HTR植入修复即刻种植体周骨缺损的实验研究

研究生物性硬组织再生（ｈａｒｄ ｔｉｓｓｕｅ ｒｅｇｅｎｅｒａｔｉｏｎ,ＨＴＲ）材料促进即刻的种植体周上部缺损新骨形成的作用。方法：１２只小猪犬随机分为植入ＨＴＲ即刻种植组和未植入ＨＴＲ对照组;分别对于种植后４、８、１６、２４周处死动物,应用Ｘ线、组织学以及多色荧光标记等方法观察两组新骨形成的速度和和数量的差异。结果：在４个时间内,ＨＴＲ植入形成的速度以及数量均高于植入ＨＴＲ组。结论ＨＴＲ能促进即     

膜引导骨再生技术在即刻牙种植中的临床研究

目的：评价膜引导骨再生（GBR）技术在即刻牙牙种植术中的临床效果。方法：132例即刻植入BLB、Branemark、ITI及Frinlit-2四种种植系统共193个，对其进行定期临床和放射学检查。结果：193例即刻种植体中124个行GBR技术，经12个月以上观察，失败4个。结论：只要种植体取得初期稳定性，对种植体与拔牙窝间存在的间隙，采用膜引导再生技术处理，即刻种植可以取得良好的临床效果。即刻植入种植体同时常常需要使用GBR技术。采用即刻植入技术同时使用GBR技术的病例，其临床效果令人满意。GBR技术用于即刻种植所产生的临床效果良好。     

冷冻异体骨膜引导骨组织再生的实验研究

目的：探讨用冷冻异体骨膜作为引导骨组织再生膜的可能性;方法：取兔颅骨顶部骨膜经冷冻处理,在３１只日本大耳白兔的下颌骨造成两处骨缺失,采取同体对照,一处表面覆盖冷冻异体骨膜,另一处不覆盖。分别在第４、８、１２、１６周处死动物,行Ｘ线及组织学观察。结果：冷冻异体骨膜不产生排斥反应,可在体内维持８￣１２周,具有良好的阻挡纤维组织长入骨创面、分隔不同细胞及引导组织再生的功效。结论：冷冻异体骨膜是一种理想的     

引导组织再生即刻种植术的临床研究

目的 评价引导组织再生（ＧＴＲ）即刻种植术后的临床效果,探讨影响其效果的临床因素。方法 将２５颗种植立即植入２５例患者的新鲜拔牙窝,聚四氟乙烯（ＰＴＦＥ）膜覆盖于牙槽嵴顶封闭拔牙窝,松驰唇颊侧粘骨膜瓣,严密缝合。术后当天、１０天、１、２、３、４、５和６个月拍Ｘ光片检查种植体周骨缺隙骨再情况。术后６个月拆除ＰＴＦＥ膜。完成修复后随访观察一年。结果 无种植体松动或脱落;术后２个月新生骨充满种植体周缺隙     

异种脱细胞真皮基质引导即刻种植种植体周围骨缺损再生能力的实验研究

目的：运用异种脱细胞真皮基质进行引导骨组织再生术（guided bone regeneration,GBR）评价修复种植体周围骨缺损能力,为临床应用提供指导。方法：在4只成年Beagle犬下颌第2、3、4前磨牙新鲜拔牙创即刻植入种植体,并在颊侧形成3mm×3mm×5mm骨缺损区,按自身同期对照研究设计,右侧为实验侧,骨缺损区上覆盖海奥膜;左侧为空白对照侧,骨缺损区不覆盖海奥膜。术后1、4个月分别处死一组动物,摘取下颌骨,采用大体观察、x线摄片、组织学观察测定等方法检测缺损区骨组织再生的情况。结果：实验侧种植体周围骨缺损区较空白对照侧新骨生成量多,加速了骨组织的再生过程。结论：异种脱细胞真皮基质具有良好的生物相容性和可降解性,可用作骨组织引导再生膜,促进骨缺损的再生修复。     

即刻种植种植体周围骨缺损间隙的处理

即刻种植技术作为一种新兴技术被诸多的学者和临床医生所研讨。它不仅可以缩短牙拔除后种植原需等待的3～6个月的时间,减少一次手术带来的痛苦,而且还可以减轻牙槽突的吸收性萎缩。然而,在即刻种植修复中,种植体与拔牙窝之间存在着的骨间隙,成为影响种植成功率的关键因素之一。如何处理种植体与牙槽窝之间的骨间隙,是否需要植骨,使用何种材料等,国内外学者进行了相关方面的研究。本文就引导骨组织再生技术、不充填任何材料和选择合适的种植体等即刻种植种植体周骨缺损间隙的处理作一综述,以期为临床提供参考。     

