Influence of surface roughness of barrier walls on guided bone augmentation: experimental study in rabbits

Background: By using the guided tissue regeneration concept it is possible to augment bone, beyond the skeletal envelope, provided certain biologic, surgical, and barrier-related demands are met. Among barrier-related factors of importance are the surface properties. Purpose: The aim of this study was to evaluate whether different surface roughness of the barrier wall influences the amount and morphology of augmented bone in a secluded space, using a titanium cylinder as barrier device placed on the rabbit skull. Materials and Methods: Cylinders of commercially pure titanium were fabricated by machining, using a turning tool. The inner cylinder wall was either left untreated or grit-blasted with titanium dioxide to increase surface roughness. The topographic profile of the inner surface of two cylinders (1 turned and 1 grit-blasted) was measured in vitro to achieve a numeric characterization of each type of surface topography. Two cylinders, one with grit-blasted and one with turned inner walls, were surgically placed and secured to the skull bone of each of eight rabbits. The plate of the cortical bone, facing the experimental area framed by the cylinder wall was removed, and care was taken to ensure total blood fill of the cylinders. After 3 months, the animals were sacrificed to obtain histology for histomorphometry. Results: The relative volume of augmented tissue in the grit-blasted cylinders (77.9 ± 10.5%) did not differ significantly from that in the turned cylinders (73.4 ± 5.5%, p =.118), neither did the volume of mineralized bone (20.1 ± 8.2% vs. 22.1 ± 7.2%, p =.064). The trabecular density of the augmented bone was higher close to the walls of both the turned and the grit-blasted cylinders compared to the overall trabecular density within the cylinders, but with no significant difference between the two groups. However, the area of mineralized bone in direct contact with the inner surface of the titanium cylinder was significantly larger in the grit-blasted (33.9 ± 13.3%) compared to the turned cylinders (12.0 ± 8.5%, p =.01). Conclusions: The use of titanium barriers with a grit-blasted inner surface compared to barriers with a turned surface resulted in the formation of similar amounts of bone beyond the skeletal envelope of the rabbit skull. However, a larger area of augmented mineralized bone was found in direct contact with the inner surface of the grit-blasted cylinders.     

Focal adhesion formation of primary human gingival fibroblast on hydrothermally and in-sol-made TiO2-coated titanium

Optimal cell adhesion of the gingival fibroblasts to dental implants is important for maintaining good implant integration. The aim of this study was to discover, if the nanoporous TiO₂-coating on titanium alloy substrates is able to increase the cell adhesion of the human gingival fibroblasts (HGF). The study consisted of three differently produced titanium groups: hydrothermally produced TiO₂-coating (HT), novel TiO₂-coating made in sol (SOL), and noncoated control group. Primary HGF cells were initiated from gingival biopsies from patients having a third molar extraction. HGF were cultivated on titanium discs for 2 and 24 h to determine the initial attachment with confocal microscope. The cell spreading and adhesion protein signals were measured. In addition, expression of adhesion proteins vinculin, paxillin, and focal adhesion kinase (FAK) were measured after 3 days of cultivation by using Western Blotting. Higher protein levels of paxillin, vinculin, and FAK were induced on both coated discs compared to noncoated discs. The difference was statistically significant (p < 0.05) concerning expression of paxillin. The cell spreading was significantly larger on SOL discs after 2 and 24 h when comparing to noncoated controls. The confocal microscope analyses revealed significantly higher adhesion protein signals on both HT- and SOL-coated titanium compared to control group. This study showed, that both methods to produce TiO₂-coatings are able to increase HGF adhesion protein expression and cell spreading on titanium surface. Accordingly, the coatings can potentially improve the gingival attachment to titanium implant surfaces.     

Attachment and proliferation of human oral fibroblasts to titanium surfaces blasted with TiO2 particles. A scanning electron microscopic and histomorphometric analysis.

