Design,fabrication,and structural safety validation of 3D-printable biporous bone augments

The use of commercial products such as a cup and liner for total hip arthroplasty for patients with severe bone defects has a high probability of failure.In these patients the cup alone cannot cover the bone defect,and thus,an additional augment or cage is required.In this study,we designed three-dimensional(3D)printable bone augments as an alternative to surgeries using reinforcement cages.Thirty-five sharp-edged bone augments of various sizes were 3D printed.A biporous structure was designed to reduce the weight of the augment and to facilitate bone ingrowth.Two types of frames were used to prevent damage to the augment’s porous structure and maintain its stability during printing.Furthermore,two types of holes were provided for easy augment fixation at various angles.Fatigue tests were performed on a combination of worst-case sizes derived using finite element analysis.The test results confirmed the structural stability of the specimens at a load of 5340 N.Although the porosity of the specimens was measured to be 63.70%,it cannot be said that the porous nature was uniformly distributed because porosity tests were performed locally and randomly.In summary,3D-printable biporous bone augments capable of bonding from various angles and bidirectionally through angulation and bottom-plane screw holes are proposed.The mechanical results with bone augments indicate good structural safety in patients.However,further research is necessary to study the clinical applications of the proposed bone augment.

The Use of Cortical Bone Wedges from the Mandibular Ramus “Wedge Technique”: For 3-Dimensional Bone Augmentation of the Atrophic Ridges. Technique Presentation and Report of Case Series

Purpose: Autogenous bone was still considered as the gold standard in bone augmentations prior to implants insertion at the atrophic ridges. However if large bone grafts are needed to augment multiple edentulous atrophic segments, extraoral donor sites may be mandatory. The aim of this report is to introduce the Fares Wedge Technique, as a new bone augmentation method that can augment multiple edentulous ridges with intraoral cortical bone grafts. Methods: This report includes patients with moderate to severe ridge atrophy in different regions of the both jaws who were treated over 6-years period (2009-215) with wedge Technique (WT). Patients received panorex immediately after the surgery, and they were examined clinically and radiographically (periapical) every 2 weeks. At 4 months, computed tomography was performed to evaluate the bone gain. Reentry was performed after 4 to 5 months to evaluate the new bone volume and quality and to insert implants. At this stage specimens for histologic examination were also obtained. Results: 39 augmentation sites in 22 patients (15 women, 7 men: mean age 47 years) were followed 12 to 52 months. The healing process was uneventful, with minimal morbidity. The success rate was 95%, and the bone gain average was 3 - 6 mm vertically and 3 - 9 mm horizontally. In two patients the graft was partially exposed and treated with shaving and rounding the exposed wedges, but the augmentations were saved. In one case the majority of the bone graft was lost. At 38 sites the patients had successfully received 114 implants. Conclusions: wedge technique can augment multiple segments of atrophic ridges with small amount of autogenic graft. The bone volume that achieved was satisfying, especially that the majority of the augmented areas were at posterior mandibular defects.

Bone block from lateral window-correcting vertical and horizontal bone deficiency in maxilla posterior site:A case report

BACKGROUND Lateral window approach for sinus floor lift is commonly used for vertical bone augmentation in cases when the residual bone height is less than 5 mm.However,managing cases becomes more challenging when a maxillary sinus pseudocyst is present or when there is insufficient bone width.In this case,we utilized the bone window prepared during the lateral window sinus lift as a shell for horizontal bone augmentation.This allowed for simultaneous horizontal and vertical bone augmentation immediately after the removal of the maxillary sinus pseudocyst.CASE SUMMARY A 28-year-old female presented to our clinic with the chief complaint of missing upper left posterior teeth.Intraoral examination showed a horizontal deficiency of the alveolar ridge contour.The height of the alveolar bone was approximately 3.6 mm on cone beam computed tomography(CBCT).And a typical well-defined'dome-shaped'lesion in maxillary sinus was observed on CBCT imaging.The lateral bony window was prepared using a piezo-ultrasonic device,then the bony window was fixed to the buccal side of the 26 alveolar ridge using a titanium screw with a length of 10 mm and a diameter of 1.5 mm.The space between the bony window and the alveolar ridge was filled with Bio-Oss,covered with a Bio-Gide collagen membrane,and subsequently sutured.Nine months later,the patient’s bone width increased from 4.8 to 10.5 mm,and the bone height increased from 3.6 to 15.6 mm.Subsequently,a Straumann^(■)4.1 mm×10 mm implant was placed.The final all-ceramic crown restoration was completed four months later,and both clinical and radiographic examinations showed that the implant was successful,and the patient was satisfied with the results.CONCLUSION The bone block harvested from the lateral window sinus lift can be used for simultaneous horizontal bone augmentation acting as a shell for good two-dimensional bone augmentation.

