Authors: Julie E. Gough, D.C. Clupper, Larry L. Hench
813
Authors: Mitsuru Takemoto, Shunsuke Fujibayashi, Tomiharu Matsushita, J. Suzuki, Tadashi Kokubo, Takashi Nakamura
Abstract: Porous bioactive titanium implant was produced by plasma-spray method and succeeding chemical and thermal treatment. This porous titanium implant possess a porosity of 40% and complex interconnective porous structure. Mechanical property of porous titanium was characterized for compressive and 4-point bending properties, as well as compressive fatigue. Bone tissue response and biocompatibility of porous bioactive titanium implant was evaluated by in vivo osteoconductive model. Ultimate compression strength and bending strength were 280 and 101 MPa. Bone ingrowth showed significant increases in treated implant, while in these untreated porous titanium implant, bone ingrowth seemed to decrease with time. These results suggest that porous bioactive titanium is a candidate for clinical applications under load-bearing conditions.
263
Authors: Qi Feng Yu, Bang Cheng Yang, Yao Wu, Xing Dong Zhang
Abstract: In this study, alkali-heat treatment in NaOH solution and heat treatment, which could
form amorphous sodium titanate on nanophase titania ceramics surface by conditioning the process, was employed to modify the structure and bioactivity of biomedical titania ceramics. After the nanophase titania ceramics was subjected to alkali-heat treatment, thin film X-ray diffraction and scanning electron microscopy results showed the titania ceramics surfaces were covered by porous sodium titanate. In fast calacification solution (FCS), the alkali-heat treated titania ceramics could induce bonelike apatite formation on its surface. Our results showed that induction of apatite-forming ability on titania ceramics could be attained by alkali-heat treatment. So it was an effective way to prepare bioactive titania ceramics by combining sintering and alkali-heat treatment.
215
Authors: S.B. Cho, Akari Takeuchi, Ill Yong Kim, Sang Bae Kim, Chikara Ohtsuki, Masanobu Kamitakahara
Abstract: In order to overcome the disadvantage of commercialized PMMA bone cement, we have developed novel PMMA-based bone cement(7P3S) reinforced by 30 wt.% of bioactive CaO-SiO2 gel powders to induce the bioactivity as well as to increase mechanical property for the PMMA bone cement. The novel 7P3S bone cement hardened after mixing for about 7 minutes. For in vitro evaluation, apatite forming ability of it was investigated using SBF. When the novel 7P3S bone
cement was soaked into SBF, it formed apatite on its surfaces within 1 week Furthermore; there is no decrease in its compressive strength within 9 weeks soaking in SBF. It is though that hardly decrease in compressive strength of 7P3S bone cement in SBF is due to the relative small amount of gel powder or its spherical shape and monosize. In vivo evaluation of the novel 7P3S bone cement
was carried out using rabbit. After implantion into rabbit tibia for several periods, the interface between novel bone cement and natural bone was evaluated by CT images. According to the results, the novel bone cement directly contact to the natural bone without fibrous tissue after implantation for 4 weeks. This results indicates that the newly developed 7P3S bone cement can bond to the
living bone and also be effectively used as bioactive bone cement without decrease in mechanical property.
801
Authors: Juliane Isaac, S. Loty, A. Hamdan, Tadashi Kokubo, Hyun Min Kim, A. Berdal, J.M. Sautier
Abstract: Titanium has limitations in its clinical performance in dental and orthopaedic
applications. Over the last decade, numerous implant surface modifications have been developed
and are currently used with the aim of enhancing bone integration. In the present study, we have
experimented a bioactive titanium prepared by a simple chemical and moderate heat treatment that
leads to the formation of a bone-like apatite layer on its surface in simulated body fluids. We haved
used foetal rat calvaria cell cultures to investigate bone nodule formation on bioactive titanium.
Scanning electron microscopy (SEM) showed that cells attached and spread on the bioactive
surfaces. After 22 days of culture, bone nodules were detected on the material surface. Furthermore,
the mineralized bone nodules remained attached to the bioactive titanium surface but not to
untreated titanium. SEM observations and EDX microanalysis of sectioned squares showed that
bone-like tissue directly bonded to bioactive titanium, but not pure titanium. These results indicated
the importance of the implant surface composition in supporting differentiation of osteogenic cells
and the subsequent apposition of bone matrix allowing a strong bond to bone. Furthermore, these
findings may provide promising strategies for the development of biologically active implants.
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