ABSTRACT
BACKGROUND:Polyvinyl alcohol is a biocompatible and biodegradable polymer. It is widely used in clinical areas because of its water-soluble, film forming, emulsification, adhesiveness, tasteless, and nontoxic. OBJECTIVE:To review the applications of polyvinyl alcohol and its composite materials in bone, cartilage, skin, vessels and other tissue engineering scaffolds. METHODS:A computer-based online search of CNKI database from January 2000 to December 2011, PubMed database and Elsevier (ScienceDirect) database from January 1980 to December 2012, was performed by the first author with key words of“poly(vinyl alcohol), composite material, tissue engineering scaffold”both in Chinese and English. Literatures concerning polyvinyl alcohol and its composite materials in bone, cartilage, skin, vessels and other tissue engineering scaffolds were included, and repetitive research was excluded. RESULTS AND CONCLUSION:Although there are not enough strength, complications and other shortcomings in vivo, due to its good biocompatibility and biodegradable properties, polyvinyl alcohol and its composite materials have made great progress in tissue engineering applications from the laboratory to the pre-clinical research. But its long-term effects need further research. It wil be a main research aim of scaffold materials in the future to improve the interaction of cel s with the scaffold materials by surface modification, to prepare biomimetic materials by cel microenvironment simulation, to improve the hydrophilicity, the adhesion of cel s, and cel differentiation and proliferation, to bionic the structure and function of the natural extracel ular matrix by building three-dimensional porous structure and control ing the release of cel growth factors, to meet the need of tissue regeneration by congruity or harmony of degradation and mechanical strength.
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BACKGROUND: Bone-induced protein and its carrier are widely used at present; however, the source is limited, and the preparation is complex. Demineralized dental matrix (DDM) is a natural compound containing many osteoinductional proteins and carriers, thus DDM is an ideal material as the substitute of allogenic bone transplantation.OBJECTIVE: By co-culture of MC-3T3 osteoblast and DDM, to evaluate the biocompatibility of DDM via measuring proliferation and alkaline phosphatase (ALP) activity of osteoblast.DESIGN, TIME AND SETTING: A randomized controlled experiment was performed in Stomatology Hospital of Lanzhou University and Stomatology Hospital of Liwan from November 2007 to May 2009.MATERIALS: DDM was supported by Shenzhen Chuangbo Biological Products Development Co., Ltd.; hydroxyapatite (HAP) was supported by Nanjing Emperor Nano Material Co., Ltd.METHODS: 0.1 g HAP and DDM were added in to a 24-well plate, three wells per samples, and the MC-3T3 osteoblasts were seeded onto the surface of samples. After culturing for 2, 4, and 6 days, the cell proliferation percentage was calculated according to MTT assay. ALP activity was evaluated by the quantitative ALP assay.MAIN OUTCOME MEASURES: The effect of DDM on the proliferation and ALP activity of osteoblasts.RESULTS: The proliferation of osteoblasts in DDM group was obviously higher than that in HAP group. With culture time increasing, the ALP activity of osteoblasts in two groups was all augmented, and DDM group was higher than HAP group. There was significant difference between the two groups (P < 0.05).CONCLUSION: DDM can promote adhesion and proliferation of osteoblasts, and promote osteoblastic growth, displaying a great biocompatibility.
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Objective:To study the characteristics of condylar path in the patients with severe dental attrition.Methods:Using D5A De nar fully adjustable articulator and the Pantronic recording system, the kinemat ic character of condylar paths of 15 patients with severe occlusal attrition was investigated. In addition, the effects of posterior condylar determinants on oc clusal rehabilitation were studied in 5 cases. Results: The mean intercondylar distance of the patients was (60.72?4.40) mm, and the immediate side shift (ISS) was 1.35 mm(right)and 1.24 mm(left),the progressive si de shift (PSS) were 14.65 degrees (right) and 17.11 degrees (left),respectively. The Pantronic protrusive condylar guidance (PRO) were 23.45 degrees (right) and 26.85 degrees (left); The Pantronic nonworking path (ORB) was 26.50 degrees and the Fisher angle was present between protrusive path and nonworking path. In th e 5 cases of occlusal rehabilitation ISS, PSS and Panotronic reproducibility ind ex (PRI) were decreased.Conclusion: Occlusal rehabilitation main ly affect ISS, PSS and PRI.