自体骨髓细胞增强多孔钛碳灰石涂层植入物在兔体内的早期骨整合

目的评价接种自体骨髓细胞的多孔钛碳灰石涂层植入物在体内的骨整合能力。方法多孔钛金属(￠4mm×10mm)最大孔径约240μm,通过碱加热处理及浸泡模拟体液涂层碳灰石后,接种兔髂嵴提取的自体骨髓间充质细胞。细胞接种的植入物(第1组)植入兔远端股骨,未接种的植入物植入对侧股骨做为对照(第2组)。实验动物分别在第10、20和42天后杀死。活体内的荧光标记物作为骨内生长的组织学判断。结果两组处理20天后植入物周围骨组织和植入物的联系没有明显差异。但是第1组孔槽内骨组织的形成明显多于第2组。处理后的42天,两组平均的骨植入物接触区域和骨组织的形成是相似的。接种自体成骨细胞,加强了涂碳灰石多孔钛植入物的骨整合能力,特别是在处理后早期。结论多孔钛碳灰石涂层植入物作为一种成功的生物植入物,将有广阔的临床应用价值。     

Effect of zoledronate acid treatment on osseointegration and fixation of implants in autologous iliac bone grafts in ovariectomized rabbits

One main problem associated with alveolar bone augmentation in implant dentistry is resorption of grafted bone, which may be further compromised by systemic skeletal disorders such as osteoporosis. Zoledronate acid (ZOL) is the most potent bisphosphonate to treat osteoporosis and therefore it is hypothesized to be able to invert the negative effect of osteoporosis on osseointegration and fixation of dental implants in autologous bone grafts. In this study, 56 rabbits received bilateral ovariectomy (OVX) (40 rabbits) or sham operation (16 rabbits). Three months later, 8 animals from each group were sacrificed for bone mineral density (BMD) examination. Then the remaining animals underwent bilateral autologous iliac bone grafting with simultaneous implantation of titanium implants in tibiae and were divided into 5 groups (n = 8): Sham, OVX, Loc-ZOL (local treatment), Sys-ZOL (systemic treatment) and Loc + Sys-ZOL (local plus systemic) group. At 3 months after implantation, all animals were sacrificed and specimens were harvested for examinations. Both BMD and histological examinations of femurs showed osteoporotic changes after ovariectomy, while systemic treatment with ZOL restored mineralized bone. Micro-CT examination demonstrated that OVX group showed significant decrease of mineralized bone and implant-bone contact when compared with sham control, whereas both systemic and local treatments of ZOL significantly increased mineralized bone and implant-bone contact in ovariectomized animals. However, the best effects were observed in Loc + Sys-ZOL group (combined use of ZOL) and most of bone indices were similar to (IBCR, p > 0.05) or higher than (BV/TV, Conn.D and Tb.N) (p < 0.01) those of the sham group, except Tb.Th, which was still significantly lower (p < 0.01), and Tb.Sp, which was further decreased (p < 0.01). The aforementioned effects were also confirmed by histomorphometric analysis of bone indices on implant-bone contact and mineralized bone. In addition, biomechanical testing further supported the beneficial effect of ZOL treatment and maximal removal torque of titanium implants was observed in Loc + Sys-ZOL group. In conclusion, our study suggests that both systemic and local treatments with ZOL can invert negative effect of osteoporosis and promote osseointegration and fixation of dental implants in autologous bone grafts under osteoporotic condition. Combined systemic and local use of ZOL exerts best effects when compared to their single use.     

