Characterization and biocompatibility analysis of different silanes coupling c(RGDfK) cyclic peptide on titanium surfaces / 口腔疾病防治

Objective@#To compare the efficiency and biocompatibility of four different silanes on immobilizing c(RGDfK) peptide on titanium surface.@*Methods @# After alkali-heat treatment (group OH), the titanium surface was treated with 3-aminopropyltriethoxysilane (APTES) (group OHAP), 3-chloropropyltriethoxysilane (CPTES) (group OHCP) (3-mercaptopropyltrimethoxysilane (MPTS) (group OHMPT) and 3-isobutyryloxy propyltrimethoxysilane(γ- MPS) (group OHMPS) to immobilize the c(RGDfK) cyclic peptide and constructa titanium-silane-c(RGDfK) coating. The NT group was the blank control group. The surface morphology and wettability of the coatings were detected using scanning electron microscopy and contact angle measurement. The elemental composition of the titanium surface was analyzed using X-ray photoelectron spectroscopy. After fluorescent staining with 4’,6-diamino-2-phenylindole (DAPI) and phalloidin, the adhesion of mouse preosteoblast MC3T3-E1 cells on the surface of the materials was observed using laser confocal microscopy. Cell counting kit-8 (CCK-8) and alkaline phosphatase (ALP) activity assays were used to evaluate the proliferation and osteogenic differentiation of MC3T3-E1 cells on the surface of the materials, respectively. @*Results @#Scanning electron microscope observation showed a spongy-like 3-dimensional network formed on the titanium surface after alkali-heat treatment with silane-c(RGDfK) coating adhesion. The wettability of each group was greatly improved compared to the untreated titanium surface. The element ratios of Si/Ti and amide-N/Ti in the OHMPS group were the highest. The OHAP group exhibited the best cell adhesion effect. The cell proliferation and ALP activity of the OHAP, OHMPT, and OHMPS groups were significantly higher than the control group (P <0.05); there was no statistical difference between the OHCP group and the control group.@*Conclusion @#MPTS, CPTES and γ-MPS covalently immobilized cyclic peptide c(RGDfK) on the titanium surface, which promoted adhesion, proliferation and osteogenic differentiation of MC3T3-E1 cells. Theγ-MPS conjugated C (RGDfK)cyclic peptide exhibited the best effect. MPTS, CPTES and γ-MPS coupled with c(RGDfK) cyclic peptides had similar biological properties.

Influence of titanium nanotubular surfaces, produced by anodization, on the behavior of osteogenic cells: in vitro evaluation / Influência da superfície nanotubular do titânio, produzido por anodização, no comportamento de células osteogênicas: avaliação in vitro

Objective: The objective of this study was to evaluate in vitro the influence of the anodized surface of Ti35Nb7Zr alloy on the behavior of osteogenic cells, for future application in biomedical implants. Material and Methods: For the development of this research, samples of commercially pure titanium (TiCp) and samples of Ti35Nb7Zr alloy were anodized, both were characterized by scanning electron microscopy (SEM) and were plated afterwards with human osteoblast-like cells (MG63 line) (2 x 104). Cell adhesion, cytotoxicity test, formation of mineralization nodules and a comet assay were also performed in different periods. The bottom of the plate was used as a control, without a sample. Results: SEM analysis showed that the topography of both samples presented surfaces covered by nanotubes. Cellular morphology exhibited spreading in both samples proposing an intimate cell- material liaison. After 3 days, the Ti35Nb7Zr group exhibited greater cell viability than the TiCp group (p<0.01). Regarding calcium content, there was no statistical difference between the anodized groups, but there was a difference between the experimental groups and the control group (p<0.01). In the comet assay, the percentage of DNA in the comet tail did not exhibit any significant difference (p>0.05) among the groups in the evaluated periods. Conclusion: It was concluded that this process of anodization was efficient to form nanotubes, as well as promote a positive influence on the behavior of osteogenic cells without promoting cell damage. (AU)

