Dental implantation, when performed immediately after tooth extraction, simplifies the treatment procedure, resulting in satisfaction for dentists and patients. Dental implants with nanotopography surface modification have been used to promote osseointegration immediately after implantation. We compared two different nanotopography surface implants on the effects of osseointegration immediately after tooth extraction: TiO 2 nanotubes (NT-TiO 2 ) fabricated by anodization and Sr-loaded nanotopography Ti (NT-Sr) formed via magnetron sputtering technology. Sr-loaded nanotextured Ti nanotubes (NT-Sr) were fabricated via magnetron sputtering using 99.99% SrTiO 3 as the sputtering target. TiO 2 nanotubes (NT-TiO 2 ) were fabricated by anodization in 0.5 wt% hydrofluoric acid (HF). After the surface topography, hydrophilicity, chemical components, and interface bonding strength were analyzed, two different nano-topographies were applied for in vivo cellular activity evaluation. Subsequently, the implants with NT-Sr and NT-TiO 2 surfaces were inserted into the fresh socket immediately after tooth extraction. Radiological scanning, histological analysis, and biomechanical tests were carried out to investigate implant osseointegration. The results showed that nanotubes with diameters of 15–80 nm were distributed on the NT-TiO 2 surface, while the NT-Sr group showed 20–40 nm nanoparticles deposited on the surface. Compared to NT-Sr, the NT-TiO 2 surface possessed better hydrophilicity and favorable cellular adhesion and proliferation. The NT-Sr surface possessed greater interfacial bonding strength than the NT-TiO 2 group, and greater bone formation, higher bone-to-implant contact (BIC%), and maximum pull-out force were observed in the NT-Sr group. The above results indicated that although the NT-TiO 2 surface showed favorable in vitro bioactivity, the NT-Sr surface, with higher interface bonding strength, showed better in vitro osteogenesis, and would be more favorable for immediate implantation.

目前牙种植体发展的趋势是将种植体表面处理成具有微/ 纳米的仿生表面结构,进而实现快速有效的骨整合[1,2].首先,从生物力学角度来看,微米级表面可以增强分子的转运和细胞的迁移[3].纳米级结构可以改变细胞的排列方式,纳米级的尺寸和沟槽的方向可影响细胞骨架的排列和细胞的粘附.

An easier method for constructing the hierarchical micro-/nano-structures on the surface of dental implants in the clinic is needed. In this study, three different titanium surfaces with microscale grooves (width 0.5-1, 1-1.5, and 1.5-2 μm) and nanoscale nanoparticles (diameter 20-30, 30-50, and 50-100 nm, respectively) were obtained by treatment with different concentrations of hydrofluoric acid (HF) and at different etching times (1%, 3 min; 0.5%, 12 min; and 1.5%, 12 min, respectively; denoted as groups HF1, HF2, and HF3). The biological response to the three different titanium surfaces was evaluated by in vitro human bone marrow-derived mesenchymal stem cell (hBMMSC) experiments and in vivo animal experiments. The results showed that cell adhesion, proliferation, alkaline phosphatase activity, and mineralization of hBMMSCs were increased in the HF3 group. After the different surface implants were inserted into the distal femurs of 40 rats, the bone-implant contact in groups HF1, HF2, and HF3 was 33.17%±2.2%, 33.82%±3.42%, and 41.04%±3.08%, respectively. Moreover, the maximal pullout force in groups HF1, HF2, and HF3 was 57.92±2.88, 57.83±4.09, and 67.44±6.14 N, respectively. The results showed that group HF3 with large micron grooves (1.5-2.0 μm) and large nanoparticles (50-100 nm) showed the best bio-functionality for the hBMMSC response and osseointegration in animal experiments compared with other groups.

