For which clinical indications in dental implantology is the use of bone substitute materials scientifically substantiated?

Purpose: The objective of this systematic review was to provide a basis for an expert consensus group to evaluate the influence of different particulate bone substitute materials in local bone augmentation procedures in conjunction with dental implant placement on implant survival and histology. Materials and methods: The following indications were analysed with either simultaneous or delayed dental implant placement: external or internal maxillary sinus floor elevation and vertical and/or lateral alveolar ridge augmentation. Retro- and prospective studies written in English or German including 20 or more patients (for randomised, controlled trials and prospective, split-mouth trials with 5 or more patients) were eligible for this review. The review focused on (1) performance of the augmentation procedures (total augmentation loss, gain of vertical and horizontal alveolar ridge dimensions, histomorphometric data of the augmented areas) and (2) dental implant success criteria (survival rates of the inserted dental implants, peri-implant bone levels under functional loading). Results: From over 3800 abstracts identified, 72 full-text articles fulfilled the inclusion criteria and were further evaluated (52 studies on maxillary sinus floor elevation procedures and 21 studies on vertical and/or lateral alveolar ridge augmentation). The majority of the included studies were prospective studies including a rather limited number of patients and short observation periods. Conclusions: There is a high level of evidence that survival rates of dental implants placed into augmented areas are comparable with survival rates of implants placed into pristine bone. For maxillary sinus floor elevation, all investigated bone substitute materials performed equally well compared with bone, with high dental implant survival rates and adequate histomorphometric data. For the alveolar ridge augmentation procedures, the heterogeneity of the available data did not allow identification of a superior grafting technique.     

Effects of leukocyte–platelet-rich fibrin (L-PRF) in different intraoral bone grafting procedures: a systematic review

This systematic review aimed to assess the effects of leukocyte–platelet-rich fibrin (L-PRF) on bone regeneration, soft tissue healing, and postoperative complications in patients undergoing ridge preservation, ridge augmentation, and maxillary sinus augmentation procedures. A comprehensive literature search was conducted by two independent reviewers. Only randomized and non-randomized controlled clinical trials were selected. Outcome data were extracted and critically analyzed. A total of 17 articles were included in the qualitative synthesis. The use of L-PRF in extraction sockets was associated with a modest beneficial effect by decreasing alveolar ridge remodeling and postoperative pain when compared to natural healing. In contrast, the use of L-PRF in maxillary sinus augmentation procedures was not associated with more favorable outcomes, and its use in ridge augmentation procedures could not be assessed adequately as it was reported in only one study. No meta-analysis could be conducted due to the heterogeneity of the selected studies. The limited evidence on the effects of L-PRF in intraoral bone grafting procedures highlights the need for further research to fully assess its clinical indications, with an emphasis on the application of standardized protocols for the preparation of this autologous product.     

Is autologous platelet concentrate beneficial for post-extraction socket healing? A systematic review

The aim of this systematic review was to assess if the use of autologous platelet concentrates may be beneficial to the healing of extraction sockets. Medline, Embase and Cochrane Central Register of Controlled Trials were searched using a combination of specific search terms. Hand searching of the relevant journals and of the bibliographies of reviews was also performed. Prospective comparative studies evaluating the effect of a platelet concentrate on fresh extraction sockets were included. Outcome variables related to hard and soft tissue healing, aesthetics and postoperative discomfort were considered. A methodological study quality assessment was made. The initial search yielded 425 articles, eight were finally included. 207 tooth extractions (104 tests and 103 controls) in 115 patients were evaluated. The articles provided a broad range of variable outcomes to assess the regenerative potential of platelet concentrate and its possible benefits to the treatment. Favourable effects on hard and soft tissue healing and postoperative discomfort reduction were often reported. A large heterogeneity was found regarding study design, sample size, surgical techniques and methods for preparing platelet concentrates. Standardization of experimental design is needed in order to detect the true effect of platelet concentrates in regenerative procedures of extraction sockets.     

