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OBJECTIVES The aim of the present study was to investigate the composition, morphology, bulk structure and ionic release of two brands of titanium orthodontic brackets: Orthos2 (Ormco, USA) and Rematitan (Dentaurum, Germany). METHODS Five specimens of each group were examined with computerized X-ray microtomography, to reveal the morphology and structure(More)
AIM To evaluate the pitting and crevice corrosion characteristics of stainless steel (SS) and NiTi endodontic files in R-EDTA and NaOCl irrigating solutions. METHODOLOGY The corrosion behaviour of two H-files produced from different SS alloys (Mani, AISI 303 SS, Dentsply Maillefer, AISI 304 SS) and one file produced from NiTi alloy (Maillefer) was(More)
AIM To evaluate the elemental composition, microstructure and hardness of Ni-Ti endodontic instruments and to assess the relevance of shape memory and superelastic properties. METHODOLOGY Ten brands of Ni-Ti endodontic instrument were evaluated (EndoSequence, Ergoflex K, FlexMaster, Hero 642, Hyflex X-File, K3 Endo, Liberator, NRT, Profile and ProTaper).(More)
OBJECTIVE To compare the galvanic coupling of conventional and metal injection molded (MIM) brackets with commonly used orthodontic archwires. MATERIALS AND METHODS Six of each type of bracket were suspended in lactic acid along with a sample of orthodontic wire (three nickel-titanium and three copper-nickel-titanium) for 28 days at 37 degrees C. The(More)
OBJECTIVES To compare the alterations in esthetic appearance and slot morphology/integrity of two main types of esthetic brackets caused after clinical use. MATERIALS AND METHODS Sixteen ceramic (CR) and 16 plastic (PR) central incisor brackets were obtained from 16 young adult patients at the end of treatment in a prospective randomized manner. As(More)
OBJECTIVE The purpose of this study was to determine the effect of various thermal treatments on the fatigue resistance of a nickel-titanium (NiTi) engine-driven endodontic file. STUDY DESIGN Fifteen groups of 5 files each of ISO 30 and taper .04 were tested in this study. The cutting tip (5 mm from the end) of files from 14 groups were heat treated for(More)
PURPOSE To compare various characteristics of two new-generation laboratory-processed resin composites (BelleGlass HP/SDS-Kerr and Sinfony/3M-ESPE). The properties evaluated were degree of C=C conversion, microhardness, roughness, biaxial flexural strength and polymerization shrinkage-strain. MATERIALS AND METHODS All specimens were subjected to a first(More)
OBJECTIVES To determine monomer conversion and polymerization shrinkage of a resin composite after different pre-heating procedures and storage intervals. METHODS For a commercial resin-based composite the immediate (5 min) and final (24h) degree of conversion was measured on top and bottom surfaces utilizing FTIR spectroscopy. Composite pre-heating(More)
The purpose of this study was to examine the effect of loading rate on the bond strength of brackets bonded to enamel. Forty premolars were used and brackets were bonded with a chemically cured or a light-cured adhesive, mounted on a testing machine, and debonded under shear stress at two loading velocities: a standard 1 mm/min, and a fast 200 mm/min which(More)
AIM To determine the elemental composition, microstructure, and hardness of two different brands of titanium (Ti) orthodontic brackets. MATERIALS AND METHODS Four specimens of each brand were embedded in epoxy resin and, after metallographic grinding and polishing, were studied under a metallographic microscope. The bonding base morphology of each bracket(More)