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Bueno LS, Borges AFS, Navarro MFL, Nicholson JW, Hill RG, Sidhu SK. Determination of chemical species of fluoride during uptake mechanism of glass-ionomer cements with NMR spectroscopy. Dent Mater 2021; 37:1176-1182. [PMID: 33962790 DOI: 10.1016/j.dental.2021.04.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 04/07/2021] [Accepted: 04/24/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The aim of the present study was to determine the chemical species formed inside glass-ionomer cements after fluoride uptake and to investigate the depth of penetration of fluoride ions within the cement matrix. METHODS An experimental fluoride-free glass with composition 2SiO2-AlO3-CaO was produced. The glass powder was mixed with aqueous poly(acrylic acid) (PAA), and allowed to set. The resulting specimens were stored in 20ml KF solution with 1000ppm fluorine for 24h and then placed into the same amount of water as for 24h. A fluoride selective electrode was used to give the F concentration of the respective solutions. 19F MAS-NMR spectra were recorded on powdered cement specimens using a Bruker AVANCE-NEO 600 spectrometer. In addition, SEM observation and EDX chemical analysis were conducted on the cross-section of a carefully fractured specimen. RESULTS Fluoride was shown to be mainly present in the surface layers of the specimen after placement in the KF solution, and only a small fraction was re-released into water. 19F NMR spectroscopy showed that AlF complexes were formed within the cement. SIGNIFICANCE The fluoride taken up by a free-fluoride glass ionomer cement mostly occupies surface layers and is retained because it bonds to aluminum within the matrix. This finding explains why the majority of fluoride taken up by conventional glass ionomer cements is retained.
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Affiliation(s)
- Lígia S Bueno
- Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil.
| | - Ana Flávia S Borges
- Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | | | - John W Nicholson
- Queen Mary University of London, Barts & The London School of Medicine and Dentistry, Institute of Dentistry, Turner Street, London, UK; Bluefield Centre for Biomaterials, 67-68 Hatton Garden, London, UK.
| | - Robert G Hill
- Queen Mary University of London, Barts & The London School of Medicine and Dentistry, Institute of Dentistry, Turner Street, London, UK
| | - Sharanbir K Sidhu
- Queen Mary University of London, Barts & The London School of Medicine and Dentistry, Institute of Dentistry, Turner Street, London, UK.
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Positive correlation between fluoride release and acid erosion of restorative glass-ionomer cements. Dent Mater 2018; 35:135-143. [PMID: 30502961 DOI: 10.1016/j.dental.2018.11.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 11/06/2018] [Accepted: 11/07/2018] [Indexed: 01/26/2023]
Abstract
OBJECTIVE The aim of this study was to determine whether there is a correlation between acid erosion and fluoride release of conventional glass ionomer cements. METHODS Ten specimens for each material were prepared for fluoride release tests and five for acid erosion tests separately. After placed in pH cycling solution, concentration of fluoride was measured by a fluoride-ion selective electrode each day for 15 days. For the acid erosion test, specimens were immersed in a lactic acid solution and their depth measured with a spring-loaded dial gauge. The data were submitted to 3-way ANOVA, followed by Tukey's test (p<0.05) RESULTS: All materials showed ability to elute fluoride in the 15 day period of the test, with the same pattern of high fluoride release at the first 24h. Despite this, the amount of fluoride released was statistically different among the 18 groups, with the highest for Maxxion R and the lowest for Chemfil Rock (p>0.05). The highest acid erosion values were registered for Magic Glass, Ion Z, VitroFil and Maxxion R, which exceeded the maximum stipulated by the relevant ISO test (ISO 9917-1). A positive linear correlation (r2=0.4886) was found for both properties, i.e., higher fluoride release is related to higher acid erosion. SIGNIFICANCE Acid erosion and fluoride release are related properties of GICs, though factors such as pH and P/L ratio lead to differences between actual values for individual brands of these materials.
