Search results for " titanium"

The Photocatalytic Activity of Novel, Substituted Porphyrin/TiO2-Based Composites

2010

Four novel porphyrins, 5-[3-(3-phenoxy)-propoxy]phenyl porphyrin, 5,15-di-[3-(3-phenoxy)-propoxy] phenyl porphyrin, 5,10,15-tri-[3-(3-phenoxy)-propoxy]phenyl porphyrin, 5,10,15,20-tetra-[3-(3-phenoxy)- propoxy]phenyl porphyrin, and their corresponding Cu(II) porphyrins, were synthesized and characterized spectroscopically. The photodegradation of 4-nitrophenol in aq. suspension was used to determine the photocatalytic activity of polycrystalline TiO2 samples which had been impregnated with the Cu(II) porphyrins, as sensitizers. The photocatalytic activity of the composite depends mainly on the amount of sensitizer on the TiO2 surface rather than the nature of the substituted porphyrins.

Mechanical and metallurgical properties of titanium alloy friction stir welded butt joints

2011

Octave Spanning Supercontinuum in Titanium Dioxide Waveguides

2018

International audience; We report on the experimental generation of an octave-spanning supercontinuum in a 2.2 cm-long titanium dioxide optical waveguide with two zero dispersion wavelengths. The resulting on-chip supercontinuum reaches the visible wavelength range as well as the mid-infrared region by using a femtosecond fiber laser pump at 1.64 µm.

The influence of NiTi alloy on the cyclic fatigue resistance of endodontic files

2020

Background: The aim of this study was to analyze the influence of NiTi alloy in endodontic rotary instruments on cyclic fatigue resistance. Methods: One hundred and sixty-four (164) sterile endodontic rotary files were selected and distributed into the following study groups: A: 25.08 F2 ProTaper Universal (PTU) (n = 41)

Differences in cyclic fatigue lifespan between two different heat treated NiTi endodontic rotary instruments: WaveOne Gold vs EdgeOne Fire

2019

Background Aim of this study is to investigate the cyclic fatigue resistance of the Gold treated WaveOne Gold and the Firewire treated EdgeOne Fire instruments. The null hypotesis was that there were no differences between the lifespan of Gold treated and FireWire treated instruments when subjected to cyclic fatigue tests. Material and Methods 40 new NiTi instruments with a length of 25 mm were tested: 20 Wave One Gold Medium (WOG), tip size 35 and variable taper (Dentsply Maillefer, Ballaigues, Switzerland) and 20 Edge One Fire (EOF) (EdgeEndo, Albuquerque, New Mexico) tip size 35 and the same variable taper. A mobile support for the electric handpiece and a stainless-steel block containin…

The Effect of surface topographical changes of two different surface treatments rotary instrument

2018

Background One of the major innovations in endodontics has been the introduction of nickel-titanium (NiTi) alloy. This study evaluated the surface topographical changes of two different surface treatments rotary instrument after instrumentation and sterilization. Material and Methods 240 Extracted teeth were included in this study. 90 new AlphaKite and Revo-S NiTi rotary instruments were selected and divided into two groups (Group A 45 AlphaKite and group B 45 Revo-S). Each group were divided into three subgroups: (A1, B1) n=5 files were used as a control, (A2,B2) n=20 files were used to prepare three root canals using endodontic rotary motor then sterilized by autoclave for one cycle under…

Comparison of working length control consistency between hand K-files and Mtwo NiTi rotary system

2016

Background: The purpose of this study was to investigate the consistency of working length control between hand instrumentation in comparison to engine driven Mtwo nickel-titanium rotary files. Material and Methods: Forty extracted maxillary molars were selected and divided onto two parallel groups. The working lengths of the mesiobuccal root canals were estimated. The teeth were fixed in a phantom head. The root canal preparation was carried out group 1 (n=20) with hand K-files, (VDW, Munich, Germany) and group 2 (n=20) with Mtwo instruments (VDW, Munich, Germany). Vestibulo-oral and mesio-distal directional x-ray images were taken before the preparation with #10 K-file, inserted into the …

Bacterial inactivation/sterilization by argon plasma treatment on contaminated titanium implant surfaces: in vitro study

2015

Background: Surface treatment by argon plasma is widely used as the last step of the manufacturing process of ti- tanium implant fixtures before their sterilization by gamma rays. The possibility of using such a technology in the daily clinical practice is particularly fascinating. The aim of the present study was to assess the effects of the argon plasma treatment on different titanium implant surfaces previously exposed in vitro to bacterial contamination. Material and Methods: Sterile c.p. titanium implant discs with turned (T, Sa: 0.8μm), sandblasted/acid-etched (SAE, Sa: 1.3μm) and titanium plasma sprayed (TPS, Sa: 3.0μm) surface were used in this study. A strain of Ag- gregatibacter a…

Repair of a spinal pseudomeningocele in a delayed postsurgical cerebrospinal fluid leak using titanium U-clips: Technical note

2020

Abstract Introduction Chronic cerebrospinal fluid leak (CCFL) represents a possible event following spine surgery, with an incidence rate ranging from 5 to 18%. In literature have been reported few modification techniques that involved the use of titanium U-clips with the aim to reduce dural traumatism during its closure but only after non-accidental durotomy. Case illustration We report the case of a 47-year-old female with history of L5-S1 microsurgical discectomy. After one year the patient was admitted to our unit because she presented progressive skin swelling in the lumbar region, intermittent headache and recurrent episodes of lipothymia. One-year MRI showed a voluminous subcutaneous…

Microbial Leakage at the Implant-Abutment Connection Due to Implant Insertion Maneuvers: Cross-Sectional Study 5 Years Postloading in Healthy Patient…

2015

The aim of this study was to test if stress on the prosthetic connection during insertion maneuvers can induce micro-warping at the implant connection. From September 2011 to July 2013, patients with implants loaded for at least 5 years that were placed with 2 different insertion implant mounters—MP (conventional) and ME (mountless)—were selected from all of those who had received dental implant therapy in the past and were attending routine check-up or spontaneous visits during the study period. Samples were obtained from inside the connection and the abutment surface using absorbent sterile paper tips. Quantitative real-time polymerase chain reaction was performed for total bacterial coun…