Effect of three kinds of medium molecular weight proteins on the corrosion resistance of Ni-Ti and stainless steel arch wires / 口腔疾病防治

Objective @#To explore the influence and mechanism of different types of proteins on the corrosion resistance of alloy to provide a reference for the safe application and surface modification of nickel-titanium (Ni-Ti) and stainless steel bow wires in the clinic.@*Methods@#The effects of fibrinogen, IgG and mucin on the electrochemical corrosion resistance of Ni-Ti and stainless steel arch wires were tested by the potentiodynamic polarization method, and the repair ability of passive films on surfaces treated with the three proteins were tested by the cyclic polarization method. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to determine the types of corrosion products, and the surface morphology after corrosion was analyzed by scanning electron microscopy (SEM) and atomic force microscopy (AFM).@*Results @#The addition of fibrinogen, IgG or mucin to an alloy has different effects on its corrosion resistance. Adding protein can reduce the corrosion resistance of stainless steel alloys and slow the corrosion process of Ni-Ti alloys. The addition of mucin can improve the corrosion resistance of Ni-Ti alloy and the repair ability of passive film. Compared with mucin and IgG, fibrinogen can reduce the pitting resistance of Ni-Ti and stainless steel alloys.@*Conclusion @#Different types of proteins interact differently with the arch wire, form different deposition morphologies on the surface, and participate differently in the corrosion process of the alloy.

Comparison of the biological safety of three metal dental materials / 实用口腔医学杂志

Objective:To evaluate the biological safety of commercial pure Ti (cpTi),Ti alloy Ti6Al4V and stainless steel 316L.Methods:According to the GB/T16886.5-2003 and YY/T0127.2-2009 standards,the extraction of the 3 materials was respectively prepared,cck-8 assay was used to test their cytotoxicity,single cell gel electrophoresis was used to test their genotoxicity,and in vivo test was used to test their acute systemic toxicity.Results:The cytotoxicity of 100％ extractions of 316L,Ti6Al4V and cpTi was graded to 2,1 and 0,the olive tal moment(OTM) 10.79 ±0.39,9.84 ± 1.78 and 0.92 ± 1.43,the percentage of tail DNA (1.22 ±0.06) ％,(0.92 ± 0.43) ％ and (0.43 ± 0.01) ％ respectively.No systemic toxicity and no body weight change was observed in the acute systemic toxicity test in mice.Conclusion:cpTi has better biologic safety than Ti6Al4V and 316L.

The study of cytocompatibility of Co-Cr alloy and Ti alloy / 天津医药

Objective To investigate the cytocompatibility of the liching liquids of Co-Cr alloy and Ti alloy on human gingival fibroblasts (HGF). Methods The HGF were treated in vitro with leaching liquids of Co-Cr alloy and Ti alloy, respectively. The DMEM cell medium containing 10% fetal bovine serum was served as a negative control. The viability of HGF treated by two dental alloys were evaluated by means of MTT, and the contents of intracellular reduced glutathione (rGSH) were assayed by kits. The tumor necrosis factor-α(TNF-α) contents were determined in the culture supernatant by ELISA in two groups. The effects of these alloys on the expression of caspase-3 were examined by real time-PCR method. Results Compared with the control group, HGF treated with Co-Cr alloy leaching liquids showed a lower viability ( P ＜0.05), while Ti alloy leaching liquid promoted the proliferation of HGF. In Co-Cr alloy group, the rGSH content was significantly decreased (P＜0.05), while TNF-α content was significantly increased (P＜0.05) compared with control group. There were no significant differences in rGSH and TNF-α contents between the Ti alloy group and control group (P＞0.05). The expression of caspase-3 was significantly higher in Co-Cr alloy group than that of control group (P＜0.05), while there was no significant difference in the expression of caspase-3 between Ti alloy group and control group. Conclusion Results suggest that Co-Cr alloy possesses cytotoxicity, while there is better cell compatibility for Ti alloy.

In vivo bone response and interfacial properties of titanium-alloy implant with different designs in rabbit model with time.