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Yan Z, Sidhu SK, McCabe JF. The influence of microstructure on thermal response of glass ionomers. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2007; 18:1163-6. [PMID: 17268863 DOI: 10.1007/s10856-007-0153-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2006] [Accepted: 03/29/2006] [Indexed: 05/13/2023]
Abstract
This study was designed to determine the dimensional changes caused by thermal stimuli of glass ionomers with different glass/matrix ratios. Four cylindrical specimens were made for each of four powder/liquid ratios (3:1, 2.5:1, 2:1 and 1.5:1) for a conventional luting glass ionomer, two high viscosity restorative glass ionomers and a restorative resin-modified glass ionomer. The thermal characteristics were determined using a thermal mechanical analyzer (TMA) by heating the samples from 25 degrees C to 70 degrees C at 10 degrees C per minute. All glass ionomers and the resin-modified glass ionomer lost water on heating. The results of the thermal response of these materials were explained in terms of the opposing effects of thermal expansion and desiccation on heating. The contraction on heating of glass ionomer and related materials was found to relate to the glass/matrix ratio but not directly proportional to it. Materials with lower P/L ratios contracted the most when heated to 70 degrees C. The water loss from conventional and resin-modified glass ionomer with different glass/matrix ratios compensated for their thermal expansion and led to a minimal dimensional change when heated up to 50 degrees C. This outcome may be interpreted as an example of smart behaviour of these materials.
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Affiliation(s)
- Zhuoqun Yan
- School of Dental Sciences, University of Newcastle, Framlington Place, Newcastle upon Tyne, NE2 4BW, UK.
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Yoda A, Nikaido T, Ikeda M, Sonoda H, Foxton RM, Tagami J. Effect of curing method and storage condition on fluoride ion release from a fluoride-releasing resin cement. Dent Mater J 2006; 25:261-6. [PMID: 16916227 DOI: 10.4012/dmj.25.261] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The purpose of this study was to evaluate fluoride ion release from a resin-modified glass ionomer cement (Fuji IILC improved, FLC) and a fluoridated resin cement (Panavia F, PF) following different curing methods and storage conditions. The specimens, which were either light-cured (LC) or chemical-cured (CC), were stored in either distilled water (DW) or demineralizing solution (DS; pH 4.5) for 1, 3, 7, 15, 30, 60, and 90 days. Fluoride ion release was measured using a fluoride ion-specific electrode. Data (n = 5) were statistically analyzed using one- and three-way ANOVA (p = 0.05). A "burst effect" was observed in the first week from both materials. However, fluoride ion release from FLC was seven times higher than that from PF. Storage in demineralizing solution accelerated the amount of fluoride release from both materials. In addition, LC yielded a lower amount of fluoride ion release from both materials, as compared to CC. It was concluded that both curing mode and storage medium influenced the amount of fluoride release from the tested materials.
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Affiliation(s)
- Akira Yoda
- Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
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Wiegand A, Buchalla W, Attin T. Review on fluoride-releasing restorative materials--fluoride release and uptake characteristics, antibacterial activity and influence on caries formation. Dent Mater 2006; 23:343-62. [PMID: 16616773 DOI: 10.1016/j.dental.2006.01.022] [Citation(s) in RCA: 490] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2005] [Revised: 11/10/2005] [Accepted: 01/10/2006] [Indexed: 10/24/2022]
Abstract
OBJECTIVES The purpose of this article was to review the fluoride release and recharge capabilities, and antibacterial properties, of fluoride-releasing dental restoratives, and discuss the current status concerning the prevention or inhibition of caries development and progression. METHODS Information from original scientific full papers or reviews listed in PubMed (search term: fluoride release AND (restorative OR glass-ionomer OR compomer OR polyacid-modified composite resin OR composite OR amalgam)), published from 1980 to 2004, was included in the review. Papers dealing with endodontic or orthodontic topics were not taken into consideration. Clinical studies concerning secondary caries development were only included when performed in split-mouth design with an observation period of at least three years. RESULTS Fluoride-containing dental materials show clear differences in the fluoride release and uptake characteristics. Short- and long-term fluoride releases from restoratives are related to their matrices, setting mechanisms and fluoride content and depend on several environmental conditions. Fluoride-releasing materials may act as a fluoride reservoir and may increase the fluoride level in saliva, plaque and dental hard tissues. However, clinical studies exhibited conflicting data as to whether or not these materials significantly prevent or inhibit secondary caries and affect the growth of caries-associated bacteria compared to non-fluoridated restoratives. SIGNIFICANCE Fluoride release and uptake characteristics depend on the matrices, fillers and fluoride content as well as on the setting mechanisms and environmental conditions of the restoratives. Fluoride-releasing materials, predominantly glass-ionomers and compomers, did show cariostatic properties and may affect bacterial metabolism under simulated cariogenic conditions in vitro. However, it is not proven by prospective clinical studies whether the incidence of secondary caries can be significantly reduced by the fluoride release of restorative materials.
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Affiliation(s)
- Annette Wiegand
- Department of Operative Dentistry, Preventive Dentistry and Periodontology, University of Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany.
