Aim: Orthodontic brackets during their wear cause demineralization of enamel, which is the initial step in caries development. The prevention of such spots is crucial to ensure healthy teeth, but patients’ compliance is not the most optimal way. The aim of this study was to compare the antimicrobial properties of fluoride-containing orthodontic materials to the materials without additional fluoride. Materials and Methods: Antibacterial effectiveness of orthodontic materials with fluoride – Transbond Plus SEP Bonding agent, Transpond Plus Adhesive agent, Fuji I Band cement, Fuji Ortho LC Adhesive agent, Ortho Solo Bonding agent, and without antimicrobial substances – Transpond XT Bonding agent, Transbond XT Primer were tested with the inhibition on most common causes L. achidophilus (ATCC 4356) and S. mutans (ATCC 10449) and compared to negative control. Antimicrobial effectiveness of each material was measured with the agar diffusion method and expressed with the diameters of inhibition zones around the disk. Results: Materials containing fluoride showed more antimicrobial effectiveness compared to materials without fluoride or negative control (p&amp;lt;0.001), respectively. Materials from the group with no antibacterial substances were not statistically different compared to the negative control (P&amp;gt;0.05). Conclusion: Materials containing fluoride showed more significant antimicrobial effectiveness when compared to the materials without antimicrobial substance and thus might have the potential of antimicrobial properties in vivo.

In-air micro-proton-induced X-ray/gamma-ray emission analysis of the acid resistance of root dentin after applying fluoride-containing materials incorporating calcium.

This study employed an in-air micro-proton-induced X-ray/gamma-ray emission system to assess the effectiveness of fluoride-containing materials (FCMs) incorporating calcium in preventing root caries. Dentin surfaces of human third molars were coated with one of three FCMs: fluoride-releasing glass-ionomer cement (F7) and experimental materials in which half (P1) or all (P2) of the strontium in F7 was replaced with calcium. Dentin without FCM coating served as the control. Specimens were immersed in saline at 37°C for 1 month, sectioned, and then demineralized. Calcium loss after demineralization was lower in the Ca-substituted groups than in the Ca-unsubstituted groups (p<0.05). Calcium loss was negatively correlated with fluoride uptake (p<0.01). In the F7, P1, and P2 groups, the retraction of the dentin surface was significantly suppressed as compared with the control group. FCMs incorporating calcium improved the acid resistance of root dentin and could help prevent root caries.

Fluoride release from different tooth colored restorative materials: An in vitro study

This in vitro study evaluated the amount of fluoride released from fluoride-containing materials over a period of (30) days. Twenty eight disk samples (2.5 mm depth × 10 mm diameter) were prepared and divided into four groups: GroupI Vitremer glass ionomer, group II resin composite Tetric, group III resin composite Definite, and group IV Compoglass. The samples were stored in an incubator at 37°C for (24) hours. Each disk was suspended in an individual plastic tube containing (3) ml of deionized water. The water was changed every (24) hours, fluoride release was determined at each day for (30) days, after buffering the solution with equal volume of TISAB. The fluoride release was measured with a fluoride-ion selective specific electrode previously calibrated from (0.05) to (100) ppm. Fluoride release was expressed in part per million (ppm). ANOVA test was used to evaluate the data. The results revealed that Vetrimer glass ionomer released significantly more fluoride (4l ppm) for the first day than all the other products. This was followed by Compoglass which exhibits more fluoride release than the other two types (32 ppm), the Tetric composite resin Was the third material in the amount of fluoride released (3.75 ppm), and finally the resin composite Definite released fluoride in about (0.75 ppm). All fluoride release was decreased from day (1) to (30) observation period.

Effect of Polishing Systems on Fluoride Release and Surface Roughness of Different Restorative Materials

Secondary caries is an important factor in the replacement of the restorations, and it is thought that fluoride-releasing materials may prevent this problem. Furthermore, the fluoride release of the materials may be increased by polishing process. Available knowledge about the effect of polishing systems (PS) on the fluoride release of materials is limited. Therefore, this study was conducted to evaluate the effect of PS on the fluoride release of fluoride-containing materials. Restorative materials were divided into 6 groups: Fuji IX GP, Fuji II, Dyract XP, Beautifil II, Beautifil-Bulk, and Filtek Ultimate. Each group was also divided into four subgroups: Mylar strip, Sof-Lex Discs, Sof-Lex Diamond, and OneGloss. Fluoride release was determined using a fluoride ion-selective electrode. Surface roughness was evaluated with a profilometer. Two-way repeated measure and one-way ANOVA tests were used for statistical analysis. The initial rapid fluoride release was observed only in Fuji IX. The PS increased the fluoride release of Fuji IX and Fuji II and Dyract XP materials while reducing the fluoride release of resin-based materials. The highest surface roughness values were obtained with OneGloss. Further, a significant relationship between fluoride release and surface roughness was found. The polishing provides an increase in fluoride release, especially in glass-ionomer-based materials. This article revealed that there is a relationship between fluoride release and surface roughness. Proper PS must be chosen according to the material to provide the best clinical benefits in terms of fluoride release and surface roughness.

