Glass Ionomer Cement

The aim of the study was to assess, compare and evaluate the adhesive strength and compressive strength of different brands of glass ionomer cements to a ceramometal alloy. (A) Glass ionomer cements: GC Fuji II (GC Corporation, Tokyo), Chem Flex (Dentsply DeTrey, Germany), Glass ionomer FX (Shofu-11, Japan), MR dental (MR dental suppliers Pvt Ltd, England). (B) Ceramometal alloy (Ni–Cr: Wiron 99; Bego, Bremen, Germany). (C) Cold cure acrylic resin. (E) Temperature cum humidity control chamber. (F) Instron Universal Testing Machine. Four different types of Glass ionomer cements were used in the study. From each type of the Glass ionomer cements, 15 specimens for each were made to evaluate the compressive strength and adhesive strength, respectively. The 15 specimens were further divided into three subgroups of five specimens. For compressive strength, specimens were tested at 2, 4 and 12 h by using Instron Universal Testing Machine. To evaluate the adhesive strength, specimens were surface treated with diamond bur, silicone carbide bur and sandblasting and tested under Instron Universal Testing Machine. It was concluded from the study that the compressive strength as well as the adhesive bond strength of MR dental glass ionomer cement with a ceramometal alloy was found to be maximum compare to other glass ionomer cements. Sandblasting surface treatment of ceramometal alloy was found to be comparatively more effective for adhesive bond strength between alloy and glass ionomer cement.

Glass polyalkenoate cements (GPCs) have been used in dentistry for over 40 years. These novel bioactive materials are the result of a reaction between a finely ground glass (base) and a polymer (acid), usually poly(acrylic acid) (PAA), in the presence of water. This article reviews the types of PAA used as reagents (including how they vary by molar mass, molecular weight, concentration, polydispersity and content) and the way that they control the properties of the conventional GPCs (CGPCs) formulated from them. The article also considers the effect of PAA on the clinical performance of CGPCs, including biocompatibility, rheological and mechanical properties, adhesion, ion release, acid erosion and clinical durability. The review has critically evaluated the literature and clarified the role that the polyacid component of CGPCs plays in setting and maturation. This review will lead to an improved understanding of the chemistry and properties of the PAA phase which will lead to further innovation in the glass-based cements field.

The ability of a restorative material to withstand fracture is of crucial importance especially in stress-bearing area. Therefore, the study aims to analyse the fracture toughness of a large number of dental restorative materials categories. The fracture toughness (K(IC)) of 69 restorative materials belonging to ten materials categories-micro-hybrid, nanofilled, microfilled, packable, ormocer-based, and flowable resin-based composites (RBC), compomers and flowable compomers, as well as glass ionomer cements (GIC) and resin-modified GIC was measured by means of the single-edge notched-beam method after storing the samples (n = 8) for 24 h in distilled water. Data were analyzed with the one-way analysis of variance (ANOVA) followed by the Tukey's test and partial eta-squared statistics (p < 0.05). Large variations between the tested materials within a material category were found. The lowest fracture toughness was reached in the GIC group, followed by the microfilled RBCs, resin-modified GIC, and flowable compomers, which do not differ significantly among each other as a material group. The ormocer-based, packable, and micro-hybrid RBCs performed statistically similar, reaching the highest fracture toughness values. Between the two categories of flowables-composites and compomers-no differences were measured. The correlation between K(IC) and filler volume (0.34) and respective filler weight (0.40) was low. K(IC) increased with the volume fraction of fillers until a critical value of 57%, following with a plateau, with constant values until ca. 65% volume fraction. Above this value, K(IC) decreased slightly. Due to the very large variability of the fracture toughness within a material type, the selection of a suitable restorative material should have not been done with respect to a specific material category, especially in stress-bearing areas, but by considering the individual measured material properties.

The surface texture changes of three kinds of glass-ionomer cements were compared with glazed and polished cement surfaces after thermal cycling in a storage media [lactic acid solution (pH 4.0)]. The changes were measured with regard to the surface roughness, colour-change, gloss, hardness, toothbrush wear, and SEM (scanning electron microscope) observation in the laboratory. The glazed cement surface was not affected after thermal cycling in the lactic acid solution.