The purpose of this study was to determine the effect of c.p. titanium surfaces blasted with TiO2 particles on the biological responses of human gingival fibroblasts (HGF). Fibroblast morphology and attachment were investigated on turned (control) titanium surfaces and those blasted with 45 microns (standard), 45-63 microns, and 63-90 microns TiO2 particles. The specimens were analyzed using a confocal laser scanner and SEM. The cell profile areas were measured using a semiautomatic interactive image analyser. The figures were expressed as percent of attachment. The turned samples had the smoothest surfaces and the roughest were those blasted with 63-90 microns. All TiO2 blasted specimens had homogeneous surfaces. Cells appeared to flatten, spread and form cellular bridges with the adjacent cells. Fibroblasts on the turned titanium surfaces appeared to follow the direction of the fine irregularities on the surface but tended to spread haphazardly on the blasted surfaces. The attachment assays showed no significant difference in the percentage of fibroblast cell attachment on the standard surfaces compared to the turned surfaces. Both surfaces blasted with 45-63 microns or 63-90 microns had significantly (P < 0.05) lower percentages of cell attachment than the control. The surfaces blasted with 63-90 microns particles had the lowest rate of cell attachment. A significant correlation (P < 0.01) was found between the degree of particle size and attachment of fibroblasts after 1-72 h. It is concluded that surface micro-texture influences the attachment and growth of HGF: surfaces blasted with 45 microns TiO2 do not inhibit fibroblast attachment and smooth or finely grooved surfaces could be conducive to cellular attachment.     

两种生长因子对人牙周膜成纤维细胞在钛金属表面附着和生长的影响

目的：研究两种生长因子对牙周膜成纤维细胞在然金属表面附着和生长的影响。方法：将纯钛、钛75试件入在12孔培养板内，取生长良好的第五代人牙周膜成纤维细胞（PDLF）接种在试件表面，分别在接种后4h、12h、24h、72h进行贴壁细胞地数。结果：接种后4h、12h、24h、72h、bFGF组纯钛、钛75表面细胞附着数与空白对照组的差异均有显著性（P＜0．05），rhBMP－2组纯钛、然75表面细胞附着数在初期（24h）与空白对组无显著性差异（P＞0．05）。72h时与空白对照组差异有显著性（P＜0．05），表明bFGF促进细胞附着和生长作用显著，而rhBMP－2促进细胞生长作用较促附着作用明显。结果：PDLF在钛金属表面的附着和生长可被生长因子所增强，但不同的生长因子对细胞附着和生长的生物学效应不尽相同。     

牙骨质基质提取物吸附于光滑钛表面上的实验研究

目的:探讨牙骨质提取物能否良好地吸附在光滑钛表面上.方法:以含131I标记的牙骨质基质胍提取物的DMEM培养液为实验组,以131I处理的DMEM培养液为对照组,将金属钛片放置在以上两组溶液中孵化1h,钛片干燥后放置X线感光胶片上曝光约3h,分析感光照片的灰度值.结果:牙骨质基质提取物处理组的图象灰度面积和灰度值均显著高于仅用碘化物处理的空白对照组(P＜0.01).结论:牙骨质基质提取物能较好地吸附在光滑的钛表面上.     

Influence of a Nanoporous Zirconia Implant Surface of on Cell Viability of Human Osteoblasts

Purpose : The dense nonretentive surface of zirconia implants was modified into a nanoporous surface using selective infiltration etching surface treatment. The aim of this study was to investigate the influence of such a nanoporous modified zirconia surface on the attachment of human osteoblasts. Materials and Methods : Human osteoblasts were cultured for 21 days on (i) selective infiltration etched zirconia (nanoporous surface), (ii) polished zirconia, (iii) polished titanium, or (iv) airborne particle abraded acid etched (SLA) titanium disks. After the culture period the following parameters were assessed: number of cells, the morphology of the cells, the attachment of the cells, alkaline phosphatase activity, and the level of total protein (α= 0.05). Results : Statistical analysis revealed a significantly higher cell count on the third (F = 17.4, p < 0.001) and eighth day (F = 163, p < 0.001) for nanoporous zirconia and SLA titanium surfaces compared to polished specimens. The number of cells (nanoporous zirconia 160 ± 20/mm², SLA titanium 133 ± 15/mm²) and cell size (nanoporous zirconia 50.7 ± 3 μm, SLA titanium 42.5 ± 4 μm) were significantly higher than polished specimens. Nanoporous zirconia specimens demonstrated comparable alkaline phosphatase activity (0.0036 ± 0.0035 ng/μl) and intracellular protein content (72.7 ± 0.9 ng/μl) compared to other tested groups. Scanning electron microscopy revealed that cells attached on the polished surface using finger‐like processes, whereas on the nanoporous surface, finger‐like processes were not observed, as the cell membrane appeared to be in close proximity to the underlying surface. Conclusion : The findings of this study suggest that a nanoporous zirconia surface favors cell growth and attachment compared to a polished surface. It was proposed that a nanoporous zirconia surface may improve clinical performance of zirconia implants.     