Additive manufacturing of porous titanium metaphyseal components: Early osseointegration and implant stability in revision knee arthroplasty

AimsMetaphyseal cones and sleeves are components used in revision knee arthroplasty to ensure load transfer, encourage bone on-growth and prevent stress shielding. Additive manufacturing of titanium alloy implants is a novel technique with limited clinical outcome reports in the literature. The aim of this study was to determine radiographic evidence of osseointegration and early results of a single manufacturer porous titanium metaphyseal components in the proximal tibia.MethodsWe retrospectively reviewed the prospectively collected database of two institutions. Patients who underwent revision knee arthroplasty using porous titanium components by a single manufacturer were identified. Immediate post-operative and latest follow-up radiographs were independently analysed by 2 reviewers to determine metaphyseal bone contact and level of osseointegration in relevant Knee Society Radiographic Evaluation and Scoring System zones.Results22 patients (15 males; 7 females) with a mean age of 71 (49–92) years were included. The mean follow-up period was 14 months (2–44 months). Cones were used in 16 patients and sleeves in 6. Interobserver reliability assessment showed substantial agreement (weighted Kappa 0.71, (95% CI: 0.60, 0.81). There was significant correlation between the bone contact in the immediate postop radiograph and osseointegration at final follow-up (kendall’s tau-b: 0.698, p < 0.001). Infection free prosthetic joint survival was 20/22 at final follow-up.ConclusionPorous titanium metaphyseal components produced with additive manufacturing provided excellent osseointegration and no early clinical failures. Partial or complete contact of the cone with native bone in the immediate postoperative radiograph resulted in osseointegration in all cases.     

Machine oil inhibits the osseointegration of orthopaedic implants by impairing osteoblast attachment and spreading

The most important factor contributing to short‐term and long‐term success of cementless total joint arthroplasties is osseointegration. Osseointegration leads to a direct structural and functional connection between living bone and the surface of an implant. Surface contaminants may remain on orthopaedic implants after sterilization procedures and impair osseointegration. For example, specific lots of hip replacement Sulzer Inter‐OP^TM acetabular shells that were associated with impaired osseointegration and early failure rates were found to be contaminated with both bacterial debris and machine oil residues. However, the effect of machine oil on implant integration is unknown. Therefore, the goal of this study was to determine if machine oil inhibits the osseointegration of orthopaedic implants. To test this hypothesis in vivo we used our murine model of osseointegration where titanium alloy implants are implanted into a unicortical pilot hole in the mid‐diaphysis of the femur. We found that machine oil inhibited bone‐to‐implant contact and biomechanical pullout measures. Machine oil on titanium alloy discs inhibited early stages of MC3T3‐E1 osteogenesis in vitro such as attachment and spreading. Inhibition of osteoblast attachment and spreading occurred in both areas with and without detectable oil. Osteoblast growth was in turn inhibited on discs with machine oil due to both a decrease in proliferation and an increase in cell death. Later stages of osteogenic differentiation and mineralization on titanium alloy discs were also inhibited. Thus, machine oil can inhibit osseointegration through cell autonomous effects on osteoblast cells. These results support routine testing by manufacturers of machine oil residues on orthopaedic implants. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:979–987, 2015.     

仿生电活性涂层钛植入材料促进骨结合的实验研究

目的评价仿生电活性钛酸钡(BaTiO3,BTO)/聚偏氟乙烯-三氟乙烯P(VDF-TrFE)涂层钛植入材料促进骨结合性能的效果。方法首先将直径为2 mm、长度为5 mm的医用纯钛圆柱进行表面喷砂-酸蚀处理,然后将BaTiO3/P(VDF-TrFE)溶液均匀涂覆在钛柱表面。待烘干后对涂层表面进行电晕极化处理。采用扫描电镜、能谱分析、原子力显微镜、水接触角测量仪分别对材料表面形貌、元素组成、表面粗糙度和亲疏水性进行表征检测,PLLA涂层钛柱作为对照材料。选取实验兔4只,在双侧胫骨位置各制备3个间隔为1 cm的圆形缺损,在左侧胫骨植入PLLA涂层钛柱,右侧胫骨植入仿生电活性涂层钛柱,术后4周和12周分别取材进行硬组织的骨形态检测分析。采用SPSS15.0软件对数据进行统计分析。结果理化性能表征检测显示,BaTiO3/P(VDF-TrFE)涂层和PLLA涂层均匀附着在钛柱表面,涂层厚度约50μm,且表面结构致密。电活性涂层可见钛酸钡纳米颗粒均匀分布在P(VDF-TrFE)基体内。两种涂层表面的粗糙度和水接触角无明显差异。电活性涂层具有稳定的压电性能,且压电常数接近生理量级。动物实验显示,术后4周,仿生电活性涂层材料表面和新骨结合紧密,涂层材料稳定无降解;而PLLA涂层材料表面由于材料有部分降解导致新骨结合较差,电活性涂层的骨结合率明显高于PLLA涂层。术后12周,两组的新骨成熟程度均增加,骨陷窝明显,仿生电活性涂层仍然保持稳定状态;而PLLA涂层进一步发生降解,和新骨结合程度弱于电活性涂层组。结论仿生电活性BaTiO3/P(VDF-TrFE)涂层钛可能作为一种具有促进骨整合功能的种植体涂层材料。     