Background: Using implants for dental applications are well-accepted procedures as one of the solutions for periodontal defect repair. Suitable design and materials, their reaction with the surrounding hard tissues and interfacial biomechanical properties are still considered to be the primary criteria which need to be addressed systematically. In the present study, a thorough and systemic approach was made to identify a suitable implant, considering the above criteria after both in vitro and in vivo animal trials. Materials and Methods: Titanium alloy (Ti-6Al-4V) implants, with thread and without thread models, were implanted to the mid-metaphysial portion of the tibia of the right hind leg of three white Australian Chinchilla rabbit species and their effects and response to the surrounding bone were investigated. Parameters studied included hematological and biochemical features (serum alkaline phosphatase and calcium), both preoperatively and postoperatively, consecutively for 7 days and after 1-3 months. The interfacial integrity and compositional variation along the interface were studied using scanning electron microscope (SEM) with energy dispersive analysis of X-ray (EDAX) and histopathology from 1 to 3 months consecutively. Finally, biomechanical properties were studied with the help of push-out test. Results: Bone remineralization started through the process of electro-physiological ionic exchanges, which helps in formation of osteoblastic cells in the area of bony injury. The SEM-EDAX results confirmed the initial stability for the Ti (with thread) implant, but the regeneration of new bone formation was faster in the case of Ti (Without thread) implant, and hence could be used for faster healing. These have also been substantiated through push-out and histopathlogical tests. Conclusion: From the physico-chemical and biomechanical observations, it was found that that smooth type implants were well accepted in the physiological condition although chances of elemental leaching from the surface were also observed. Increase of the surface roughness can help into the formation of physico-chemical bondage with the surrounding hard tissues.

Comparison of Cytocompatibility Between Grit Blasted Titanium Alloy (Ti-6Al-4V) with or without Pure Titanium Coating / 대한정형외과연구학회지

PURPOSE: A composite of aluminum and vanadium (Ti-6Al-4V) is one of the most common compositions of titanium-based alloys. Unfortunately, vanadium has been found to cause adverse reactions. We evaluated the effects of vanadium containing titanium alloy (Ti-6Al-4V) on an osteoblast-like cell line (SaOS-2). MATERIALS AND METHODS: We studied the biologic and morphologic responses of SaOS-2 cell to Ti alloy with grit blasting and Ti coated Ti alloy with grit blasting. We performed energy-dispersive x-ray spectroscopy (EDS) and scanning electron microscopy (SEM) investigations and performed a cell proliferation assay, ALP activity, and cell migration assay of SaOS-2 cells. RESULTS: The morphologic assessment of cells through SEM showed that the two surfaces were covered with similar amounts of small slender osteoblast like cells. The amount of proliferation, ALP activity and the migration extent of SaOS-2 cells on the surfaces of each group were not statistically different. CONCLUSION: We used a grit-blasted Ti-coated Ti alloy, coated using electron beam deposition, and a grit-blasted Ti alloy to evaluate the toxicity of Ti-6Al-4V on SaOS-2 cell. Compared with pure titanium, the vanadium-containing Ti-alloy did not show an adverse effect on SaOS-2 cells.

Non-extraction treatment in Class III malocclusion by using improved superelastic NiTi wire / 대한치과교정학회지

Nonextraction camouflage treatment in mild Class III malocclusion is achieved by backward movement of the lower dentition and forward movement of the upper dentition. Many camouflage treatment modalities have been used for distal tipping and distal movement of mandibular posterior teeth. The amount of distal movement of mandibular dentition can be improved in cases of severe crowding, even without the patient's cooperation, by using miniscrews for anchorage. However, miniscrew insertion may be unsuccessful, and it may contact the adjacent root because of the distal movement of dentition. Distal tipping of mandibular dentition can be achieved using multiloop edgewise archwires and intermaxillary elastics. However, the complexity of this wire design causes discomfort to patients. Recently, a new treatment using improved superelastic NiTi wires (ISWs) and intermaxillary elastics has been introduced. ISWs can deliver orthodontic force more effectively, and their use with molar tip-back treatment has several advantages-this approach is effective, simple, and easy to use and reduces patient discomfort. The aim of this study was to report a case of camouflage treatment using ISW with tip-back and intermaxillary elastics for distal tipping of mandibular posterior dentition and to evaluate the effectiveness of this treatment in a clinical setting.

