单个种植体即刻种植即刻负重骨结合情况的动物实验研究

目的本实验设计了单个种植体即刻种植即刻负重的动物模型,目的在于研究种植体周围硬组织的变化.方法选取8只成年狗,体重10～15 kg.分别拔除每只狗的双侧下颌第二前磨牙;同时,各植入一枚ITI种植体,分别以20Ncm及30Ncm的扭矩旋入.实验侧即刻以树脂冠行上部结构修复,对照侧无负荷.每只狗在植入种植体后和处死后拍X线片,观察其影像学的改变.动物分别于1个月和3个月处死后取标本,观察其组织学的改变.结果16枚种植体中14枚种植体获得良好的骨结合,种植体周围包绕着致密的骨组织,未观察到任何间隙和结缔组织长入.实验侧1枚种植体脱落,对照侧1枚种植体松动.结论单个种植体的即刻种植即刻负重是一个可行的选择.     

种植体长度对即刻负载种植体骨界面生物力学分布的影响

目的:建立包含不同长度标准直径种植体的下颌骨三维有限元模型,分析不同长度种植体对即刻负载种植体骨界面应力应变分布的影响.方法:采用薄层CT扫描下颌骨和自主开发的USIS软件建立直径4.1mm不同长度螺纹种植体即刻负载的三维有限元模型,用ANSYS软件分析长度分别为6、8、10、12、14mm的种植体,在垂直和颊舌向45o加载150N力时种植体骨界面的von Mises应力、应变值.结果:随着种植体长度的增加,种植体骨界面的应力和应变值均呈下降趋势.种植体骨界面应力值在长度从6mm增加到8mm时下降最明显,尤其是颊舌向加载时;而种植体长度从8mm增加到10mm及从10mm增加到12mm和从12mm增加到14mm时,骨界面应力值下降并不很明显.种植体骨界面应变值也是在长度从6mm增加到8mm及8mm增加到10mm时下降最明显.结论:种植体长度的增加能降低骨界面应力和应变值,呈负相关关系;但只在长度从6mm增加到8mm时应力值降低才较明显.这提示临床上尽量不要采用长度为6mm的种植体,并应适当地选择足够长度的种植体.     

微创即刻种植术与微创即刻负重种植术

本文对当前微创即刻种植术和微创即刻负重种植术的应用进行了评述,阐述了它们的概念、要求、禁忌证、主要手术过程及研究现状。     

即刻种植即刻负重中PRF对软组织愈合的促进作用

目的:观察即刻种植即刻负重中应用富血小板纤维蛋白(PRF)种植体周围软组织的生长情况.方法:拔除5只beagle犬双侧下颌第四前磨牙(PM4),立即植入柱形螺纹纯钛种植体并即刻负重.采用自身对照方式,实验侧采用PRF填塞种植体颊侧缺损和远中拔牙窝;对照侧种植体颊侧缺损以血凝块充填,远中拔牙窝用明胶海绵填塞.术后第二天开始观察软组织的愈合情况,连续观察10天.结果:种植后实验组软组织的愈合时间平均为5.80天,对照组为8.20天.结论:即刻种植即刻负重种植中使用PRF,可促进软组织的愈合,缩短软组织愈合的时间.     

非埋入种植及即刻负重对牙种植体周早期骨吸收的影响

目的:评价种植体即刻负重的临床效果.方法:选择30例患者植入49颗ITI种植体.其中18例采用传统种植方式(32颗),12例采用非埋入式种植及即刻负重(17颗).分别在植入后当天、1周、1月、3月、6月、12月拍摄根尖片,测量骨吸收量.结果:所有种植体均无失败,传统种植方式组在各时间段骨吸收量与即刻负重组均无明显差异.讨论:早期理论认为种植体植入后需在无干扰、无负荷状态下完成骨结合,即需要潜入式种植和长达数月的愈合期.但进一步研究表明对新植入种植体施加的我荷只要控制在一定范围内,则可作为一种生理性刺激促进植入体周围骨组织改建矿化.结论:非埋入种植及即刻负重不会影响种植体周早期骨吸收,可获得较好的临床效果.     

前牙种植修复即刻负重的回顾性研究

目的回顾性分析758例HBIC-Ⅰ纯钛人工牙种植体前牙缺失种植修复即刻负重的临床效果。方法对从1997年10月至2007年1月在河北医科大学口腔医院颅颌面种植中心经治的资料完整的758例前牙缺失人工牙种植修复即刻负重病例(共计植入1112颗HBIC-Ⅰ纯钛人工牙种植体)进行回顾性研究。结果1112颗HBIC-Ⅰ纯钛人工牙种植体前牙种植术后观察6个月～10年,累计失败15颗,成功率98.65%;未发现与种植术相关的其他并发症。结论HBIC-Ⅰ纯钛人工牙种植体的临床应用效果较好,能够较好满足临床前牙缺失患者种植修复即刻负重的要求。     