In vivo investigation on connective tissue healing to polished surfaces with different surface wettability

Objectives: Connective tissue in contact to transgingival/‐dermal implants presents itself as tight scar formation. Although rough surfaces support the attachment they increase bacterial colonisation as well. In contrast to surface roughness, little is known about the influence of surface wettability on soft‐tissue healing in vivo. We therefore investigated the influence of different surface wettabilities on connective tissue healing at polished implant surfaces in vivo. Material and methods: Three polished experimental groups (titanium, titanium coated with hydrophobic nano‐crystalline diamond (H‐NCD) and titanium coated with hydrophilic nano‐crystalline diamond (O‐NCD) were inserted into the subcutaneous connective tissue of the abdominal wall of 24 rats. Animals were sacrificed after 1 and 4 weeks resulting in eight specimen per group per time point. Specimen were subjected to histological evaluation (van Giesson's staining) and immunohistochemistry staining for proliferating cell nuclear antigen (PCNA), fibronectin and tumour necrosis factor‐alpha (TNF‐α). Results: Histological evaluation revealed dense scar formation at the titanium and H‐NCD surfaces. In contrast, the connective tissue was loose at the O‐NCD surface with a significantly higher number of cells after 4 weeks. O‐NCD demonstrated a strong expression of PCNA and fibronectin but a weak expression of TNF‐α. In contrast, the PCNA and fibronectin expression was low at the titanium and H‐NCD, with a strong signal of TNF‐α at the H‐NCD surface. Conclusions: Hydrophilicity influences the connective tissue healing at polished implant surfaces in vivo positively. The attachment of connective tissue and the number of cells in contact to the surface were increased. Moreover, the inflammatory response is decreased at the hydrophilic surface. To cite this article:
Kloss FR, Steinmüller‐Nethl D, Stigler RG, Ennemoser T, Rasse M, Hächl O. In vivo investigation on connective tissue healing to polished surfaces with different surface wettability.
Clin. Oral Impl. Res. 22 , 2011; 699–705
doi: 10.1111/j.1600‐0501.2010.02038.x     

Attachment of human marrow stromal cells to titanium surfaces

The attachment of human bone marrow stromal cells to titanium alloy (Ti6Al4V) surfaces was investigated. Titanium disks were polished and modified by surface roughening and by passivation in nitric add. Cell attachment to titanium surfaces and tissue culture plastic (TCP) was determined by tetrazolium bromide (MTT) assay at 2, 6, 24, and 48 hours after seeding. Cell proliferation was determined by thymidine incorporation. Attachment on titanium surfaces was 75.6% to 94.9% of attachment on TCP control. The difference between cell attachment on the TCP compared with smooth or rough titanium was statistically significant (P < .05). However, no statistically significant difference was found between attachment to TCP and passivated titanium. Cell proliferation on titanium surfaces after 24 hours was approximately 70% of proliferation on TCP. There was a statistically significant difference (P < .05) between proliferation on tissue culture and smooth and passivated titanium but not on rough titanium. These results indicate that titanium provides a surface that is conducive to cell attachment and that passivating titanium improves cell attachment, approaching levels seen with TCP, a surface specifically developed to enhance cell attachment. Increasing surface roughness results in improved cell proliferation on titanium.     

