放疗对纯钛种植体周围骨组织影响的骨计量学研究

目的　探讨种植体金属材料对放射线的影响。方法　本实验通过兔胫骨骨内植入纯钛植入体与不锈钢植入体建立植入体骨整合的动物模型 ,并在此基础上进行放疗 ,标本通过骨计量学参数的测定。结果　放疗对纯钛种植体周围骨质影响甚小 ,而对不锈钢种植体周围骨质影响较重。结论　钛金属具有良好的生物相容性 ,理化性能好 ,密度低 ,放射引发的二次身线小 ,是目前较理想的植入材料。     

高压氧对种植后颌骨放疗的影响

目的 探讨高压氧对种植后放疗的恢复治疗作用。方法 通过兔胫骨骨内植入纯钛植入体，建立植入体骨整合的动物模型，并在此基础上进行放疗，对种植后颌骨放疗进行高压氧恢复治疗，通过形态学观察和骨计量学参数的测定。结果 实验结果表明高压氧治疗可促进种植区骨质生成，控制放射损伤，缩短放射损伤恢复时间。结论 高压氧可作为种植后放疗患者的辅助治疗。     

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。     

紫外线处理微弧氧化种植体的早期成骨研究

目的研究C波段紫外线(ultraviolet C,UVC)处理的微弧氧化(micro-arc oxidation,MAO)纯钛种植体植入兔胫骨后的早期成骨方式。方法实验分2组,MAO组和UVC-MAO组。MAO组将医用纯钛种植体经微弧氧化处理后植入新西兰大白兔胫骨。UVC-MAO组将医用纯钛种植体经过微弧氧化处理后,用15 W UVC灭菌灯对钛种植体照射48 h,经过25.0 kGyγ射线消毒后植入新西兰大白兔胫骨。2周后取出胫骨,用锥形束CT观察种植体表面成骨情况;制作胫骨硬组织切片,并以亚甲基蓝-酸性品红染色,光学显微镜观察两组种植体的成骨方式。结果 MAO组可见靠近种植体骨环底端的为成骨细胞及软组织,无任何骨组织,骨环斜面有从周围成熟骨生长的骨组织及类骨质,但所有组织与种植体表面均有一定距离,而非密切接触材料表面。UVC-MAO组可见种植体骨环底端及骨环斜面表面紧密接触类骨质及成骨细胞,还有已经分化的新生骨组织;所有组织与种植体表面紧密接触,无间隔。结论紫外线处理微弧氧化后的种植体,更有利于成骨细胞粘附于种植体表面,形成新生骨质并紧密贴附于种植体表面,骨环周围成熟骨质同时向种植体生长,有利于种植体早期的接触成骨。     

放疗对狗下颌纯钛种植体与骨接触作用的影响

目的:观察放疗对狗下颌纯钛种植体与骨接触作用的影响。方法:8只成年雄性杂种狗,拔除双侧下颌第3、4前磨牙和第1磨牙,形成无牙区。拔牙后3个月,用电子直线加速器照射一侧下颌无牙区,单一剂量15Gy。另一侧不接受照射,作为对照。放疗后3个月,狗双侧下颌无牙区各植入纯钛种植体4枚,其中两枚种植体无任何辅助治疗措施。种植术后1.5个月和3个月分别处死2只动物取材。结果:放疗侧种植体的种植体-骨接触率与对照侧相比,有明显下降,在统计学上有显著差异(P=0.0001<0.01);放疗后种植体周围骨小梁体积百分比具体数值下降,统计学上差异不明显(P=0.071>0.05)。结论:放疗会影响狗下颌纯钛种植体与骨的接触作用。     