Four-year experience with titanium implants for cranio-facial rehabilitation in plastic surgery

Summary The osseointegrated system developed by Brånemark was used in twenty-two patients to anchor ear and orbital prostheses. The clinical experience with special attention to the stability of the implants, skin conditions and patient satisfaction is presented and discussed from the point of the plastic surgeon.     

A technique for intraoperative creation of patient-specific titanium mesh implants

Prefabricated, patient-specific alloplastic implants for cranioplasty reduce surgical complexity, decrease operative times, minimize exposure and risk of contamination, and have resulted in improved aesthetic results. However, in creating a prefabricated custom implant using a patient’s computed tomography data, a stable, unalterable defect must be clearly defined before surgery. In the event that an intraoperative modification of an exiting skull defect is required, or in cases of tumour resection in which the size of the skull defect is unknown preoperatively, these prefabricated implants cannot be used. The ideal method for alloplastic cranioplasty would enable cost-effective creation of a patient-specific implant with the capacity for intraoperative modification.The present article describes a novel technique of cranioplasty that uses a patient’s computed tomography data to create a custom forming tool (ie, mold), enabling intraoperative creation of a patient-specific titanium mesh implant. The utility of these implants in creating a custom reconstructive solution in cases in which the size of the skull defect is unknown preoperatively will be demonstrated using two case presentations.     

Reconstruction of caprine mandibular segmental defect by tissue engineered bone reinforced by titanium reticulum

Objective: To investigate the feasibility of using natural poritos as scaffolds in bone tissue engineering (TE) and repair of caprine mandibular segmental defect with titanium reticulum reinforced. Methods: Natural poritos with a pore of 190-230 μn in size and porosity of about 50% -65% was molded into the shape of granules 5 mm×5 mm×5 mm in size. Expanded autologous caprine marrow mesenchymal stem cells were induced by recombinant human morphogenetic protein-2 ( rhBMP2 ) to improve osteoblastic phenotype. Then marrow derived osteoblasts were seeded into poritos in density of 4×107/ml and incubated in vitro for 48 hours prior to implantation. Then osteoblastic cells/poritos complexes were implanted into mandibular defect and the defect was reinforced by titanium reticulum. Implantation of poritos alone acted as the control. Bone regeneration was assessed 4, 8, 16 weeks after implantation using roentgenographic analysis and histological observation was done after 16 weeks. Results: New bone could be observed histologically on the surface and in the pores of natural coral in all specimens in the cell-seeding group, whereas in the control group there was no evidence of osteogenesis process in the center of the construction. The results showed that new bone grafts were successfully restored 16 weeks after implantation. Conclusions: This study suggests the feasibility of using porous coral as scaffold material transplanted with marrow derived osteoblasts by TE method. By means of titanium reticulum reinforcement, mandibular defect could be successfully restored. It shows the potentiality of using this method for the reconstruction of bone defect in clinic.     

