The effect of platelet-rich plasma combined with autogenous bone graft for bone regeneration in bone defects

The objective of the present study was to evaluate the effect of PRP on bone healing both quantitatively and qualitatively using histomorphometrical methods in a rabbit model. The examined materials were autogenous bone, PRP alone, a mixture of autogenous bone and PRP, and whole blood (as a control). These materials were implanted into artificial defects prepared in rabbit tibiae. The observation period was set at 1, 2, 3, and 4 weeks. All specimens were used for histologic evaluation and 2- and 4-week specimens were used for histomorphometrical evaluations. The bone quantity increased when autogenous bone was applied but the percentage of mature bone in the autogenous bone site was smaller than in the PRP applied site. The results of this study suggested that the quantity of newly formed bone increased when autogenous bone was applied, but not when PRP only was applied. However, PRP might accelerate bone maturation by activating bone remodeling. According to this study, the bone quality could be altered by the application of PRP.     

The pubic bone graft

We introduce a new technique for harvesting cancellous bone, the pubic bone graft. The pubic bone graft is a predictable and efficient technique that yields an ample harvest of rich cancellous bone. With experience gained from multiple fresh cadaver dissections, we present this technique in detail, including our most recent clinical application to graft alveolar clefts and its advantages over the traditional technique of bone graft harvesting.     

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。     

高压氧影响自体游离植骨的观察

目的研究高压氧能否促进非血管化新鲜自体游离植骨在受植区的生长愈合过程,能否加快游离移植骨的爬行替代过程。方法选用4只成年杂种狗,随机分成两组,每组2只,实验组（HBO组）在植骨后第3天即进行高压氧治疗。术后10周处死动物,分别从游离植骨的中央区、周边区、移植骨和受植骨交界处取标本,甲酸和硝酸脱钙、石蜡包埋、切片、HE染色。结果所有部位移植骨均发生了“爬行替代”的组织学改变,表现为新骨与旧骨相互参杂。在HBO组中,移植骨与受植骨的结合比非HBO快,新骨形成较非HBO组多。结论HBO可以加快移植骨与受植骨的结合,促进移植骨“爬行替代”过程中的新骨形成,但不能改变自体游离植骨的生长方式。     

前牙常规拔除同时植骨对种植体植入术的影响

目的:探讨常规前牙拔除后,牙槽窝和缺失区唇侧同时植骨对种植体植入术的影响。方法:20例26颗前牙拔除术后牙槽窝剩余骨量不足,即刻植骨术+GBR。结果:26颗前牙植骨后临床成功率100%,种植区均获得良好的骨高度及宽度,满足了种植体植入及后期美学修复的要求。结论:前牙常规拔除后牙槽窝和缺失区唇侧骨量不足而行同时植骨的方法,对提升种植体植入术和美学修复的临床效果,提供了一种治疗思路和方法且可靠而有效。     

The evaluation of processed cancellous bovine bone as a bone graft substitute

OBJECTIVE: To determine the ability of a novel bovine cancellous bone xenoimplant to act as an osteoconductive graft in an ovine femoral defect model. An autograft harvested from the xenoimplant site was placed in a contralateral limb defect for comparison. MATERIAL AND METHODS: The xenoimplant used had been rendered immunologically inert by a novel defatting and deproteinating process. Following surgical implantation of cores into condylar cancellous bone defects, fluorochrome labels were administered to 12 sheep at 2 1/2, 4 1/2 and 8 weeks. Incorporation of the xenoimplants and autografts into the host bone was compared radiographically and histomorphometrically at 10 weeks. RESULTS: Radiographically, the degree of osteointegration was comparable. Histomorphometric data, consisting of labelled surface (LS) estimates, confirmed osteoconductive properties of both the xenoimplants and autografts. Remodelling activity was greatest in the xenoimplants at 2 1/2, weeks. At 4 1/2 weeks, there was more activity in the autograft, but by 8 weeks they were performing similarly. Xenoimplant-LS estimates were comparable or greater than those of the autograft at all times. CONCLUSIONS: Processed bovine cancellous bone xenoimplants were osteoconductive in this model and show promise for development as a biomaterial in human and veterinary orthopaedic surgery.     

牙周植骨术联合钴铬烤瓷冠保留松动基牙的疗效分析

目的：评价牙周植骨术联合夹板式钴铬合金烤瓷联冠保留末端松动牙的临床疗效。方法：第一磨牙缺失,末端牙松动伴有牙周骨内缺损,拟行夹板式固定义齿修复的患者10例。应用牙周植骨术联合夹板式钴铬合金烤瓷联冠保留末端松动牙,随访观察治疗后患牙0个月,3个月,6个月的牙周指数,修复前后咀嚼效率,X线片的变化情况。结果：患牙的探诊深度,临床附着丧失值在术后3个月、6个月均显著下降（P〈0.05）,基牙的探诊深度值在术后3个月显著下降（P〈0.05）,临床附着丧失值变化无统计学差异,夹板完成后咀嚼效率显著提高（P〈0.05）;全部病例中基牙牙槽骨无继续吸收,术牙骨量均有一定程度增加。结论：牙周植骨术联合夹板式钴铬合金烤瓷联冠保留末端松动牙可获得较满意的近期临床疗效。     