高压氧对放疗后狗下颌纯钛种植体与骨接触作用的影响

目的 :观察高压氧对放疗后狗下颌纯钛种植体与骨接触作用的影响。方法 :8只成年雄性杂种狗 ,拔除双侧下颌第三、四前磨牙和第一磨牙。拔牙后 3个月 ,用电子直线加速器照射一侧下颌无牙区。另一侧不照射作为对照侧。放疗后 3个月 ,狗双侧下颌拔牙区各植入纯钛种植体 4枚 ,手术中、手术前、手术后接受高压氧治疗 ,另外 4只不作处理。种植术后 1.5个月和 3个月高压氧治疗组与未进行高压氧治疗组分别处死 2只动物取材 ,观察种植体与骨组织的接触率及骨小梁体积百分比。结果 :高压氧辅助治疗对放疗侧种植体 -骨接触率无明显影响(P >0 .0 5 )。种植体周围骨小梁体积百分比显著下降 (P <0 .0 5 )。结论 :高压氧对放疗后狗下颌纯钛种植体与骨接触作用无明显影响     

BMP与透明质酸钠复合物对放疗后种植体骨愈合影响的实验研究

目的　 (1)观察放疗对狗下颌种植体周围骨形成蛋白 (BMP)分布与活性的影响 ;(2 )观察局部应用BMP与透明质酸钠复合物对放疗后种植体骨愈合作用的影响。方法　 4只成年雄性杂种狗 ,拔除双侧下颌第 3、4前磨牙和第 1磨牙 ,形成无牙区。拔牙后 3个月 ,用电子直线加速器照射一侧下颌无牙区 ,单一剂量 15Gy。另一侧不接受照射 ,作为对照。放疗后 3个月 ,狗双侧下颌无牙区植入纯钛种植体各 4枚 ,其中每侧各 2枚种植体在局部使用BMP与透明质酸钠的复合物。种植术后 1 5个月和 3个月分别处死 2只动物取材。结果　 (1)放疗侧种植体周围骨的BMP免疫染色范围和强度均明显弱于非放疗侧 ;(2 )局部应用BMP与透明质酸钠的复合物后 ,放疗侧种植体 -骨接触率和骨小梁体积百分比有明显增加。结论　 (1)放疗后种植体周围BMP明显减少 ,活性显著下降 ;(2 )局部应用BMP与透明质酸钠复合物可以加快放疗后狗下颌骨的再生和重建 ,提高放疗后狗下颌纯钛种植体的种植体 -骨接触率和骨小梁体积百分比。     

经微弧氧化处理的钛铌锆锡合金种植体的动物实验研究

目的研究微弧氧化（MAO）处理钛铌锆锡合金（TNZS）种植体的生物学性能，从界面形态学和组织学角度证实微弧氧化表面处理技术在钛合金种植体中应用的可行性和价值。方法将未作处理的与微弧氧化处理的钛铌锆锡合金种植体植入兔一侧胫骨内髁，对侧以纯钛种植体作为对照，分别于植入后4、26周取材，采用X线摄片检测和苏木精-伊红染色方法对3种种植体-骨界面改建过程进行动态观察，比较各组之间的异同。结果随着时间的延长，所有种植体愈合良好，X线片显示在2个观察时间点，TNZS和MAO-TNZS种植体周围均无明显阴影，骨质密度和骨小梁的排列与宿主骨基本一致，与对照组纯钛之间无明显差异；组织学观察发现，4周时所有种植体-骨界面之间有轻微间隙，可见由大量细胞外基质和纤维组织充填，骨内可见大量类骨质沉积，提示骨再建活跃；26周时MAO-TNZS种植体-骨界面间隙消失，种植体周围新生骨板层与宿主骨融为一体, 界面区出现典型的哈佛系统，达到了骨整合。结论经微弧氧化处理的钛铌锆锡种植体能与骨形成骨性结合，显示了良好的生物相容性及较好的稳定性，并具有临床应用潜力，值得进一步研究。     

骨质疏松对完成骨整合的大鼠股骨钛种植体稳定性的影响

目的研究骨质疏松对已完成骨整合种植体的稳定性的影响。方法在雌性Wistar大鼠股骨远端干骺端植入纯钛种植体,经过8周愈合期后随机分组,Sham组(30只)施行假手术,手术组(30只)施行双侧卵巢摘除术,于术后3周、6周、12周收集带种植体的股骨标本进行Micro-CT扫描分析、组织学观察及生物力学实验,评估OP对种植体周围骨组织及其稳定性的影响。结果 Sham组各时间点测量结果未见显著差异(P>0.05),而手术组Micro-CT扫描分析测得的骨小梁数目和厚度,骨组织体积比均随时间的增加而明显下降,骨小梁间隙则明显增高(P<0.05),手术组骨整合率也随时间增加明显减低(P<0.01)。组织学观察示手术组种植体周围骨小梁和致密骨质层随时间的增加,骨质吸收逐渐加重。手术组测得种植体的最大拔出力随时间增加明显减低(P<0.05)。结论骨质疏松的发生,会使已完成骨整合的钛种植体周围骨小梁和致密骨质层发生骨质吸收,降低骨整合率,导致种植体稳定性减低。     

