rhBMP-2在种植体周围骨缺损修复中应用的组织学观察

目的:研究rhBMP-2及不同载体在种植体周围骨缺损修复中的应用。方法:在beagle犬下颌骨植入种植体,颊侧形成裂开性骨缺损,置入复合了不同浓度rhBMP-2的珊瑚羟基磷灰石人造骨(CHA)或可吸收胶原海绵(ACS)。种植体植入后2、4、8、12周,获取含种植体骨标本,进行组织学观察。结果:2周时,rhBMP-2组可见极少量的新生骨组织。4周时,rhBMP-2/ACS组新骨组织由牙槽骨顶端向缺损区中心方向生长;rhBMP-2/CHA组人造骨颗粒内部和周围出现呈岛状生长的新生骨组织。8周时,rhBMP-2/ACS组的新骨形成大片状结构;rhBMP-2/CHA组人造骨颗粒周围较多骨岛形成。12周时,rhBMP-2组的缺损区内骨量和骨高度进一步增加,与种植体形成骨性结合。浓度为0.05 mg/ml和0.2 mg/ml,载体为CHA或ACS促进骨再生作用差异无统计学意义。结论:以CHA或ACS为载体rhBMP-2能促进种植体周围骨缺损区内的骨组织再生并与种植体表面较好地结合。     

Effect of recombinant human bone morphogenetic protein-2 on bone regeneration and osseointegration of dental implants

Recombinant human bone morphogenetic protein-2 (rhBMP-2) induced bone regeneration and osseointegration was evaluated in bony defects created within the hollow chamber of endosseous dental implants in 14 foxhound dogs. Bilateral extractions of mandibular premolars were performed and surgical implantation of 104 hollow cylinder implants followed after 8 weeks of healing. Experimental implants had their hollow chamber filled with 20 microg of rhBMP-2 delivered with a bovine collagen carrier, whereas the control implants had their apical chamber left empty. Dogs were followed for 2, 4, 8 and 12 weeks. Histomorphometric evaluation and immunohistochemical analysis were performed. Minimal bone was regenerated at 2 weeks for both groups. At 4 weeks, bone fill averaged 23.48% for the rhBMP-2 and 5.98% for the control group (P<0.05). At 8 weeks, mean bone fill was 20.94% and 7.75% for the rhBMP-2 and the controls, respectively (P<0.05). At 12 weeks, mean bone fill was 31.39% and 24.31% for the rhBMP-2 and control implants, respectively (P>0.05). Bone-implant contact (BIC) increased for both groups over time and at 8 weeks the rhBMP-2 BIC value was 18.65% and for the control 7.22% (P<0.05). At 12 weeks, the BIC was 43.78% and 21.05% for the rhBMP-2 and the control group, respectively (P<0.05). Immunohistochemical staining for type II collagen was positive only for parts of the collagen carrier and formation of cartilaginous intermediate was not observed in any of the specimens. The results suggest that, in confined defects adjacent to dental implants, rhBMP-2 can induce bone regeneration in close apposition to the implant surface.     

The effect of combination of recombinant human bone morphogenetic protein-2 and basic fibroblast growth factor or insulin-like growth factor-I on dental implant osseointegration by confocal laser scanning microscopy