Objetivo: O objetivo deste estudo foi avaliar in vitro a influência da superfície anodizada da liga Ti35Nb7Zr no comportamento de células osteogênicas, para futura aplicação em implantes biomédicos. Material e Métodos: Para o desenvolvimento desta pesquisa, amostras de titânio comercialmente puro (TiCp) e amostras da liga Ti35Nb7Zr foram anodizadas, ambas foram caracterizadas por microscopia eletrônica de varredura (MEV) e posteriormente plaqueadas com células semelhantes a osteoblastos humanos (linha MG63) (2 x 104). Foram realizados em diferentes períodos a adesão celular, teste de citotoxicidade, formação de nódulos de mineralização e ensaio do cometa. O fundo da placa foi usado como controle, sem amostra. Resultados: A análise em MEV mostrou que a topografia de ambas as amostras apresentava superfícies cobertas por nanotubos. A morfologia celular exibiu espalhamento em ambas as amostras, propondo uma ligação íntima célula-material. Após 3 dias, o grupo Ti35Nb7Zr exibiu maior viabilidade celular do que o grupo TiCp (p<0.01). Em relação ao teor de cálcio, não houve diferença estatística entre os grupos anodizados, mas houve diferença entre os grupos experimentais e o grupo controle (p<0.01). No ensaio do cometa, a porcentagem de DNA na cauda do cometa não apresentou diferença significativa (p> 0.05) entre os grupos nos períodos avaliados. Conclusão:Concluiu-se que esse processo de anodização foi eficiente para formar nanotubos, além de promover uma influência positiva no comportamento das células osteogênicas sem promover dano celular. (AU)

The effects of high-fat diet on implant osseointegration: an experimental study

OBJECTIVES: In this study, we investigated whether a high-fat diet (HFD) affected the bone implant connection (BIC) in peri-implant bone. MATERIALS AND METHODS: Four male rabbits were used in this study. Dental implant surgery was introduced into each tibia, and four implants were integrated into each animal. In both the normal diet (ND) group (n=2) and HFD group (n=2), 8 implants were integrated, for a total of 16 integrated implants. The animals continued with their respective diets for 12 weeks post-surgery. Afterward, the rabbits were sacrificed, and the BIC was assessed histomorphometrically. RESULTS: Histologic and histomorphometric analyses demonstrated that BIC was not impaired in the HFD group compared to the ND group. CONCLUSION: Within the limitations of this study, we found that HFD did not decrease the BIC in rabbit tibias.

Zinc ions improve the stability of titanium implants under the condition of osteoporosis / 中国组织工程研究

BACKGROUND:Zinc can improve bone reaction to titanium implants through regulation of osteoblast activity under the condition of osteoporosis. OBJECTIVE:To study the zinc ions effect on improving the stability of titanium implants under the condition of osteoporosis. METHODS:After removal of the ovary, 28 female Sprague-Dawley rats presented with osteoporosis symptoms for 12 weeks and then, they were randomly divided into two groups. Two kinds of titanium implants with (experimental group) or without zinc (control group) were inserted into the bilateral femoral metaphysis longitudinal y in the ovariectomized rats, separately. Three rats were selected from each group for double fluorescence labeling examination. Mineral apposition rate was calculated at postoperatively 6 weeks. Another four rats were selected from each group for histomorphometry analysis at postoperatively 12 weeks. Biomechanical test was in the remaining rats in the two groups to calculate the maximum push-out force and maximum shear force at 12 weeks postoperatively. RESULTS AND CONCLUSION:The double fluorescence labeling examination revealed that the mineral apposition rate was improved in the experimental group as compared with the control group (P<0.05). New bone formation occurred in the two groups. However, larger new bone amount, higher bone area ratio and bone-to-implant contact were detected in the experimental group (P<0.05 or P<0.01). The maximum push-out force and maximum shear force were also superior in the experimental group to the control group (P<0.05 or P<0.01). These findings indicate that zinc ions are capable of promoting bone formation and improving implant fixation in ovariectomized rats.

Experimental research on porous titanium implant fabricated by three-dimensional printing with different sintering temperatures / 国际生物医学工程杂志

Objective The aim of this study was to evaluate the feasibility of three-dimensional printing (3DP) for the preparation of porous titanium implant and to investigate the impacts on microstructure and mechanical properties with different sintering temperatures.Methods The CAD model of the specimens was designed to be 25 mm in diameter,20 mm in height,and with 0.5 mm pore size mesh.On every cross-section,80％ bonding area was designed.Titanium powder (purity of 98.5％,75 μm diameter) was selected as raw material.Polyvinyl alcohol powder (160 μm diameter) was selected as a binder,and polyvinylpyrrolidone powder was selected as an auxiliary binder.The green porous titanium implants were fabricated by 3DP followed by sintering at 1 200,1 300,1 400 ℃,separately,under the protection of argon gas.After sintering,the properties of porous titanium implants were evaluated,including the porosity,microstructure,microhardness,compressive strength and elastic modulus.Results After sintering,the specimen had uniform contraction and no obvious distortion.The specimen sintered at 1 200,1 300 and 1 400 ℃ sintering temperatures had porosity of (65.01±1.03)％,(46.73±0.73)％ and (41.06±0.31)％,hardness of 115.2±0.6,148.6±1.1 and 182.8±2.1,elastic modulus of (5.9±0.5),(16.2±0.9) and (34.8±1.5) GPa,compressive strength of (81.3±4.3),(135.4±8.5) and (218.6±7.1) MPa,respectively.A porous structure with three-dimensional network of connected pores was observed under scanning electron microscope.Conclusion It is feasible to fabricate porous titanium implants by three dimensional printing technique.The mechanical properties of the porous titanium implants match well with bone tissue which has excellent biomechanical compatibility.

