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Stainless Steel Wires (stainless + steel_wire)
Selected AbstractsFracture Resistance of Fiber-Reinforced PMMA Interim Fixed Partial DenturesJOURNAL OF PROSTHODONTICS, Issue 4 2006Tamer A. Hamza BDS Purpose: To compare different fiber reinforcements on fracture toughness of interim polymethyl methacrylate materials and then use the best combination to determine the optimal position for fiber placement in an interim 3-unit fixed partial denture (FPD). Materials and Methods: In the first stage of the study, five groups of notched fracture toughness specimens were fabricated and loaded to failure (Instron): (1) unreinforced (control); (2) reinforced with pre-impregnated silanized E-glass fibers (Fibrestick); (3) cold plasma-treated woven polyethylene fibers (Ribbond triaxial); (4) pre-impregnated silanized plasma-treated woven polyethylene fibers (Construct); and (5) 1.0-mm-diameter stainless steel wire. In the second stage, the optimal position (occlusal, middle, or cervical third of pontic) for reinforcement with glass fibers (regimen 2) was tested by loading a 3-unit FPD to failure. All groups were compared with analysis of variance (, < 0.05). Results: The fracture toughness (in MPam1/2) for each reinforced group (Fibrestick 2.74 ± 0.12, Construct fibers 2.59 ± 0.28, Ribbond triaxial 2.13 ± 0.20, and orthodontic wire 1.66 ± 0.09) was statistically greater (p< 0.05) than for the unreinforced group (control = 1.25 ± 0.006). Fracture loads for FPDs were greatest when the fiber reinforcements were placed in the cervical third (cervical = 1165 N). Conclusions: The use of fiber and, to a lesser extent, orthodontic wire is an effective method to reinforce interim restoration resins. [source] Electrochemical preparation of composite polyaniline coating and its application in the determination of bisphenol A, 4- n -nonylphenol, 4- tert -octylphenol using direct solid phase microextraction coupled with high performance liquid chromatographyJOURNAL OF SEPARATION SCIENCE, JSS, Issue 16 2005Minjia Huang Abstract For SPME-HPLC, metal wires with better mechanical strength are preferred over the fused silica fibers. In this article, a novel composite polyaniline (CPANI) doped with PEG and polydimethylsiloxane coating (CPANI fiber) was prepared on a stainless steel wire by a three-electrode system: the fiber was used as the work electrode, a calomel electrode and a platinum electrode were used as the reference and the counter electrodes, respectively. To evaluate the new CPANI coating, the coating was used to extract three kinds of phenols (bisphenol A, 4- n -nonylphenol, and 4- tert -octylphenol) in water samples by direct-SPME mode and then desorbed in commercial SPME-HPLC interface to separation. The extraction procedure was also optimized. Five real water samples were investigated. Good recoveries were gained when environmental samples were analyzed. [source] Mandibular reconstruction after resection of benign tumours using non-vascularised methods in a series of patients that did not undergo radiotherapyORAL SURGERY, Issue 1 2009D. Mehrotra Abstract Aim:, A case series analysis of 52 consequent subjects of immediate mandibular reconstruction after tumour resection using non-vascularised methods, undertaken at U.P. King George's University of Dental Sciences and King George's Medical University, is being reported. To assess the success of reconstruction on subjective and objective evaluation based upon Mandibular Reconstruction Assessment Scale (MRAS) questionnaire. Methods:, Patients with benign mandibular tumours irrespective of age, sex, site and socio-economic status were included. Primary reconstruction was carried out after resection in two surgical units on surgeon's choice using stainless steel wire (6/52; 12%), stainless steel reconstruction plate (10/52; 19%) or titanium reconstruction plate (36/52; 69%) without bone graft (23/52; 44%) or with bone graft (29/52; 56%). Bone grafts were harvested from iliac crest (21/52; 40%), rib (2/52; 4%) and an additional pectoralis major myocutaneous flap with iliac crest bone graft (6/52; 12%) to provide cover to the reconstruction plate was also used. Results:, The primary outcome measurements were wound healing, mouth opening, chewing efficiency, jaw movements, cosmetic achievement and speech on a five-point scale, all of which improved significantly after surgery. The overall complication rate was 17%. Three patients (6%) had loosening of the screw, two (4%) showed dehiscence of the plate, two (4%) showed tumour recurrence and one (2%) had infection of the graft that was subsequently removed. Conclusion:, Titanium reconstruction plates with iliac crest graft provided good result in the absence of microvascular reconstruction because of unavailable long operating time and lack of expertise. Long-term satisfactory rehabilitation can be achieved using removable dentures or prosthesis on dental implants on the contraption provided by the non-vascularised tissue despite non-calcified bone visible on the skiagram. [source] Long-term survey of laryngoplasty and ventriculocordectomy in an older, mixed-breed population of 200 horses.EQUINE VETERINARY JOURNAL, Issue 4 2003Part 1: Maintenance of surgical arytenoid abduction, complications of surgery Summary Reasons for performing study: Laryngoplasty (LP) is currently the most common surgical treatment for equine laryngeal paralysis, however, there have been no reports quantifying the degree of retention of arytenoid abduction following L P. ADitionally, the complications of LP have been poorly documented. Objectives: To record the degree of arytenoid abduction retention following LP and to accurately document all complications of surgery. Methods: A study (1986,1998) of 200 horses of mixed breed and workload, median age 6 years (prospective 136 cases and retrospective 64 