3D-printed bioactive ceramic scaffolds with biomimetic micro/nano-HAp surfaces mediated cell fate and promoted bone augmentation of the bone-implant interface in vivo

Calcium phosphate bio-ceramics are osteo-conductive,but it remains a challenge to promote the induction of bone augmentation and capillary formation.The surface micro/nano-topography of materials can be recognized by cells and then the cell fate are mediated.Traditional regulation methods of carving surface structures on bio-ceramics employ mineral reagents and organic additives,which might introduce impurity phases and affect the biological results.In a previous study,a facile and novel method was utilized with ultrapure water as the unique reagent for hydrothermal treatment,and a uniform hydroxyapatite(HAp)surface layer was constructed on composite ceramics(β-TCP/CaSiO_(3))in situ.Further combined with 3D printing technology,biomimetic hierarchical structure scaffolds were fabricated with interconnected porous composite ceramic scaffolds as the architecture and micro/nano-rod hybrid HAp as the surface layer.The obtained HAp surface layer favoured cell adhesion,alleviated the cytotoxicity of precursor scaffolds,and upregulated the cellular differentiation of mBMSCs and gene expression of HUVECs in vitro.In vivo studies showed that capillary formation,bone augmentation and new bone matrix formation were upregulated after the HAp surface layer was obtained,and the results confirmed that the fabricated biomimetic hierarchical structure scaffold could be an effective candidate for bone regeneration.

Gene-activated matrix harboring a miR20a-expressing plasmid promotes rat cranial bone augmentation

Gene-activated matrix(GAM)has a potential usefulness in bone engineering as an alternate strategy for the lasting release of osteogenic proteins but efficient methods to generate non-viral GAM remain to be established.In this study,we investigated whether an atelocollagen-based GAM containing naked-plasmid(p)DNAs encoding microRNA(miR)20a,which may promote osteogenesis in vivo via multiple pathways associated with the osteogenic differentiation of mesenchymal stem/progenitor cells(MSCs),facilitates rat cranial bone augmentation.First,we confirmed the osteoblastic differentiation functions of generated pDNA encoding miR20a(pmiR20a)in vitro,and its transfection regulated the expression of several of target genes,such as Bambi1 and PPARc,in rat bone marrow MSCs and induced the increased expression of BMP4.Then,when GAMs fabricated by mixing 100 ll of 2%bovine atelocollagen,20mg b-TCP granules and 0.5mg(3.3 lg/ll)AcGFP plasmid-vectors encoding miR20a were transplanted to rat cranial bone surface,the promoted vertical bone augmentation was clearly recognized up to 8 weeks after transplantation,as were upregulation of VEGFs and BMP4 expressions at the early stages of transplantation.Thus,GAM-based miR delivery may provide an alternative non-viral approach by improving transgene efficacy via a small sequence that can regulate the multiple pathways.

Treatment of Bone Defect with Modular Metal Augmentation Using a Downsized Block in Total Knee Arthroplasty: Technical Note and Report of 17 Cases

In total knee arthroplasty (TKA), a treatment of bone defect varies depending on the location and extent of defect and requires proper surgical procedure. Metal augmentation is readily available for both femoral and tibial bone defects. We report the operative technique of modular metal augmentation using a downsized block for ambiguous proximal tibial and distal femoral bone defects in primary and revision TKA. Regarding bone defects, bone loss can be minimized by using a different size of metal augmentation, and suitable reinforcement for bone defects can be achieved. Once our technique is properly used, it will be very helpful in treating bone defects.

骨增量材料中血管新生性能的作用及认识

骨增量是种植治疗中解决骨量不足状况的必要手段,骨增量成功的关键之一是植入的骨增量材料应能发生血管新生,形成与宿主组织有效血氧交换的网络。本文就骨增量材料的血管新生作用研究进展进行阐述,为促进骨增量材料的研发及其临床转化提供建议和参考。

口腔种植骨增量中的减张技术

临床上,种植位点骨量不足是种植治疗中常遇到的难题。为确保种植区符合种植条件,骨增量手术尤为重要。而骨增量手术成功的关键要素之一是创口无张力的一期愈合。减张技术是获得创口无张力愈合的关键。本文将从减张切口、减张瓣及减张缝合3个方面介绍口腔种植骨增量中的减张技术,以期为临床提供参考。