BACKGROUND: The healing period of bone-implant osseointegration usually varies from 3 to 6 months or even longer. Failure may occur during this time. This study aimed to investigate whether osseointegration of dental implants can be enhanced by the combination of growth factors. METHODS: Sixty-four implants were coated with polylactic acid and divided into four groups. Group I was applied with 1.0 mg recombinant human bone morphogenetic protein-2 (rhBMP-2) and 200 microg recombinant human basic fibroblast growth factor (rhbFGF), group II with 1.0 mg rhBMP-2 and 250 mug recombinant human insulin-like growth factor-I (rhIGF-I), group III with 1.0 mg rhBMP-2, and group IV without growth factors as control. In total, 16 rabbits were used, and two osteotomies were drilled on each side of the femur, in which four different groups were randomly placed. Four weeks after implanting, 20 mg calcein green/kg body weight was administered intravenously, and 8 weeks after implanting, 20 mg alizarin/kg body weight was administered intravenously. Twelve weeks after implanting, the animals were sacrificed. The block of bone with implants was embedded in methylmethacrylate and sectioned, and the percentage of new bone surrounding the implant was analyzed by confocal laser scanning microscopy. RESULTS: There was a statistical difference in bone formation between rhBMP-2-applied groups and the non-applied group at 4 or 8 weeks, and no significant difference between groups I and II (although bone formation in group II was greater than that in group I at 4 weeks). The bone formation in group II was greater than that in group III at 4 or 8 weeks. The formed bone in group I was also greater than the one in group III at 8 weeks, but there was no difference at 4 weeks. CONCLUSIONS: rhBMP-2 could increase new bone formation, and it acted synergistically with rhbFGF and rhIGF-I to improve bone-implant osseointegration. The combination of rhBMP-2 and rhbFGF (group 1) showed faster growth of new bone than other groups at 8 months.     

非血管化骨-人重组骨形成蛋白-2复合种植体同期移植的超微结构观察

目的对于非血管化自体骨移植同期植入种植体,目前仍有争议.近年的研究表明非血管化自体骨植入后,早期即可有新骨形成.本研究旨在探讨非血管化自体骨-种植体同期植入后种植体的愈合过程,并观察骨形成蛋白对与非血管化骨同期植入的种植体愈合过程的促进作用.方法健康犬12只,随机分为2组.在犬双侧下颌角区各截取3cm×4cm骨段,实验组骨段内植入含有重组人骨形成蛋白-2的种植体,对照组植入普通纯钛种植体.植入种植体后,将骨块及种植体植回对侧下颌角,并以不锈钢丝固定.术后2、4、6、8及12周各处死2只动物,标本行扫描电子显微镜观察.结果实验组种植体-骨界面在术后2周即可见明显的新骨形成,术后6～8周,已基本形成骨性结合;术后12周时,可见较为成熟的骨融合.而对照组骨融合在术后6～8周方开始形成,术后12周时仍未完成.实验结果显示,实验组骨融合的时间较对照组至少可提前4周.结论骨形成蛋白的骨诱导活性可以促使种植体在植入后早期与非血管化骨形成骨融合,从而为提高同期植入种植体的成功率提供了新的途径.     

Cem-Ostetic/rhBMP-2复合物促进即刻种植体周围骨组织再生的研究

目的：研究Cem-Ostetic/rhBMP-2对即刻种植骨缺损修复的生物学特性。方法：将6只狗随即分成2组,拔除犬双侧下颌第二、三、四前磨牙,即刻植入种植体,每个种植体颊侧制备标准缺损,分别植入Cem-Ostetic/rhBMP-2、Cem-Ostetic、自体骨。术后6、12周分期处死,进行大体、影像学、组织学观测。结果：术后6、12周各组均有不同程度的骨组织再生。各个时期观察显示Cem-Ostetic/rhBMP-2组新生骨与种植体间的骨结合较其他组多。结论：Cem-Ostetic/rhBMP-2能有效促进种植体周围骨缺损修复,并促进种植体-骨界面形成较完善的骨整合。     

微型支抗种植钉加载时机的动物实验研究

目的 建立支抗种植钉的动物模型,分析不同愈合期加载对种植钉稳定性的影响。方法 于绵羊牙槽骨上植入微型支抗种植钉,建立颌骨-支抗种植钉的动物模型,随机分为4组（不加力为A组,即刻加力为B组,植入2周加力为C组,植入4周加力为D组）,截取带有种植钉的上、下颌骨组织标本;上颌骨块制作不脱钙的骨磨片,光镜下观察种植钉与骨组织界面的愈合情况,下颌骨块用材料性能试验机检测种植钉与骨组织松脱瞬间的最大剪切力值,并进行统计分析。结果1）4组种植钉的剪切力值总体上有差别,A、B组的剪切力低于C、D组。2）骨纵磨片显示：种植钉与周围组织界面的结合方式在种植钉的压力侧和张力侧无明显区别;横断磨片显示：4组界面既有纤维性结合,又有骨性结合,A、D组界面以骨性结合为主,B、C组界面以纤维性结合为主,C组种植钉周围可见新生的骨组织潜行生长。结论加载时机对支抗种植钉的稳定性有一定的影响。     