Effect of heat-treated titanium surfaces on protein adsorption and osteoblast precursor cell initial attachment

The clinical success of dental implants is governed in part by surface properties of implants and their interactions with the surrounding tissues. The objective of this study was to investigate the effect of heat-treated titanium surfaces on protein adsorption and osteoblast precursor cell attachment in vitro. Passivated titanium samples used in this study were either non heat treated or heat treated at 750 degrees C for 90 minutes. It was observed that the contact angle on heat-treated titanium surfaces was statistically lower compared with the non-heat-treated titanium surfaces. The non-heat-treated titanium surface was also observed to be amorphous oxide, whereas heat treatment of titanium resulted in the conversion of amorphous oxide to crystalline anatase oxide. No significant difference in albumin and fibronectin adsorption was observed between the heat-treated and non-heat-treated titanium surfaces. In addition, no significant difference in initial cell attachment was observed between the two groups. It was concluded that heat treatment of titanium resulted in significantly more hydrophilic surfaces compared to non-heat-treated titanium surfaces. However, differences in oxide crystallinity and wettability were not observed to affect protein adsorption and initial osteoblast precursor cell attachment.     

Altered cell motility and attachment with titanium surface modifications

Background: Titanium implants are widely used in dentistry to replace lost teeth. Various surface modifications have been used to improve implant retention and osseointegration. This study is designed to compare the ability of three titanium surfaces to promote cell attachment and cell motility of cells relevant to periodontal tissues. Methods: Three clinically relevant surfaces were tested: 1) machined titanium; 2) a titanium surface roughened through acid etching (dual thermal‐etched titanium [DTET]); and 3) a titanium surface roughened with nanometer‐scale calcium phosphate deposition (nanoscale calcium phosphate–impregnated titanium [NCPIT]). Cell attachment and migration were examined for four cell types: rat osteosarcoma cells, human osteoblasts, and gingival and periodontal ligament (PDL) fibroblasts. Results: All four cell types attached to each of the three titanium surfaces equally by 2 hours, and the PDL and gingival fibroblasts generally displayed less attachment than the osteosarcoma cells and osteoblasts. The cells displayed differential motility and long‐term attachment to each of the titanium surfaces. Osteosarcoma cells displayed preferential motility on NCPIT, whereas PDL fibroblasts were more motile on machined titanium, and gingival fibroblasts moved more rapidly on both DTET and NCPIT. Osteoblasts displayed little motility on any of the titanium surfaces and lost viability on NCPIT after 24 hours. Gingival fibroblasts lost attachment to machined titanium. Conclusions: Periodontal cells displayed differential motility and long‐term attachment to titanium surfaces. Selective modification of titanium surface properties in various regions of an implant may be useful in guiding specific cell populations to specific locations where they might best aid in osseointegration and soft tissue remodeling.     

Adhesion pattern and growth of primary human osteoblastic cells on five commercially available titanium surfaces

Objective: The aim of this study is to analyze the morphology and proliferation of human osteoblastic cells in vitro on five commercially available titanium surfaces. Materials and methods: Human primary cells of the osteoblastic lineage were obtained from bone explants. The cells were plated on polished (T1), machined (T2), sand‐blasted/acid‐etched (T3), sand‐blasted/acid‐etched, modified with hydrogen peroxide rinse (T4), and plasma‐sprayed titanium (T5) disks. Cell morphology was studied after 6, 24, 72 h, 7 and 14 days of culture by scanning electron microscopy. The formation and distribution of focal adhesions was investigated by immunocytochemical staining at 3, 6 and 24 h. Cell growth was measured by an MTT assay after 3, 7 and 9 days of culture. Moreover, the production of osteocalcin and osteoprotegerin (OPG) was evaluated in the supernatants by ELISA. Results: Morphological analysis revealed that substrate topography profoundly affected cells' shape and their anchoring structures. Large lamellipodia were formed on polished and machined surfaces, while thin filopodia were more frequently observed on T3 and T4 samples. Moreover, cells formed stronger focal adhesions on T3 and T4 surfaces, and cell proliferation was higher on rough surfaces. Osteocalcin production was higher on the T4 surface, whereas OPG steadily increased on every surface. Conclusions: Taken together, these data show that all the surfaces allowed cell attachment, adhesion and proliferation, but T4 and T5 surfaces appeared to be a better substrate for the adhesion, proliferation and differentiation of cells of the osteoblastic lineage. To cite this article:
Passeri G, Cacchioli A, Ravanetti F, Galli C, Elezi E, Macaluso GM. Adhesion pattern and growth of primary human osteoblastic cells on five commercially available titanium surfaces.
Clin. Oral Impl. Res. 21 , 2010; 756–765.
doi: 10.1111/j.1600‐0501.2009.01906.x     