Analysis of tooth-bound fluoride after the application of coating materials on the enamel surface with an in-air micro PIXE/PIGE

Tooth-bound (KOH-insoluble) fluoride prevents caries via long retention within the tooth structure. Tooth-bound fluoride in the enamel was investigated after applying various fluoride-containing tooth-coating materials using an in-air micro [Formula: see text] PIXE/PIGE system. Three different fluoride-containing or a non-fluoride containing coating materials were applied to the coronal enamel surface of 24 extracted human molars. The samples were stored in water for 1 or 7 days and then sectioned into two slices. One slice was immersed in 1M KOH solution for 24 h for KOH-insoluble fluoride (KOH(T)) analysis. The second slice was not subjected to KOH treatment and was used to analyze the whole fluoride (KOH-soluble plus insoluble fluoride: KOH(U)). Fluorine and calcium distribution were measured in all the slices with [Formula: see text]PIXE/PIGE. KOH(U) was higher than KOH(T) on some materials, especially those that released more fluoride. For KOH(T), there was no significant difference among all fluoride-containing materials in the 7-day group. However, there were significant differences in the KOH(U) samples during the same period. PIXE/PIGE analysis confirmed the presence of tooth-bound fluoride in the enamel adjacent to the fluoride-containing coating materials. The amount of tooth-bound fluoride depended on the type of material.

Effect of topical fluoride application on enamel after in‐office bleaching, as evaluated using a novel hardness tester and a transverse microradiography method

This study evaluated the effect of topical fluoride application on enamel hardness after in-office bleaching. Twelve human incisors were cut along the long axis, resulting in 24 halves used in four treatment groups (n = 6 in each group): (i) untreated group (C); (ii) in-office bleaching material (B); (iii) treatment with surface reaction-type prereacted glass-ionomer varnish after in-office bleaching (B+PRG); and (iv) treatment with acidulated phosphate fluoride solution after bleaching (B+F). All specimens were subjected to pH-cycling for 4 wk. Knoop hardness was measured using a Cariotester. The decalcification of enamel was assessed quantitatively by measuring the integrated mineral loss (ΔIML). Games-Howell analysis was used to assess statistical significance of between-group differences. The Knoop hardness decreased significantly after bleaching for all groups. In treatment groups B+PRG and B+F, the Knoop hardness returned to the original unbleached values after the first pH cycle and did not change afterwards. In treatment groups C and B there was a gradual decrease in the Knoop hardness until the fourth pH cycle. The integrated mineral loss, ΔIML, was significantly higher in treatment group B+F after 2 wk than in the other treatment groups. After 4 wk, the ΔIML in treatment group B was significantly higher than in treatment group B+PRG. The application of fluoride-containing materials after bleaching results in recuperation of hardness to levels similar to those of unbleached enamel.

Fluorine binding with dentin adjacent to fluoride-containing luting materials

Tooth-bound (KOH-insoluble) fluoride contributes to caries prevention because of its low acid solubility and long retention within tooth structure. The purpose of this study was to evaluate tooth-bound fluoride in dentin, taken up from fluoride-containing luting materials, using an in-air [Formula: see text]PIXE/PIGE system. The dentin surface of tooth root cross-sections and an acrylic resin were cemented with four different fluoride-containing luting materials. Specimens were stored in a remineralizing solution for 4 or 8 weeks and then sectioned into two slices. Two adjacent slices were used for measurement of fluorine and calcium concentration using in-air [Formula: see text]PIXE/PIGE. For analysis of the KOH-insoluble fluoride ((KOH(+)), one slice was immersed in 1 mol/L KOH solution for 24 h. The other slice was not treated with KOH in order to analyze KOH-soluble and -insoluble fluoride (whole fluoride, KOH(−)). KOH(+) levels were lower than KOH(−) levels for all materials at both duration periods. Higher concentration of fluorine was detected at deeper areas in the 8-week groups than in the 4-week groups for all materials. The material, which has the largest fluoride release, shows the lowest ratio of KOH(+) to KOH(−). PIXE/PIGE analysis confirmed the presence of tooth-bound fluoride in dentin adjacent to fluoride-containing luting materials.