Differential effects of bone graft substitutes on regeneration of bone marrow

Background: This study used a rat tibial marrow ablation model to test the hypothesis that bone remodeling within the medullary canal varies with bone graft materials of different chemical compositions and structural properties, impacting marrow cavity restoration. Bone graft materials were selected based on their relative resorption or degradation in vivo and their osteogenic properties. Methods: Following ablation of the right tibial marrow in male Sabra‐strain rats, materials were implanted in the proximal marrow cavity: poly‐d,l ‐lactide‐co‐glycolide 75 : 25 (PLGA); coralline‐hydroxyapatite (HA), calcium‐sulfate (CaSO4), collagen–HA–tricalcium phosphate granules, anorganic bovine bone mineral, demineralized bone matrix (DBM), 45S5 Bioglass (BG), PLGA with BG 50 : 50, PLGA : BG 80 : 20, and PLGA and PLGA:BG 50 : 50 plus bone marrow (BM). Control tibias were ablated but received no implants. At 2 (endosteal bone healing), 4 (marrow cavity remodeling) and 8 weeks (marrow restoration), six to eight animals per group were euthanized and tibias processed for histomorphometry of proximal and distal medullary canals. Results: Control tibias showed primary bone in proximal and distal medullary canals at 2 weeks, with trabeculae surrounded by cellular marrow. At 4 and 8 weeks, control trabeculae were thinned and marrow had more fat cells. In the treated tibias, trabecular bone volume (TBV) varied with time and was material specific. Most implants supported comparable TBV at 2 weeks. Sites with CaSO4 or DBM exhibited decreased TBV with time whereas trabecular bone was retained in proximal tibias containing other materials, closely juxtaposed to the implants. TBV did not always correlate directly with implant volume, but changes in BM volume were correlated inversely with TBV. Addition of BM increased marrow restoration in sites containing PLGA; however, BM reduced restoration of marrow when added to PLGA : BG. Although the presence of implants in the proximal tibia resulted in retention of trabecular bone, there was a time‐dependent reduction in TBV in distal canals; the rate and extent of the distal TBV reduction were implant dependent. Conclusions: Thus, although many materials can support bone formation in the marrow cavity, bone quality, quantity, and physical relationship to the implant, and its rate of resorption differ in a material‐dependent manner, resulting in differences in the restoration of marrow. Clinical relevance: Bone graft materials should be selected not only for their ability to support new bone formation but also for their impact on the remodeling phase of bone healing.     

Effect of platelet-rich plasma on bone regeneration in autogenous bone graft

In this study, we evaluated the effect of platelet-rich plasma (PRP) on bone regeneration in an autogenous bone graft in a canine model. The mandibular premolar teeth had been bilaterally extracted previously, and the ridges had been allowed to heal for 3 months. After this period, continuity resection was performed on both sides of the mandible. One defect (the PRP group) was reconstructed with the original particulate bone mixed with PRP. As a control, the contralateral defect (non-PRP group) was reconstructed with the original particulate bone alone. Biopsies after 6 weeks showed lower levels of bone formation in the PRP group than in the non-PRP group, and fluorescence microscopy revealed a delay in the remodelling of grafts loaded with PRP. These findings suggest that the addition of PRP does not appear to enhance new bone formation in autogenous bone grafts.     

The model graft: reconstruction of the maxilla using a fibular bone graft template

The reconstruction of the partial maxillectomy decfect with a free graft depends on a team approach in a coordinated manner. However, this is not always possible due to physical limitations or, unfortunately, pragmatic factors in the era of managed care. A surgical template oftentimes is the critical measure of success in these cases, but may not be available or easily created for the previously mentioned reasons. In this article, we describe the use of redundant fibular bone as a template for reconstruction of the partial maxillectomy defect. This is a satisfactory alternative to a dental template in many cases, and, we believe, in some cases, may even be superior because it is the graft itself. As a result insetting can be hastened and precious ischemic time can be lessened-all favoring a successful, functional result.     

Effects of scaffold architecture on cranial bone healing

In the present study, polycaprolactone–tricalcium phosphate (PCL/TCP) scaffolds with two different fibre laydown patterns, which were coated with hydroxyapatite and gelatine, were used as an approach for optimizing bone regeneration in a critical-sized calvarial defect. After 12 weeks, bone regeneration was quantified using microcomputed tomography (micro-CT) analysis, biomechanical testing, and histological evaluation. Notably, the experimental groups with coated scaffolds showed lower bone formation and lower biomechanical properties within the defect compared to the uncoated scaffolds. Surprisingly, the different laydown pattern of the fibres resulted in different bone formation and biomechanical properties: the 0°/60°/120° scaffolds revealed lower bone formation and biomechanical properties compared to the 0°/90° scaffolds in all the experimental groups. Therefore, future bone regeneration strategies utilizing scaffolds should consider scaffold architecture as an important factor during the scaffold optimization stages in order to move closer to a clinical application.     