即刻种植种植体周围骨缺损间隙的处理

即刻种植技术作为一种新兴技术被诸多的学者和临床医生所研讨。它不仅可以缩短牙拔除后种植原需等待的3—6个月的时间,减少一次手术带来的痛苦,而且还可以减轻牙槽突的吸收性萎缩。然而,在即刻种植修复中,种植体与拔牙窝之间存在着的骨间隙,成为影响种植成功率的关键因素之一。如何处理种植体与牙槽窝之间的骨间隙,是否需要植骨,使用何种材料等,国内外学者进行了相关方面的研究。本文就引导骨组织再生技术、不充填任何材料和选择合适的种植体等即刻种植种植体周骨缺损间隙的处理作一综述,以期为临床提供参考。     

即刻种植种植体周围骨缺损的Beagle犬动物模型建立

目的:评估即刻种植后种植体周围骨缺损植骨与否对骨结合的影响,建立一种符合即刻种植种植体周围骨缺损特点的动物模型。方法:以成年Beagl e犬为实验动物,拔除犬双侧下颌P2、P3、P4牙。于远中根拔牙窝的远中距牙根间隔5-6mm处预备种植窝,即刻植入种植体。植入种植体后保证沿下颌骨长轴向骨缺损范围达3-4mm。骨缺损区不植入骨粉,直接用胶原膜覆盖为实验组。骨缺损区植入骨粉并覆盖胶原膜为对照组。于术后3个月末处死动物取材,进行组织学观察。结果:X线观察:实验组与对照组缺损处到3个月时均被新生骨充填。组织切片染色镜下观察:实验组与对照组骨缺损处可见大量骨细胞,骨改建基本完成。结论:种植体与拔牙窝内壁之间的3-4mm范围骨间隙即使不植骨,也会有新骨生成、并且可以与种植体表面发生骨结合。成功构建了与临床即刻种植骨缺损相似,并可作为研究即刻种植骨界面骨性结合的实验动物模型。     

引导组织再生术在即刻牙种植术修复上的应用研究

目前在临床上进行的牙种植体植入手术,基本上都是等拔牙窝完全愈合后再进行。如果在拔牙后立即进行牙种植体植入手术,就可减少１次外科创伤,也可使牙槽骨的废用性吸收受到较好的抑制,为临床上更理想的效果［１］。另一方面,牙种植体植入后,往往发生植入窝上的纤维性结缔组织向植入窝内侵入,使牙种植体在组织内的稳定性受到影响。为了防止这一现象的发生,近年来国外出现了引导组织再生技术,这种技术可以阻止纤维性结缔组织对牙种植体植入窝的侵入,引导正常的骨组织再生。现就对引导组织再生术在即刻牙种植术修复上的应用作一综述。…     

骨融合式牙种植体即刻种植的研究进展

骨融合式牙种植体是目前修复牙列缺失的理想方法，被誉为人类第三副牙齿。按种植方式分为即刻种植和延期种植两种。本文综述了国内外关于即刻种植研究的最新进展，包括引导骨再生术（ｇｕｉｄｅｄ ｔｉｓｓｕｅ ｒｅｇｅｎｅｒａｔｉｏｎ，ＧＴＲ）的应用，植骨材料的选择和促骨生长因子的应用等，并讨论了即刻种植的可行民生及存在的问题。     

Contribution of the periosteum to bone formation in guided bone regeneration. A study in monkeys

