放疗对骨组织及种植体周围骨结合影响的研究进展

种植义齿逐渐成为牙列缺损和牙列缺失成年患者的最佳修复方法。对于头颈部恶性肿瘤患者,通常采取手术切除联合放化疗。然而,放疗对机体颌骨组织产生一定的损害,进而间接影响种植体周围的骨结合。本文将主要就放疗对骨组织的影响及放疗对种植体周围骨结合的作用作一综述。     

放疗和高压氧对颌面部骨结合种植体的影响

口腔颌面部恶性肿瘤病人术后，往往造成面部畸形。为提高病人术后的生活质量，将骨结合种植体置入残骨或移植骨用于骨内固定面部假体和牙科义齿修复，经临床证明已是一项成熟可行的重建技术。然而，放疗在恶性肿瘤治疗中占重要角色，尤其当种植区域的骨组织接受照射时，种植体的成功率明显降低。近年来，临床和动物研究已证明高压氧（HBO）在防止放射性组织损伤中发挥的作用。到目前为止，这也是唯一知道能用于抵制照射损伤，改善种植体成功率的一项可行技术。现将有关文献内容综述如下：1放疗剂量与骨组织的损伤和修复。放疗可造成骨组织…     

增龄变化对钛种植体骨结合影响的实验研究

目的探讨增龄变化对钛种植体骨结合的影响，为临床判断种植预后提供理论依据。方法选择雄性SD大鼠36只，随机分成青年群、成年群和老年群，在双侧胫骨内侧窝距关节0．5cm处分别植入钛种植体2颗。三组大鼠分别在术后14天、28天、56天随机各处死4只，摘取胫骨，制作带种植体的非脱钙硬组织切片，观察组织学变化，计算骨结合率。结果青年群的成骨能力最强，种植体与骨的结合连续、紧密，成年群次之，老年群最差。老年群成骨量及骨接触率均低于青年群和成年群。以上情况对松质骨影响大，对皮质骨影响小。结论增龄变化可影响钛种植体与骨组织的结合，种植体周围新骨形成量及骨结合率随年龄增长而降低。     

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。     

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.     

低钙对微种植体骨结合影响的实验研究

目的 通过建立低钙动物模型来研究低钙状态对微种植体骨结合的影响.方法 将24只实验用健康哈白兔随机分为实验组和对照组,每组12只.实验组定量低钙饲料饲养,对照组正常饲料饲养,定期测量血清钙、镁、磷含量及骨密度值,当实验组骨密度值低于对照组后,进行统计学分析,差异有显著性,有统计学意义,即为低钙模型建立成功,即可进行微种植体的植入.植入后再分别将实验组和对照组随机分为A组：即刻加力组、B组：6周后加力组、C组：8周后加力组及D组：10周后加力组,以镍钛弹簧施力1.47N,于施力当天拍摄X线片,力值持续4周后进行标本制备、扫描电镜下观察.结果 实验组A组6枚种植体全部松动、脱落,种植失败;其余各组种植体在植入和施力后稳定性均良好,扫描电镜显示,对照组4组、实验组B、C、D三组均形成骨结合,且结合程度随时间的延长逐渐增强.结论 低钙实验组在微种植体植入后不可进行即刻加力,需等待＂二期负载＂,且随着＂无负载愈合期＂的延长,其骨结合程度增强,稳定性增强.     

骨康散对骨质疏松症种植体周围骨结合影响作用实验研究

目的：观察中药骨康散Ⅱ号对去势大鼠(骨质疏松模型)骨的代谢及种植体与骨结合情况。方法：制作去势大鼠(骨质疏松模型)模型，植入种植体，同时给予骨康散Ⅱ号灌胃，观察骨康散Ⅱ号对种植体周围骨代谢、骨微观结构的影响。结果：实验组去势大鼠较对照组血中骨钙素水平显著性下降；骨与种植体结合更连续，紧密，矿化程度更高。结论：骨康散Ⅱ号能有效抑制去势大鼠高转换型骨量丧失，促进种植体周围新骨的形成和矿化。缩短种植体与骨的愈合时间，提高骨结合的质量，对闭经期骨质疏松有一定的治疗作用。     

不同种植方法对即刻负载正畸种植体骨结合的影响

目的 通过比较助攻法和自攻法植入的即刻负载正畸种植体的骨结合情况,评价不同种植方法对种植体及周围组织的影响. 方法 以3只犬的最后一颗前磨牙与第一磨牙根间区、第一磨牙近远中根根分歧的颊侧为植入点,植入24枚正畸种植体;每只犬植入8枚,自攻法(自攻组)植入4枚,助攻法(助攻组)植入4枚.镍钛弹簧即刻提供1.47～1.96 N水平力,持续9周.光学显微镜和荧光显微镜评价种植体周围骨组织的变化和骨结合率. 结果 两组种植体均与骨组织形成骨结合,其间未见结缔组织.自攻组可见较多的陈旧骨,助攻组的骨生长和再生更活跃.自攻组种植体的骨结合率[(41.7±10.7)%]高于助攻组[(25.9±8.0)%],差异有统计学意义(P<0.01). 结论 即刻负载不影响正畸种植体的骨结合.自攻法对骨组织损伤小,且骨结合率高于助攻组.     