实验性骨质疏松对种植体周自体骨移植愈合影响的研究

目的研究实验性骨质疏松（OP）对兔种植体周自体骨移植愈合的影响。方法将20只雌性日本大耳白兔随机分成对照组和实验组,实验组行双侧卵巢切除术,对照组接受假手术。术后12周测量股骨骨密度（BMD）,证实OP状态。同时在2组家兔左侧胫骨近中干骺端制备骨缺损,行自体髂骨移植和同期种植体植入手术。植骨术后第8、12周分2批处死动物,切取标本制作不脱钙硬组织切片,进行组织形态学观察和骨计量学检测。结果实验组BMD显著低于对照组（P<0.001）,证实OP造模成功。植骨术后第8、12周,种植体在2组植骨区均达到了骨结合。然而,实验组植骨区内骨皮质厚度（TCB）、松质骨区骨量（BVC）、种植体骨结合率（IBCR）均显著低于对照组（P<0.01）,且新生骨量也明显少于对照组。结论实验性OP虽然不会延迟自体骨移植内种植体骨结合,但可促进植骨吸收,减少BVC,降低IBCR。因而,对于行自体骨移植同期牙种植的患者,OP是一个重要的危险因素。     

Alveolar ridge augmentation with rhBMP-2 and bone-to-implant contact in induced bone.

The objective of this study was to examine alveolar ridge augmentation following implantation of recombinant human bone morphogenetic protein (rhBMP-2) with an allogeneic freeze-dried demineralized bone matrix (DBM) mixed with autologous blood. A second objective was to evaluate bone-to-implant contact in induced bone. Bilateral surgically created supraalveolar ridge defects in five young adult beagle dogs were implanted with the rhBMP-2-DBM-blood device. Transmucosal dental implants were placed at weeks 8 and 16 postsurgery The animals were euthanized 24 weeks following ridge augmentation. Healing was uneventful in all animals. Radiographic observations indicated substantial bone formation, including regions of radiolucency, at week 8. At week 16, the radiolucencies were generally resolved, and the trabecular structure of the induced bone resembled that of the adjacent residual bone. There were no remarkable differences in radiographic observations between weeks 16 and 24 after ridge augmentation. Histologic analysis revealed dense woven and lamellar induced bone. Any residual DBM appeared remineralized, at least in part. A large portion of the dental implants (approximately 70%) were housed in induced bone with evidence of limited crestal resorption. There was no significant difference in bone density between induced and residual bone, and the levels of bone-to-implant contact were similar (approximately 55%). The rhBMP-2 construct used in this study has a potential to augment alveolar ridge defects. Also, no difference in levels of osseointegration may be expected in induced and residual bone following a two-stage procedure of rhBMP-2-induced ridge augmentation and dental implant placement.     

Effect of recombinant human bone morphogenetic protein-2 in dehiscence defects with non-submerged immediate implants: an experimental study in Cynomolgus monkeys