单牙种植体即刻负重的临床研究:即刻种植与非即刻种植的比较

本研究假设单牙缺失后种植体支持式义齿的即刻负重是成功的,在此基础上进行新鲜拔牙创内即刻种植和已愈合拔牙创上非即刻种植的单牙种植体即刻负重的临床比较研究。 材料和方法 1997～1998年收治26位患者,年龄范围18～70岁;共有28个牙位为单颗牙缺失行种植义齿修复,其中19枚种植体为即刻种植,9枚     

种植领域即刻负重的评判标准

由于种植体植入时或是植入早期的稳定性对种植体的成功有很大的影响,因此对种植体何时负重和即刻负重的要求也越来越高。种植体的稳定性与牙槽骨的密度、高度和皮质骨,松质骨的形状、种植体的设计和外科技术有很重要的关系。目前,测量种植体稳定性的很多方法和器械已经应用到临床。     

即刻负重种植修复的临床观察

目的:观察即刻负重种植修复的临床效果,并对其临床应用问题进行探讨。方法:24例患者共计105个种植体,即刻负重修复缺牙,观察时间12-24个月。结果:1例患者2个种植体修复1个月时脱落;1例患者1个种植体在3个月时脱落;1例患者1个种植体在3个月时因松动而拔出,其余101个种植修复体临床效果良好,成功率达96.19%。结论:选择适当的病例,即刻负重种植修复可应用于临床,近期效果满意。     

种植牙即刻负重的生物力学的三维有限元分析

目的 用三维有限元的方法分析牙种植体不同角度即刻负重的骨界面应力分布规律.方法 选成人无牙下颌骨进行薄层螺旋CT扫描,将扫描图像导入通用外科手术集成系统,建立下颌骨三维网格模型.模拟标准的螺纹实心种植体,建立种植体一下颌骨即刻负重的三维有限元模型.以150 N的力轴向加载和分别10.、20.、30.侧向加载,应用ANS...     

������ֲ��������������������Ӧ��

由于种植体生物相容性的不断改良和完善,目前的牙种植体均能获得理想的可预期的骨结合,在新拔除患牙的牙槽窝内即刻植入种植体已经成为一种常规的术式拔牙后即刻种植可有利于减少外科手术次数,有利于牙槽嵴骨量的保存,降低治疗费用并减少缺牙时间,更易被患者接受.但由其解剖生理因素决定,牙槽嵴在牙缺失后通常要出现唇侧骨板的吸收萎缩,这常导致种植体唇面暴露,出现美学上的问题.即刻种植的同时,在充分理解和使用引导骨再生原理的基础上配合骨增量材料的应用才能获得理想的修复效果,本文就我们的临床体会结合文献进行了分析讨论.     

Bucco-lingual crestal bone changes after immediate and delayed implant placement

BACKGROUND: Implants placed immediately after tooth extraction offer several advantages, but many authors have reported problems in filling the residual gap between the implant and the socket walls. Barrier and grafting techniques have been tested and yield varying results, so it has been suggested that the timing of implant placement may be important for success. The aim of this study was to analyze bone healing and coronal bone remodeling around 35 implants, 20 placed immediately after tooth removal and 15 placed 6 to 8 weeks after extraction. METHODS: All the implants were submerged and placed within the alveoli confines, leaving circumferential defects because the implants did not contact the bone at their coronal aspects; stabilization was achieved in the bone apically. After implant placement the mean distance from buccal bone to lingual bone was 10 mm (SD 1.522) for immediate implants and 8.86 mm (SD 2.356) for delayed implants. No membrane or filling materials were used. Primary flap closure was accomplished in all cases. RESULTS: At second-stage surgery all peri-implant defects were filled, and the mean distance from buccal bone to lingual bone was 8.1 mm (SD 1.334) for immediate implants and 5.8 mm (SD 1.265) for delayed implants. This pattern of coronal bone remodeling, showing a narrowing of the bucco-lingual width, was clinically similar for the two groups, although it should be noted that the delayed implants exhibited smaller bucco-lingual bone width already at the first measurement: it can be speculated that early remodeling may start immediately after tooth extraction and continue, non-uniformly, even after delayed implant placement. CONCLUSIONS: This study suggests that circumferential defects could heal clinically without any guided bone regeneration (GBR) in both experimental groups, and that the procedure was virtually free from complications in the postoperative period, probably because of the absence of barrier membranes and/or grafting materials. Histologically, peri-implant defects of over 1.5 mm heal by connective tissue apposition, rather than by direct bone-to-implant contact, but clinically this healing may be very successful. No histological analysis was carried out in the present study, but even the largest residual gaps were filled with hard tissue that could not be probed. Thus, such outcomes can be considered clinically successful. The different rate of bone remodeling around immediate or delayed implants could have implications for the preferred timing of implant placement in sites of high esthetic concern.     