Impact of osteoporosis in dental implants: A systematic review

AIM: To assess the failure and bone-to-implant contact rate of dental implants placed on osteoporotic subjects.METHODS: Extensive examination strategies were created to classify studies for this systematic review. MEDLINE (via PubMed) and EMBASE database were examined for studies in English up to and including May 2014. The examination presented a combination of the MeSH words described as follow: “osteoporosis” or “osteopenia” or “estrogen deficiency” AND “implant” or “dental implant” or “osseointegration”. Assessment of clinical and/or histological peri-implant conditions in osteoporosis subjects treated with titanium dental implants. The examination included a combination of the MeSH terms described as follow: “osteoporosis” or “osteopenia” or “estrogen deficiency” AND “implant” or “dental implant” or “osseointegration”.RESULTS: Of 943 potentially eligible articles, 12 were included in the study. A total of 133 subjects with osteoporosis, 73 subjects diagnosed with osteopenia and 708 healthy subjects were assessed in this systematic review. In these subjects were installed 367, 205, 2981 dental implants in osteoporotic, osteopenic and healthy subjects, respectively. The failure rate of dental implant was 10.9% in osteoporotic subjects, 8.29% in osteopenic and 11.43% in healthy ones. Bone-to-implant contact obtained from retrieved implants ranged between 49.96% to 47.84%, for osteoporosis and non-osteoporotic subjects.CONCLUSION: Osteoporotic subjects presented higher rates of implant loss, however, there is a lower evidence to strengthen or refute the hypothesis that osteoporosis may have detrimental effects on bone healing. Consequently, final conclusions regarding the effect of osteoporosis in dental implant therapy cannot be made at this time. There are no randomized clinical trial accessible for evaluation and the retrospective nature of the evaluated studies shall be taken in account when interpreting this study.     

Osseointegration of porous titanium and tantalum implants in ovariectomized rabbits: A biomechanical study

BACKGROUNDToday, biological fixation of uncemented press-fit acetabular components plays an important role in total hip arthroplasty. Long-term stable fixation of these implants depends on the osseointegration of the acetabular cup bone tissue into the acetabular cup implant, and their ability to withstand functional loads.AIMTo compare the strength of bone-implant osseointegration of four types of porous metal implants in normal and osteoporotic bone in rabbits.METHODSThe study was performed in 50 female California rabbits divided into non-ovariectomized (non-OVX) and ovariectomized groups (OVX) at 6 mo of age. Rabbits were sacrificed 8 wk after the implantation of four biomaterials [TTM, CONCELOC, Zimmer Biomet''s Trabecular Metal (TANTALUM), and ATLANT] in a 5-mm diameter defect created in the left femur. A biomechanical evaluation of the femur was carried out by testing implant breakout force. The force was gradually increased until complete detachment of the implant from the bone occurred.RESULTSThe breakout force needed for implant detachment was significantly higher in the non-OVX group, compared with the OVX group for all implants (TANTALUM, 194.7 ± 6.1 N vs 181.3 ± 2.8 N; P = 0.005; CONCELOC, 190.8 ± 3.6 N vs 180.9 ± 6.6 N; P = 0.019; TTM, 186.3 ± 1.8 N vs 172.0 N ± 11.0 N; P = 0.043; and ATLANT, 104.9 ± 7.0 N vs 78.9 N ± 4.5 N; P = 0.001). In the OVX group, The breakout forces in TANTALUM, TTM, and CONCELOC did not differ significantly (P = 0.066). The breakout force for ATLANT in the OVX group was lower by a factor of 2.3 compared with TANTALUM and CONCELOC, and by 2.2 compared with TTM (P = 0.001). In the non-OVX group, the breakout force for ATLANT was significantly different from all other implants, with a reduction in fixation strength by a factor of 1.9 (P = 0.001).CONCLUSIONTANTALUM, TTM, and CONCELOC had equal bone-implant osseointegration in healthy and in osteoporotic bone. ATLANT had significantly decreased osseointegration (P = 0.001) in healthy and in osteoporotic bone.     