BACKGROUND: Alveolar ridge aberrations commonly compromise optimal dental implant installation. To offset any variance between an aberrant alveolar ridge and prosthetic designs, bone augmentation procedures become necessary. The objective of this study was to evaluate bone formation and osseointegration at alveolar dehiscence defects following augmentation of the defect site with recombinant human bone morphogenetic protein-2 (rhBMP-2) in an absorbable collagen sponge carrier (ACS) at dental implant installation including transmucosal positioning of the dental implant. METHODS: Four adult male Cynomolgus monkeys received dental implants in contralateral extraction socket sites with surgically created 6 x 4 mm buccal dehiscence defects following elevation of mucoperiosteal flaps. Contralateral sites received rhBMP-2/ACS (rhBMP-2 at 1.5 mg/ml; 0.1 mg/defect) or served as sham-surgery controls. The flaps were adapted and sutured around the healing abutments leaving the implants in a transmucosal position. The animals were sacrificed at 16 weeks postsurgery and block sections of the implant sites were harvested and prepared for histometric analysis. RESULTS: One dental implant from each treatment group failed to osseointegrate. Another 3 dental implants (sham-surgery controls) failed to osseointegrate with newly-formed bone in the defect area. Thus, 7 of 8 defect sites (4/4 animals) receiving rhBMP-2/ACS compared to 4 of 8 sites (2/4 animals) receiving sham-surgery exhibited evidence of osseointegration with newly formed bone in the defect area. Mean +/- SD defect height amounted to 5.3 +/- 0.2 and 5.4 +/- 0.1 mm for the rhBMP-2/ACS and sham-surgery sites, respectively. Vertical bone gain in rhBMP-2/ACS treated defects (3.9 +/- 0.3 mm) did not differ significantly from that in the sham-surgery control (3.7 +/- 0.4 mm; P > 0.05; paired t-test, N = 4). There were also no significant differences noted for coronal bone-implant contact (3.0 +/- 0.6 versus 3.6 +/- 0.5 mm), and bone-implant contact within the defect site (28.5% +/- 15.1% versus 27.4% +/- 31.7%) and within resident bone (46.9% +/- 26.8% versus 47.8% +/- 39.4%) for the rhBMP-2/ACS and control sites, respectively. CONCLUSIONS: The observations in this study point to a substantial native osteogenic potential of the alveolar process that has previously not been explored and show that surgical reentry observations of new bone formation may not necessarily indicate that osseointegration has occurred. Bone formation in control defects was substantially greater than predicted, limiting the value of adding an osteoinductive biologic construct.     

TM种植体-骨结合界面的显微CT观察

目的 研究TM种植体-骨结合界面及其上 1/3倒楔形间隙的成骨情况.方法 用医用钝钛钛棒加工成两组种植体,实验组为锥度5.44°、表面进行喷砂酸蚀处理的TM种植体,锥度从种植体上1/3处开始变化;对照组为仿straumann的表面喷砂酸蚀(sandblast large grit and acid-etching,SLA)圆柱状螺纹种植体.建立Beagle犬下颌骨种植模型,3只犬每只植入实验组TM种植体和对照组仿straumann -SLA圆柱状螺纹种植体各4枚,3只实验犬分别于4周、8周和12周处死,截取下颌骨行显微CT三维重建,观察种植体-骨结合界面及上1/3间隙的成骨情况.结果 8周时实验组TM种植体上1/3倒楔形间隙开始有骨修复,12周时对照组仿straumann-SLA种植体颈部骨质有吸收迹象,实验组TM种植体颈部骨质仍得到良好保存.结论 TM种植体能形成良好骨结合界面,体部上1/3的锥度设计可保存颈部皮质骨.     

兼具微米-纳米钛表面的生物力学研究

目的:通过拔出力试验研究兼具微米-纳米纯钛表面对骨整合速度的影响。方法:采用电化学处理的方法(EE组)在纯钛表面产生兼具微米-纳米的微结构,将电化学表面处理试件植入日本大耳白兔右侧胫骨中,以喷砂加酸蚀组(SLA组)、机械加工组(M组)为对照组。种植术后4周、7周、10周、13周后,用万能材料试验机将试件从骨内拉出,分别测定各个周期的拔出力。结果:4周、7周、10周、13周时,EE、SLA和M组试件的拔出力存在差异,其中EE组高于SLA组和M组(P<0.05)。结论:兼具微米-纳米的电化学表面处理可明显提高骨-种植体界面的愈合速度。     

Effects of anodized implants coated with Escherichia coli-derived rhBMP-2 in beagle dogs