Traditionally, endodontic treat- ment requires instrumentation of the root canal to remove infectious debris, leaving clean canal walls. After the instrumenta- tion and irrigation of debris from the can- al is complete, the root canal is filled with gutta-percha inserted with an endodontic sealer. These sealers to be used with gutta percha have included calcium hydroxides, zinc-oxide and eugenol cements, and glass ionomer cements. When Resilon™ (Pen- tron® Clinical Technologies, LLC, Walling- ford, CT) was introduced 4 years ago, much concern was expressed for this obturation material, ranging from how would it geo- metrically fill canals compared to gutta- percha to whether it could provide a seal equal to zinc oxide/eugenol (ZOE) or AH- 26 (epoxy resin root canal sealer). In the meantime, the literature has been filled with numerous peer-reviewed articles re- porting on many aspects involving Resi- lon. This article addresses the concerns and discusses some of the literature that ...

ARTICLE INFO ABSTRACT Purpose: Although glass ionomer cements have undergone various modifications and have different properties until today, their physical properties, especially the surface hardness, are low compared to other restorative materials and therefore the use as direct restorative material is limited. The chemical structure of the powder part of the cement formed from fluorosilicate glass powder is similar to glass. However, there are trace amounts of B 2 O 3 (boroxide) and fluoroborate-containing compounds in the powder, there is no study on the subject in the literature. Today, it is expected to increase the physical properties and the surface hardness by the addition of BPO 4 (borophosphate), which is used commercially for strengthening of glass, with the addition of traditional glass ionomer cement powder. Materials and Methods: The aim of this study was to investigate in vitro the effect of the addition of BPO 4 on surface hardness after addition of BPO 4 at 5%, 10% and 15% by weight of two different conventional glass ionomer cement materials Micron Superior and Nova Glass F. Results: As a result of testing the samples in this study, it was observed that there was a statistically significant increase in the surface microhardness of the glass ionomer cements reinforced by adding 5% by weight of BPO 4 to the powder part. Conclusions: The development of the physical properties of Glass ionomer cements, which have a wide range of indications in dentistry, will lead to more successful restorations, especially in pediatric dentistry clinics. More studies are needed to investigate the effect of borophosphate reinforced Glass ionomer cements on their physical and chemical properties.

The aims of this study were to evaluate clinically and microbiologically the effects of two resin-modified glass-ionomer cements (RMGICs) used as liners after incomplete dentine caries removal and to identify Streptococcus mutans and Streptococcus sobrinus strains isolated from dentine samples, before and after indirect pulp treatment. Twenty-seven primary molars with deep carious lesions, but without signs and symptoms of irreversible

Glass Ionomer Cements (GICs) are one of the most important dental restorative materials. Improvement of biological and mechanical properties of these materials has been taken into consideration. The aim of this work was to preparation and characterization of GICs by melting method and evaluation of adding Hydroxyapatite (HA) micro and nanoparticles on compressive strength of GICs. In this research, the ceramic part of GIC was prepared using melting method, and micro and nano-hydroxyapatite were synthesized from natural bone. HA micro and nanoparticles were added to GICS in different weight percents (0, 1, 3, 5 and 7 wt.%). The microstructure of synthesized products, chemical composition of the ceramic part of glass ionomer cement and the size and shape of HA nanoparticles were studied by Scanning Electron Microscopy (SEM), X-ray Fluorescence (XRF) and Transmission Electron Microscopy (TEM), respectively. The phase analysis of GICs composite was carried out by X-ray Diffraction (XRD) technique. Finally, the compressive strength of composite samples were determined and compared. TEM confirmed the nanometric scale of hydroxyapatite particles. Results of the compression test showed that adding HA micro and nanoparticles with the values of less than 5% by weight had no distractive effect on compressive strength of GICs. The final result of this research was gaining GICs containing HA micro and nanoparticles with improved equivalent mechanical properties. The improvement of GICs properties in dentistry applications can be achieved by adding bioactive materials like HA micro and nanoparticles.