Effect of platelet-rich plasma with autogenous bone graft for maxillary sinus augmentation in a rabbit model.

PURPOSE: To evaluate the effect of platelet-rich plasma (PRP) on autogenous bone graft remodeling during sinus augmentation in a rabbit model. MATERIALS: Twelve New Zealand White rabbits were divided randomly into 3 groups based on their time of sacrifice (2, 4, and 8 weeks). All animals underwent a general anesthetic and harvesting of an autogenous bone graft from the right iliac crest with subsequent bilateral maxillary sinus augmentation. PRP was prepared via standard approved technique by acquiring 21 cc of autogenous blood and performing differential centrifugation to obtain PRP. One cc of PRP was produced that was mixed with bovine topical thrombin and calcium chloride. The left maxillary sinus received only autogenous bone, while the right maxillary sinus received a mixture of PRP mixed with autogenous bone, thus each animal acted as its own control. Equal volumes of bone were inserted in each maxillary sinus. Animals were sacrificed at 2, 4, and 8 weeks and all specimens were harvested for peripheral quantitative computed tomography (pQ-CT), static, and dynamic and histomorphometric analysis. RESULTS: Student t tests were performed comparing bone density via pQ-CT analysis, histomorphometric parameters of total bone area, and bone apposition rate. PRP had no statistically significant effect on bone graft healing in maxillary sinus augmentation when compared using standard pQ-CT, static, and dynamic histologic criteria. CONCLUSION: This study fails to find a direct stimulatory effect of PRP on healing of autogenous bone grafts using pQ-CT, static, and dynamic histomorphometric analyses.     

Immediate loading of the grafted maxillary sinus using platelet rich plasma and autogenous bone: a preliminary study with histologic and histomorphometric analysis

OBJECTIVE: The goal of this clinical study was to evaluate dental implant survival rates using the concept of a nonfunctional, immediate loading protocol with nonsplinted dental implants in the grafted maxillary sinus during a 52-week period. Random histomorphological and histomorphometric analysis was completed to evaluate the early healing effect of platelet rich plasma (PRP) and 50% autogenous bone combined with 3 different substitute graft materials. MATERIALS: Four to 8 months after grafting the sinus with PRP sprayed autogenous bone combined with 3 different substitute graft materials in a 50:50 composite ratio, 27 hydroxyapatite- coated dental implants were surgically placed in 41 patients and immediately loaded between 48 hours and 5 days later with custom titanium abutments and acrylic provisional restorations placed out of functional occlusion. Six months later, definitive ceramometal restorations were cemented on to the custom abutments. RESULTS: During a 52-week observation period, no implants were lost. Between 4 and 8 months of graft healing time, histologic and histomorphometric analysis revealed formation of new vital bone in different graft specimens ranging from 77% to 100%. CONCLUSION: The preliminary results of this clinical study indicate that immediate nonfunctional loading using PRP and 50% autogenous bone combined with different substitute graft materials is a predictable protocol in the grafted maxillary sinus as early as 4 months of postgrafting. The high implant survival rate is due to the early formation of large percentages of new vital bone as confirmed by using histologic and histomorphometric analysis.     

Plasma rich in growth factors (PRGF) in intraoral bone grafting procedures: A systematic review

Purpose

This systematic review aimed at assessing the effects of PRGF in new bone formation, soft tissue healing and post-operative pain and swelling in sites that underwent ridge preservation, ridge augmentation and maxillary sinus augmentation procedures.