This study evaluated the effects of Escherichia coli-derived rhBMP-2 (ErhBMP-2) coated onto anodized implants to stimulate bone formation, osseointegration and vertical bone growth in a vertical bone defect model. Six young adult beagle dogs were used. After a 2-month bone healing period, anodized titanium implants (8 mm in length) were placed 5.5 mm into the mandibular alveolar ridge. Eighteen implants coated with ErhBMP-2 (BMP group) and another 18 uncoated implants (control group) were installed using a randomized split-mouth design. The implant stability quotient (ISQ) values were measured. Specimens were fabricated for histometric analysis to evaluate osseointegration and bone formation. The ISQ values at 8 weeks after implant placement were significantly higher in the BMP group than in the control group (p < 0.05). Histological observations showed that the changes in bucco-lingual alveolar bone levels were higher in the BMP group than in the control group (p < 0.05). The ErhBMP-2 coated anodized implants can stimulate bone formation and increase implant stability significantly on completely healed alveolar ridges in dogs. Further studies evaluating the effects of ErhBMP-2 on osseointegration in the bone–implant interface are warranted.     

骨诱导活性材料复合富血小板血浆修复犬种植体周围骨缺损

目的从组织学角度评价骨诱导活性材料(osteoinduction active material,OAM)复合富血小板血浆(platelet-rich plas-ma,PRP)对种植体周围骨缺损的修复效果。方法Beagle犬4只,拔除下颌1、2、4前磨牙。每只犬左右两侧实验牙位随机分为实验侧和对照侧,实验侧第4前磨牙牙位为实验A组,第1、2前磨牙牙位为实验B组,对照侧第1、2前磨牙牙位为对照组。3个月后植入种植体,制备种植体周围骨缺损。实验A组骨缺损区植入OAM/PRP;B组植入OAM;对照组植入磷酸三钙。8、16周分别处死动物2只,进行组织学观察,能谱分析种植体-新骨界面Ca含量。结果8周时,A、B组新骨与种植体形成区段性骨结合,对照组种植体边缘为纤维性界面。各组间种植体-新骨界面Ca含量存在显著性差异。16周时,实验A、B组可见哈佛氏系统,新骨与种植体形成骨整合,对照组为纤维性结合。实验各组Ca含量均显著高于对照组。结论OAM及PRP/OAM能促进种植体周围骨缺损修复。     

神经生长因子对口腔种植体早期骨结合影响的实验研究

目的 观察外源性神经生长因子(nerve growth factor,NGF)对口腔种植体骨愈合的影响,以期缩短口腔种植体骨愈合时间.方法 在12只新西兰大白兔下颌骨双侧各植入种植体1枚,右侧为实验组:种植体边缘骨膜下注射1.0μgNGF;左侧为对照组:同样部位注射相同剂量的生理盐水.注射1次/d,连续7 d.术后2、4、8周分别处死动物各4只,获取下颌骨,制作种植体骨磨片甲苯胺蓝染色标本,行大体、放射学和组织学观察以及骨计量学分析.结果 术后2、4周各组下颌骨种植体周围新生骨密度低于正常骨组织,种植体骨结合率对照组2周(26.67±3.88)%、4周(52.59±5.07)%;实验组2周(42.24±6.67)%、4周(72.25±6.30)%;术后8周两组骨密度与正常骨组织相近,实验组新生骨小梁出现哈弗系统,种植体骨结合率两组相比,差异无统计学意义.结论 口腔种植术后早期加入外源性NGF能够加速种植体周围骨小梁的形成和成熟,增加骨结合面积,提高种植体骨结合率,缩短口腔种植体骨愈合时间.     

高海拔低氧环境对种植体骨结合的影响

目的:比较不同海拔高度对牙种植体周围成骨及种植体固位的影响。方法:选择广州、西宁、果洛3地区作为不同海拔地区分组,将微型种植体植入3地区饲养的兔胫骨中,通过X线观察、生物力学测试及硬组织切片法分析3地区种植体骨结合的差异。结果:X线显示,种植体植入4周时,广州组种植体周围X线骨密度最高,果洛组最低;生物力学最大拔出力(N)在4周时3组分别为194.5±4.5、176.3±6.7、165.6±2.71,12周时分别为206.7±6.5、180.5±4.8和168.3±5.2,广州组明显高于后2组(P<0.05);组织学染色分析显示,4周时3组骨接触率(%)分别为48.85±3.3、40.76±2.4和36.87±4.13(P<0.05);12周时3组骨接触率分别为50.34±5.1、41.62±2.8和39.78±3.7,广州组明显高于后2组(P<0.05)。结论:高海拔低氧环境影响种植体的骨结合。     