不同钛表面形貌对人牙龈成纤维细胞生物学行为的影响

目的:良好的种植体颈部软组织封闭是种植体远期成功的重要因素之一。生物封闭的的主要决定因素之一是种植体颈部的表面形貌。本实验的目的是通过比较三种不同的纯钛表面形貌结构对人牙龈成纤维细胞的生物学行为的影响,寻找一种有利于牙龈胶原纤维附着的较理想的种植体颈部表面形貌,为种植体颈部设计提供指导。方法:本研究采用机械加工处理、电化学腐蚀、电化学腐蚀加酸蚀的方法在纯钛金属表面形成三组不同的表面形貌结构;用激光共聚焦显微镜检测其表面粗糙度;扫描电镜观察其表面微观形态并用X射线能谱色散谱仪检测其表面成分;将其与人牙龈成纤维细胞共同培养,MTT法检测表面细胞的增殖情况;细胞计数仪进行表面细胞计数;扫描电镜观察表面细胞的形状及排列。结果:机械加工组表面较光滑,呈浅的等向排列的微沟纹,表面粗糙度Sa为0.8783±0.2578μm;电化学腐蚀组表面略粗糙,呈圆形或椭圆形浅碟状凹,直径约10～15μm,分布均匀,凹内含有散在的小孔,小孔的直径约为1-5μm,表面粗糙度Sa为1.7530±0.3711μm;电化学腐蚀加酸蚀组表面略粗糙,呈圆形或椭圆形浅碟状凹,直径约10～15μm,分布均匀,凹内含有散在的小孔,小孔的直径约为1-5μm,表面见均匀的半球形纳米突起形成,直径约50～100nm,表面粗糙度Sa为1.6763±0.3440μm。表面成分检测显示三组均未有任何污染物在钛表面。牙龈成纤维细胞在各组钛片表面生长良好,形态正常,各组钛片对于细胞没有明显的毒性,生长曲线与正常细胞的生长曲线规律一致。机械加工组表面细胞沿着材料表面微沟纹平行排列,细胞扁平,伸展较差,细胞伸出的伪足较短;电化学腐蚀组表面细胞自由分布,细胞丰满,伸展良好,细胞伸出的伪足较长,有的伪足伸入到邻近凹内;电化学腐蚀加酸蚀组表面细胞丰满,伸展良好,伸出大量伪足,伪足很长,呈细丝状或带状,可伸入到相隔较远的凹孔内,呈悬空样,也可相互交织成网状。结论:电化学腐蚀加酸蚀可在纯钛表面形成均匀分布的直径为10-20μm的凹及直径为1-5μm的孔,凹及孔的表面均匀布满了直径为50-100nm的半球状突起。电化学腐蚀加酸蚀表面促成纤维细胞粘附作用最强。本实验中形成的微米凹、孔形态及半球形纳米形态均有利于成纤维细胞的粘附。电化学腐蚀加酸蚀方法形成的表面是一种较为理想的种植体颈部表面,可以为种植体颈部设计提供指导。     

The effects of titanium nitride-coating on the topographic and biological features of TPS implant surfaces

Objectives

Titanium nitride (TiN) coating has been proposed as an adjunctive surface treatment aimed to increase the physico-mechanical and aesthetic properties of dental implants. In this study we investigated the surface characteristics of TiN-coated titanium plasma sprayed (TiN-TPS) and uncoated titanium plasma sprayed (TPS) surfaces and their biological features towards both primary human bone marrow mesenchymal stem cells (BM-MSC) and bacterial cultures.