低钙对微种植体骨结合影响的实验研究

目的 通过建立低钙动物模型来研究低钙状态对微种植体骨结合的影响.方法 将24只实验用健康哈白兔随机分为实验组和对照组,每组12只.实验组定量低钙饲料饲养,对照组正常饲料饲养,定期测量血清钙、镁、磷含量及骨密度值,当实验组骨密度值低于对照组后,进行统计学分析,差异有显著性,有统计学意义,即为低钙模型建立成功,即可进行微种植体的植入.植入后再分别将实验组和对照组随机分为A组:即刻加力组、B组:6周后加力组、C组:8周后加力组及D组:10周后加力组,以镍钛弹簧施力1.47N,于施力当天拍摄X线片,力值持续4周后进行标本制备、扫描电镜下观察.结果 实验组A组6枚种植体全部松动、脱落,种植失败;其余各组种植体在植入和施力后稳定性均良好,扫描电镜显示,对照组4组、实验组B、C、D三组均形成骨结合,且结合程度随时间的延长逐渐增强.结论 低钙实验组在微种植体植入后不可进行即刻加力,需等待"二期负载",且随着"无负载愈合期"的延长,其骨结合程度增强,稳定性增强.     

低钙对微种植体骨结合影响的实验研究

目的 通过建立低钙动物模型来研究低钙状态对微种植体骨结合的影响.方法 将24只实验用健康哈白兔随机分为实验组和对照组,每组12只.实验组定量低钙饲料饲养,对照组正常饲料饲养,定期测量血清钙、镁、磷含量及骨密度值,当实验组骨密度值低于对照组后,进行统计学分析,差异有显著性,有统计学意义,即为低钙模型建立成功,即可进行微种植体的植入.植入后再分别将实验组和对照组随机分为A组:即刻加力组、B组:6周后加力组、C组:8周后加力组及D组:10周后加力组,以镍钛弹簧施力1.47N,于施力当天拍摄X线片,力值持续4周后进行标本制备、扫描电镜下观察.结果 实验组A组6枚种植体全部松动、脱落,种植失败;其余各组种植体在植入和施力后稳定性均良好,扫描电镜显示,对照组4组、实验组B、C、D三组均形成骨结合,且结合程度随时间的延长逐渐增强.结论 低钙实验组在微种植体植入后不可进行即刻加力,需等待"二期负载",且随着"无负载愈合期"的延长,其骨结合程度增强,稳定性增强.     

RGD序列与种植体骨整合

RGD序列由精氨酸、甘氨酸和天冬氨酸组成,存在于多种细胞外基质中,可与11种整合素特异性结合,能有效地促进细胞对生物材料的粘附。将RGD序列固定于钛或钛合金种植体表面,可以促进成骨细胞对钛或钛合金表面的粘附,进一步促进种植体骨整合,提高种植义齿的成功率。RGD序列的空间结构、修饰密度、周围序列对其活性都有一定影响。本文就RGD序列的生物学效应和它在种植体骨整合中的应用及其影响因素作一综述。     

富含血小板血浆诱导口腔种植体周围骨再生的实验研究

目的:通过犬下颌骨种植周围缺损模型,探讨与评估富含血小板血浆与磷酸三钙联合应用后,对种植体骨结合的效应。方法:采用自身对照,在6只成年杂种犬双侧下颌骨下缘各植入2颗纯钛种植体(共24颗)并在种植体周围造成缺损。右下颌2颗为对照组,在缺损处填入磷酸三钙和生理盐水的混合物,左下颌2颗为实验组,在缺损处填入磷酸三钙和富血小板血浆的混合物;术后4、8、12周分别处死2只犬,先后行大体观察、电镜观测和组织学观察。结果:大体观察实验组比对照组缺损处愈合更平整且种植体更稳定;4、8、12周电镜观测时均示实验组和对照组有显著性差异,实验组种植体骨结合率高;组织学观察在实验组可见大量成骨细胞、骨细胞及新生骨小梁,新生骨组织较成熟,而对照组成骨细胞少、骨小梁细而少、纤维组织多见。结论:富含血小板血浆可能具有促进新骨形成及种植体骨结合的效应。     

Implant Osseointegration in Circumferential Bone Defects Treated with Latex‐Derived Proteins or Autogenous Bone in Dog's Mandible