加载时机对硬腭骨膜下种植体愈合结果的影响

目的研究硬腭骨膜下种植体加载时机对其愈合结果的影响。方法6只杂种猪分为3组,每组2只,每只植入4枚硬腭骨膜下种植体。分别于植入后4周、8周、12周时给予种植体9．8N的骀向持续载荷。加载4周后处死动物。测量从骨面去除每个种植体的拉出力,对标本进行组织学检查,拉出的种植体表面进行扫描电镜观察和能谱分析。结果21个植体成功愈合,3组种植体拉出力以中位数（四分位数间距）表示,依次为41．550（4．75）N,50．800（14．675）N和52．800（17．65）N（P〉0．05）。各组样本均存在三种愈合形式：炎性纤维愈合、纤维愈合和骨性愈合。炎性纤维愈合植体拉出力最小,而骨性愈合植体拉出力最大。结论对于愈合期在1个月以上的硬腭骨膜下种植体,加载时机不会显著影响其愈合结果;愈合类型对硬腭骨膜下种植体的结合强度起关键作用。     

Surface-etching enhances titanium implant osseointegration in newly formed (rhBMP-2-induced) and native bone

PURPOSE: The influence of surface modifications on osseointegration in newly formed bone is not well established. The purpose of this study was to compare osseointegration at acid-etched versus turned implants in newly formed and native bone. METHODS: Supra-alveolar peri-implant defects were created in 8 hound/Labrador mongrel dogs. Titanium implants 10 mm long (2 turned and 1 dual acid-etched) were placed 5 mm into the surgically reduced alveolar crest, creating 5-mm supra-alveolar peri-implant defects. Recombinant human bone morphogenetic protein-2 (rhBMP-2; 0.4 mg) in a collagen carrier was used to induce new bone formation. A macroporous, expanded polytetrafluoroethylene device was used to delineate new bone formation. The animals were euthanized at 8 weeks for histometric analysis of the experimental sites. RESULTS: There were no significant differences in rhBMP-2-induced bone density (mean +/- SD) at acid-etched versus turned implants (20.6% +/- 5.3% vs 23.8% +/- 4.7%; P = .232). However, there was a significant difference in bone-implant contact in favor of the acid-etched implants (12.3% +/- 6.8% vs 7.9% +/- 3.1%; P = .05). Native bone density averaged 63.9% +/- 7.5% and 64.5% +/- 9.0% for acid-etched and turned implants, respectively (P = .641). Nevertheless, bone-implant contact was significantly enhanced at acid-etched versus turned implants (59.7% +/- 11.3% vs 40.7% +/-21.2%; P =.005). CONCLUSIONS: Surface dual acid-etching of titanium implants has a positive effect on osseointegration in newly formed and native bone. Significant differences in bone density do not appear to influence this effect.     

Restoration of occlusal function using osseointegrated implants in the canine mandible reconstructed by rhBMP-2

Abstract: Bone morphogenetic proteins have been found to be one of the most promising osteoinductive substances and they are expected to be utilized clinically for the reconstruction of defective mandibles. However, newly formed bone induced by recombinant human bone morphogenetic protein-2 (rhBMP-2) has not yet been proven able to withstand the masticatory force applied by oral implants. In this study, we examined the qualitative changes in an rhBMP-2-induced mandible from the functional force of osseointegrated oral implants. Segmental (30 mm) bone defects were created in the mandibles of beagles. A poly D,L-lactic coglycolic acid-coated gelatin sponge impregnated with rhBMP-2 was grafted to the resected canine mandible. The new bone was formed 8 weeks after surgery and the Brånemark system fixtures were implanted into the reconstructed mandible. After another 8 weeks, the prosthesis was placed over the oral implants. The prosthesis was maintained in occlusion with the opposing natural dentition for 0, 4, 12, 24, or 48 weeks before the animal was euthanized. The quality of regenerated bone was then evaluated histologically and the osseointegration ratio between oral implants and the bonemeasured. During the first 4 weeks, the ratio remarkably increased from 48.9% to 64.5%. After 48 weeks, the ratio approached about 74.5%. The bone loaded for 48 weeks had undergone extensive remodeling and consolidation; its quality was better and maturer than that of bone that was not loaded. These results indicated that the newly formed bone induced by rhBMP-2 was able to withstand the masticatory force applied by oral implants and had become as functionally mature as a natural bone.     