Objectives. Resin-modified glass ionomer cements (RMGI) are hybrid materials prepared by incorporation of polymerizable components (typically 2-hydroxyethyl methacrylate (HEMA) with possible addition of multifunctional methacrylates) into a conventional acid–base mixture (a polymeric acid with powdered calcium fluoro-aluminosilicate glasses). During setting, the photopolymerization process and the acid–base reaction affect each other. The aim of this work was to examine the effect of a 45% aqueous solution of poly(acrylic acid) (PAA) and the liquid component of a commercial glass ionomer cement on HEMA and triethyleneglycol dimethacrylate (TEGDMA) photopolymerization.Methods. The polymerization was initiated by 2,2-dimethoxy-2-phenylacetophenone (DMPA) and camphorquinone (CQ)/coinitiator system. The reaction course was monitored under Ar and air by isothermal differential scanning calorimetry.Results. The main effect of addition of polyacid solution (PAA and commercial) up to 10 wt% to HEMA on the polymerization initiated with DMPA was earlier onset of autoacceleration. For the process initiated by the CQ-based system, the addition of 5 wt% of PAA solution strongly accelerated the polymerization and increased the conversion, both in Ar atmosphere as well as in air. TEGDMA photopolymerization was not influenced or slightly retarded by the presence of 3 wt% of PAA solution (the upper limit of solubility), depending on the initiating system used.Significance. Under initiation conditions used in curing of commercial dental products (CQ-based two component initiating system), the presence of polyacid-aqueous solution in HEMA-based photocurable component increases markedly the polymerization rate and the conversion both in Ar atmosphere as well as in air. This result contributes to a characterization of the setting process of RMGIs.

The aim of this study was to evaluate in vitro the antimicrobial activity of glass ionomer (GIC) and zinc oxide-eugenol (ZOE) cements against Candida albicans. Standardized GIC and ZOE specimens were maintained in contact with C. albicans suspension (1 ´ 106 cells/ml) at 37°C for 24 h, 48 h or 7 days. A control group without any testing cement was included. After the incubation period, aliquots of 0.1 ml were plated on Sabouraud's agar, and then the number of colonies was counted. The results were expressed as values of logarithms of colony-forming units per milliliter (log CFU/mL) and were analyzed statistically by Kruskal-Wallis ANOVA. After 48 h of incubation, the ZOE group presented no growth of C. albicans. GIC and control groups presented similar mean values at all tested periods. According to the results obtained, it could be concluded that, under the experimental conditions, ZOE cement was more effective in vitro against C. albicans than GIC.

The aim of this study was to synthesize glass ionomer-silk fiber composite and examining the effect of adding natural degummed silk fiber on the mechanical properties of glass ionomer cement (GIC). For this purpose, natural degummed silk fibers with 1 mm length and 13-16 µm diameter were added to the ceramic component of a commercial glass ionomer cement in 1, 3, and 5 wt. %. Compressive strength (CS), three-point flexural strength (FS) and diametral tensile strength (DTS) of the prepared glass ionomer-silk fiber were measured. Analysis of variance (ANOVA) was used to compare the obtained results. Moreover, SEM technique was used for the investigation of the surface morphology of the as-prepared composite and the fractured area. The results showed that the highest compressive strength, flexural strength and diametral tensile strength were obtained using 3, 3, and 5 wt. % of silk fiber, respectively. However, at 3 wt. % of silk fiber, all three measures of strength exhibited a significant increase compared to the commercial GIC. Therefore, it can be suggested that the addition of 3 wt. % silk fiber to the ceramic component of GIC is desired for dental restorations and orthopedic implant applications, where the maximum strength in all three modes of loading would be beneficial.

Data sourcesThe Cochrane Central Register of Controlled Trials (CENTRAL) and Medline were searched. Manufacturers of dental floss were also contacted to identify any trials.Study selectionOnly clinical trials and field studies of two years or longer were included.Data extraction and synthesisThe studies were analysed to determine the retention rates of the various materials studied (UV-light-, light- and auto-polymerising resin-based sealants, fluoride-releasing materials, compomers, flowable composites and glass-ionomer-cement-based sealants). A meta-analysis was conducted using a random effects model for longitudinal logistic regression and Bayesian statistics.ResultsNinety-eight clinical reports and 12 field trial reports were identified; 49 trials used random allocation. Auto-polymerising sealants had the observation time of up to 20 years. % year retention rates are shown in the table. Retention rates for UV-light-polymerising materials, compomers and glass-ionomer-cement-based sealants (5-year retention rates were <19.3%) were poor, while retention rates for UV-light-polymerising materials, compomers and glass ionomer cement-based sealants were classified as inferior.ConclusionsThis meta-analysis suggested that resin-based sealants can be recommended for clinical use. The faster and less error-prone clinical application of light-polymerising materials, however, makes them the preferred choice for daily dental practice.