Clinical analysis of internal fixation with grip-type of Ni-Ti alloy plate in treatment of multiple ribs fractures / 中国基层医药

ObjectiveTo analyze the clinical effect of internal fixation with grip-type of Ni-Ti alloy plate in treatment of multiple ribs fractures.MethodsClinical data of 50 patients with multiple ribs fractures treated by internal fixation t with grip-type of Ni-Ti alloy plate were retrospectively analyzed.ResultsThe chest pain alleviated,the shape of bony thorax recovered, paradoxical respiration vanished, and dyspnea relieved significantly in all cases after operation.Two months after operation, chest X-ray indicated healed fractures, internal fixation without loosening and breaking off, no chest deformity in all patients.Followed up 2 to 14 months,an average of 9 months,and no complication was found.ConclusionThe internal fixation with grip-type of Ni-Ti alloy plate in treatment of multiple ribs fractures was simple ,convenient,less invasive ,good tissue compatibility, stable fixation, less complications, and clinical results were satisfactory.

Effect of Nickel-Titanium Shape Memory Alloy Embracing Internal Fixer on Long Spiral or Oblique Fracture: 23 Cases Report / 中国康复理论与实践

@#ObjectiveTo investigate the effect of nickel-titanium(Ni-Ti) shape memory alloy embracing internal fixer on oblique or spiral fracture.Methods23 cases with spiral or oblique fracture accepted internal fixation with Ni-Ti shape memory alloy embracing.The time of bone healing,articular function,the appearance and function of the wound extremity were evaluated after 9～34 months follow-up.ResultsAll fractures healed in 4～16 weeks after operation.None infection,nonunion,embracing emersion or break had been found. The fine rate was 91.3%.ConclusionThe effect of Ni-Ti shape memory alloy embracing internal fixer on long spiral or long oblique fracture is satisfactory.

A study concerning the characteristics of Korean Ni-Ti alloy orthodontic wire / 대한치과교정학회지

To estimate the characteristics of Korean Ni-Ti alloy orthodontic wire, this study investigated compositions, tensile properties, bending properties, heat treatment effects, and ion releasing degrees, and compared these characteristics to those of the imported Ni-Ti alloy wire. The results obtained are as follows; 1. Ti and Ni elements in ORTHOLLOY were in a range showing superelasticity, and there was a little difference in the Ni and Ti contents of ORTHOLLOY as compared with those of SENTALLOY. 2. The results of the tensile test concerning ORTHOLLOY exhibited a superelastic effect, indicating an area of a definite amount of stress in spite of the changes in the range from 2% to 8% in the strain rate. 3. ORTHOLLOY presented higher load values than SENTALLOY in the same deflection values when the wire was tested in three-point bending. A load range displaying a superelastic effect was 80-100g, 140-180g, and l50-200g respectively, in wire diameters of 0.014", 0.016", and 0.018". 4. By heat treatments at 400degreesC and at 500degreesC, a load range showing the effect of superelasticity was lessened by the duration of the heat treatment time. The superelastic effect was destroyed as a result of the 10 minutes heat treatment at 600degreesC. 5. The quantity of the Ni ion released from ORTHOLLOY, tended to be greater than the amount of released Ni ion in SENTALLOY. The Co ion released was very little(<0.01ppm) in SENTALLOY and ORTHOLLOY irrespective of the lapse of time. Released Ni ions on the 1st day were at the maximum, and the releasing rate showed plateaus after three days. 6. The surface morphology of SENTALLOY was relatively regular irrespective of the lapse of time, and the corrosion tendency was not observed. However, the surface morphology of ORTHOLLOY was rather irregular and showed pitting corrosion after immersion.