Methods

15 mm × 1 mm TPS and TiN-TPS disks (P.H.I. s.r.l., San Vittore Olona, Milano, Italy) were topographically analysed by confocal optical profilometry. Primary human BM-MSC were obtained from healthy donors, isolated and expanded. Cells were seeded on the titanium disks and cell adhesion, proliferation, protein synthesis and osteoblastic differentiation in terms of alkaline phosphatase activity, osteocalcin synthesis and extracellular mineralization, were evaluated. Furthermore, adhesion and proliferation of Streptococcus pyogenes and Streptococcus sanguinis on both surfaces were also analysed.

Results

TiN-TPS disks showed a decreased roughness (about 50%, p < 0.05) and a decreased bacterial adhesion and proliferation compared to TPS ones. No difference (p > 0.05) in terms of BM-MSC adhesion, proliferation and osteoblastic differentiation between TPS and TiN-TPS surfaces was found.

Conclusions

TiN coating showed to modify the topographical characteristics of TPS titanium surfaces and to significantly reduce bacterial adhesion and proliferation, although maintaining their biological affinity towards bone cell precursors.     

Bone reactions to oxidized titanium implants with electrochemical anion sulphuric acid and phosphoric acid incorporation

Background: The importance of the surface properties of implants for a successful osseointegration has been emphasized. It is generally known that bone response to implant surfaces is considerably related to the various surface properties. Purpose: The purpose of this study was to investigate bone tissue reactions to multifactorial biocompatibility of the surface oxide of electrochemically oxidized titanium implants. The ultimate objective was to improve surface quality, resulting in enhancement of clinical outcomes of osseointegrated implants. Materials and Methods: Three different surface types of commercially pure titanium (c.p. Ti) implants were prepared. Turned implants were used for controls and test implants were prepared by the micro arc oxidation (MAO) method, either in sulphuric acid (S implants) or in phosphoric acid (P implants). Implants were inserted in the femur and tibia of 10 mature New Zealand White rabbits. The bone response was evaluated by biomechanical tests, histology, and histomorphometry. The follow‐up time was 6 weeks. Results: The mean peak values of the removal torque showed significant differences between control and test S implants (p =.022) but showed no significant differences between control and test P implants (p =.195) or between test S and test P implants (p =.457). In addition, the histomorphometric comparisons of the bone‐to‐metal contact around entire implants demonstrated 186% increase in S implants (p =.028) and 232% increase in P implants (p =.028) compared with the paired control groups. Quantification of the bone area in the threads did not show any significant differences. Conclusions: The present results suggest that the primary mode of action in strong bone response to S implants is mechanical interlocking, and to P implants, it is biochemical interaction. It is possible that the phosphate groups in the titanium oxide of P implants provide potential chemical bonding sites for calcium ions and hydroxyapatite of the bone matrix during biologic mineralization.     

微纳复合结构对成纤维细胞黏附增殖的影响

目的：探讨经不同方法处理后的纯钛表面对成纤维细胞黏附增殖的影响。方法：将36个试件分平均为3组：机械抛光组（A组）;喷砂酸蚀组（B组）;喷砂酸蚀碱热组（C组）,每组均12个试件。通过扫描电子显微镜（SEM）观察分析3组试件表面微观结构和细胞在试件表面的铺展情况,激光共聚焦显微镜（CLSM）检测各试件表面的粗糙度;运用CCK-8试剂盒在450 nm波长下检测各试件对成纤维细胞（ L929）黏附与增殖的吸光度值（ OD值）。结果：A组表面光滑,试件表面成纤维细胞骨架大多呈梭形铺展,伸展较差;B组和C组表面粗糙,且C组表面可见微纳复合结构,试件表面成纤维细胞骨架呈三维空间向铺展,表面黏附成纤维细胞数量明显多于A组和B组。观察第1,3,5 d试件表面细胞增殖情况,可见粗糙表面较光滑表面更利于成纤维细胞的增殖。结论：喷砂酸蚀碱热方法处理后的纯钛表面形成微米-纳米复合孔洞,表面活性好,促进成纤维细胞早期黏附及表面铺展,且不抑制细胞的增殖。     