cases) undergoing LP (using 2 stainless steel wires) and combined ventriculocordectomy was undertaken; 198 owners completed questionnaires, a median of 19 months following surgery. The degree of arytenoid abduction achieved was endoscopically, semi-quantitatively evaluated using a 5-grade system, at 1 day, 7 days, and 6 weeks after surgery. Results: On the day following LP, 62% of horses had good (median grade 2) arytenoid abduction, 10% had excessive (grade 1), and 5% had minimal (grade 4) abduction (overall - median grade 2). Due to progressive loss of abduction, moderate (median grade 3, range 1,5) abduction was present overall at 1 and 6 weeks after LP. Further surgery was required to re-tighten prostheses in 10% of cases with excessive loss of abduction, or to loosen prostheses in 7% of horses which had continuing high levels of LP abduction and significant post operative dysphagia. LP wound problems (mainly seromas and suture abscesses) were reported to last <2 weeks in 9% of cases, <4 weeks in 4% and >4 weeks in 4%. The (partially sutured) laryngotomy wounds discharged post operatively for <2 weeks in 22% of cases, <4 weeks in 7% and for >4 weeks in 2%. Coughing occurred at some stage post operatively in 43% of cases and its presence correlated significantly with the degree of surgical arytenoid abduction. This coughing occurred during eating in 24% of cases and was not associated with eating (or dysphagia) in the other 19% of cases. Chronic (>6 months duration) coughing occurred in 14% of cases, but appeared to be due to intercurrent pulmonary disease in half of these horses. Conclusions: Suturing the cricotracheal membrane allows most laryngotomy wounds to heal quickly. Laryngoplasty wound problems were of little long-term consequence when stainless steel wire prostheses were used. Potential relevance: A significant loss of LP abduction occurs in most horses in the 6 weeks following surgery and efforts should be made to find ways to prevent such loss. However, excessive LP abduction is associated with post operative dysphagia and coughing. [source] Theoretical investigation of elastic flexural properties for multistranded orthodontic archwiresJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 3 2002Brian K. Rucker Abstract The bending and torsional stresses during flexure were detailed and simplified for a single twisted strand, which emulates a spring. General expressions were derived to evaluate the elastic properties (i.e., strength, stiffness, and range) of multistranded wires by combining the effects of a number of outer twisted strands, with or without an inner strand. Specific expressions were solved for single-stranded, twisted, and coaxial wires. Initially, we considered the following multistranded wire configurations: two- (twin), three- (triple), four-strand (quad) twisted, and coaxial wires. The elastic properties of the twin and quad wires were essentially subsets of the triple wire. For a given overall wire diameter (D) and helix angle (,), the ranges of multistranded wires were independent of wire configurations. By varying the , from 45 to 85°, the D from 0.394 to 0.546 mm (15.5 to 21.5 mil), and the stress at the proportional limit from 1.03 to 3.28 GPa (150 to 475 ksi), the theoretical elastic properties of triple and coaxial stainless steel wires matched many of the properties of conventional nickel titanium leveling wires. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 338,349, 2002 [source] Titanium-niobium, a new finishing wire alloyORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 1 2000Michel Dalstra The mechanical properties of the newly introduced titanium-niobium finishing wires were investigated. Both in bending and torsional loading mode, the stiffness, yield point, post-yield behavior, and springback of titanium-niobium wires were experimentally determined and compared to those of equally sized stainless steel wires. The experimentally obtained values were also validated with theoretical values from engineering formulas of cantilever deformations. The ratios for these parameters for the two materials proved to be different in bending and torsion. The stiffness of titanium-niobium in bending is roughly half of that of stainless steel, whereas in torsion it is roughly one-third. These characteristics enable the clinician to use titanium-niobium for creative bends without the excessive force levels of steel wires. The springback of titanium-niobium in bending is 14% lower than that of steel, whereas in torsion it is about the same or even slightly higher than that of steel, thus making it possible to utilize the wire for even major third-order corrections. Finally, the weldability of titanium-niobium wires was found to be good, so it is possible to weld wires of different dimensions together for the generation of differentiated force systems. [source] Modified Oligosaccharides as Potential Dental Plaque Control MaterialsBIOTECHNOLOGY PROGRESS, Issue 5 2004Eun-Seong Seo Metabolic acids produced by oral pathogens demineralize tooth surfaces, leading to dental caries. Glucosyltransferases are the key factor in this process. We synthesized various modified oligosaccharides and tested them for their inhibitory effects on glucosyltransferase activity. Oligosaccharides were produced using a mixed-culture fermentation of Lipomyces starkeyi and Leuconostoc mesenteroides and then further modified as iron- and sulfate-oligosaccharides. Iron- and sulfate-oligosaccharides reduced glucosyltransferase activity of Streptococci from 17% to 43% and prevented the formation of insoluble biomass on the surface of glass vials or stainless steel wires in the presence of sucrose. They also reduced the growth and acid productions of oral pathogens including S. mutans, S. sobrinus, Eikenella corrodens, Prevotella intermedia, and Actinobacillus actinomycetemcmitans. [source] | ||||||||||