Search results for "Ionomer"
showing 10 items of 76 documents
Thermo-setting glass ionomer cements promote variable biological responses of human dental pulp stem cells.
2017
To evaluate the in vitro cytotoxicity of Equia Forte (GC, Tokyo, Japan) and Ionostar Molar (Voco, Cuxhaven, Germany) on human dental pulp stem cells (hDPSCs).hDPSCs isolated from third molars were exposed to several dilutions of Equia Forte and Ionostar Molar eluates (1/1, 1/2 and 1/4). These eluates were obtained by storing material samples in respective cell culture medium for 24h (n=40). hDPSCs in basal growth culture medium were the control. Cell viability and cell migration assays were performed using the MTT and wound-healing assays, respectively. Also, induction of apoptosis and changes in cell phenotype were evaluated by flow cytometry. Changes in cell morphology were analysed by im…
Evaluation of marginal sealing quality of restorations with low shrinkage composite resins
2020
Background This study compared the quality of marginal sealing in the gingival wall of class II preparations of two low-shirinkage resins of the bulk fill type with a conventional resin isolated or associated with a glass ionomer cement (GIC). Material and methods 40 human molars were divided into 4 groups and 80 occlusal-mesial and occlusal-distal restorations were performed with the following materials: SureFil SDR flow, Filtek Bulk Fill Posterior, Z250 resins and Riva Light Cure GIC. 40 restorations were evaluated in Scanning Electron Microscopy (SEM) with Elemental Microanalysis Spectrometry (EDS) initially and the remainder after a period of 6 months of aging in a 37 ± 5°C oven. An ave…
In-vitro-Studie der Interferenz von kieferorthopädischer Bebänderung und Füllungswerkstoffen
1992
Discoloring and layers on bands and restorations during fixed orthodontic therapy are well known clinical phenomenon. Because of the complexity of etiological factors an in-vitro model was used in this study. Aim of the study was to examine the amounts and sort of metals which are dissolved. Therefore, respectively 25 normed MOD-cavities in Frasaco-teeth were filled with a non-gamma-2-amalgam (Amalcap plus, Vivadent) and condensed manually or mechanically. In addition, ten crowns of a high golden (Maingold SG, Heraeus) as well as a palladium basis alloy (Albabond A, Heraeus) were casted. Then they were banded with stainless steel bands (Dentaurum) and cemented with a glass ionomer cement (K…
Bond strength and elemental analysis of oxidized dentin bonded to resin modified glass ionomer based restorative material
2019
Background This study aimed to investigate the influence of hesperidin application on the bonding of resin-modified glass ionomer-based restorative material to dentin treated with oxygen-induced endodontic irrigants. Material and Methods One hundred human permanent molars were categorized into five groups (n= 20/group), treated with various irrigants as follows: Group C; distilled water (control group), Group SH; 5.25% NaOCl, Group SH+H; 5.25% NaOCl + 5 % hesperidin, Group HP; 10% H2O2, Group HP+H; 10% H2O2 + 5 % hesperidin. Specimens were bonded with RMGI based restorative material. For each group, half of the specimens were evaluated for µSBS by a universal testing machine and the other h…
Influence of the volume of restorative material on the concentration of stresses in the restorative interface.
2020
Background To evaluate the microtensile strength in the adhesive interface depending on the volume of the composite resin used to restore class I cavities. Material and Methods Forty-eight human third molars received a standardized class I cavity preparation and they were separated into six experimental groups: G1 - single-bottle adhesive system; G2 - bonding system with load; G3 - single-bottle adhesive associated with low-viscosity composite resin; G4 - loaded adhesive associated with low-viscosity composite; G5 - resin-modified glass ionomer associated with single-bottle adhesive; and G6 - resin-modified glass ionomer associated with loaded adhesive. All cavities were restored with a uni…
The effect of bacterial cellulose nanocrystals on the shear bond strength of resin modified glass ionomer cement to dentin
2020
Background The present study aimed to investigate the effect of bacterial cellulose nanocrystals (BCNC) on the shear bond strength (SBS) of resin modified glass ionomer cement (RMGIC) to dentin. Material and Methods A total of 48 freshly extracted intact third molars were randomly divided into four main groups with three different concentrations (0.3%, 0.5% and 1% wt) of BCNC with RMGIC and control group without BCNC. These specimens were kept in distilled water at 37° C for 24h. Shear bond strength was examined, using the universal testing machine. Kruskal-Wallis test and Dunn`s post-hoc test were applied for analysis of data. P<0.05 was considered as the level of significance. Results The…
Clinical study on resin composite and glass ionomer materials in II class restorations in permanent teeth
2020
Background Glass ionomer cements (GIC) used for restoration of missing dental structures have high biocompatibility and remineralization potential. However, low mechanical resistance excludes their use for long-term restorations of extensive lesions, particularly on approximal surfaces in permanent dentition. GIC with increased viscosity have much better physical properties, which involves better bonding and wear resistance, so they can be considered as an alternative to composite resin materials. The aim of this study was to perform a clinical and radiological assessment of restorations in permanent teeth, made with an increased viscosity GIC - Equia Fil (Ivoclar Vivadent) with Equia Coat …
Morphology and mechanical properties of extruded ribbons of LDPE/PA6 blends compatibilized with an ethylene-acrylic acid copolymer
2003
Two grades of low density polyethylene (LDPE) were blended with polyamide-6 (PA) in the 75/25 and 25/75 wt/wt ratios and shaped into ribbons with a Brabender single screw extruder. An ethylene-acrylic acid copolymer (EAA) was used in the 2 phr concentration as a compatibilizer precursor (CP). The morphology of the ribbons and its evolution during high temperature annealing were investigated by scanning electron microscopy (SEM). The results confirmed that EAA does actually behave as a reactive compatibilizer for the LDPE/PA blends. In fact, in the presence of EAA, the interfacial adhesion is improved, the dispersion of the minor phase particles is enhanced and their tendency toward fibrilla…
In vitro investigation of the impact of remaining tooth structure on the tensile failure loads of overdenture copings
2019
Background The purpose of this in vitro study was to evaluate the impact of the remaining tooth structure on the retention of overdenture cast metal copings. Material and Methods A freshly extracted intact mandibular human canine (length 25 mm) was selected and endodontically treated. An incisal reduction of 4 mm with no ferrule preparation was performed and a post space of 12 mm was created. By using polyvinyl siloxane duplication material and autopolymerizing polymethylmethacrylate resin, ten resin teeth analogs (control group) were obtained. A second set of ten resin teeth analogs (group 1) was created by preparing on the original natural tooth a 360o ferrule design of 1 mm in height and…
Structural and electrochemical investigation on re-cast Nafion membranes for polymer electrolyte fuel cells (PEFCs) application
2006
Abstract Starting from a 5 wt% ion power Nafion® solution and dissolving the dry residue in a suitable solvent (10 wt% solution in dimethylacetammide), re-cast Nafion films were developed for polymer electrolyte fuel cells (PEFCs) application. The used Doctor-Blade casting technique allowed to prepare scaled-up membranes comparable to the commercial Nafion ones with good mechanical resistance, thickness homogeneity and an excellent reproducibility. The differences between the re-cast membrane nanostructure and that of the commercial Nafion were investigated by synchrotron small-angle X-ray scattering. The obtained re-cast membrane shows at ambient conditions a semi-crystalline structure wit…