Objective To review the progress and clinical application of malleable bone paste/putty. MethodsRecent literature about malleable bone paste/putty was reviewed and analyzed. ResultsThe preparation and clinical application of malleable bone paste/putty have become increasingly mature. Many kinds of malleable bone paste/putty have been applied extensively and the good clinical results have been achieved in the treatment of the irregular bone defects. The materials and methods for preparing malleable bone paste/putty are different. Then they have different bone repair abilities. ConclusionMalleable bone paste/putty provides effective method to treat irregular bone defects. But the malleable bone paste/putty still has some shortage, so further researches should be carried out.
【Abstract】 Objective To increase the viscosity of chitosan/glycerol phosphate（C/GP）and to improve its preparation technique in order to develop the appl ication range of C/GP. Methods Chitosan was treated by high-pressure vapor steril ization in order to prepare high viscous C/GP（HV-C/GP）and prepare C/GP by standard methods. The rheologic changes of HV-C/GP and C/GP were detected dynamically by the Gemini rheometer. The initial solution viscosity, gelation temperature and gelation time were evaluated after the viscosity of the materials were increased. Two gelation materials were placed into continuous flow thermostated cells under the same condition and harvest them at predetermined time intervals, 1st, 2nd, 5th, 10th and 25th days, then they were dried, weighed and the mass loss rate was calculated. Ultrastructure of the freeze-dried samples was visual ized by the scanning electron microscope. Results The initial viscosity of C/GP was 1.81 Pas and that of HV-C/GP was 17.24 Pas. The latter one increased 10 times as well as the former one. The gelation temperature of C/GP was 37°C and that of HV-C/GP was 34°C. There was no remarkable difference in gelation time between them. The mass loss rate of HV-C/GP at first day was 72.5% and at 25th days was 90.8%, while that of C/GP was 55.4% and 78.2%. Porous network structure was observed by the scanning electron microscope in both of them. The pore diameter of C/GP was 50-100 μm and that of HV-C/GP was 30-50 μm, which was obviously smaller than the former. Conclusion The viscosity of HV-C/GP prepared by improved technique obviously increases and the thermosensitivity has no significant changes. The degradation time of HV-C/GP in vitro lengthens. The micrographs show that the HV-C/GP gels are porous and the pore diameter are smaller than C/GP.