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• Experimental RMGICs containing alternate monomers to HEMA were developed. • Release of monomers was tested in deionized water (DW) or ethanol/DW using HPLC. • Cytotoxicity of all materials was studied on normal human oral fibroblast (NHOF-1). • HPLC methods confirmed the presence of all monomers released from RMGICs. • Some promising compositions released less monomers compared to commercial RMGICs. Resin-modified glass ionomer cements (RMGICs) present several advantages (e.g. fluoride release), but their reported cytotoxicity has been associated with hydroxyethyl methacrylate (HEMA) monomer release. Therefore, different monomers were tested for use in RMGICs in order to improve their biocompatibility and reduce monomer release. Eight experimental liquid compositions were prepared replacing different percentages of HEMA (conventional monomer used in commercial RMGICs) with hydroxypropyl-methacrylate (HPM) and/or tetrahydrofurfuryl-methacrylate (THFM), which are known to have better biocompatibility. Moreover, two commercial materials (Fuji-Plus and RelyX) and two compositions, based on these (home), were included as controls. Monomer release of all materials (commercial, home and experimental) were tested using high-performance liquid chromatography (HPLC) methods after immersing discs in deionized-water (DW) or ethanol:DW. Cytotoxicity of the materials extracts was tested on normal human oral fibroblast line (NHOF-1) using 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay. Three experimental materials containing THFM (F3, R3 and R4) showed less or similar monomer release compared to corresponding commercial products. Furthermore, two experimental materials (F3 and F4) showed similar effects on NHOF-1 cells compared to the negative control medium. The lower monomer release and higher cell viability of some experimental THFM compositions are encouraging. THFM partially replacing HEMA is potentially a suitable alternative for producing biocompatible RMGICs. [ABSTRACT FROM AUTHOR]

In view of the need for aesthetics, restorations of teeth will typically be completed using tooth colored restorative materials. With the advent of biomimetic restorative materials, such as glass ionomer cements (GIC), much greater emphasis is now being placed on how well such materials can resist the challenge of acids that are present in foods and drinks, or gastric contents that are regurgitated. This laboratory study compared the dissolution and behavior of five GIC materials (GC Fuji® VII, GC Fuji® Bulk, GC Fuji® IX Fast, Fuji® IX Extra and GC Equia® Forte Fil) when exposed to three acids (citric acid, phosphoric acid and lactic acid), versus ultrapure deionized water, which was used as a control. Discs of each material GIC were submerged in solutions and percentage weight changes over time determined. Subsequently, the GIC materials were also placed as a part of standardized Class II sandwich restorations in bovine teeth (n = 20), and submerged in the solutions, and the extent of GIC dissolution and protection of the adjacent tooth was scored. Weight loss increased with time and with acid concentration. Overall, the most soluble material was GC Fuji® IX Extra, while GC Fuji® IX Fast and GC Fuji® Bulk were less soluble, and the least soluble material was GC Equia® Forte Fil. The most destructive solution for both the discs and for GIC restorations in teeth was 10% citric acid, while the least destructive acid was 0.1% lactic acid. The more recent GIC materials GC Fuji® Bulk and GC Equia® Forte Fil showed increased acid resistance over the older GIC materials, and this further justifies their use in open sandwich Class II restorations in more hostile environments. [ABSTRACT FROM AUTHOR]

Fluoride is considered to be an important caries-preventive agent as it decreases the solubility of tooth minerals. The aim of the present study was to investigate the amount of fluoride ion released, over a 9 day period, from four restorative glass ionomer cements (GIC). Elemental analysis, for O, F, Na, Mg, Al, Si, P, S, Ca, Sr, Zn, and Zr, was performed on three conventional glass ionomers [ChemFil ROCK (Dentsply), Fuji IX (GC), and Riva self-cure (SDI)] and one resin-modified glass ionomer, Ketac Nano (3M ESPE) using Energy Dispersive Spectrometry (EDS). A digital caliper was used to measure the length and diameter of each sample. The fluoride release, in µg/cm2, from the samples in deionized water was measured for 9 days using a fluoride ion selective electrode and analyzed using the SPSS. The release of fluoride on day 1 from Fuji IX was significantly higher (6.19±1.04 µg/cm2) than that from Ketac Nano (3.88±0.13 µg/cm2), Riva self-cure (3.19±0.66 µg/cm2), and ChemFil ROCK (1.68±0.08 µg/cm2). The value found for Fuji IX was comparable to that found in various other experimental settings. The difference in fluoride release on day 1 between Ketac Nano and Riva self-cure was not significant. The fluoride release from day 5 to day 9 stabilized at a lower level for all the ionomers and no statistically significant difference in the level of release was present between them during that period. I concluded that there is a wide range in the release of the fluoride ion among restorative glass ionomer cements with the highest level of release on day 1 being observed in Fuji IX, followed by Ketac Nano, Riva self-cure, and ChemFil ROCK. [ABSTRACT FROM AUTHOR]

Over the last years, diverse commercial resin-based composites have dominated as dental filling materials. The purpose of the present study was to determine organic and inorganic eluates from five restorative materials using GC/MS and ICP–OES and to compare the effect on cell survival of human gingival fibroblasts of a conventional and a bioactive resin. Five commercially available restorative materials were employed for this study: ActivaTM Bioactive Restorative, ENA HRi, Enamel plus HRi Biofunction, Fuji II LC Capsule, and Fuji IX Capsule. Disks that were polymerized with a curing LED light or left to set were immersed in: 1 mL methanol or artificial saliva for GC/MS analysis, 5mL deionized water for ICP–OES, and 5mL of culture medium for cell viability. Cell viability was investigated with a modified staining sulforhodamine B assay.The following organic substances were detected: ACP, BHT, BPA, 1,4-BDDMA, CQ, DBP, DMABEE, HEMA, MCE, MeHQ, MOPA, MS, TMPTMA, and TPSb and the ions silicon, aluminum, calcium, sodium, and barium. Activa Bioactive Restorative was found to be biocompatible. Elution of organic substances depended on material's composition, the nature of the solvent and the storage time. Ions' release depended on material's composition and storage time. The newly introduced bioactive restorative was found to be more biocompatible. [ABSTRACT FROM AUTHOR]