富血小板纤维蛋白在上颌窦提升术中应用研究进展

富血小板纤维蛋白（platelet rich fibrinogen,PRF）是具备多种功能的生物诱导基质,其被认为是一种安全、简单、高效、成骨效果可预期的材料。近年来,学者们将PRF应用于上颌窦提升术中,并开展了相关的基础与临床研究。然而,关于血小板来源的生长因子在上颌窦提升术中的作用,国内外学者的研究结果并未达成一致。文章在回顾相关文献的基础上,对PRF在上颌窦提升术中应用研究进展及应用现状做一综述。     

Maxillary sinus augmentation with autologous bone harvested from the lateral maxillary wall combined with bovine‐derived hydroxyapatite: clinical and histologic observations

Objective: The aim of this study was to determine the clinical efficacy of a mixture of autologous bone harvested from the lateral wall of the maxilla using bone shavers and bovine‐derived hydroxyapatite (HA) placed as a graft to elevate the maxillary sinus floor. The histological picture of tissue found in the sinus, the survival rate and the success of the implants were all evaluated. Material and methods: A total of 90 titanium implants were placed in 34 patients. In all of them, the lateral maxillary wall was harvested as a particulate bone graft, subsequently mixed with bovine‐derived HA and packed in the sinus cavity. The lateral access window was then covered with a bioresorbable porcine‐derived collagen membrane. In 32 sinuses, a two‐stage surgery was performed, while in the remaining 10 cases a one‐stage surgery was carried out. In the two‐stage approach, 14 randomly selected biopsies were obtained at the time of implant insertion after a healing period of 9 months. The histological specimens were histologically and histomorphometrically evaluated. Results: One implant was lost, leading to a survival rate of 98.9%. The new bone consisted of lamellae of living bone contained osteocytes and in close contact with bovine bone particles that were partly infiltrated by newly formed bone. Bovine bone particle resorption could not be found. The histomorphometric analysis showed the following averages: 29% of newly formed bone and 21% of anorganic bovine bone. The marrow spaces made up the remaining 50% of the specimens. Conclusion: Sinus lift graft with autologous bone harvested from the maxillary lateral wall combined with demineralized bovine bone leads to a predictable outcome regarding the amount of bone formation in sinus floor augmentation. To cite this article:
de Vicente JC, Hernández‐Vallejo G, Braña‐Abascal P, Peña I. Maxillary sinus augmentation with autologous bone harvested from the lateral maxillary wall combined with bovine‐derived hydroxyapatite: clinical and histologic observations.
Clin. Oral Impl. Res. 21 , 2010; 430–438
doi: 10.1111/j.1600‐0501.2009.01877.x     

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??Platelet-rich fibrinogen??PRF??is considered to be a safe??simple??efficient and predictable graft biomaterial with multiple functions. In recent years??studies concerning the application of PRF in maxillary sinus augmentation have been conducted. However??there is still no consensus on the effect of platelet-derived growth factor on maxillary sinus elevation. Our article is a review regarding the clinical application and research advancement of maxillary sinus lift with PRF.     

Bio-Oss骨粉在上颌窦提升牙种植术中的临床应用

目的：评价上颌窦提升，植Bio-Oss骨粉在上颌后牙种植的方法和效果。方法：对11例牙槽骨高度不足的上颌后牙种植进行上颌窦提升，植Bio-Oss骨粉，同期种植7例，延期种植4例。结果：6个月后，X线片显示Bio-Oss骨粉改建形成了新骨，增加了牙槽骨高度，满足了种植要求，7例同期种植可见种植体与Bio-Oss诱导的新骨形成紧密的骨性结合，种植体植入9个月后进行二期修复。结论：Bio-Oss骨粉植入提升上颌窦增加了上颌后牙区的牙槽骨高度，拓展了种植的适应证，免疫除了自体取骨手术，方法简单，值得临床推广。     

Histomorphometric Analysis of Human Maxillary Sinus Lift with a New Bone Substitute Biocomposite: A Preliminary Report