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Palmer G, Jones FH, Billington RW, Pearson GJ. Chlorhexidine release from an experimental glass ionomer cement. Biomaterials 2004; 25:5423-31. [PMID: 15130727 DOI: 10.1016/j.biomaterials.2003.12.051] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2003] [Accepted: 12/19/2003] [Indexed: 11/18/2022]
Abstract
Glass ionomer cements (GIC) can potentially be used as matrices for the slow release of active species, as has been shown previously for fluoride ions. This study investigated the use of an experimental GIC as a carrier for the release of chlorhexidine acetate (CHA) at included concentrations ranging from 0.5% to 13.0% of CHA by weight. Release into water was examined using high-performance liquid chromatography. All measurable chlorhexidine was released within 22 h1/2, however this was less than 10% of the total mass incorporated in the specimens. An increased percentage of CHA incorporated into the powder gave an increased release into the surrounding water. The bulk of the CHA was retained within the cement. For comparison, the surface chemistry of a CHA-containing GIC was examined using X-ray photoelectron spectroscopy before and after prolonged immersion in water. This confirmed retention of a large amount of CHA. Spectra after leaching appeared very similar to those from a CHA-free GIC after immersion in a CHA solution. In order to explore the effect of CHA-inclusion on the cement properties, compressive strengths, working and setting times were also measured. In general, compressive strengths were found to be decreased in direct proportion to the quantity of CHA added, while working and setting times increased.
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Affiliation(s)
- G Palmer
- Department of Biomaterials, Eastman Dental Institute for Oral Health Care Sciences, University College London, 256, Gray's Inn Road, London WC1X 8LD, UK.
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Nicholson JW, Aggarwal A, Czarnecka B, Limanowska-Shaw H. The rate of change of pH of lactic acid exposed to glass-ionomer dental cements. Biomaterials 2000; 21:1989-93. [PMID: 10941920 DOI: 10.1016/s0142-9612(00)00085-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The rate of change of pH of aqueous lactic acid at pH 4.2-4.5 (i.e. a little below that of active caries in vivo) in contact with disks of various commercial glass-ionomer cements has been determined in two configurations. In the first of them, a thin film set-up, 20 microl of solution was spread across the surface of a cement disk (diameter: 13 mm), and its pH determined by pressing a flat-ended electrode against the film at varying time intervals. In the second, a similar disk was immersed in 1.5 ml of solution, removed after varying time intervals, after which the pH of the solution was measured using a round-ended electrode. The latter measurement was more reliable, in that the pH electrode had time to equilibrate, whereas the former was more realistic because the film was approximately the same thickness as that of saliva on a tooth surface. Both series of experiments showed measurable differences in pH after only 30 s, with the thin-film configuration showing a range of pH changes of 0.5-1.2 units depending on the cement and the small volume configuration showing a range of 0.1-0.5 units, also depending on the cement. After 10 min, in the small volume experiments, the pH had generally increased further. The extent and speed of the change in pH led to the conclusion that ability of glass-ionomers to increase pH is likely to be an important mechanism of caries protection under clinical conditions.
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Affiliation(s)
- J W Nicholson
- Dental Biomaterials Department, GKT Dental Institute, King's College London, Guy's Hospital, UK.
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Khouw-Liu VH, Anstice HM, Pearson GJ. An in vitro investigation of a poly(vinyl phosphonic acid) based cement with four conventional glass-ionomer cements. Part 1: Flexural strength and fluoride release. J Dent 1999; 27:351-7. [PMID: 10377610 DOI: 10.1016/s0300-5712(98)00061-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE To investigate the flexural strength and fluoride release of four conventional glass-ionomer cements: Ketac-Molar (KM), HiFi (HF), Vivaglass Fil (VF), Ketac-Fil (KF) and a newly developed glass polyphosphonate cement, Diamond Carve (DC). METHOD Disc specimens (10 mm diameter, 1 mm thick) were prepared and mould stored at 37 degrees C. After one hour, the specimens were removed from their mould and immersed in 20 ml of deionised water until required for testing. Biaxial flexural strength was determined at 1 hour and at 1, 7, 30 and 90 days after the start of mixing. Measurements of fluoride release from the specimens were carried out at 2 hours and at 1, 3, 7, 14, 30, 60 and 90 days after the start of mixing using a fluoride ion selective electrode. The results were analysed using ANOVA and student 't' tests. RESULTS All the materials displayed different flexural strength patterns. KM and DC became stronger whilst KF and VF plateaued in strength with time. HF peaked in strength and then became weaker. At 90 days, the mean flexural strengths in decreasing order was as follows: KM > or = VF > or = DC > or = HF > KF. An initial fast rate of fluoride release followed by a slower but steady release of fluoride was observed in each of the materials. The mean cumulative fluoride release in decreasing order was as follows: VF > KF > or = HF > DC > KM. VF released significantly higher level and KM significantly lower level of fluoride than the other materials. CONCLUSIONS The acid used to form the cement could not be used to predict changes in cement strength behaviour with respect to time. DC increased in strength with time and its flexural strength at 90 days was comparable to that of HF and VF. The cumulative and rate of fluoride release varied for the materials. DC had a low fluoride release consistent with a fast setting material with good early resistance to water.
