Influence of a resorbable collagen membrane for alveolar bone graft on clinical outcomes and ridge volume stability in cleft alveolus

This study compared the clinical outcomes, graft quality, and graft quantity after alveolar bone grafting with and without a resorbable collagen membrane. Twenty unilateral cleft patients undergoing defect repair with cancellous iliac bone were assigned to either the collagen membrane group (Mb group) or standard group without a membrane (St group). Postoperative pain and swelling, bone density, and bone volume and quality were assessed. The Mb group showed significantly lower postoperative pain than the St group (P < 0.001) and significantly less swelling (P < 0.01) on day 3 postoperative. The reduction in bone density was significantly greater in the St group than in the Mb group at 1 and 3 months postoperative (P ≤ 0.001), but not at 6 months. The reduction in bone volume in the St group was significantly greater than that in the Mb group at 3 months (29.11 ± 6.26% vs 17.67 ± 11.89%, P = 0.016) and 6 months postoperative (40.95 ± 6.81% vs 25.67 ± 11.51%, P = 0.002). Nine cases in the Mb group versus six in the St group showed good bone quality. In conclusion, the collagen membrane facilitated predictable clinical outcomes in bone maturation, bone volume preservation, and bone bridging in the alveolar bone graft.     

块状异质植骨材料用于牙槽嵴骨增量的研究进展

各种原因所致的牙槽嵴骨量不足是口腔种植临床实践中亟需解决的问题之一。与自体骨相比,块状异质植骨材料因其独特的优势成为研究的热点。本文根据目前已经应用或有望应用于牙槽嵴骨增量领域的块状异质植骨材料的性能特点,分类讨论了无机陶瓷类材料、天然有机高分子材料及有机合成高分子材料的应用现状和最新研究进展,并对块状异质植骨材料的研究方向和前景进行了展望。     

钛网+膜联合使用修复种植体周围牙槽骨缺损的实验研究

目的 探讨联合使用钛网+Bio-Gide膜修复比格犬种植体周围牙槽骨缺损的效果。方法 选择3只成年比格犬,拔除双侧下颌P1-M1,牙槽窝愈合6个月。将3只比格犬（共6侧）随机分为3组,A组使用种植体+骨粉+钛网,B组使用种植体+骨粉+Bio-Gide膜,C组使用种植体+骨粉+钛网+Bio-Gide膜。每侧选取3个位点制备种植窝,在颊侧制作4 mm×4 mm×4 mm牙槽骨缺损,植入种植体并分别覆盖钛网或Bio-Gide膜。于术后6个月处死动物并取材,Micro-CT扫描并三维重建。使用SPSS17.0软件包对测量结果进行统计学分析。结果 Micro-CT扫描及三维重建结果显示,C组的骨小梁数目、骨小梁厚度、骨密度等数据显著高于另外两组（P<0.01）,骨小梁分散度显著低于另外两组（P<0.01）。结论 联合使用钛网+Bio-Gide膜,对比格犬种植体周围牙槽骨缺损的修复作用显著优于单纯使用钛网或Bio-Gide膜。     

Clinical outcomes of vertical bone augmentation to enable dental implant placement: a systematic review

Background: This review addressed the focused question of what is the predictability of vertical ridge augmentation techniques for patients, who were diagnosed with insufficient alveolar bone volume for the placement of dental implants.
Material and Methods: A systematic online review of three main databases was performed between 1966 and 1 November 2007. Four groups of vertical bone augmentation techniques have been identified and evaluated: (1) guided bone regeneration, (2) distraction osteogenesis, (3) onlay bone grafting, and (4) an array of different techniques. Data extraction was based on the following outcomes: (a) success and failure rate of the procedure (vertical bone gain/loss), (b) complication rate of the procedure, and (c) implant survival, success and failure rate.
Results: The initial search identified 189 papers from the electronic database. The review produced seven papers for GBR, 13 reporting distraction osteogenesis, five for onlay bone grafting and three describing different techniques.
Conclusions: For the concept of vertical ridge augmentation to enable dental implant placement, there are clinical and histological data supporting its potential use. Given the confined number of investigators using these techniques and the low number of patient treatments reported in the literature, the generalizability of this approach is limited at this time.     