Coating of titanium implants with type-I collagen.

PURPOSE: Type-I collagen, the major structural protein in bone, has beneficial properties regarding bone regeneration. Little is known about the potential effects of collagen coating on orthopedic implants. METHODS: 3 to 6 microg/cm2 of lyophilized type-I collagen was absorbed on titanium rods. Six coated and uncoated pins of 0.9 mm diameter were inserted into the tibia of adult male Wistar rats for 1, 2, 4, 7, 14, and 28 days. Specimens were embedded in methacrylate-based Technovit 9100N resin. From one portion cutting and grinding sections were obtained. The implant was removed from the other half that was depolymerized, sectioned, and mounted for immunohistochemistry. RESULTS: At day 4, the interface around the collagen-coated implants displayed a granulation tissue with higher numbers of cathepsin D-positive mononucleated cells compared to the uncoated implants (p<0.05). Active osteoblasts, reactive for osteopontin, were increased around the collagen-coated pins at day 4 and 7 (p<0.01). After 28 days of implantation, direct bone contact averaged 74.9% around the collagen-coated implants and 62.1% around uncoated implants (NS). The amount of newly formed bone averaged 76.3% around the collagen-coated pins and 67.8% around the uncoated pins (NS). The histomorphometric findings were confirmed by SRmicroCT in two specimens. CONCLUSIONS: The earlier observation of mononuclear phagocytozing cells and the earlier and higher expression of bone-specific matrix proteins suggest an increased early bone remodeling around titanium pins through collagen coating. A tendency towards increased bone formation was observed around the coated implants.     

Prophylaxis of infection and effects on osseointegration using a tobramycin-periapatite coating on titanium implants—An experimental study in the rabbit

No options are available for local antibiotic delivery from uncemented implants. By loading a porous titanium implant with a biomimetic HA-coating (PeriApatite, PA) with antibiotics, we could obtain adequate local antibiotic concentrations and reduce infection susceptibility. This study investigated the efficacy of a tobramycin-loaded PA-coated titanium foam implant in preventing infection, as well as the effects on osseointegration. In 72 New Zealand White rabbits, an uncoated (Ti), PA-coated (PA), or Tobramycin-PA-coated (PA-tobra) titanium foam rod was implanted intramedullary in the left tibiae after contamination of the implant bed with none (control), 10³, 10⁴ or 10⁵ CFU Staphylococcus aureus. PA-tobra implants were loaded with 2.4 mg tobramycin. After 28 days analysis was done by bacteriology, histopathology and histomorphometry. Six percent of the contaminated PA-tobra rabbits were infected, whereas this was 53 and 67% for PA and Ti, respectively (p < 0.001). Quantitative cultures were also significantly lower in the PA-tobra group (p = 0.003). None of the control rabbits were infected. Histopathological and histomorphometrical scores were both better for the PA-tobra group, although only significant compared to Ti. No significant differences were observed between PA and Ti rabbits. We conclude that the application of tobramycin to PA-coated titanium foam implants appears to be an effective local antibiotic strategy for uncemented implants for infection prophylaxis and has a beneficial effect on implant fixation, which will result in improved long-term implant survival. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 710–716, 2009     

A system of osseointegrated implants and its application to dental and facial rehabilitation

Summary The Branemark system of osseointegration is described. Its use in the edentulous patient is presented. Extraoral prostheses, nose, eye and ear can be retained using a modification of this technique.     

Clinical aspects of osseointegration in joint replacement. A histological study of titanium implants

In an experimental clinical study, 25 implants of pure titanium were inserted into the proximal tibia of 11 volunteer patients, four with rheumatoid arthritis and seven with osteoarthritis. The implants were removed from five weeks to 24 months later and detailed histological analysis was performed. The implants generally healed with direct bone-metal contact, showing so-called osseointegration. Only one of the 21 implants which had been in place for over five months did not show osseointegration, probably because of inadequate primary contact with bone. The presence of rheumatoid disease did not prevent osseointegration, but accompanying osteoporosis seemed to be a risk factor.     