不同管径TiO2纳米管对小型猪体内种植体的基因表达及骨整合的影响

目的探讨表面具有TiO2纳米管结构的纯钛种植体周围的基因表达以及不同管径的纳米管对种植体-骨界面成骨的影响。方法在小型猪体内植入表面具有TiO2纳米管结构的纯钛种植体,术后3周、5周和8周取出种植体骨块,制作不脱钙磨片,利用光学显微镜,观察术后3周、5周和8周种植体周围骨的组织学表现;并采用定量PCR法检测种植体周围alkaline phosphatase（ALP）、osterix（OSX）、collagen-I（COL-I）的表达。结果与机械切削的纯钛种植体相比,表面具有TiO2纳米管结构的纯钛种植体在骨-种植体接触面积和基因表达方面都有显著的增加,尤其是表面具有70nm纳米管的种植体。结论 TiO2纳米管通过调节种植体-骨界面的成骨活动获得良好的分子应答和骨整合,纳米管的管径可以被精确调控以获得更好的骨生成。     

Immunocompetent cells adjacent to stainless steel and titanium miniplates and screws

Subepithelial soft tissue and bone obtained from the implant bed in the vicinity of stainless steel and titanium miniplates and screws were evaluated with respect to the presence of immunocompetent cells. The study included tissue specimens from 19 patients, in whom the implants (14 stainless steel and 5 titanium) had been in situ for more than 6 months. The ABC (avidin-biotin-complex) immunoperoxidase staining technique using monoclonal antibodies defining T lymphocytes (CD3⁺), macrophages (CDllc⁺) and Class II MHC (HLA-DR) was performed on EDTA demineralized, frozen bone tissue, and on fresh frozen soft tissue specimens. The results showed scattered T lymphocyte clusters, small numbers of macrophages and abundant expression of HLA-DR in the soft tissue adjacent to both stainless steel and titanium implants. There was no substantial difference in tissue reactions between implants of the two materials. The demineralized bone sections disclosed presence of immunocompetent cells in the connective tissue lining the periphery of the screw holes. Metal particles were seen in both the soft tissue and the bone specimens. We conclude that a mild tissue reaction takes place in the vicinity of miniplates and screws of stainless steel and titanium, and that the intensity of the reaction indicates that the implants are well tolerated by the host tissue.     

钛种植体表面新型抗菌涂层预防种植术后早期感染的动物实验研究

目的：通过在犬下颌骨内植入种植体,观察新型抗菌涂层预防种植术后早期感染的实际效果。方法：选择2岁龄牙周健康的雄性Beagle犬4只,拔除双侧下颌第三前磨牙,并在近远中根拔牙窝内预备种植窝行即刻种植术。随机选取2只植入载有新型抗菌涂层的种植体作为实验组,另外2只植入仅微弧氧化处理的种植体作为对照组,并用丝线在所有种植体的颈部结扎,术后给予高糖软食,诱导种植体周围发生早期感染。结扎2个月后对种植体周进行临床指标检查和X线摄片,通过扫描电镜观察种植体／骨组织界面。结果：2个月后,实验组种植体周的临床检查指标明显低于对照组护〈0．05）。X线检查可见：实验组种植体周围无明显的牙槽骨吸收和透射影像,对照组种植体周围可见明显的骨吸收和裂隙状透射影像。扫描电镜观察可见：实验组种植体／骨界面结合较好,未见明显间隙,而对照组种植体与骨组织之间存在明显的间隙。结论：在钛种植体表面构建的新型抗菌涂层具有显著的预防种植术后早期感染的效果。     