应用齿贝骨粉及矿化胶原膜修复小型猪拔牙创骨缺损的效果观察

目的：比较 Bio-Oss骨粉和齿贝骨粉修复拔牙窝骨缺损的成骨效果,评估齿贝牙科骨粉在拔牙窝骨缺损修复中的可靠性。方法：以引导骨再生术（GBR）为基本原理,在小型猪拔牙区制造骨缺损,分别植入齿贝牙科骨粉及Bio-Oss骨粉。术后12周进行肉眼观察、影像学检查及组织学染色。影像学检查测量骨缺损的成骨密度,采用SPSS 22.0软件包进行配对t检验,观察骨缺损修复情况。分析组织切片中新生骨在骨缺损区域所占面积的百分比,得出新生骨百分率,比较2种不同材料骨粉修复拔牙窝骨缺损的效果。结果：术后12周,CT显示不同组的拔牙窝骨缺损完全被新生骨填充,2种骨粉修复骨缺损效果无显著差异。组织学切片显示,与Bio-Oss骨粉相比,齿贝骨粉填充骨缺损区成骨量略有减少,但两者差异不显著。结论：齿贝牙科骨粉在拔牙窝骨缺损修复中具有可靠性,有必要做进一步临床研究。     

上颌菲薄牙槽骨劈开同期人工牙种植的初步观察

目的：评价上颌菲薄牙槽骨在行骨劈开同时植入种植体及人工骨后的临床效果。方法：对9例上颌牙缺失、剩余牙槽骨宽度为3-4mm、高度大于12mm的病例，行骨劈开，植入29颗种植体，同时在缺隙处植入Bio—Oss骨粉。结果：术后6-8个月X线片检查种植体骨结合良好。行二期手术，重新暴露术区，发现牙槽嵴植骨区已矿化，27颗种植体牙槽嵴顶骨厚度5-6mm．种植体已形成骨结合。有2颗种植体唇／颊侧部分骨质菲薄如牛皮纸，需采用骨组织引导再生技术。所有病例修复后美学效果好。追踪12个月以上，无种植体失败。结论：牙槽骨劈开同期植入种植体。解决了上颌菲薄牙槽骨患者的种植修复难题，操作简单，效果良好。在严格控制适应证的前提下，可在临床推广应用。     

Validity of a regenerative procedure for a minor bone defect with immediate implant placement: a systematic review and meta-analysis

Objective: This systematic review evaluates implant survival and the change in the width of the horizontal ridge following immediate implant placement with or without a regenerative procedure.

Materials and methods: An electronic search of MEDLINE, EMBASE, and the LILACS database of the Cochrane Central Register of controlled trials was performed, along with a manual search, up to April 2018. Randomized controlled trials (RCTs) and quasi-randomized controlled clinical trials (CCTs) with >10 subjects were eligible for this systematic review. A meta-analysis of the risk difference in implant failure between the regenerative and non-regenerative procedure groups was performed using a fixed-effect model. In addition, a meta-analysis of the change in alveolar bone width was conducted using a fixed-effect model.

Results: Seven studies (six RCTs and one CCT) were included. A meta-analysis of three studies found no statistically significant risk difference in implant failure between the regenerative procedure and non-regenerative procedure groups. A meta-analysis of four studies showed that horizontal shrinkage of the alveolar ridge in the site of immediate implant placement was statistically significantly lower with the regenerative procedure than without it (<1 year follow up studies: weighted mean difference (WMD) 0.75?mm, 95% confidence interval 0.41–1.09, p?<?.00001; ≥1 year follow up study: WMD 1.22, 95% confidence interval 0.52–1.91, p?=?.00006; total: WMD 0.84?mm, 95% confidence interval 0.53–1.14, p?<?.00001).

