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Chen Z.-X.,The 359 Hospital of Chinese PLA | Wang C.,Beihang University
Chinese Journal of Tissue Engineering Research | Year: 2013

Background: Bone mass deficiency is common during implantation in the maxillary posterior region. Some patients do not want to accept extra surgery for increasing bone because of surgical trauma or medical expenses. Technology of the tilted implant has been proposed, but it has not been recognized and has a lack of relevant evidence. Objective: To investigate the stress distribution of per-implant bone which is subjected to different loading conditions when the different abutment angulations are applied, and to analyze the safety factor of different implants to verify the feasibility of the tilted implant in the maxillary posterior region. Methods: The finite element models of the different angulate abutments were established in commercial software packages. The safety factor of implant in the same power load was observed, and stress and strain condition of the implant and the surrounding bone was also observed. Results and Conclusion: With the increased abutment angulation, the maximum strain of pre-implant bone was significantly increased, and the safety factor of implant decreased gradually. Thus, the tilted implant is not recommended in the maxillary posterior region. Source


Weng Z.-Q.,Chinese PLA General Hospital | Sun M.,The 359 Hospital of Chinese PLA | Tang X.-Y.,Anhui Medical University | Wu Z.-A.,The 359 Hospital of Chinese PLA | And 2 more authors.
Chinese Journal of Tissue Engineering Research | Year: 2013

Background: Nano-calcium titanate, prepared with different modifiers, have properties of good osteogenesis, bone conductibility and biocompatibility. Objective: To observe the influence of nano-calcium titanate materials on the proliferation and differentiation of osteoblasts. Methods: Nano-calcium titanate was prepared with modifiers such as polyethylene glycol, acetyl trim ethyl ammonium bromide and sodium citrate. Meanwhile, nano-calcium titanate without modifier was prepared. All the four kinds of nano-calcium titanate materials were used to prepare nano-calcium titanate extracts under the concentration of 0.1, 1.0, 10 g/L, respectively. The proliferation of osteoblasts was observed through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and alkaline phosphatase activity of osteoblasts was observed. Osteoblasts cultured in normal condition served as contrast. Results and Conclusion: The proliferation of osteoblasts cultured in the calcium titanate extracts prepared with polyethylene glycol, acetyl trim ethyl ammonium bromide and sodium citrate and without modifier was obviously improved under the concentration of 1.0 and 10 g/L. Absorbance value of the cells cultured in the above-mentioned four kinds of calcium titanate extracts 1.0 and 10 g/L) for 3, 6, 9 days exceeded the contrast (P < 0.05, P < 0.01), as well as the alkaline phosphatase activity (P < 0.05, P < 0.01). Calcium titanate prepared with polyethylene glycol, acetyl trim ethyl ammonium bromide and sodium citrate and without modifier has no cytotoxicity effect on osteoblasts, and can promote the proliferation and differentiation of osteoblasts. Source


Fan A.-M.,The 359 Hospital of Chinese PLA | He Z.,The 359 Hospital of Chinese PLA | Zhang L.-L.,The 359 Hospital of Chinese PLA | Feng T.-C.,The 359 Hospital of Chinese PLA | Liu F.-G.,The 359 Hospital of Chinese PLA
Chinese Journal of Tissue Engineering Research | Year: 2014

BACKGROUND: The calcaneus is cancellous bone with thin cortical bone, and mostly prone to collapse compression fracture after injuries. Surgical reduction and fixation can basically restore joint integrity and calcaneus form, patients often need bone graft to fill the bone and receive Kirschner wire fixation to support bone graft and maintain reduction. OBJECTIVE: To explore the advantages and defects of small incision reduction graft and percutaneous Kirschner wire fixation in treatment of calcaneal fractures. METHODS: 26 patients with calcaneal fractures were treated with small incision reduction graft (autograft or allograft bone) plus percutaneous Kirschner wire fixation, and clinical data of the involved patients were retrospectively analyzed. Bohler and Gissane angles of calcaneal bone were observed after fixation. Maryland foot scoring system was applied to evaluate the clinical efficacy of bone graft and fixation, soft tissue complications after fixation were also observed. RESULTS AND CONCLUSION: All 26 patients were followed up for 6-12 months. Compared with before surgery, calcaneus Bohler and Gissane angles were significantly increased after treatment; according to the Maryland foot scores, excellent and good rate was 85%. Small incision reduction graft and percutaneous Kirschner wire fixation is reliable treatment method of intra-articular calcaneal fractures, with fewer complications. © 2014, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved. Source


Wu Z.-a.,The 359 Hospital of Chinese PLA | Xuan Z.-g.,The 359 Hospital of Chinese PLA | Wang C.-f.,The 359 Hospital of Chinese PLA | Liu S.,The 359 Hospital of Chinese PLA | Sun M.,The 359 Hospital of Chinese PLA
Journal of Clinical Rehabilitative Tissue Engineering Research | Year: 2011

BACKGROUND: Nanosized hydroxyapatite with different size and morphology has different surface performance and bioactivity. Different sized nanohydroxyapatite was synthesized via surface modification of hydroxyapatite; by this method, the application of nanosized hydroxyapatite can be extended. OBJECTIVE: To analyze the effect of experimental parameters, such as type of organic modifiers and pH value, etc. on the size of hydroxyapatite synthesized by hydrothermal method. METHODS: Hydroxyapatite with different sizes was synthesized starting from phosphoric acid and calcium nitrate and using D-sorbitol, sodium polyacrylate and Tween 80 as organic modifiers at different pH values. RESULTS AND CONCLUSION: In the absence of organic modifier, the size of hydroxyzpatite was decreased rapidly with the increase in pH values. The presence of sodium polyacrylate was beneficial to the formation of small-size hydroxapatite. The addition of D-sorbitol favored the formation of large-size hydroxyapatite. The presence of Tween 80 decreased the size of hydroxyapatite in some extent. Source

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