雌激素对骨质疏松时种植体骨愈合的影响:Ⅱ骨计量学和电镜观察

目的 :研究雌激素替代治疗对骨质疏松时种植体骨愈合的影响。方法 :选用32周龄雌性SD大鼠36只 ,并随机分为假手术组、卵巢切除组及雌激素组。卵巢切除12周后于大鼠胫骨近中干骺端植入纯钛螺纹状种植体 ,雌激素组同时肌注苯甲酸雌二醇。种植术后4周及12周分两批处死大鼠 ,摘取胫骨 ;标本分别进行扫描电镜观察和骨计量学测量。结果 :在种植后4周及12周时 ,雌激素组除12周时皮质骨结合率与卵巢切除组无显著差异外 ,其它各项骨计量学参数均显著高于卵巢切除组 (P<0.05或P<0.01) ;而与假手术组比较 ,除骨矿化速度及4周时单位骨量外 ,其他各项指标均无显著差异 (P>0.05)。电镜观察种植体—骨界面愈合雌激素组和假手术组均优于卵巢切除组。结论 :雌激素替代治疗可促进实验性骨质疏松大鼠种植体骨愈合 ;该方法有助于增加临床绝经性骨质疏松患者牙种植体骨整合率     

两种钛种植体与骨结合界面的组织学研究

目的　对两种表面形态不同的钛种植体在不同种植时期骨结合界面情况进行研究。方法　在恒河猴下颌磨牙区分期分别植入CDIC和ITI-TPS钛种植体,采用同体对照的方法,对两种种植体与骨结合界面情况进行组织学观察。结果　口腔检查未见种植体松动及周围组织明显炎症表现。各期种植体骨界面X线影像均未见明显透射暗影,仅种植1个月的CDIC种植体颈部见少量角形吸收。光镜和扫描电镜观察见种植1个月后两种种植体骨界面有少量骨形成;1~3个月ITI-TPS种植体界面骨形成较明显,成骨量统计分析,差异有显著性;种植后1年,两者未见明显差别。结论　无载荷条件下,种植体植入后1~3个月内,ITI-TPS种植体表面骨结合形成优于CDIC种植体。随植入时间的增加,两种种植体均形成良好的骨性结合界面。     

Predicting Peri-implant Stresses Around Titanium and Zirconium Dental Implants—A Finite Element Analysis

Due to anatomical and surgical constrains the implant placement may not be parallel to each other always. Non-parallel implants are subjected to detrimental stresses at implant bone interface. Also depending on type of implant material i.e. titanium or zirconium, stresses tend to vary due to change in physical and mechanical properties. Hence stress analysis at implant bone interface between different parallel and non-parallel implants becomes significant. Evaluation and comparison of stress distribution in the bone around two parallel and non-parallel titanium and zirconium dental implants on axial and non-axial loading supporting three unit fixed prosthesis. Three dimensional finite element models (M1, M2, M3) were made of three differently angulated implants in ANSYS (11.0 Version) software and P4 processor with a speed of 3 GHz and 3 Gb RAM hardware, common for titanium and zirconium implants. Stress around the implants was analyzed on an axial load of 200 N and a non-axial load of 50 N. In both titanium and zirconium implants on axial loading in cortical bone, higher stresses were observed in M3 followed by M2 and M1. On non-axial loading higher stresses were observed in M2, followed by M3 and M1. In both titanium and zirconium implants on axial and non-axial loading in cancellous bone stresses were higher in M3 followed by M2 and M1. Zirconium implants showed lower stresses in cortical bone and higher stresses in cancellous bone compared to titanium implants. Over all Stresses in the bone were more due to titanium implants than zirconium implants. Zirconium implants led to lower peri-implant stresses than titanium implants.     