We developed a hierarchical hybrid micro/nanorough strontium-loaded Ti (MNT-Sr) surface fabricated through hydrofluoric acid etching followed by magnetron sputtering and evaluated the effects of this surface on osseointegration. Samples with a smooth Ti (ST) surface, micro Ti (MT) surface treated with hydrofluoric acid etching, and strontium-loaded nano Ti (NT-Sr) surface treated with SrTiO3 target deposited via magnetron sputtering technique were investigated in parallel for comparison. The results showed that MNT-Sr surfaces were prepared successfully and with high interface bonding strength. Moreover, slow Sr release could be detected when the MNT-Sr and NT-Sr samples were immersed in phosphate-buffered saline. In in vitro experiments, the MNT-Sr surface significantly improved the proliferation and differentiation of osteoblasts compared with the other three groups. Twelve weeks after the four different surface implants were inserted into the distal femurs of 40 rats, the bone-implant contact in the ST, MT, NT-Sr, and MNT-Sr groups were 39.70%+/- 6.00%, 57.60%+/- 7.79%, 46.10%+/- 5.51%, and 70.38%+/- 8.61%, respectively. In terms of the mineral apposition ratio, the MNT-Sr group increased by 129%, 58%, and 25% compared with the values of the ST, MT, and NT-Sr groups, respectively. Moreover, the maximal pullout force in the MNT-Sr group was 1.12-, 0.31-, and 0.69-fold higher than the values of the ST, MT, and NT-Sr groups, respectively. These results suggested that the MNT-Sr surface has a synergistic effect of hierarchical micro/nano-topography and strontium for enhanced osseointegration, and it may be a promising option for clinical use. Compared with the MT surface, the NT-Sr surface significantly improved the differentiation of osteoblasts in vitro. In the in vivo animal experiment, the MT surface significantly enhanced the bone-implant contact and maximal pullout force than the NT-Sr surface.

AIM:To evaluate the effects of hydrofluoric ( HF) acid-treated titanium surfaces on the biologi-cal activity of bone marrow mesenchymal stem cells ( BMMSCs ) . METHODS: Titanium plates were divided into 3 groups, the suface of the samples was polished in group A, etched by 12. 5 g/L HF acid for 1 min group B and etched by 12. 5 g/L HF acid for 15 min Group C. The surface of the sample was observed by scanning electron micros-copy ( SEM ) . The suxface chemical composition was assessed by energy dispersive X-Ray spectroscopy detector ( EDS) . Contact angles were detected by drop method . BMMSCs adhesion and morphology were examined by confocal microscopy and SEM. Cell viability and ALP activity were assessed by MTT assay and ALP detection kit. RESULTS:Micro/nano-scale surface structures were formed after HF etching. The sample surfaces of group B and C were loaded with fluorine. Contact angle of etching groups was significantly smaller than that of polishing group. HF-treated titani-um surfaces significantly promoted adhesion, proliferation and ALP activity of BMMSCs. Furthermore, the effects of group C was greater than those of group B. CONCLUSION:HF acid-etch may forme different size of micro/nano-scale structures and load with fluorineon on titanium surface;can improve the biological activity of BMMSCs.

This study evaluated the effect of a hierarchical hybrid micro/nanorough titanium strontium-loaded (MNT-Sr) surface on osseointegration under osteoporotic conditions.

This study aimed to compare the variation of cancellous bones at four skeletal sites: lumbar vertebra, femoral neck, mandibular angle and rib in ovariectomized sheep. Sixteen adult sheep were randomly divided into two groups: eight sheep were ovariectomized served as experimental group; the other eight untreated sheep were served as control group. Bone mineral density was assessed by dual-energy X-ray absorptiometry on lumbar vertebrae at baseline and twelve months after ovariectomy. After 12 months, lumbar vertebrae L3 and L4, femoral necks, mandibular angles and the fourth ribs were harvested for micro-CT scanning, histological analysis and biomechanical test. The results showed that bone mineral density of lumbar vertebra decreased significantly in twelfth month (p<0.05). The results of micro-CT showed that the bone volume/total volume decreased by 45.6%, 36.1% 21.3% and 18.7% in lumbar vertebrae, femoral necks, mandibular angles and ribs in experimental group (p<0.05) respectively. The trabecular number showed the same downtrend (p<0.05). Histological analysis showed trabecular area/tissue area decreased by 32.1%, 23.2% and 20.7% in lumbar vertebrae, femoral necks and mandibular angles respectively (p<0.05), but no significant difference in ribs. Specimens elastic modulus from lumbar vertebra, femoral neck and mandibular angle were 952±76MPa (628±70MPa), 961±173MPa (610±72MPa) and 595±60MPa (444±31MPa) in control group (experimental group) respectively. These datum indicated that the sensibility of cancellous bones to oestrogen deficiency in ovariectomized sheep was site-specific on a pattern as follows: lumbar vertebra, femoral neck, mandibular angle and rib.