The periosteum has been referred to as a protective barrier in the regeneration of bone defects. The objective of this study was to determine the contribution of periosteum as a natural barrier to bone formation in guided bone regeneration. Mucoperiosteal flaps were elevated bilaterally on the buccal aspect of the mandibular angle in 5 cynomolgus monkeys. Bleeding was induced by perforating the cortical bone. A hemispherical titanium mesh was fixed over the areas thus creating a void 5 mm in height between the mesh and the bone surface. One one side the mesh was covered with an ePTFE membrane (test side). The contralateral side did not receive further treatment (control side). After 4 month healing, histomorphometric analyses were used to determine the percentage of new bone in the void underneath the mesh, and the ratio between mineralized tissue and marrow spaces in new and old bone. The mean percentage of new bone tissue was 77.2 +/- 7.5% for the test sides and 68.6 +/- 8.4% for the control sides (P = 0.018, t-test). This new bone contained 80.0 +/- 3.6% mineralized tissue in the test group and 82.5 +/- 5.0% in the control group (P > 0.05, t-test). In both groups the newly formed bone exhibited significantly less mineralized tissue than the old bone (P < 0.05, t-test). It is concluded from this study that new bone formation was enhanced by the additional use of an ePTFE membrane under a periosteum-lined mucoperiosteal flap when space maintenance was excluded as a critical factor.     

Regeneration and enlargement of jaw bone using guided tissue regeneration

The purpose of this study was to present the surgical procedures and the clinical results of guided tissue regeneration (GTR) treatment aimed at regenerating local jaw bone in situations where the anatomy of the ridge did not allow the placement of dental implants. 12 patients were selected for ridge enlargement or bony defect regeneration. A combined split- and full-thickness flap was raised in areas designated for subsequent implant placement. Following perforation of the cortical bone to create a bleeding bone surface, a PTFE membrane was adjusted to the surgical site in such a way that a secluded space was created between the membrane and the subjacent bone surface in order to increase the width of the ridge or to regenerate bony defects present. Complete tension-free closure of the soft tissue flap was emphasized. Following a healing period of 6 to 10 months, reopening procedures were performed and the gain of bone dimension was assessed. In 9 patients with 12 potential implant sites, a sufficient bone volume was obtained to allow subsequent implant placement. The gain of new bone formation varied between 1.5 and 5.5 mm. In 3 patients, acute infections developed which necessitated early removal of the membranes and no bone regeneration could be achieved. The results of the study indicate that the biological principle of GTR is highly predictable for ridge enlargement or defect regeneration under the prerequisite of a complication-free healing.     

生物可吸收引导组织再生膜的实验研究

目的探索生物可吸收性引导组织再生膜（BGTRM）对种植体周骨组织形成的作用。方法8只犬一侧种植体顶部覆盖BGTRM膜，另一侧为未放BGTRM膜的对照组，于4周、3月、6月处死动物，以X线、组织学和计算机测量手段观察和比较两组种植体周骨质形成的情况。结果四周时，BGTRM组种植体周骨质的量和密度明显高于对照组，六月时，两组骨质形成已无明显差异。结论BGTRM具有促进种植周骨质形成的功能。     

Osteogenesis by guided tissue regeneration and demineralized bone matrix

AIM: To evaluate in a discriminating capsule model whether bone formation by guided tissue regeneration (GTR) may be influenced by concomitant implantation of demineralized bone matrix (DBM). MATERIALS AND METHODS: Thirty 4-month-old male albino rats of the Wistar strain were used in the study. Following surgical exposure of the mandibular ramus, a hemispherical, Teflon capsule (5.0 mm in diameter), loosely packed with a standardized amount of DBM, was placed with its open part facing the lateral bone surface of the ramus. At the contralateral side, an empty capsule was placed, serving as control. After healing periods of 15, 30, and 120 days, groups of 10 animals were sacrificed and 40-70 microm thick undecalcified sections of the capsules were produced. In the sections, the cross-sectional areas of (1) the space created by the capsule, (2) newly formed bone, (3) DBM particles, (4) loose connective tissue as well as the (5) height of the capsules, and (6) that of the newly formed bone were measured. RESULTS: Increasing bone fill was observed in both test and control sites from 30 to 120 days. After 30 days of healing, the mean amount of bone was approx. 3% of the cross-sectional area of the capsules at the test sites while it was 8% in the control sites (p<0.05). However, no statistically significant differences were observed between the test (46%) and control (64%) sites after 120 days regarding any of the measured parameters (p>0.05). The newly formed bone in the DBM group at 120 days, on the other hand, appeared more dense than that in the control capsules. CONCLUSION: DBM used as an adjunct to GTR did not provide any added effect on bone formation but increased the density of the newly formed bone.     