Effects of Simvastatin on bone healing around titanium implants in osteoporotic rats

Objectives: Osteoporosis is known to impair the process of implant osseointegration. The recent discovery that statins (HMG‐CoA reductase inhibitors) act as bone anabolic agents suggests that statins can be used as potential agents in the treatment of osteoporosis. Therefore, we hypothesized that statins will promote osteogenesis around titanium implants in subjects with osteoporosis. Material and methods: Fifty‐four female Sprague Dawley rats, aged 3 months old, were randomly divided into three groups: Sham‐operated group (SHAM; n=18), ovariectomized group (OVX; n=18), and ovariectomized with Simvastatin treatment group (OVX+SIM; n=18). Fifty‐six days after being ovariectomized (OVX), screw‐shaped titanium implants were inserted into the tibiae. Simvastatin was administered orally at 5 mg/kg each day after the placement of the implant in the OVX+SIM group. The animals were sacrificed at either 28 or 84 days after implantation and the undecalcified tissue sections were obtained. Bone‐to‐implant contact (BIC) and bone area (BA) within the limits of implant threads were measured around the cortical (zone A) and cancellous (zone B) bone regions. Furthermore, bone density (BD) of zone B in a 500 μm wide zone lateral to the implants was also measured. Results: There were no significant differences in BIC and BA measurements in zone A in any of the three groups at either 28 or 84 days after implantation (P>0.05). By contrast, in zone B, significant differences in the measurement of BIC, BA, and BD were observed at 28 and 84 days between all three groups. Bone healing decreased with lower BIC, BA, and BD around implant in OVX group compared with other two groups, and Simvastatin reversed the negative effect of OVX on bone healing around implants with the improvement of BIC, BA, and BD in zone B. Conclusion: Osteoporosis can significantly influence bone healing in the cancellous bone around titanium implants and Simvastatin was shown to significantly improve the osseointegration of pure titanium implants in osteoporotic rats.     

不同表面形貌掺锶羟基磷灰石涂层钛种植体的体内实验研究

目的:观察不同微弧氧化时间处理对纯钛表面形成的掺锶羟基磷灰石涂层表面形貌的影响,以及不同表面形貌特征对其表面成骨特性的影响。方法:经5、10、15 min 3种微弧氧化时间在钛表形成3组掺锶羟基磷灰石涂层,分别采用扫描电镜观察表面形貌;采用表面粗糙度仪测量涂层表面粗糙度数值。然后再将3种钛种植体植入新西兰兔体内,术后4、12周取材,采用组织染色法观察植入体表面骨形成情况和骨接触率(Bone Implant Contact,BIC)。结果:随着微弧氧化时间的延长,涂层表面形貌成多孔状且越加不规则,粗糙度增加;丽春红染色显示4周时植入体表面有新骨形成,12周时转化为成熟的骨组织并与涂层形成紧密的骨结合。随植入时间的延长种植体表面骨接触率逐渐增加,而且15 min组和10 min组的骨接触率在第4周和12周均高于5 min组。结论:不同微弧氧化时间可以改变掺锶羟基磷灰石涂层的表面特性,而粗化的的涂层表面结构有利于骨组织的形成。     

Influence of homeopathic treatment with comfrey on bone density around titanium implants: a digital subtraction radiography study in rats

Objective: The objective of this study was to evaluate the influence of homeopathic treatment with comfrey (Shymphytum officinalis 6CH) on radiographic bone density and area around titanium implants. Material and methods: Forty‐eight rats were divided into two groups of 24 animals each: a control group (C) and a test group (SO). Each animal received one titanium micro‐implant placed in the tibia. The animals in Group SO were subjected to 10 drops of comfrey 6CH per day mixed into their drinking water until the day of sacrifice. Eight animals of each group were sacrificed at 7, 14 and 28 days post‐surgery, respectively. Standardized digital radiographs were obtained on the day of implant installation (baseline images) and on the day of sacrifice (final images). Digital subtraction of the two corresponding images was performed to evaluate changes in bone density and the area related to change around the implant between baseline and final images. Results: Subtraction images demonstrated that a significant difference existed in mean shade of gray at 14 days post‐surgery between Group SO (mean 175.3±14.4) and Group C (mean 146.2±5.2). Regarding the area in pixels corresponding to the bone gain in Group SO, the differences observed between the sacrifice periods and groups were only significant at 7 days sacrifice between Group SO (mean 171.2±21.9) and Group C (mean 64.5±60.4). Conclusion: Within the limits of this study, comfrey administration promotes an increase in radiographic bone density around titanium implants in the initial period of bone healing.