Influence of controlled immediate loading and implant design on peri-implant bone formation

AIM: Tissue formation at the implant interface is known to be sensitive to mechanical stimuli. The aim of the study was to compare the bone formation around immediately loaded versus unloaded implants in two different implant macro-designs. MATERIAL AND METHODS: A repeated sampling bone chamber with a central implant was installed in the tibia of 10 rabbits. Highly controlled loading experiments were designed for a cylindrical (CL) and screw-shaped (SL) implant, while the unloaded screw-shaped (SU) implant served as a control. An F-statistic model with alpha=5% determined statistical significance. RESULTS: A significantly higher bone area fraction was observed for SL compared with SU (p<0.0001). The mineralized bone fraction was the highest for SL and significantly different from SU (p<0.0001). The chance that osteoid- and bone-to-implant contact occurred was the highest for SL and significantly different from SU (p<0.0001), but not from CL. When bone-to-implant contact was observed, a loading (SL versus SU: p=0.0049) as well as an implant geometry effect (SL versus CL: p=0.01) was found, in favour of the SL condition. CONCLUSIONS: Well-controlled immediate implant loading accelerates tissue mineralization at the interface. Adequate bone stimulation via mechanical coupling may account for the larger bone response around the screw-type implant compared with the cylindrical implant.     

From an immediate implant placement in the post-extraction phase towards immediate loading application: current status

The fresh extraction socket site in the immediate post-extraction phase possesses unique characteristic wound healing cascade. Marked horizontal and vertical resorption of the edentulous ridge occurred shortly following tooth extraction. In periodontally involved teeth, when partial/full socket wall destruction is evident, the ingrowth of connective tissue into the extraction site is unavoidable leading to a deficient ridge. The use of bone substitute materials aiming to preserve the alveolar ridge by stabilizing the blood clot, thus maintaining the volume of the site and at the same time serves as an osteoconductive scaffold which facilitates continual bone formation. immediate Implant placement, is also a reliable, predictable, and successful procedure. Comparative studies regarding immediate implant placement vs. delayed placement (healed sites) reported similar high survival rate for both procedures. The addition of nonfunctional immediate provisionalization (clearance of all contacts in centric occlusion and during eccentric movements to avoid full functional loading of the implant during healing) achieving an instant aesthetic solution, has been shown to have predictable results. However, a meticulous surgical protocol should be followed. In recent years, an immediate functional loading of cross-arch splinted implants proved to be a reliable and successful approach. Moreover evidence-based data comparing immediate, early and delayed loading failed to show significant difference between those treatment modalities. Apparently, primary stability of implants is an important factor in achieving predictable success. It seems that the addition of controlled loading did not impair those results. A systematic review of the current literature related to this procedure showed a survival rate of over 95% in 34 prospective/retrospective studies. Since clinical parameters were proved to be equal whether implants were placed immediate post-extraction or delayed in a healed alveolar ridge, it appears that cross-arch immediate loading of implants placed in extraction and/or healed edentulous ridges is a predictable procedure with long term stability of the results.     

A model to evaluate bone substitutes for immediate implant placement

A calcified alloplast was evaluated as a gap-filling material around implants placed immediately into fresh extraction sockets. Periodontal measurements and computed tomography scans were obtained to evaluate the clinical effectiveness of the alloplast when compared with demineralized freeze-dried bone. To determine whether this alloplast would be a suitable grafting material, 14 patients were selected to evaluate the extraction socket as a model for routine histologic confirmation of the efficacy and biocompatibility of bone substitutes. The results of this study showed the following: (1) human extraction sockets can be models for the study of bone/implant interaction; (2) the alloplast was well tolerated and demonstrated no inflammation through histologic evaluation of core biopsies; (3) the alloplast was a suitable material when used as a gap-filling graft in sockets around immediately placed implants; and (4) dental computed tomography scans and periodontal measurements around grafted implants 6 months after the procedure provide valuable clinical information about graft healing and osteointegration.     

Early osteotomy with delayed implant placement: a step further for immediate loading

The commonly used implantation technique involves a 2-stage surgical protocol for load-free and submerged healing to ensure predictable osseointegration. This article presents a new approach that benefits from previous bone and soft tissue protocols. It combines new surgical and insertion techniques to perform immediate loading with delayed implant placement, avoiding the problems of discomfort, inconvenience, and anxiety associated with healing periods. It maintains a similar success rate to the present common technique. After osteotomy, bone healing passes through 3 stages (i.e., inflammation, fibrous tissue, and maturation). In the new approach, implant insertion is performed 2 weeks after drilling (i.e., during the fibrous phase). The insertion timing is so selected because collagen formation and revascularization represent an acceptable implant bed configuration. Flap surgery offers the optimal osteotomy approach, but esthetic outcomes are definitely compromised. Accordingly, adopting the punch technique alleviates several postoperative problems, such as pain, tenderness, and swelling. Moreover, the punch technique avoids the sutures needed to adjust the gingiva around the abutment. It provides both cosmetic and functional properties.