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Affiliation(s)
- V H Khouw-Liu
- Department of Paediatric Dentistry, Eastman Dental Institute, University of London, UK
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Rothwell M, Anstice HM, Pearson GJ. The uptake and release of fluoride by ion-leaching cements after exposure to toothpaste. J Dent 1998; 26:591-7. [PMID: 9754748 DOI: 10.1016/s0300-5712(97)00035-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES The cariostatic action associated with the glass-ionomer cement (GIC) is usually attributed to its sustained release of fluoride. However the ability of the GIC to act as a fluoride reservoir, taking it up from an external source (e.g. toothpaste, mouthwash) and subsequently releasing it over time, may also be a contributory factor. This study investigated the reservoir effect of various recently introduced ion-releasing cements: two resin-modified glass-ionomer cements (Fuji II LC, Vitremer), a compomer (acid-modified composite resin) (Dyract), and a recently introduced conventional glass-ionomer (Fuji IX). METHODS Specimens were exposed to a fluoridated toothpaste after 28 and/or 58 days. The release of fluoride into the storage water, both before and after exposure, was monitored using a differential electrode cell. RESULTS There was no significant difference in the fluoride releases from Vitremer and Fuji II LC. These materials released significantly more fluoride than Fuji IX and Dyract. All the materials released more fluoride on the day after exposure to an external fluoride source compared with the day before exposure. Release rates returned to baseline within 3 days. Within the time periods of the study, only the uptake/re-release of Fuji IX was adversely affected by late exposure. All the materials showed an enhanced uptake and release on repeated exposure to the external fluoride source. CONCLUSIONS All the materials under test (Dyract, Fuji II LC, Vitremer and Fuji IX) released significant amounts of fluoride and reacted positively to exposure to an external fluoride source.
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Affiliation(s)
- M Rothwell
- Biomaterials Department, Eastman Dental Institute, London, UK
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TENUTA LMA, PASCOTTO RC, NAVARRO MFDL, FRANCISCHONE CE. LIBERAÇÃO DE FLÚOR DE QUATRO CIMENTOS DE IONÔMERO DE VIDRO RESTAURADORES. ACTA ACUST UNITED AC 1997. [DOI: 10.1590/s0103-06631997000400005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A liberação de flúor de quatro cimentos de ionômero de vidro usados para restauração— Photac Fil (PF), Vitremer (VT), Fuji II LC (F2) e Fuji IX (F9) — foi testada durante 14 dias. As leituras do flúor liberado para água deionizada foram realizadas por um eletrodo específico para esse íon, acoplado a um analisador de pH/íons. Os dados foram submetidos a análise de variância e teste de Tukey-Kramer. A quantidade de flúor liberada foi significantemente maior para o PF em relação aos outros materiais (PF > VT > F9 > F2), sendo que VT/F9 e F2/F9 não apresentaram diferença significante entre si (p < 0,05).
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Abstract
Conventional glass-ionomer cements with varying amounts (5-15%) of borax (Na2B4O7.10H2O) as modifier were prepared. These mixtures were spatulated with an aqueous solution of polyacrylic acid with a powder to liquid (P/L) ratio of 1.5:1. Properties such as working time, setting time, compressive strength, diametral tensile strength, solubility and fluoride release of these cements were determined. It was observed that the working time and setting time of the resultant cements shortened with the addition of borax. Certain physical properties such as compressive and diametral tensile strength, solubility and disintegration of these glass-ionomer cements deteriorated with borax addition but fluoride release from them was unaffected.
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Affiliation(s)
- R K Bansal
- Department of Chemistry, Indian Institute of Technology, New Delhi
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Brown D, McCabe JF, Clarke RL, Nicholson J, Curtis R, Sherriff M, Hatton PV, Strang R, Ireland AJ, Watts DC. Dental materials: 1993 literature review. J Dent 1995; 23:67-93. [PMID: 7738270 DOI: 10.1016/0300-5712(95)98973-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Affiliation(s)
- D Brown
- United Medical and Dental Schools, Guy's Hospital, London
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