This in vitro study compared the effectiveness of 6 luting systems on the retention of prefabricated titanium posts. A total of 120 single-rooted teeth were sectioned at the cementoenamel junction and treated endodontically. Roots were mounted in copper cylinders, and prefabricated, parallel-sided titanium posts were cemented according to the manufacturer's instructions. Two resin-ionomer hybrid cements and 2 resin cements were tested with corresponding dentin bonding agents. A glass ionomer cement was also tested, and zinc-phosphate cement served as the control. Samples were tested in an Instron universal testing machine to catastrophic tensile failure. Advance cement with Prime and Bond systems was found to be statistically more retentive than all other groups tested (P < .05). Cement It with Bond It and Permalute with Permalute Primers A and B systems demonstrated significantly greater retention than Ketac Cem cement, Resinomer with One-Step system and zinc-phosphate cement (P < .05). There was no statistically significant difference among Ketac Cem cement, Resinomer with One-Step system, and zinc-phosphate cement.

Adhesives and lining/base materials should relieve the stresses concentrated at the tooth/restoration interface. The study aimed at comparing the mechanical properties of eight adhesives and six glass-ionomer cements (GICs). The adhesives were applied on dentin disks, whereas 2 mm × 3 mm × 2 mm GICs specimens were prepared in a teflon mold. Vicker’s hardness (VH), elastic modulus (E), creep (Cr) and elastic work (We/Wtot) were measured with a micro hardness indenter. One-way ANOVA and Tukey’s test were used to compare the mechanical properties within each materials’ type and among the materials’ classes. Enamel and dentin were used as references. Significant differences were detected within each materials’ type and among the materials’ classes and enamel and dentin. GICs were superior to adhesives in VH and E and showed a VH similar to dentin. GICs presented mechanical properties more similar to enamel and dentin than adhesives.

The objective of the study was to evaluate initial curing shrinkage and volumetric change during water storage of six resin-modified glass ionomer cements (Dyract, DeTrey Dentsply; Fuji II LC, GC Dental Int.; Ionosit Fil, DMG; VariGlass VLC, DeTrey Dentsply; Vitremer, 3M Dental Products; Photac-Fil, ESPE), a hybrid composite (blend-a-lux, Blendax) and a chemical-cured glass ionomer cement (ChemFil Superior, DeTrey Dentsply). The curing shrinkage was determined 5 min and 24 h after polymerization and mixing, respectively. Volumetric changes were examined after 14 d and 28 d water storage. Curing shrinkage and volumetric changes were evaluated using the hydrostatic principle. In addition, the total water content of the materials was measured after 28 d water storage. Curing shrinkage of most of the resin-modified glass ionomers was greater than the hybrid composite and the chemical-cured glass ionomer cement. After a 28 d water storage, the resin-modified glass ionomers showed volumetric expansion and the chemical-cured glass ionomer showed volumetric loss. All of the examined glass ionomer materials had a higher total water content than the composite. SIGNIFICANCE. The large curing shrinkage of the resin-modified glass ionomer materials measured in this in vitro study could affect the marginal integrity of glass ionomer restorations.

This study investigated the time elapsed after setting of glass ionomer cements on the bond strength to composite resin restorations. Bovine incisors received cavity preparations on the buccal surface (6 mm  6 mm  2 mm) and the specimens were tested according to cement type (conventional and resin-modified) and time elapsed before performing the restorations: GC10m: conventional glass ionomer cement and 10 min time elapsed after setting; GC24h: conventional cement and 24 h after setting; GC7d: conventional cement and 7 days after setting; GRM10m: resin-modified glass ionomer cement and 10 min after setting; GRM24h: resin-modified cement and 24 h after setting; and GRM7d: resin-modified cement and 7 days after setting. Specimens were subjected to micro-shear testing and the data were analyzed by Analysis of Variance and Tukey′s test (p ¼0.05). Bond strength of restorations performed on conventional cement after 10 min of time elapsed presented the lowest mean values and differed statistically from values at 24 h and 7 days. Resin-modified cement after 24 h presented the highest mean values and differed statistically from values at 10 min and 7 days. The time elapsed after setting of glass ionomer cement may interfere in the bond strength to composite restorations.