数字化技术在口腔种植骨增量中的应用及研究进展

种植区牙槽骨骨量不足是影响口腔种植效果的重要因素,骨增量是解决这一问题的有效途径。数字化技术的应用为口腔种植骨增量提供了新手段。本文就数字化技术在口腔种植骨增量中的应用和研究进展进行简要阐述。

“改良”上颌窦底提升

上颌后牙缺失时,由于缺乏牙的功能性刺激以及上颌窦气化作用导致种植所需的剩余骨高度不足,剩余骨量无法保证种植体的初始稳定性时,需要采取上颌窦底提升增加上颌后牙区骨量。“改良”上颌窦底内提升是通过使用富血小板纤维蛋白(platelet-rich fibrin,PRF),在内镜(endoscope)辅助下实现同期植入种植体(simultaneous implants placement)的一种改良的、微创的牙槽嵴入路上颌窦底提升(sinus floor elevation),简称“PESS”。“PESS”在一定程度上优化了上颌窦底提升,减小了手术创伤。本文阐述了“PESS”的原理、适应证、临床操作流程及注意事项,以期为“PESS”在临床中的应用提供技术支持。

生物材料在上颌窦内提升术中的临床应用进展

上颌后牙区常因缺牙后牙槽骨吸收或上颌窦气化导致剩余骨量不足,造成种植修复困难,上颌窦内提升术作为其解决方案之一也在一定程度上受到骨量限制。随着材料学的发展,包括自体骨、同种异体骨、异种骨、合成骨移植材料等骨增量材料以及血小板浓缩物等骨移植辅助材料在医学领域逐渐广泛应用,上颌窦内提升术的适应证得到进一步扩大。将两种或几种材料复合使用或研发复合型材料以实现多种材料性能的互补可能是未来的发展趋势,既能兼顾各种材料的特点,达到更好的成骨效果,还能缩短成骨时间。

黏性骨在口腔临床治疗中的应用研究进展

在口腔医学领域中,黏性骨(sticky bone)一般指由第二代血浆基质制品可注射型富血小板纤维蛋白(injectable platelet rich fibrin,i-PRF)与一定质量的骨增量材料(bone grafting materials)混合制备而成的凝胶团块状骨移植物。黏性骨既富含血浆基质所提供的生长因子和纤维蛋白支架等组织再生所需基本要素,又具备一定的可塑性,在骨增量、上颌窦底提升和牙槽嵴保存等临床治疗中有着广阔的应用前景。本文总结临床经验和相关研究,对黏性骨的基本情况和目前在临床治疗中应用作一介绍,以期为后续研究提供参考。

下颌舌侧减张技术在骨增量中的应用研究进展

骨增量技术是解决种植位点牙槽嵴高度和宽度不足的有效方法,术区稳定无张力一期愈合是保证复杂骨增量手术成功的关键。下颌舌侧减张技术近年来逐渐在临床应用,在颊侧减张的基础上该技术能进一步降低组织瓣张力,维护术区稳定性,提升手术成功率。本文就下颌舌侧重要解剖结构、常用减张器械及下颌舌侧减张术式的临床应用作一综述。

牙槽骨重度缺损的前牙拔牙窝不翻瓣骨增量位点重建后种植修复病例报告1例

本病例报告了1例牙槽骨重度缺损的前牙拔除后采用牙槽窝不翻瓣骨增量的改良拔牙位点保存与重建技术,9个月后行种植手术,期间应用种植体支持的临时修复体行牙龈塑形,完成最终修复后取得了良好的美学效果,随访期功能稳定。本病例的诊疗过程及效果提示,这种改良的不翻瓣拔牙位点保存技术是可行的,但远期效果仍需进一步观察。

钛网植骨联合上颌窦底提升术改善上颌磨牙区严重骨缺损病例1例

目的面对上颌磨牙区偏离牙弓曲线水平向严重缺损伴骨高度不足,本病例尝试选用钛网作为支架,联合上颌窦底提升术实现局部区域的水平向和垂直向骨增量。方法患者术前CBCT显示,26牙位处剩余骨宽度约3.3 mm,高度约4.9 mm,27牙位处剩余骨宽度约5.2 mm,高度约5.1 mm。病例治疗采用了钛网维持颊侧水平向成骨空间,采集自体骨混合人工骨植骨,并应用富血小板纤维蛋白,同时联合侧壁开窗上颌窦底提升术改善垂直向骨量。结果术后5个月,取出钛网,CBCT显示,26牙位处较术前骨宽度增加了2.0 mm,高度增加了3.2 mm;27牙位处较术前骨宽度增加了1.2 mm,高度增加了4.0 mm,获得了理想的骨增量效果。术后6个月,进行经牙槽嵴顶上颌窦底提升术和种植体植入术,种植体初期稳定性良好。术后1年,种植修复完成,CBCT显示,26牙位处较术前骨宽度增加了2.9 mm,高度增加了4.5 mm;27牙位处较术前骨宽度增加了0.9 mm,高度增加了6.6 mm,结果显示骨增量效果稳定,恢复了正常的咬合功能,并取得一定的美学效果改善。结论该病例结果表明,钛网植骨联合上颌窦底提升术可以获得较为充分稳定的骨增量效果,是一种可靠的用来改善上颌磨牙区骨量不足的方法。