Background: In sites with diminished bone volume, the osseointegration of dental implants can be compromised. Innovative biomaterials have been developed to aid successful osseointegration outcomes. Purpose: The aim of this study was to evaluate the osteogenic potential of angiogenic latex proteins for improved bone formation and osseointegration of dental implants. Materials and Methods: Ten dogs were submitted to bilateral circumferential defects (5.0 × 6.3 mm) in the mandible. Dental implant (3.3 × 10.0 mm, TiUnite MK3?, Nobel Biocare AB, Göteborg, Sweden) was installed in the center of the defects. The gap was filled either with coagulum (Cg), autogenous bone graft (BG), or latex angiogenic proteins pool (LPP). Five animals were sacrificed after 4 weeks and 12 weeks, respectively. Implant stability was evaluated using resonance frequency analysis (Osstell Mentor?, Osstell AB, Göteborg, Sweden), and bone formation was analyzed by histological and histometric analysis. Results: LPP showed bone regeneration similar to BG and Cg at 4 weeks and 12 weeks, respectively (p ≥ .05). Bone formation, osseointegration, and implant stability improved significantly from 4 to 12 weeks (p ≤ .05). Conclusion: Based on methodological limitations of this study, Cg alone delivers higher bone formation in the defect as compared with BG at 12 weeks; compared with Cg and BG, the treatment with LPP exhibits no advantage in terms of osteogenic potential in this experimental model, although overall osseointegration was not affected by the treatments employed in this study.     

种植体表面修饰影响骨结合机制研究进展

<正>钛及其合金具有化学稳定性高,弹性模量等力学性能与骨组织比较匹配等优点,是广泛应用的人体硬组织修复材料。钛及其合金本质上是生物惰性     

补骨合剂促进口腔种植体骨整合的免疫组织化学研究

目的：通过观察补骨合剂对口腔骨内种植体骨整合免疫组织化学指标的影响,探讨补骨合剂促进骨整合的作用机理。方法：成年杂种犬20只,拔除左侧下颌第二、三、四前磨牙,3个月后各植入CDIC种植体3枚,随机分为实验组和对照组,实验组每日予补骨合剂1ml/kg灌胃,分别于术后1、2、4、8、12周取出标本进行免疫组织化学分析,观察种植体一骨界面骨整合情况。结果：实验组第1周种植体－－骨形成蛋白（BMP）平均灰度显著增高（P＜0.01）,较对照组提前约1周。结论：补骨合剂可以促进口腔骨内种植体骨整合。该药物可促进BMP的早期释放和聚集,提高种植体－－骨界面的BMP浓度,促进其成骨。     

Xive种植系统的临床效果观察

目的：评价Xive种植系统用于缺牙区种植修复的临床效果。方法：临床选择53例患者，对骨量充足的23例患者进行即刻种植修复，并于24小时内完成。另30例患者进行常规种植手术。共植入Xive种植体112枚，并对其进行定期的临床和放射学检查。结果：53例患者中有23例患者接受即刻种植修复，涉及67枚种植体，经6个月以上观察，失败1枚，1枚弃用。30例患者接受常规种植修复，无失败病例。观察期最短8个月，最长20个月。种植体成功率为98．2％。结论：Xive种植系统用于种植修复的临床效果是满意的。     

Peri‐Implant Bone Density in Senile Osteoporosis‐Changes from Implant Placement to Osseointegration

Purpose: The aim of this study was to examine healing over time after implant body placement in a senile osteoporosis model and a control group. Materials and Methods: In this study, 16‐week‐old male mice were used. The senile osteoporosis model consisted of senescence‐accelerated prone 6 mice and the control group consisted of senescence‐accelerated resistant 1 mice. Titanium‐coated plastic implants were used as experimental implants whose dimensions were 3.0 mm in length, 1.1 mm in apical diameter, and 1.2 mm in coronal diameter. Bone samples were collected at 5, 7, 14, 21, and 28 days after implant placement. A micro‐quantitative computed tomography (QCT) system was used to scan these samples and a phantom in order to quantitate bone mineral measurements. Bone mineral density (BMD) of each sample was measured. Each sample was also examined by light microscopy after QCT imaging. At 14 and 28 days after implant placement, the bone‐implant contact (BIC) ratios were calculated from light microscopy images and were divided into cortical bone and bone marrow regions. Results: When BMD was compared between the osteoporosis and control groups using micro‐QCT, the osteoporosis group had a significantly lower BMD in the region 0–20 µm from the implant surface in the bone marrow region at 14 days onward after implant placement. Compared with the control group, the osteoporosis model also had significantly lower BMD in all regions 0–100 µm from the implant surface in the bone marrow region at 14 days after placement. However, in the cortical bone region, no statistically significant difference was observed in the regions at the bone‐implant interface. Light microscopy revealed osseointegration for all implants 28 days after implant placement. The osteoporosis model tended to have lower BICs compared with that of the control group, although this did not reach statistical significance. Discussion: Our results showed that osseointegration was achieved in the osteoporosis model. However, the BMD was 30–40% lower than that of the control group in the region closest to the implant surface in bone marrow region. Peri‐implant BMD was lower in a relatively large area in the osteoporosis model during an important time for osseointegration. Therefore, this result suggests that osteoporosis might be considered as a risk factor in implant therapy. Conclusion: The osteoporosis model had a lower BMD than the control group in the region closest to the implant during an important time for osseointegration. This result suggests that senile osteoporosis might be a risk factor in implant therapy. However, the osteoporosis model and the control group had no difference in peri‐implant BMD in the cortical bone region. This suggests that risk might be avoided by implant placement that effectively uses the cortical bone.