ABSTRACT
The purpose of this study was to compare the cytotoxicity of an epoxy resin-based sealer (AH Plus) and a silicone-based sealer (Roeko Seal Automix, RSA). Cytotoxicity was assessed using the MTT assay for mitochondrial enzyme activity and haemocytometer viable cell counting after 24, 48 and 72-h exposure to L929 cells. AH Plus and RSA showed no statistically significant difference in the degree of toxicity. Both sealers had a low toxic influence on the cells during the experimental period. This study indicates that epoxy resin-based sealer AH Plus and the silicone-based sealer RSA have similar levels of cytotoxicity to mouse fibroblasts.
Subject(s)
Biocompatible Materials , Cells, Cultured/drug effects , Epoxy Resins/toxicity , Fibroblasts/drug effects , Root Canal Filling Materials/toxicity , Silicones/toxicity , Analysis of Variance , Animals , Mice , Mutagenicity TestsABSTRACT
AIM: The present study was designed to evaluate and compare the corrosion rates of the stainless-steel endodontic files when immersed in 0.2% chlorhexidine gluconate, 5.25% NaOCl, chlorinated soda with KOH, and 17% EDTA irrigating solutions. METHODOLOGY: Corrosion rates of stainless-steel K-files in irrigating solutions were determined electrochemically by the Tafel extrapolation method. The cutting flutes of files were immersed in solutions and used as an electrode. A saturated calomel electrode (SCE) was used as a reference, and a platinum plate was used as a counter electrode. In order to determine corrosion rates, the linear part of anodic currents obtained from electrochemical current-potential curves, was extrapolated to corrosion potentials. RESULTS: The corrosion rates of stainless-steel files in the tested solutions from the highest to the lowest were: 0.2% chlorhexidine gluconate>5.25% NaOCl>chlorinated soda with KOH>17% EDTA. The differences between the corrosion rates of files were not found to be statistically different for chlorinated soda with KOH and EDTA (P >0.05), but statistically significant differences were found amongst other groups. CONCLUSIONS: The results of the present study indicated that 0.2% chlorhexidine gluconate, 5.25% NaOCl and chlorinated soda with KOH cause severe corrosion on the surface of selected stainless-steel files.
Subject(s)
Chlorhexidine/analogs & derivatives , Dental Alloys , Dental Instruments , Root Canal Irrigants , Root Canal Preparation/instrumentation , Stainless Steel , Analysis of Variance , Corrosion , Dental Alloys/chemistry , Edetic Acid , Electrochemistry , Hydroxides , Microscopy, Electron, Scanning , Potassium Compounds , Sodium Bicarbonate , Sodium Hypochlorite , Stainless Steel/chemistry , Surface PropertiesABSTRACT
In this study, the effect of different root canal sealers on 1%, and 2% methylene blue (MB) solutions and India ink were analyzed using spectrophotometry. One hundred and twelve specimens were used in this study. One hundred and five plastic tubes were filled with Sealapex, Endomethasone, Sultan, AH Plus or Ketac Endo. Twenty-one plastic tubes were used for each group. Seven plastic tubes were not filled, serving as controls. Seven specimens were taken from each group randomly and immersed in 0.8 ml 1% MB, 2% MB or black India ink. The optical density of the solutions after 0, 24, 48 and 72 hours of immersion was measured in a spectrophotometer at 416 nm. The optical density (OD) of the solutions was stable for the control group. The OD values for the 1% MB solutions were increased in the Sealapex and Sultan groups. The OD values for the 2% MB solutions were also increased for Sealapex and AH Plus. OD values were decreased for all India ink groups. The change in OD values relating to each time interval was statistically analyzed for each test material using two-way ANOVA. In the dye leakage studies, India ink, when compared to MB solutions, was a more reliable tracer as no dissolution of the root canal sealers occurred in contact with India ink.
Subject(s)
Administration, Topical , Carbon , Coloring Agents/chemistry , Hydrocortisone , Methylene Blue/chemistry , Root Canal Filling Materials/chemistry , Thymol/analogs & derivatives , Analysis of Variance , Anti-Inflammatory Agents/chemistry , Calcium Hydroxide/chemistry , Dental Leakage/classification , Dexamethasone/chemistry , Drug Combinations , Epoxy Resins/chemistry , Eugenol/chemistry , Formaldehyde/chemistry , Glass Ionomer Cements/chemistry , Humans , Immersion , Optics and Photonics , Reproducibility of Results , Salicylates/chemistry , Solubility , Spectrophotometry , Thymol/chemistry , Time Factors , Zinc Oxide/chemistryABSTRACT
The fracture toughness of five different resin-based inlay/onlay materials was investigated by means of critical stress intensity factor (KIC) using the SEN three-point bending test procedure (BS 5447: 1977). KIC values were determined from specimens prepared by both the direct and indirect techniques. Tests were performed immediately, after 1 day, 1 month and 3 month time intervals. Also, fractured surfaces of specimens were observed using SEM photographs.
Subject(s)
Composite Resins/chemistry , Inlays , Acrylic Resins/chemistry , Bisphenol A-Glycidyl Methacrylate/chemistry , Dental Stress Analysis , Materials Testing , Methacrylates/chemistry , Polyurethanes/chemistry , Stress, Mechanical , Surface Properties , Time FactorsABSTRACT
In this article effect of light exposure time on hardness of visible light cured composites with different microfiller ratios were investigated. For this purpose specimens with heights 1, 2, 3 mm and 6 mm in diameter were prepared. During the preparation of the specimens, half of the specimens were cured with visible light for 40 seconds and the other half for 60 seconds. Surface hardness values were measured from the top and bottom of the specimens immediately after the light source was removed with Barcol Hardness tester. Surface hardness were also measured 24 hours and 7 days later. Results were statistically evaluated.
