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FDI-Unilever Poster Competition Winners and Finalists
Biocompatibility of Ti-8Ta-3Nb alloy in primary rat calvarial cells
Y-J Kim, D-Z Cui, I-G Cho and H-J Chung Email: [email protected]
Introduction: β-titanium alloys are useful in biomedi-cal application because of their excellent mechanical properties. Ti-8Ta-3Nb alloy was newly developed β-titanium alloy at Center for Titanium(Ti) and Special Alloys, Chonnam National University. Materials & Methods: In this study, biocompatibility of a new β-type Ti-8Ta-3Nb alloy was assessed by SEM, cell proliferation, alkaline phophatase(ALP) analysis, and RT-PCR method. Results: Proliferation rate on Ti-8Ta-3Nb implant surface was equivalent to commercially pure(cp) titanium surface. In comparison to Ti-6Al-4V alloy, cp Ti and Ti-8Ta-3Nb alloy enhanced ALP activ-ity in vitro(p<0.05). In RT-PCR analysis, collagen type I, osteocalcin, and bone sialoprotein mRNA were ex-pressed in all test materials. Conclusion: The present study did not show any difference in vitro biocompat-ibility between Ti-8Ta-3Nb implant and cp titanium as evaluated by osteoblast prolifreation and differentiation. These properties could make Ti-8Ta-3Nb alloy a new implant material for medical and dental fields.
Experimental study on repairing periodontal defects by tissue engineering methods ZY Tang, JQ Ling, JC Lin and YQ Deng Email: [email protected]
Introduction: To evaluate the effects of transplanting MSC-NC complex combining guided tissue regeneration (GTR) in the treatment of periodontal bone defects in the Mongrel dogs. Materials & Methods: MSC isolated from the Mongrel dogs were cultured in vitro. Added mineralisation medium for osteogenic differentiation, The osteogenic ability of cells were detected. MSC were seeded into porous NC particles and PLGA-NC complex membrane, the morphological characters of MSC were observed with phase contrast microscope and scanning electron microscope. After 10 days of co-cul-ture of MSC and NC, the complexes were transplanted into experimentally induced alveolar bone defects of dogs by GTR therapy using PLGA-NC covered mem-branes. The defects were histologically assessed and stained 8 weeks later. Results: : MSC induced clearly showed the ability of osteogenic potential. The stain-ing of mineralised nodules and type collagen were both positive. There was a good biocompatibility between
MSC and NC, as there was with MSC and the PLGA-NC complex membrane. The defects were restored by transplanting with MSC-NC complex. Conclusion: MSC showed promise in acting as a periodontal tissue precursor cell. All the results indicated that the methods of bone tissue-engineering can be applied to improving periodontal regeneration.
Morphology and adhesion of S.oralis influenced by Ni2+ from nickel-chromium alloy F. Zhen, X. Chun, Z. Yunfeng, X. Xiaorong and L. Weicai Email: [email protected]
Introduction: This research aimed to investigate the influence of nickel ions (Ni2+) from nickel-chromium alloy on morphology and adhesion of Streptococcus oralis (S.oralis). Materials & Methods: S.oralis was cultivated with six concentrations of Ni2+: 3.75ppm, 7.5ppm, 15ppm, 30ppm, 60ppm and 120ppm. After 24hrs, bacteria were collected and separated into two parts. One part was observed with SEM to reveal changes in morphology. The other part was tested the adhesion ability of S.oralis with the liquid-scintillation method. Results: At 120ppm, S.oralis changed from ovoid to rod-shape and the chains formed became shorter. The adhesion inhibition rate was 48.06% when Ni2+ was 3.75ppm. This rate rose with the increas-ing of Ni2+ concentration and reached 83.94% when Ni2+ was 120ppm, which was much higher than those of positive groups (P<0.05). Conclusion: Ni2+ can change the morphology of S.oralis and suppress its adhesion ability, which may cause dysbacteriosis around the margin of nickel-chromium alloy prostheses.
Characterising dental follicle cells and inducing them to orientate differentiation H. Liu, Z. Wang and Y. Jin Email: [email protected]
Introduction: To investigate whether dental follicle cells (DFC) can be used as seeding cells in periodontal tissue engineering. Materials & Methods: DFC cells from dog embryo tooth germs were cultured and treated by EMPs, BMP-2. Collagen gel and CBHA were used as the scaffolds cultured. The scaffolds containing DFC were transplanted into nude mice for histochemical analysis. Results: DFC expressed mineralised associated proteins such as COL, BSP, OPN, ON. OCN, ALP and mcpr1 mRNA, DFC were capable of inducing mineralisation by day 20. EMPs associated with BMP-2 could sig-
FDI-Unilever Poster Competition Finalists
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International Dental Journal (2006) Vol. 56/No.6
nificantly promote DFC proliferation, ALP expression, mineralise nodule formation. CAP was detected in DFC after treated with BMP-2, and negative with EMPs. They are all dose depend. Only cells-made carrier implants formed a few mineralised matrix but stained negative for anti-CAP mAb. Conclusion: DFC presented char-acterisation of osteoblast/cementoblast. DFC can be triggered to differentiate toward a cementoblast/osteob-last phenotype by EMPs/ BMP-2. Dental Follicle Cells can be valuable in periodontal tissue engineering.
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