Transplantation of Autologous Chondrocytes Seeded on a Fibrin/Hyaluronan Composite Gel Into Tracheal Cartilage Defects in Rabbits: Preliminary Results

Reconstruction of tracheal defects is one of the most difficult procedures in head and neck surgery. To date, various reconstructing techniques have been used with no consensus on the best approach. This study investigated the feasibility of using a fibrin/hyaluronic acid (HA) composite gel with autologous chondrocytes for tracheal reconstruction. Chondrocytes from autologous rabbit auricular cartilages were expanded and seeded into a culture dish at high density to form stable tracheal cartilages mechanically using a fibrin/HA composite gel. A 1‐cm long by 0.5‐cm wide defect was created by a scalpel on the cervical tracheae of six rabbits. Tissue‐engineered cartilages using fibrin/HA composite were trimmed and fixed to the defect boundaries with tissuecol. Postoperatively, the site was evaluated endoscopically, histologically, radiologically, and functionally. None of the six rabbits showed signs of respiratory distress. Postoperatively, in all cases, rigid telescopic examination showed that the implanted scaffolds were completely covered with regenerated mucosa without granulation or stenosis. Histologically, the grafts showed no signs of inflammatory reaction and were covered with ciliated epithelium. Even when grafts were broken and migrated from their original insertion site, the implanted cartilages were well preserved. However, the grafts did show signs of mechanical failure at the implantation site. The beat frequency of ciliated epithelium on implants was very similar to that of normal respiratory mucosa. In conclusion, implants with autologous chondrocytes cultured with fibrin/HA showed good tracheal luminal contour, functional epithelial regeneration, and preservation of neocartilage without inflammation but lacked adequate mechanical stability.     

钛颗粒对大鼠成骨细胞影响的mRNA差异显示研究

目的 观察钛金属颗粒对大鼠成骨细胞基因表达的影响。寻找与假体周围骨溶解有关的新基因,方法 在含10%牛血清的DMEM培养基中培养Wistar幼鼠成骨细胞,达80%丰满后加入0.1%钛颗粒,再培养24h后收获细胞并提取总RNA。用mRNA差异显示技术比较处理组与对照组之间在mRNA表达上的差别,将有差别的表达带回收、扩增、克隆化,用于Reverse Northern杂交、Northern杂交及测序,将测序细果与NCBI数据库比较,结果 在处理对照间找到35条差异表达带,经Reverse Norhern杂交得到5个阳性克隆,经测序及NCBI数据库分析,其中被命名为G46T的基因与单核细胞趋化蛋白-3达92%同源,另外4个是新基因。结论 钛颗粒可引起鼠成骨细胞基因表达的变化;G46T基因可能与假体周围骨溶解有关。     

硅胶假体植入同期结合自体脂肪颗粒移植在乳房整形中的应用效果

目的 观察硅胶假体植入同期结合自体脂肪颗粒移植在乳房整形中的应用效果。方法 选取2020年 10月-2022年6月于我院行乳房整形的54例患者为研究对象,采用随机数字表法分为对照组和观察组,各 27例。对照组采用硅胶假体植入,观察组在对照组基础上给予自体脂肪颗粒移植,比较两组临床手术指标、 胸部隆起值、乳房整形效果满意度及并发症发生情况。结果 观察组手术时间长于对照组（P＜0.05）;两组 术中出血量、伤口愈合时间比较,差异无统计学意义（P ＞0.05）;观察组术后1、3、6个月胸部隆起值均 大于对照组（P ＜0.05）;观察组乳房大小、松弛状态、乳房对称性、乳房形态满意度评分均高于对照组 （P ＜0.05）;观察组并发症发生率为7.41%,低于对照组的18.52%（P ＜0.05）。结论 硅胶假体植入同期结 合自体脂肪颗粒移植在乳房整形中的应用效果确切,可改善乳房形态,提高患者的乳房整形满意度,降低 胸部隆起值,使胸围保持相对稳定,且术后并发症发生几率较小,值得临床应用。     