Bone marrow mesenchymal stem cell response to nano-structured oxidized and turned titanium surfaces

Objectives: The aim of this study was to analyse the topographic features of a novel nano‐structured oxidized titanium implant surface and to evaluate its effect on the response of human bone marrow mesenchymal stem cells (BM‐MSC) compared with a traditional turned surface. Methods: The 10 × 10 × 1 mm turned (control) and oxidized (test) titanium samples (P.H.I. s.r.l.) were examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM) and characterized by height, spatial and hybrid roughness parameters at different dimensional ranges of analysis. Primary cultures of BM‐MSC were seeded on titanium samples and cell morphology, adhesion, proliferation and osteogenic differentiation, in terms of alkaline phosphatase activity, osteocalcin synthesis and extracellular matrix mineralization, were evaluated. Results: At SEM and AFM analyses turned samples were grooved, whereas oxidized surfaces showed a more complex micro‐ and nano‐scaled texture, with higher values of roughness parameters. Cell adhesion and osteogenic parameters were greater on oxidized (P<0.05 at least) vs. turned surfaces, whereas the cell proliferation rate was similar on both samples. Conclusions: Although both control and test samples were in the range of average roughness proper of smooth surfaces, they exhibited significantly different topographic properties in terms of height, spatial and, mostly, of hybrid parameters. This different micro‐ and nano‐structure resulted in an enhanced adhesion and differentiation of cells plated onto the oxidized surfaces.     

Enhanced initial cell responses to chemically modified anodized titanium

Background: Previously, we reported that anodized porous titanium implants have photocatalytic hydrophilicity. However, this effect was not always sufficient for the significant improvement of bone apposition. Purpose: The purpose of this study was to improve the photocatalytic properties of porous titanium implants by the fluoride modification of the anodized titanium dioxide (TiO₂), and to investigate the initial cell response to it. Materials and Methods: The ideal concentration of ammonium hydrogen fluoride (NH₄F‐HF₂) used in this study was determined by a static water contact angle assay. The ideal concentration of NH₄F‐HF₂ was 0.175%, and experimental disks were treated with this concentration. A pluripotent mesenchymal cell line, C2C12, was cultured on the disks in order to investigate cell attachment, morphology, and proliferation. Results: Cell attachment after 30 minutes of culturing was significantly higher for the ultraviolet‐irradiated, fluoride‐modified anodized TiO₂ (p < .05), and the simultaneous scanning electron microscope observation showed a rather flattened and extended cell morphology. The proliferation rate after 24 hours was also significantly higher for the fluoride‐modified anodized TiO₂. Conclusion: Fluoride chemical modification enhances the hydrophilic property of the anodized TiO₂ and improves the initial cell response to it.     

不同种植体表面改性对细菌生物膜的影响

目的:研究临床常用的3种钛种植体不同表面处理对口腔内常见菌群牙龈卟啉单胞菌(Porphyromanusgingivalis,P.gingivalis)、具核梭杆菌(Fusobacterium nucleatum,F.nucleatum)及血链球菌(Streptococcus sanguis,S.sanguis)生物膜黏附的影响。方法:将钛片分成3组进行表面改性处理,分别为:电解沉积羟基磷灰石(HA)组、微弧氧化(MAO)组和大颗粒喷砂酸蚀(SLA)组,进行表面性能检测;在3组钛片上分别培养Pg、Fn及Ss 4 d,通过菌落形成单位(CFU)法、噻唑蓝(MTT)法和扫描电子显微镜(SEM)探究细菌的黏附情况。结果:(1)SEM观察表面形貌可见HA组表面大量不规则的棒状结构;MAO表面“火山口”样结构,孔径在0.1~1μm之间;SLA表面为不规则凹陷,大小不一且边缘锋利。3组表面粗糙度Ra值:SLA组0.05);Pg生物膜在MAO组钛片上活性最高,与另外2组有统计学差异(P<0.01)。(3)利用SEM观察显示,细菌活性与种植体表面形态结构有关。结论:细菌在种植体表面黏附受到表面形貌影响,与粗糙度及物理构型有关。对于Pg、Ss和Fn 3种细菌,SLA在3种表面处理中细菌粘附量最少。     