增材制造Ti-6Al-4V钛合金种植体骨结合的动物实验研究

目的探讨增材制造Ti-6Al-4V（TC4）钛合金种植体动物体内的骨结合和成骨效果,为进一步临床应用提供实验依据。 方法选择健康雄性新西兰兔42只,以兔双侧后腿股骨髁部为种植体植入区,将实验兔先分为2周（A组）、8周（B组）2个大组,每组21只;每大组中再分为3个亚组,分别为A1组、A2组、A3组和B1组、B2组、B3组,每小组7只。A1组和B1组实验兔双侧后腿股骨髁部分别植入原始表面和表面改性TC4钛合金种植体各1枚;A2组和B2组实验兔植入原始表面TC4钛合金种植体和钛骨种植体各1枚;A3组和B3组实验兔植入表面改性TC4钛合金种植体和钛骨种植体各1枚;使2周、8周均含有3种种植体各14枚。术后2、8周观察并比较分析3种种植体的植入成功率和骨结合情况,观察指标为：骨体积分数（BV/TV）、骨小梁面积密度（BS/BV）、骨小梁厚度（Tb.Th）、骨小梁数量（Tb.N）和骨小梁间隔（Tb.Sp）。对各组不同时段种植体骨界面骨密度指标,使用SPSS 21.0软件包对数据进行双因素方差分析,验证不同表面、不同时间对种植体骨结合水平的影响,并采用Tukey′s多重比较检验分析组间统计学差异。 结果3种种植体不脱钙组织切片、骨块微CT扫描及光学显微镜观察显示,随着植入后的时间进展,3种种植体表面骨组织的量逐渐增多,分布逐渐变密。2周时,表面改性TC4钛合金种植体组的BV/TV、Tb.N显著高于原始表面和钛骨组,差异有统计学意义（P<0.05）;Tb.Th显著高于钛骨组（P<0.05）;BS/BV、Tb.Sp显著低于钛骨组,差异有统计学意义（P<0.05）。8周时,3种种植体的BV/TV、BS/BV、Tb.Th、Tb.N和Tb.Sp差异均无统计学意义（P>0.05）。 结论表面改性TC4钛合金种植体2周时即能形成更多的骨组织,骨小梁的分布更密集,骨结合能力更强,有望成为口腔种植体的优选材料。     

种植术后放疗对兔胫骨种植体骨结合影响的实验研究

目的:探讨种植术后放疗对种植体周围骨密度、种植体骨结合的影响。方法:在16只日本大白兔双侧后肢胫骨同一位置各植入纯钛种植体1枚,2周后随机选取8只作为放疗组,一次性给予60Co15Gy剂量的放疗,余下8只作为对照组不接受放射治疗。通过大体观察、双能X线分析、组织形态学、骨计量学分析及骨-种植体磨片观察等手段,研究术后4、8、16、24周时种植体骨结合情况,应用F检验对实验结果进行统计学分析。结果:术后4周时放疗组种植体周围骨密度比未放疗组降低(P<0.05),种植体骨结合率也较未放疗组降低;术后8周时放疗组种植体周围出现明显的骨结合现象,相当于未放疗组术后4周时的水平;术后16周以后放疗组与未放疗组种植体周围骨密度及种植体骨结合率的差异无显著性。结论:放疗可在一段时间内延缓种植体周围骨的生长,降低骨种植体结合率。