目的:评价纯钛经氢氟酸酸蚀+阳极氧化及氢氟酸酸蚀+磁控溅射处理后纯钛表面涂层的理化性能.方法:30个纯钛钛片平均分成两组,A组进行氢氟酸酸蚀+阳极氧化处理,B组进行氢氟酸酸蚀+磁控溅射处理.处理后的样品通过扫描电镜(SEM)、原子力学显微镜(AFM)观察其表面形貌,通过X射线能谱分析(EDS)、X射线衍射物相(XRD)观察表面化学成分,通过环氧树脂对接拉伸实验检测涂层的结合强度.结果:SEM显示两种表面处理后都可形成微/纳米级表面形貌,其中A组表面形貌为纳米管;B组表面形貌为纳米柱.AFM显示两种表面处理后形成的微/纳米级表面,粗糙度相近.EDS显示两种处理的表面都载入氟元素,其中B组以钛酸锶为靶材进行溅射后,表面载入锶元素.XRD显示两种表面主要晶相均为α钛.环氧树脂对接拉伸实验显示B组结合强度高于A组(P＜0.01).结论:两种处理方法在纯钛表面构建了不同结构的微/纳米涂层,其中氢氟酸酸蚀+磁控溅射表面载入锶元素,但都未形成新的晶相.磁控溅射组涂层的结合强度优于阳极氧化组.

AIM: To examine the coating of strontium-substituted titanium implant and to observe the effects of the coating surface on early osseointegration in vivo. METHODS: Strontium-substituted biomimetic surface titanium implants were manufactured by radio-frequency magnetron sputtering. The morphology and the component of the coating were examined by SEM and energy dispersive X-ray spectroscopy( EDS). The surface-coated implants( experimental group) and machanically-surfaced implants( control group) were randomly inserted into the distal femura of 20 SD rats,dual fluorochrome sequential labeling was used for osseointergration observation. 4 weeks after the surgery, the morphology was observed by histological examination. The maximal pull-out force of the specimens was measured by universal material testing machine. RESULTS: The strontium-substituted coating presented a micro / nanorough structure,in the coating the content of Sr was 1. 2%. Stronger osteogenic activity at early stage of bone healing was observed in experimental group. The bone implant contact,mineral apposition ration and maximal pull-out forces of experimental group were significantly higher than those of control group( P 0. 05). CONCLUSION: Modification with strontium-substituted biomimetic surface can promote osseointegration of dental implants in early stage of implantation.

Objectives: To investigate the normal range and characteristics of saliva secretion in the minor salivary glands (MSGs).Design: The flow rates of MSGs were measured in 4 anatomical locations of oral mucosa, and the relationship between MSG flow rates and whole saliva flow rates were assessed in 300 healthy subjects stratified by age and sex. An additional 30 young females were further evaluated for flow symmetry, effects of stimulation, circadian effects in MSGs, and the relationship with the flow rates of major salivary glands.Results: (1) The mean saliva flow rates were 2.10 +/- 0.66 (lower labial glands), 2.14 +/- 0.62 (upper labial glands), 2.88 +/- 0.72 (buccal glands) and 2.15 +/- 0.51 (palatal glands) mu l/min/cm(2), respectively. The flow rate of buccal glands was significantly higher than the rates of SMGs in other locations (P < 0.01). (2) 5-year-old children had the lowest MSG flow rates (P < 0.0001) while the 10-14-year-old group had the highest (P < 0.001). (3) MSG flow rates were independent of sex (P > 0.05), right vs. left (P > 0.05), and citric acid (2.5%) stimulation (P > 0.05). (4) Only labial MSG displayed a significant secretory circadian rhythm with the highest rate in the evening (P < 0.05). (5) A weak correlation was found between the flow rate of palatal glands and that of unstimulated whole saliva (r = 0.195, P = 0.007).Conclusions: Our findings provide a reference for functional evaluation of MSGs and for donor site selection of MSG transplantation for treatment of severe dry eye syndrome. (C) 2014 Elsevier Ltd. All rights reserved.