In Vitro Evaluation of a Novel Autologous Aortic Valve (Biovalve) With a Pulsatile Circulation Circuit

We have used in‐body tissue architecture technology to develop an autologous valved conduit with intact sinuses of Valsalva (biovalve). In this study, we fabricated three different forms of biovalves and evaluated their function in vitro using a mock circulation model to determine the optimal biovalve form for aortic valve replacement. A cylindrical mold for biovalve organization was placed in a dorsal subcutaneous pouch of a goat, and the implant that was encapsulated with connective tissue was extracted 2 months later. The cylindrical mold was removed to obtain the biovalve (16 mm inside diameter) that consisted of pure connective tissue. The biovalve was connected to a pulsatile mock circulation system in the aortic valve position. The function of the three biovalves (biovalve A: normal leaflets with the sinuses of Valsalva; biovalve B: extended leaflets with the sinuses of Valsalva; biovalve C: extended leaflets without the sinuses of Valsalva) was examined under pulsatile flow conditions using saline. In addition, the mock circuit was operated continuously for 40 days to evaluate the durability of biovalve C. The regurgitation rate (expressed as a percent of the mean aortic flow rate during diastole) was 46% for biovalve A but only 3% for biovalves B and C. The durability test demonstrated that even after biovalve C pulsated more than four million times (heart rate, 70 bpm; mean flow rate, 5.0 L/min; mean aortic pressure, 92 mm Hg), stable continuous operation was possible without excessive reduction of the flow rate or bursting. The developed biovalve demonstrated good function and durability in this initial in vitro study.     

Immunohistochemical characterization of the perivascular infiltrate cells in tissues adjacent to stainless steel implants compared with titanium implants

Metallic orthopaedics implants are composed of elements that are known to be skin sensitizers in the general population. In this study, we analyzed the cells of perivascular infiltration in the tissue adjacent to titanium (n = 23) and steel (n = 8) implants after explantation of the metals by immunohistochemical methods. The following panel of monoclonal antibodies were used as parameters: CD 1a (Langerhans cells), CD 4 (T-helper cells), CD 8 (T-suppressor cells), CD 11c (monocytes and macrophages), CD 45 RO (memory cells), CD 45 RA (naive cells), eosinophil cationic proteins (ECP), neutrophil elastase, and HLA-DR. The number of perivascular total cells did not differ significantly. All cells were identified in both metal subgroups, but a statistical difference was not seen in the above-mentioned parameters. We conclude that sensitization to metals is possible in the tissue adjacent to steel and titanium implants, because all cells which play an important role in allergic delayed-type hypersensitivity (type IV) reactions are present. This phenomenon may be called a ‘pre-sensitization’ phase, because no sensitization or allergic reactions were seen in our cases. Second, in the present study, a statistical difference was not seen in the number of infiltrate cells in the tissue adjacent to steel compared with titanium implants. Received: 6 November 1999     

In vitro and in vivo performance of a novel surface treatment to enhance osseointegration of endosseous implants.

OBJECTIVE: This article shows the in vitro and in vivo characterization of a new biomimetic treatment developed to enhance the osseointegration of titanium dental implants. STUDY DESIGN: A novel biomimetic treatment of titanium was developed. Its physicochemical properties and biologic and in vivo performance were considered and studied. Mineralization capability was assessed by soaking test in simulated body fluid solution, and cytocompatibility was assessed using osteoblast-like MG63 cell culture. Histomorphometric analysis was performed at 3 time points using a sheep animal model. RESULTS: In vitro tests confirmed the biomimetic potential of the considered novel treatment. Histomorphometric analysis indicated its potential for rapid and good-quality osseointegration. CONCLUSION: The in vitro and in vivo test results indicated that the proposed novel treatment possesses a significant potential to increase the rate of osteointegration of titanium for endosseous dental implants.