双曲抛物面形态和传统近似牙槽嵴形态3D打印钛网的力学性能研究

目的探究双曲抛物面空间结构对个性化钛网的力学性能影响。方法使用3-Matic 15软件为牙槽嵴吸收患者的下颌骨三维模型进行虚拟骨增量,分别增量为双曲抛物面结构和近似牙槽嵴结构,并制作孔隙为圆形、三角形、四边形和六边形,厚度为0.2 mm、0.3 mm、0.4 mm的个性化钛网,构建有限元分析模型,施加力和约束,分析各组钛网的应力和位移。结果同一厚度下,不同孔隙结构的双曲抛物面钛网应力和位移均明显低于近似牙槽嵴形态的钛网;随厚度减小,各组钛网的应力和位移显著增加。结论双曲抛物面这一空间结构可以均匀的分散应力,减少个性化钛网的应力集中,减少钛网受力后的位移,使钛网兼具了良好的力学性能和较薄的厚度,降低了对软组织的刺激,减少钛网暴露的可能。

“以稳定为核心”的牙槽骨修复重建治疗新技术

经过40余年临床应用与不断发展,引导骨组织再生术(guided bone regeneration,GBR)已被证明是一种可靠的牙槽骨骨增量技术。GBR技术在应用过程中的核心要素是充足的血供和稳定的环境。但现有GBR技术都是在“以血供为核心”的理论体系下进行的,缺乏对稳定要素重要性的重视。我们通过文献阅读及系列临床试验,提出“以稳定为核心”的牙槽骨修复重建理念。基于新理念,创建了以单纯人工骨粉修复牙槽骨重度缺损的治疗新术式,革新了国际上必须用自体骨修复骨缺损的治疗理念。本文将从GBR技术的历史发展轨迹中寻找稳定的重要性,结合现有骨再生理论,详细阐述“以稳定为核心”的牙槽骨修复重建治疗新技术。

上颌窦底提升支架材料的临床应用现状

上颌窦底提升是解决上颌后牙区剩余牙槽嵴骨高度不足最常见的手术方法,应用支架材料能够有效维持上颌底提升空间的稳定性。本文从上颌窦底提升的生物学原理出发,简述了理想支架材料应具备的性能,着重对临床现有的上颌窦底提升支架材料的应用现状进行综述,最后对上颌窦底提升的支架材料应用进行了总结与展望。

施耐德膜增厚对穿牙槽嵴上颌窦底提升影响的研究进展

穿牙槽嵴上颌窦底提升是目前口腔种植临床公认的、微创可靠的上颌后牙区骨增量术式,但当上颌窦内存在施耐德膜增厚时,其治疗效果尚存不确定性。鉴于施耐德膜增厚是上颌窦内最常见的问题,明确其对穿牙槽嵴上颌窦底提升预后产生的影响具有重要临床意义。针对该临床问题,本文从正常施耐德膜特点、施耐德膜增厚表现及原因、施耐德膜增厚对穿牙槽嵴上颌窦底提升的影响3方面进行综述,以期为穿牙槽嵴上颌窦底提升的术前评估提供理论依据。

计算机辅助设计和计算机辅助制造预成个性化同种异体骨块在种植骨增量手术中的应用进展

计算机辅助设计和计算机辅助制造(CAD/CAM)成形技术可以预成与受区更匹配的目标骨块,目前常应用于复杂的牙槽嵴增量术,通过数字化设计生产个性化的同种异体骨块,避免了传统椅旁骨块成形的步骤,大大增加了临床操作效率,提高了移植物适应的精度,利于移植物的血管化和骨整合,在未来骨增量的临床应用中前景可期。因此,本文就CAD/CAM预成个性化同种异体骨块(CABB)在当前种植骨增量手术的应用现状进行综述,并进一步探讨其存在的问题和挑战。