Conclusion: Within the study limitations, immediate implant placement with a regenerative procedure showed similar implant survival and less shrinkage of the ridge width than immediate implant placement without a regenerative procedure. Due to the high risk of bias and small sample sizes of the included studies, further clinical studies are warranted to draw definitive conclusions.     

Clinical results of alveolar ridge augmentation with mandibular block bone grafts in partially edentulous patients prior to implant placement

A group of 15 partially edentulous patients who needed alveolar ridge augmentation for implant placement, were consecutively treated using a two-stage technique in an outpatient environment. A total of 18 alveolar segments were grafted. During the first operation bone blocks harvested from the mandibular ramus or symphysis were placed as lateral or vertical onlay grafts and fixed with titanium osteosynthesis screws after exposure of the deficient alveolar ridge. After 6 months of healing the flap was re-opened, the screws were removed and the implants placed. Twelve months after the first operation implant-supported fixed bridges could be provided to the patients. Mean lateral augmentation obtained at the time of bone grafting was 6.5 +/- 0.33 mm, that reduced during healing because of graft resorption to a mean of 5.0 +/- 0.23 mm. Mean vertical augmentation obtained in the 9 sites where it was needed was 3.4 +/- 0.66 mm at bone grafting and 2.2 +/- 0.66 mm at implant placement. Mean lateral and vertical augmentation decreased by 23.5% and 42%, respectively, during bone graft healing (before implant insertion). Mandibular sites showed a larger amount of bone graft resorption than maxillary sites. All the 40 implants placed were integrated at the abutment connection and after prosthetic loading (mean follow-up was 12 months). No major complications were recorded at donor or recipient sites. Soft tissue healing was uneventful, and pain and swelling were comparable to usual dentoalveolar procedures. A visible ecchymosis was present for 4 to 7 days when the bone was harvested from the mandibular symphysis. From a clinical point of view this procedure appears to be simple, safe and effective for treating localised alveolar ridge defects in partially edentulous patients.     

膜引导齿槽突裂骨缺损区组织再生的实验动物研究

目的 :评价膜引导齿槽突裂骨再生的效果。方法 :全麻下 ,分别在每组 2只兔双上颌形成人工齿槽突裂 ,随机作 :①聚乳酸 (PLA) 胶原 rhBMP 2膜覆盖 ;②PLA膜覆盖 ;③胶原膜覆盖 ;④空白对照。分别于术后 2周 ,1、2、3、6月处死动物切取标本 ,摄X线片 ,组织学观察 ,酶组化分析。结果 :膜覆盖骨裂 ,新生骨外形良好 ,骨改建成熟早 ,特别是PLA 胶原 rhBMP 2膜组 ,可持续控释rhBMP 2并提高骨缺损区浓度 ;空白对照组 ,生成骨质量、外形不良。结论 :引导组织再生膜具有促进齿槽突裂骨修复的作用。     

A clinical and histomorphometric study of calcium sulfate compared with freeze-dried bone allograft for alveolar ridge preservation

Background: Many materials have been found to be effective in ridge preservation. The purpose of this study is to determine whether calcium sulfate (CS) is as effective as freeze‐dried bone allograft (FDBA) in preserving postextraction ridge dimensions and to evaluate the amount of new bone formation and graft clearance through histologic analysis. Methods: Thirty‐one extraction sites were selected. Postextraction clinical measurements were made, and sites were divided randomly into the test group (CS) or the control group (FDBA). After graft placement, all individuals received the same postoperative treatment and instructions. Participants were recalled after 3 months, measurements were made, and sites were re‐entered. Bone samples were harvested and analyzed with histologic methodology for new bone formation and remaining residual graft. Results: Thirteen test and 15 control sites were evaluated. There was no significant change in vertical ridge height before or after surgery within the test and control groups (P = 0.57, P = 0.68, respectively). There was a significant decrease in bucco‐lingual ridge width for both groups (P = 0.0003, P = 0.0075, respectively), but the difference between groups was not significant (P = 0.11). Histologic analysis revealed an average of 32% new bone formation with 2.5% graft remaining for the test group and 16.7% new bone formation with 21% graft remaining for the control. Conclusions: Results indicate that CS is as effective as FDBA in preserving postextraction ridge dimensions in non‐molar extraction sites. There is greater clearance of CS with more new bone formation after ≈3 months compared with FDBA in these sites. This paper received the Maynard K. Hine Award for Excellence in Dental Research presented by the Indiana Section of the American Association for Dental Research and supported by Procter & Gamble.     