Enhancement of bone volume in guided bone augmentation by cell transplants derived from periosteum: an experimental study in rabbit calvarium bone

Bone morphology is genetically encoded and it is usually difficult to change its structure without invasive surgery. We have tried to stimulate bone augmentation by a combination of guided bone regeneration techniques and cell transplants with collagen scaffolds for the suitable skeletal framework. In vitro-expanded tibia periosteum cells were used to promote osteogenesis with collagen scaffolds and titanium (Ti) or poly-L-lactic acid (PLLA) caps as barriers to create a space facing connective tissue under calvarium skin. This approach was assessed in the defective skull bone of a rabbit model. After a 12-week healing period, histomorphometric analyses were performed to determine the percentage of newly formed mineralized tissue in the cap. The mean percentage of newly formed mineralized tissue within the cap was 15.4%+/-3.99 for the Ti cap group, 15.5%+/-4 for the PLLA cap group, 6.19%+/-4.94 for the PLLA cap+collagen carrier group and 23.1%+/-23.1 for the PLLA+collagen carrier+cell transplants group. The cell transplant group showed a significantly higher value than other groups (P<0.05, Wilcoxon signed rank test, Mann-Whitney U-test). This approach of guided bone augmentation and cultured cell transplants with collagen carrier exhibited significantly greater morphogenesis of mineralized tissue than the control over a 12-week experimental period.     

A volumetric study of guided bone regeneration around titanium implants in the New Zealand white rabbit

Previous studies have shown the ability for bone to grow under occlusive membranes. This study was undertaken to determine the time required for bone to form in the space created under the membrane and to determine the amount of bone that may be grown under the membrane. Thirty-two New Zealand white rabbits were divided into three groups. A Brånemark implant, having a diameter of 3.75 mm with a length of 7 mm, was placed in each tibia and Gore-Tex membrane was draped over the implant on the experimental side and tethered to the wound margin. Sixteen rabbits were sacrificed at six weeks, eight at twelve weeks, and eight at eighteen weeks. At six weeks the available space under the membrane was filled to 68 per cent, at twelve weeks it was 45 per cent, and at eighteen weeks 54 per cent. A comparison of bone height measurements on test and control sides showed a significant difference (p=0.0001) at the three time intervals. A comparison of grown bone volumes (test vs control) was also statistically significant (p=0.0001). The ability to grow bone under an occlusive membrane was confirmed but the long-term survival rate and ability to support load needs to be investigated.     

Bone regeneration using the principle of guided tissue regeneration

The biological principle of "guided tissue regeneration" (GTR) was developed for regenerating periodontal tissues, lost as a result of periodontal disease. This principle was based on the hypothesis that non-desirable types of tissue cells can be prevented from migrating into a wound by means of a membrane barrier and at the same time giving preference to those particular cells to repopulate the wound, which have the capacity to regenerate the desired type of tissue. This principle may have its application in many areas of surgery, aimed at regeneration of lost tissues. One such area is osseous surgery aimed at bone regeneration. In the present paper, a series of experiments in laboratory animals using the method of GTR for regeneration of various types of bone defects are presented as well as examples of application in humans for regeneration of jaw bone defects in conjunction with the placement of dental implants.     

Treatment of an early implant failure according to the principles of guided tissue regeneration (GTR)

The present case report demonstrates the application of guided tissue regeneration (GTR) in combination with antimicrobial therapy for the treatment of an early implant failure. This treatment approach both prevented further loss of bone as well as led to the regeneration of lost bone. By means of color-converted digital subtraction images, remodelling of the tissues adjacent to the defect was documented as early as one month postsurgically. The images demonstrated "bone-fill" in the apical portion of the defect and resorptive changes at the bone crest. This case report demonstrates that combined regenerative and antimicrobial therapy may be a successful treatment approach restoring osseointegration of dental implants following loss of bone due to infection. Continuously increasing bone-fill inside the defect was documented when comparing the radiograph obtained immediately before the GTR procedure and at months 1, 2, 4, 5 and 6 of the healing period, respectively. Clinical measurement obtained at the time of the surgery and at the time of the membrane removal confirmed the radiographic evidence of bone-fill by demonstrating new tissue resistant to probing in close contact to the implant surface at the site of the previous defect. Antimicrobial therapy included an antibiotic regimen during the 1st month of healing as well as topical rinses with an antiseptic (chlorhexidine) over the entire healing period of 6 months. As a result of this treatment approach, the implant was saved and could be used as an abutment for a bridge reconstruction.