The effects of Mg-ion implantation and sandblasting on Porphyromonas gingivalis attachment

Objectives: The purpose of this study was to evaluate the effect of titanium surface treatment on Porphyromonas gingivalis bacterial attachment. Materials and methods: Titanium disks of 15 mm in diameter and 1 mm in thickness (n=40) were subjected to mechanical grinding, or sandblasting. Magnesium (Mg) ions were implanted onto the titanium surface using a plasma source ion implantation method. The structure, chemistry, and surface morphologies of the titanium surfaces were analyzed using scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy and Auger electron spectroscopy. Surface roughness was measured using a laser profilometer. Half of the titanium disks in each group were dipped in saliva for 24 h. All of the titanium specimens were rinsed with distilled water. A P. gingivalis strain was cultured in anaerobic conditions at 37°C for 72 h, and all titanium specimens were dipped in the bacterial suspension at 37°C for 24 h. Specimens were examined at × 3000 magnification using a SEM. The number of bacteria in each of 10 separate fields was determined by directly counting the number of bacterial colonies that adhered to each specimen. The mean values were calculated afterward. The resulting data were analyzed to assess the significance of observed differences based on the method of the surface treatment, ion implantation, and saliva dipping. Results: The amount of P. gingivalis attached to the sandblasted specimens was greater than that on the ground specimens (P<0.001). Moreover, surfaces with Mg‐ion implantation had more attachments than nonimplanted surfaces (P<0.001). Saliva dipping acted synergistically with surface roughness and chemical composition of the specimens. Conclusions: Chemically modified surface increase the attachment of a major periodontopathic bacterium, P. gingivalis. To cite this article:
Kim ML, Jeong CM, Jeon YC, Byon ES, Jeong YS, Cho LR. The effects of Mg‐ion implantation and sandblasting on Porphyromonas gingivalis attachment.
Clin. Oral Impl. Res. 23 , 2012; 245–252.
doi: 10.1111/j.1600‐0501.2010.02138.x     

Nanoporous TiO2 Thin Film on Titanium Oral Implants for Enhanced Human Soft Tissue Adhesion: A Light and Electron Microscopy Study

Background: Previous experimental studies have demonstrated direct soft tissue attachment for nanoporous titanium dioxide (TiO₂) thin film on implants, while implants without TiO₂ thin film have not shown this capability. Purpose: The aims were to evaluate and compare TiO₂ surface‐modified experimental microimplants with unmodified microimplants with respect to tissue interaction of the human oral mucosa evaluated by light microscopy on ground sections and semithin sections and transmission electron microscopy on ultrathin sections, and to characterize the inflammatory response and the level of the marginal bone resorption. Materials and Methods: The study was a single‐center, randomized, comparative, clinical investigation with intrasubject comparison of implants with and without TiO₂ thin film in 15 patients. Results: Two comparator microimplants showed mild erythema and expulsion of fluids. The surrounding tissues around all test implants were clinically healthy. The oral mucosa in contact with the abutment part of the microimplant was 72% for the test implants and 48% for the comparator implants, a statistically significant difference (p = .0268). No statistically significant difference was found in other histological variables. The marginal bone loss in 14 weeks was 0.5 mm for the stable test (n = 11) and 1.7 mm for the stable comparator implants (n = 9; p = .0248). Conclusions: The nanoporous TiO₂ surface modification has potential clinical benefits because of increased adherence of soft tissue and possible reduced bone resorption.