Horizontal alveolar ridge augmentation using autologous press fit bone cylinders and micro-lag-screw fixation: Technical note and initial experience

IntroductionThe use of autologous block bone grafts for horizontal alveolar ridge augmentation in dental implantology is a common surgical procedure. Typically, bone grafts are individually moulded.ObjectiveThe aim of this paper is to introduce an innovative procedure in lateral bone augmentation, where the recipient side is adjusted to the graft, not vice versa as in common procedures. Our initial clinical experience of twenty-five consecutive cases is presented.Materials and methodsAdjusted trephine drills were used to harvest partly cylindrical grafts from the retromolar region of the mandible. After preparing the recipient site with accurately fitting grinding drills, the bone grafts were transplanted.ResultsThe horizontally compromised alveolar ridges were successfully augmented and treated with dental implants. No major complication occurred during transplantation, the healing period, and subsequent implant therapy in our experimental setting with 25 patients and 38 augmentation procedures. One out of twenty-five patients presented with temporary dysaesthesia of the inferior alveolar nerve.ConclusionThe new method presented is an effective treatment option for horizontal alveolar ridge augmentation prior to single implant installation. Further studies should evaluate the donor site morbidity and long-term outcome on a larger population.     

Bioactivating a bone substitute accelerates graft incorporation in a murine model of vertical ridge augmentation

ObjectiveCompared to autologous bone grafts, allogeneic bone grafts integrate slowly, which can adversely affect clinical outcomes. Here, our goal was to understand the molecular mechanisms underlying graft incorporation, and then test clinically feasible methods to accelerate this process.MethodsWild-type and transgenic Wnt “reporter” mice were used in a vertical ridge augmentation procedure. The surgery consisted of tunneling procedure to elevate the maxillary edentulous ridge periosteum, followed by the insertion of bone graft. Micro-computed tomographic imaging, and molecular/cellular analyses were used to follow the bone graft over time. Sclerostin null mice, and mice carrying an activated form of β-catenin were evaluated to understand how elevated Wnt signaling impacted edentulous ridge height and based on these data, a biomimetic strategy was employed to combine bone graft particles with a formulation of recombinant WNT protein. Thereafter, the rate of graft incorporation was evaluated.ResultsTunneling activated osteoprogenitor cell proliferation from the periosteum. If graft particles were present, then osteoprogenitor cells attached to the matrix and gave rise to new bone that augmented edentulous ridge height. Graft particles alone did not stimulate osteoprogenitor cell proliferation. Based on the thicker edentulous ridges in mice with amplified Wnt signaling, a strategy was undertaken to load bone graft particles with WNT; this combination was sufficient to accelerate the initial step of graft incorporation.SignificanceLocal delivery of a WNT protein therapeutic has the potential to accelerate graft incorporation, and thus shorten the time to when the graft can support a dental implant.     

Simultaneous implant placement and vertical ridge augmentation with a titanium-reinforced membrane: a case report

The present report demonstrates a clinical approach to achieve vertical ridge augmentation around endosseous implants. Two implants were placed, leaving the threads exposed, in the atrophic mandibular right posterior quadrant of a male patient. Both implants were covered with a titanium-reinforced expanded polytetrafluoroethylene (e-PTFE) membrane. Second-stage surgery was performed 12 months after implant placement. Upon membrane removal, growth of mineralized tissue was observed around both implants, covering areas previously not covered by bone. Implants were then progressively loaded and restored. Titanium-reinforced e-PTFE membranes can be satisfactorily used for vertical augmentation of atrophic ridges.     