KTP-Type (Li,K)VPO4F: A Novel 4V Cathode Material for Li-Ion Batteries

In a hunt for high-energy cathode materials for Li-ion batteries, different families of fluoride-containing materials such as fluoride-phosphates AxMPO4F (A = Li, Na; M = V, Mn, Fe, Co, Ni; x = 1, 2)1,2,3have been extensively examined. Introduced to the lattice fluorine brings about not only an increase in operating voltages due to its highest electronegativity, but also a richer structural variety. In these systems the nature of alkali and transition metals strongly affects the adopting crystal structure, which in turn determines electrochemical properties. Due to a larger ionic radius compared to Li and Na and somewhat different crystal chemistry, K provides ample opportunities in searching and stabilizing new frameworks for reversible ion de/intercalation. Here we report on a novel vanadium-based AVPO4F (A = Li, K) cathode material adopting a KTP-type framework for high power rechargeable batteries with enhanced specific energy and excellent rate capability4. KVPO4F was prepared via freeze-drying assisted solid-state route in two steps. The composition of the material was studied by TEM-EDX, ICP-AES and FTIR spectroscopy. The structure of KVPO4F was refined from powder XRD data [S.G. Pna21, a = 12.8200(3) Å, b = 6.3952(1) Å, c = 10.6115(2)] using the KFeSO4F structure as an initial model5. The refined structure was confirmed with HAADF-STEM imaging and electron diffraction. Vanadium +3 oxidation state was confirmed with EELS. For the electrochemical evaluation the initial KVPO4F material was oxidized by charging up to 4.8 V vs Li/Li+ at C/20 rate and holding at this potential for 5 hours. According to the EDX data, potassium in not completely removed and about 15% remains in the structure giving rise to a K0.15VPO4F formula. The obtained K0.15VPO4F material was tested within the 2.0–4.7 V vs Li/Li+ potential range at different rates from C/5 to 40C showing an uptake of 0.7 Li per formula unit at the average voltage of ~4 V. K0.15VPO4F exhibits a sloping voltage profile indicating a solid-solution-like de/intercalation mechanism. Ex-situ XRD and electron diffraction tomography were applied to examine the crystal structure of the recovered oxidized and lithiated electrode materials. In contrast to the noncentrosymmetric parent KVPO4F phase (Pna21), the crystal structures of both oxidized and lithiated electrode materials possess a centrosymmetric space group (Pnan); however, KTP-type structure is preserved. The difference in the unit cell volume of all three phases is small and does not exceed 2.2%. LixK0.15VPO4F shows remarkable capacity retention at 40C maintaining more than 50% of theoretical (156 mAh/g) or 75% of initial specific capacity (111 mAh/g at C/5). Rapid kinetics of the Li de/intercalation is also evidenced by rate capability measurements (figure 1). Synthesis, structure and electrochemical properties of the obtained cathode material will be discussed in detail. A special focus will be given on structural peculiarities and substitution in the metal sublattice and their effect on the electrochemical performance in a Li anode cell. Figure 1. Rate capability measurements of (K,Li)VPO4F. References Barker, J.; Saidi, M. Y.; Swoyer, J. L. J. Electrochem. Soc. 2003, 150, A1394−A1398.Okada, S.; Ueno, M.; Uebou, Y.; Yamaki, J. J. Power Sources 2005, 146, 565−569.Ellis, B. L.; Makahonouk, W. R. M.; Makimura, Y.; Toghill, K.; Nazar, L. F. Nat. Mater. 2011, 10, 772−779.Fedotov, S. S.; Khasanova, N. R.; Samarin, A. Sh.; Drozhzhin, O. A.; Batuk, D.; Karakulina, O. M.; Hadermann, J.; Abakumov, A. M; Antipov, E. V. Chem. Mater. 2016, DOI: 10.1021/acs.chemmater.5b04065Recham, N.; Gwenaelle, R.; Sougrati, M. T.; Chotard, J.-N.; Frayret, C.; Mariyappan, S.; Melot, B. C.; Jumas, J.-C.; Tarascon, J.-M. Chem. Mater. 2012, 24, 4363–4370. Figure 1

Effect of Fluoride-containing Restorative Materials on Dentin Adhesion and Demineralization of Hard Tissues Adjacent to Restorations.