Carga inmediata sobre implante único: estudio clínico prospectivo / Immediate load in single-tooth restorations: a clinical prospective study

Introducción: la carga inmediata se ha convertido en una alternativa viable de tratamiento que ofrece múltiplesbeneficios a los pacientes como función y estética inmediata, reducción del trauma quirúrgico y disminución del tiempo total de tratamiento. Se hizo un estudio prospectivo controlado para la colocación de implantes en casos clínicos de restauración de dienteúnico que recogiese el consenso propuesto en la literatura para evaluar el éxito clínico bajo el protocolo de carga inmediata: implantes de conexión interna, cónicos, de superficie texturizada y un mínimo de 32 Ncm de torque inicial. Métodos: se colocaron21 implantes Renova® (Lifecore Biomedical Inc., Chaska, MN) en 17 pacientes adultos (6 hombres y 11 mujeres) rango de edad entre 18 y 74 años, sistémicamente sanos con necesidad de reemplazo de diente único en sectores anterior y premolar de ambos maxilares. Resultados: la tasa de éxito acumulativa a 18 meses fue de 95,2%. Se obtuvieron valores de éxito similares a los reportados con el protocolo de carga convencional y se encontró correlación directa entre la distancia desde el hueso al punto decontacto y el porcentaje de presencia de papila en el espacio interproximal. Conclusión: los resultados indican que el protocolo de carga inmediata para el tratamiento de restauraciones de diente único en la zona anterior mediante implantes temporalizadosinmediatamente, sin función oclusal, es una alternativa viable con tasas de éxitos mayores al 95%, comparables a las logradas con el protocolo de carga convencional.

Introduction: immediate loading of implants has become a viable treatment alternative that offers multiple benefitsfor patients such as providing immediate function and esthetics, reduction of surgical trauma and less treatment time. A controlled prospective clinical trial was conducted to evaluate the success of immediately loaded implants for single-tooth restoration following consensus protocols in recent literature. Methods: twenty-one 3.75 x 13mm RBM-treated surface internal connection implants (Renova®, Lifecore Biomedical Inc., Chaska Mn.) were placed in 17 systemically healthy patients (6 males, 11 females), ages between 18 and 74 years who required single-tooth replacement in the anterior and premolar regions of both jaws. Results: the 18-month cumulative success rate for this study was 95.2%. According to the statistical analysis in this study, immediate loading of implants for single-tooth restoration compares favorably to the two-stage protocol and a direct correlation between the distancefrom bone to contact point and papilla filling was found. Conclusions: results from the present study indicate that the single-tooth restoration in the anterior area with immediately loaded surface-treated threaded titanium implants and no occlusal function is a viable treatment alternative with a success rate greater than 95%, comparable to the conventional loading protocol.

Avaliação radiográfica, biomecânica e microscópica de enxerto ósseo xenogênico associado a implantes de titânio em mandíbula de coelhos / Radiographic, biomechanical and microscopic evaluation of xenogenic bone graft associated to titanium implants in rabbits mandible