Purpose: To analyze radiographic and histological outcomes of maxillary sinus floor augmentation using a calcium-sulfate based allograft containing demineralized bone matrix particles.
Materials and Methods: Fifteen maxillary sinus lift procedures with simultaneous placement of titanium implants were performed in 12 patients of both genders aged 36–71 years. Each sinus cavity was filled by the biocomposite. After 3 months of healing, all surgical sites were uncovered and bone biopsies were retrieved for undecalcified histology and histomorphometry. The ratio between the original and the grafted sinus height (GSH/OSH) was computed using a panoramic radiography taken immediately after surgery and at 3 months of healing, and the two ratios were compared by Wilcoxon signed-rank test.
Results: By 3 months, all implants were stable without clinical and radiographic signs of infection. Significant changes in GSH/OSH during healing were seen (2.7 ± 0.6 initially vs. 2.6 ± 0.5 after healing; p  = 0.01). Histologic findings showed newly formed bone surrounding the residual grafted particles without inflammation. At 3 months, mean regenerated bone density was 33.8 ± 8.6%; marrow spaces amounted to 32.3 ± 10.3%; residual graft was 33.9 ± 9.0%. Similar histomorphometric and radiographic results were obtained independently from patient age or sex.
Conclusions: The analysed putty seems to be a safe and effective graft material for maxillary sinus floor augmentation by accelerating bone regeneration and thus reducing the healing time.     

Effect of platelet-rich plasma on sinus lifting: a randomized-controlled clinical trial

Objective: The combination of anorganic bovine bone (ABB) with platelet‐rich plasma (PRP) has been widely used in bone regeneration procedures although its benefits are still unclear. The purpose of this study was to evaluate whether or not PRP improves the efficacy of ABB in sinus floor augmentation. In addition, we have investigated the effect of residual bone height and tobacco on implant survival in sinus augmentation procedures. Patient and Methods: Eighty‐seven patients recruited for this study underwent 144 sinus floor augmentation procedures using ABB alone or ABB plus PRP (ABB+PRP) in a randomized clinical trial. A total of 286 implants were placed in the augmented bone, and their evolution was followed up for a period of 24 months. In order to investigate on a histological level and any adjunctive effects, we performed an ancillary study in five edentulous patients with a symmetrical severely resorbed maxilla. In these patients, a bilateral sinus augmentation was randomly performed using ABB or ABB+PRP in a split‐mouth design, and after 6 months, bone biopsies were taken from the implant sites for histological and histomorphometric analysis. Results: Overall, 96.2% of ABB and 98.6% of ABB+PRP implant success were obtained during the monitoring period and differences were not found between sites grafted with and without PRP in the 87 patients studied. Densitometry assessments and graft resorption were similar in both experimental groups. However, the histological and histomorphometrical analysis in the five edentulous patients revealed that bone augmentation was significantly higher in sites treated with ABB+PRP (p0.05). Another outcome from our study is that the lack of initial bone support (p0.05) and smoking (p=0.05) appeared to have a negative effect on the treatment success, which was accentuated when both circumstances coincided. Conclusions: PRP is not a determining factor for implant survival in sinus lifting procedures. However, this study revealed that PRP can improve the osteoconductive properties of ABB by increasing the volume of new bone formed. Moreover, in sinus augmentation procedures the implant's survival rate appears to be more influenced by the residual bone height or by tobacco than by the type of bone graft.     

The prevalence of surgical complications of the sinus graft procedure and their impact on implant survival