Localized maxillary ridge augmentation with a block allograft for dental implant placement: case reports

Autogenous block bone grafts have been highly successful in treating human periodontal defects, restoring esthetics, and developing adequate bone volume for dental implant placement. Limitations in available donor bone, the need for an added surgical procedure, and other potential complications have made the use of allogenic bone graft materials an important alternative. One patient described in this report presented with fractured root syndrome of the right maxillary incisor with severe resorption of the buccal plate. After atraumatic tooth extraction, a staged treatment approach involving localized ridge augmentation with an allogenic iliac bone block material and dental implant placement was used. The host bone completely incorporated the graft with only minor resorption, which enabled the implant to be placed. The allogenic bone block material used in this study was an effective alternative to harvesting and grafting autogenous bone for implant site development. The cases presented in this article clinically demonstrate the efficacy of using a block allograft in generating effective new bone fill for dental implant placement.     

Extensive augmentation of the alveolar ridge using autogenous calvarial split bone grafts for dental rehabilitation

Free autogenous iliac bone is the most commonly used graft material for an extensive alveolar ridge reconstruction. The application of iliac bone, however, is associated with problems, such as transplant loss resulting from postoperative infection and late bone resorption. A bone-graft material more suitable than iliac bone is therefore still needed. This paper describes a concept for alveolar-ridge reconstruction using calvarial split bone, and the related surgical techniques. Clinical and radiological follow-up examinations were undertaken to evaluate the potential benefit of calvarial split bone in alveolar-ridge reconstruction. Between 1999 and 2002, 13 patients with a mean age of 54 years (range 31-70 years) underwent surgery, seven patients in the maxilla and six in the mandible. In four cases, wound dehiscence occurred postoperatively. In one of these cases, the dehiscence was associated with a local infection. However, no bone transplants were lost. After a mean follow-up time of 19.6 months, bone resorption, measured radiologically, was minimal. Endosseous dental implants were successfully installed and maintained. Satisfactory prosthetic rehabilitation was achieved in all patients. Our preliminary experience suggests that calvarial split bone may be regarded as a promising alternative to autogenous iliac bone in connection with extensive augmentation of the alveolar ridge.     

Reconstructive periodontal therapy with simultaneous ridge augmentation. A clinical and histological case series report

Treatment of intrabony periodontal defects with a combination of a natural bone mineral (NBM) and guided tissue regeneration (GTR) has been shown to promote periodontal regeneration in intrabony defects. In certain clinical situations, the teeth presenting intrabony defects are located at close vicinity of the resorbed alveolar ridge. In these particular cases, it is of clinical interest to simultaneously reconstruct both the intrabony periodontal defect and the resorbed alveolar ridge, thus allowing insertion of endosseous dental implants. The aim of the present study was to present the clinical and histological results obtained with a new surgical technique designed to simultaneously reconstruct the intrabony defect and the adjacently located resorbed alveolar ridge. Eight patients with chronic advanced periodontitis displaying intrabony defects located in the close vicinity of resorbed alveolar ridges were consecutively enrolled in the study. After local anesthesia, mucoperiosteal flaps were raised, the granulation tissue removed, and the roots meticulously scaled and planed. A subepithelial connective tissue graft was harvested from the palate and sutured to the oral flap. The intrabony defect and the adjacent alveolar ridge were filled with a NBM and subsequently covered with a bioresorbable collagen membrane (GTR). At 11-20 months (mean, 13.9+/-3.9 months) after surgery, implants were placed, core biopsies retrieved, and histologically evaluated. Mean pocket depth reduction measured 3.8+/-1.7 mm and mean clinical attachment level gain 4.3+/-2.2 mm, respectively. Reentry revealed in all cases a complete fill of the intrabony component and a mean additional vertical hard tissue gain of 1.8+/-1.8 mm. The histologic evaluation indicated that most NBM particles were surrounded by bone. Mean new bone and mean graft area measured 17.8+/-2.8% and 32.1+/-8.3%, respectively. Within their limits, the present findings indicate that the described surgical approach may be successfully used in certain clinical cases to simultaneously treat intrabony defects and to reconstruct the resorbed alveolar ridge.