The effect of electrosurgery on alveolar bone

The facial marginal alveolar bone of dogs was exposed with a full-thickness flap and touched by an activated electrosurgery electrode for periods of 0, 1, 5 and 10 seconds. Microscopic results were evaluated after periods ranging from 0 hours to 28 days. Various electrode exposure times produced similar changes in bone and periodontal ligament. The extent of the destruction was greater than that found in surgical areas not exposed to electrosurgery; healing and remodeling phases were also delayed in the electrosurgical sites.     

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目的    评价牙周植骨术联合夹板式金属烤瓷联冠修复牙周骨缺损的临床疗效。方法    2008—2009年在新疆医科大学第一附属医院口腔修复科门诊选择患慢性牙周炎伴牙列缺损拟行固定义齿修复的患者15例。应用牙周植骨术联合夹板式金属烤瓷联冠修复基牙牙周骨缺损,随访观察疗效。结果    随访观察6个月,治疗总有效率为93.4%。治疗后6个月的各项牙周指标（PD、CAL、BI）均较治疗前有所改善,治疗前后差异均有统计学意义（P < 0.05）。结论    对于慢性牙周炎伴牙列缺损患者,牙周植骨术联合夹板式金属烤瓷联冠修复基牙牙周骨缺损的近期疗效较佳。     

Effect of Gusuibu graft on bone formation.

PURPOSE: We compared the amount of new bone produced by Gusuibu in collagen grafts to that produced by bone grafts and collagen grafts. MATERIALS AND METHODS: Twenty bone defects were created in the parietal bone of 14 New Zealand White rabbits. In the experimental group, 5 defects were grafted with Gusuibu extract mixed with absorbable collagen sponge, and 5 defects were grafted with autogenous endochondral bone. In the control groups, 5 defects were grafted with absorbable collagen sponge alone (active control) and 5 were left empty (passive control). Animals were killed on day 14 and the defects were dissected and prepared for histologic assessment. Serial sections were cut across each defect. Quantitative analysis of new bone formation was made on 150 sections using image analysis. RESULTS: A total of 24% and 90% more new bone were present in defects grafted with Gusuibu in collagen grafts than those grafted with bone and collagen, respectively. No bone was formed in the passive control group. CONCLUSIONS: Gusuibu in collagen grafts have the effect of increased new bone formation locally and can be used as a bone graft material.     

The three-dimensional cancellous bone architecture of the human mandibular condyle

In the present study, we tested the hypothesis that the cancellous bone of the mandibular condyle is inhomogeneous and anisotropic. For this purpose, 11 mandibular condyles from embalmed human cadavers were scanned in a micro-CT system. Within each condyle, 9 volumes of interest were selected from different mediolateral and supero-inferior regions. Several bone parameters were calculated to describe the morphology. It appeared that the cancellous bone of the condyle could be approximated by parallel plates. These plates were almost vertically oriented at an angle of 17 degrees relative to the sagittal plane, i.e., perpendicular to the condylar axis. In the superior regions of the condyle, the cancellous bone had the largest bone volume fraction (0.19), associated with the thickest trabeculae (0.11 mm), and the highest trabecular number (1.72 mm(-1)). The lowest bone volume fraction (0.15) was found more inferiorly. The degree of anisotropy increased from superior to inferior across the condyle. No mediolateral differences in bone morphology were found, but superiorly central regions contained more bone than peripheral regions. The plate-like trabeculae could indicate that the condyle is optimally adapted to sustain loads from all directions in a plane perpendicular to the condylar axis. The high bone mass and lower anisotropy in the superior regions could enable the condyle to sustain multiple load directions. Toward the collum, the trabeculae are more aligned. This could point to stresses acting predominantly in one direction.     

Effect of bone block graft with rhBMP-2 on vertical bone augmentation

The effectiveness of vertical bone augmentation was evaluated in the cranial bone of 15 rabbits using a block of deproteinized bovine bone plus 10% porcine collagen (DBBB) and a cortico-cancellous human bone block (CHBB) with recombinant human bone morphogenetic protein-2 (rhBMP-2) in comparison with a guided bone regeneration (GBR) technique. The rabbits were divided into six groups: DBBB alone, DBBB/rhBMP-2, DBBB/membrane, CHBB alone, CHBB/rhBMP-2 and CHBB/membrane groups. After 12 weeks, the rabbits were killed. The CHBB groups showed higher values than the DBBB groups in terms of vertical height, the area of new bone fill and the maintained grafted area. In the CHBB groups, the CHBB/rhBMP-2 group revealed similar results to GBR. This animal study verifies that a CHBB with rhBMP-2 could be an alternative treatment option for vertical bone augmentation.