BACKGROUND: Grafting of the maxillary sinus floor has been performed successfully over the last decade. The ultimate goal of this procedure is to allow surviving implants to support a functional prosthesis. Surgical complications of the procedure are rarely reported and their impact on implant survival has been investigated even to a lesser extent. The purpose of this study was to evaluate the prevalence of surgical complications of the sinus graft procedure and their impact on implant survival. METHODS: The study consisted of 70 patients who underwent 81 sinus graft procedures using the lateral wall approach from 1995 to 2000. A total of 212 screw-shaped implants were placed in the grafted sinuses and were restored by fixed prosthesis. Mean follow-up period for the implants was 43.6 months. Intra- and postoperative complications were thoroughly documented regarding clinical signs, times of occurrence, and treatment regimens. RESULTS: Perforation of the Schneiderian membrane was the major intraoperative complication, observed in 36 of the 81 sinuses (44%). Of the 70 patients, seven (10%) suffered from postoperative complications, specifically related to the sinus graft procedure, which included an uncommon cyst formation and an infection. Membrane perforations were strongly associated with the appearance of postoperative complications (specific and non-specific to the procedure) (P < 0.001). However, no association was found between membrane perforations or postoperative complications and implant survival. CONCLUSIONS: Intraoperative complications may lead to postoperative complications. Surgical complications did not significantly influence implant survival.     

上颌窦内提升术植骨与不植骨对种植体骨结合的影响

目的探讨上颌窦内提升术植骨与不植骨对种植体骨整合的影响及两者之间的差异。方法将120枚需要进行内提升手术的种植体随机平均分为两组,第一组60枚为实验组,在上颌窦内提升后植入骨材料同期植入种植体;第二组60枚为对照组,上颌窦内提升后不植骨同期植入种植体。对两组种植体进行临床追踪（平均18个月）,观察种植体骨整合、临床检查指标、种植体存留率及影像学变化。结果仅有1例种植体覆盖螺丝暴露,种植体颈部出现骨吸收。所有两组种植体均能完成修复,种植体存留率达到100%,无1例脱落。种植体均能正常行使咀嚼功能,骨整合良好。影像学检查种植体周围均有新骨生长,骨整合良好。结论上颌窦内提升术后不植骨可以取得与植骨同样的效果,可以明显减少患者的种植牙费用,是一种值得推广应用的手术方法。     

Mesenchymal stem cells and platelet-rich plasma enhance bone formation in sinus grafting: a histomorphometric study in minipigs

Objectives: Autologous, allogenic, and alloplastic materials for sinus augmentation have specific drawbacks, which has stimulated an ongoing search for new materials and tissue‐engineering constructs. We investigated whether mesenchymal stem cells (MSCs) and platelet‐rich plasma (PRP) seeded on a fluorohydroxyapatite (FH) scaffold can improve bone formation and bone‐to‐implant contact (BIC) in maxillary sinus grafting. Material and Methods: Bilateral sinus augmentation procedures were performed in eight minipigs. MSCs, PRP, and FH scaffold (test site) or FH alone (control site) were grafted in each maxillary sinus. Distal to the osteotomy, one dental implant per sinus was placed in the grafting material through the facial sinus wall. The animals were killed 3 months after grafting, and block sections of the implant sites were harvested and prepared for histomorphometric analysis. Results: After 12 weeks, a significant increase in bone formation occurred in the test sites compared with the control sites (42.51%versus 18.98%; p=0.001). In addition, BIC was significantly greater in the test sites compared with the control sites in the regenerated area (23.71%versus 6.63%; p=0.028). Conclusions: These findings show that sinus augmentation with MSCs–PRP, combined with FH may enhance bone formation and osseointegration of dental implants compared with FH alone in minipigs.     

Maxillary sinus augmentation with platelet-rich plasma and fibrinogen cryoprecipitate: a tomographic pilot study

The purpose of this study was to evaluate the clinical efficacy of platelet-rich plasma, autologous bone, and autologous fibrinogen as cryoprecipitate in maxillary sinus augmentation procedures. Six patients (age range, 29-58) undergoing sinus augmentation procedures were included in the study. Platelet-rich plasma and autologous fibrinogen in the form of cryoprecipitate were prepared from 300 ml of blood. Sinus augmentation was performed with intraoral bone grafts, platelet-rich plasma, and cryoprecipitate. The amount of regeneration was then evaluated quantitatively and qualitatively with Spiral TC (Dentascan) pre- and postoperatively 6 months after the intervention. Orthopantomography was performed preoperatively 3 and 6 months after the surgery. A mean platelet concentration of 320.5% was obtained from the baseline platelet blood count. The tomographic analysis indicated an average bone augmentation of 6.27 mm (range, 3.5-10 mm). Radiologically, a satisfactory morphological recovery of the maxillary jaw was obtained. No graft resorption was noticed. Orthopantomography indicated mineralization as early as 3 months postoperatively in the entire study population. This technique appeared to be safe and effective. Our preliminary results encourage the clinical use of platelet-rich plasma associated with cryoprecipitate.     