This study evaluated (1) the dentin bond strength of fluoridated restorative systems following aging and (2) the enamel/dentin microhardness around restorations after a pH-cycling regimen. Sixty-four human third molars and four restorative systems were used. A resin-modified glass ionomer (GC Fuji II LC) was used as a fluoride-containing material in the positive control group, while Adper Easy Bond adhesive and Filtek Z350 XT composite resin, which are not fluoridated, were used together in the negative control group. Beautifil II composite resin and FL-Bond II adhesive, both fluoride-containing materials, were compared to Bond Force and Estelite Sigma Quick restorative system, which only contain fluoride in the adhesive. For dentin bond strengths, specimens of each material were fabricated for two test groups (n=8): group 1: tested after 24 h; group 2: tested after 1 year of storage in artificial saliva. Both groups were tested using a microtensile method. For the cross-sectional microhardness test, standardized Class V cavities were prepared and filled with the different restorative systems. After experiencing repeated thermocycling and being subjected to pH-cycling, the teeth were sectioned. The microhardness was measured in enamel and dentin at 50 μm from the cavity wall and at six depths in relation to the surface subjected to pH cycling. None of the restorative systems showed decreased bond strength after storage for one year in artificial saliva. No significant differences in microhardness were observed among the restorative materials on enamel and dentin. All the restorative systems evaluated presented stable bond strength after one year of storage. The pH cycling caused a reduction in the superficial enamel microhardness close to the cavity wall. In dentin, the demineralization affected the superficial and sub-surface areas.

Efficacy of calcium- and fluoride-containing materials for the remineralization of primary teeth with early enamel lesion.

The aim of the study was to determine the efficacy of different products containing fluoride, calcium and phosphate for enamel remineralization in eroded primary teeth. A total of 90 sound primary canine teeth were randomly divided into 5 groups of 18 teeth each: 1) control (polished enamel), 2) 5% DuraShield sodium fluoride varnish, 3) 500 ppm fluoridated toothpaste, 4) casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) cream, and 5) Clinpro White varnish containing functionalized tri-calcium phosphate (fTCP). Enamel microhardness (EMH) was measured in all samples before and after demineralization and after 28 days of remineralization. Also 8 samples in groups 2 to 5 and four samples of sound and demineralized enamel were examined with atomic force microscopy (AFM). All data were analyzed with one-way ANOVA (p<0.05). Mean microhardness of demineralized enamel was significantly lower than in enamel at baseline (p<0.001). Remineralization significantly increased microharness in groups 2 to 5 compared to the control group (p<0.001). Percent EMH after remineralization with CPP-ACP was significantly higher than after fTCP (p=0.029), toothpaste (p< 0.001) or fluoride varnish (p<0.001); however, there was no significant difference between toothpaste and fluoride varnish (p=0.062). Microhardness increased more after fTCP treatment than after treatment with sodium fluoride varnish (p<0.001) or fluoridated toothpaste (p=0.045). AFM images showed that enamel roughness decreased most after treatment with fTCP, followed by CPP-ACP, toothpaste and fluoride varnish. The efficacy of CPP-ACP cream for remineralizing eroded enamel was greater than fluoride toothpaste, fluoride varnish or fTCP varnish.

Evaluation of caries progression in dentin treated by fluoride-containing materials using an in-air micro-PIGE and micro-PIXE measurement system

It is well-known that fluorine (F) is involved in the progression of caries. The evaluation of caries progression has conventionally been based on the change in mineral content using transverse microradiography (TMR). The purpose of this study was to evaluate the progression of dentinal caries by the change in calcium (Ca) content using Particle-Induced Gamma-ray Emission/Particle-Induced X-ray Emission (PIGE/PIXE) techniques at the Wakasa Wan Energy Research Center. We also assessed the relationship between caries progression rate and the concentration of F penetration into dentin from dental fluoride-containing materials (FCMs). Dentin sections of six extracted human teeth were prepared to obtain various amounts of F uptake using three types of FCMs. F and Ca distribution of specimens were obtained using PIGE/PIXE techniques. After evaluation, the specimens were immersed in 10ml of demineralizing solution (pH 4.5) to simulate caries attack. To estimate caries progression rates, the same portions of the specimens were evaluated after caries attack treatment using PIGE/PIXE. A negative correlation between the F uptake in dentin and the rate of caries progression was observed. Therefore, caries progression in dentin was reduced by increasing the amount of F uptake from FCMs. This demonstrates that PIGE/PIXE techniques are valuable for estimating caries progression rates.