O propósito deste trabalho foi avaliar a interação de matriz óssea bovina inorgânica, (Gen-ox®) como material de enxerto e implantes de titânio em mandíbula de coelhos. A amostra constituiu-se de 32 coelhos da raça Botucatu de aproximadamente 4kg. Os incisivos inferiores destes animais foram extraídos e foi realizada um defeito de aproximadamente 4mm de diâmetro. Um dos lados foi mantido apenas com coágulo (grupo controle) e o outro lado (grupo experimental) recebeu o enxerto do material proposto. Após 60 dias foram instalados implantes bilateralmente na região do defeito. Os animais foram eutanaziados imediatamente após a instalação dos implantes e após 1, 2 e 6 meses (n=6) para o grupo microscópico a após 2 e 6 meses para o grupo do teste biomecânico (n=4). A análise constituiu de medidas da distância da crista óssea alveolar à plataforma do implante, da densidade radiográfica em valores de pixel ma região do alvéolo, de teste biomecânico de torque de remoção e microscópico através de medidas de contato osso-implante (BIC) (em µm e %) e área de osso (em µm² e %). Os resultados demonstraram que não houve diferenças significantes nem durante o tempo e nem entre os grupos na analise de distancia entre crista óssea alveolar e plataforma do implante. Na medida de densidade óssea, não houve variação significante ao longo do tempo, mas houve diferença estatisticamente significante entre os grupos, sendo maior no grupo experimental. Para o teste biomecânico também não houve variação significante do torque de remoção ao longo do tempo e nem houve diferença significante entre os grupos. Na análise de contato osso implante (BIC) não houve variação significante ao longo do tempo, mas houve diferença estatisticamente significante entre os ...

The aim of this study was to evaluate the interaction of an inorganic bovine bone matrix (Gen-ox®) as bone graft and titanium implants in rabbits mandible. Thirty-two Botucatu rabbits weighting about 4kg were used on this experiment. The mandible incisives were extracted and a defect of 4 mm of diameter was performed. One socket and defect was filled with experimental material. The opposite site was left to heal naturally and served as control. After 60 days, the implants were installed on the defect region. The animals were killed immediately after the implant installation and after 1, 2 and 6 months. Vertical bone height, bone density, biomechanical test, bone implant contact (BIC) and bone area near to implant threads were evaluated. The results showed that there was no significant differences on the distance between the alveolar bone crest to the implant platform (vertical bone height) along the time, neither between groups. On the bone density (pixel value) there was no significant difference along the time, but there was significant difference between groups, being the experimental group higher. For the biomechanical test there was no significant difference along the time, neither between groups. There was no significant differences on the bone implant contact (BIC) measures along the time, but there was significant difference between groups, being the experimental groups higher and there was interaction between time and groups. On bone area evaluation, there was no significant difference along the time, neither between the groups during the analyzed time. The graft behavior observed by the authors was similar to that of the control group, suggesting high acceptance of the material as graft option associated to titanium implants.

Usefulness of Magnetic Resonance Imaging in the Evaluation of Spine Following Instrumentation with Titanium Implants

Over the past six years, titanium alloy has been replacing the stainless steel in spinal implants owing to its magnetic resonance imaging(MRI) compatibility. However, studies about the usefulness of MRI, from a clinical standpoint, when it is used for spinal implants have been scarce. The purpose, therefore, is to determine whether postoperative MRIs would provide satisfactory information in evaluating the spine having various titanium implants. Authors reviewed the spinal MR images of sixteen patients who had previously received eleven different kinds of titanium implants, and compared postoperative images to preoperative images regarding the quality of images of spinal cord, nerve root, spinal canal, and the aforementioned implants. Types of implants included anterior cervical plate/screws, lateral cervical mass plate/screws, Halifax interlaminar clamps, anterior thoracolumbar rods/screws, posterior thoracolumbar rods/hooks, and posterior thoracolumbar transpedicular rods/screws. Anterior cervical plate/screws, lateral cervical mass plate/screws, Halifax clamps, and anterior thoracolumbar rod/screws produced small distortions of the images at the spinal canal or neural foramen. In contrast, posterior thoracolumbar transpedicular rods/screws created severe image distortions at the neural foramen in the postoperative MRIs. Metal-induced artifacts were most marked in the image from gradient echo sequence. Posterior thoracolumbar rods/hooks produced some artifacts at the posterior portion of the spinal canal. Although our series are limited in number, it can be concluded that MRI is informative and it is useful in postoperative evaluation of the spine with most types of titanium implants. However, postmyelogram computed tomography is recommended in cases where posterior thoracolumbar transpedicular rods/screws have been used.

Effect of tonifying kidney recipes on osseointegration around titanium implants in osteoporotic rats / 实用口腔医学杂志

Objective:To investigate the mechanism of the effect of tonifying kidney recipes(TKR) on osseointegration of the Titanium Implants by established animal model of osteoporosis rats.Methods:Fifty-four female SD rats were randomly divided into three groups:A:Sham group, B:ovariectomy(OVX) group C:OVX+TKR group. After operation, tonifying kidney recipes was given orally in C group. The results were observed by bone histomorphometry. Results:Trabeculae area (Tb?Ar,%), trabeculae width (Tb?Wi), combined bone lamella width (CBLW), osteoblast number (OB?N) in C group were significantly increased compared with B group (P