Maxillary sinus floor elevation and grafting with deproteinized bovine bone mineral: a clinical and histomorphometric study

Objectives: This study evaluated the histomorphometric and clinical outcomes of maxillary sinus floor elevation using deproteinized bovine bone mineral (DBBM). Material and methods: Maxillary sinuses with a residual vertical height of <5 mm were augmented with DBBM alone before implant placement 9 months later. At the time of implant surgery, trephine samples were removed and histological and histomorphometric analyses were performed to examine the percentage of bone and residual graft using point counting and software‐aided analysis. Patients were recalled for clinical and radiographic examination up to 3 years later. Results: Twenty‐five patient specimens were analysed. The percentages of regenerated bone and residual graft material were 19% and 40%, respectively. Software‐aided analysis was comparable to point counting. Twelve patients attended for clinical follow‐up. Implants placed into this regenerated bone exhibited success and survival rates of 100% after an average follow‐up of 3 years. The average vertical height gained was 7.9 mm. Conclusions: The use of DBBM alone in maxillary sinus floor elevation is a predictable method to gain vertical bone height in the posterior maxilla. To cite this article :
Lee DZ, Chen ST, Darby IB. Maxillary sinus floor elevation and grafting with deproteinized bovine bone mineral: a clinical and histomorphometric study.
Clin. Oral Impl. Res. 23 , 2012; 918–924
doi: 10.1111/j.1600‐0501.2011.02239.x     

上颌窦侧壁开窗提升术中应用CGF的骨增量影像学评价与临床对照研究

目的:探讨CGF在上颌窦底侧壁开窗提升术中的临床疗效和在Minics软件三维重建介导下的影像学变化.方法:收集因上颌后牙区骨量不足(<5 mm)拟行上颌窦侧壁开窗提升术的患者20例分为2组:实验组10例(CGF联合骨替代材料组)和对照组10例(仅使用骨替代材料组).本研究为临床对照研究,通过Minics 19.0软件三...     

Maxillary sinus augmentation with deproteinated bovine bone and platelet rich plasma with simultaneous insertion of endosseous implants.

PURPOSE: To investigate the clinical applicability of using deproteinated bovine bone mixed with autologous platelet rich plasma (PRP) in human maxillary sinus augmentations in severely resorbed posterior maxillary alveolar processes with simultaneous insertion of endosseous dental implants. MATERIALS AND METHODS: Fifteen patients with less than 5 mm of residual alveolar bone height in the posterior maxillary alveolus underwent a total of 24 maxillary sinus augmentations. Seventy endosseous implants were inserted simultaneously in the grafted sinuses. The implants were uncovered and loaded 4 months after insertion and the sinus augmentation. An osseous biopsy specimen was obtained from the augmented maxillary sinus in 1 patient. In 3 patients, computed tomography scans of the grafted maxillae were obtained and the bone density quantified and compared with native bone density using SIMPlant 7 (Columbia Scientific, Columbia, MD) software 4 months postoperatively. RESULTS: Although a total of 5 implants in 4 patients were lost, this did not result in the loss of any of the restorations, for an overall success rate of 92.9 %. Follow-up for patients in this study after insertion of the permanent restoration was between 6 and 36 months. The bone biopsy from the patients showed evidence of viable new bone formation in close approximation to the xenograft. The bone density of the grafted bone was similar or exceeded the bone density of the surrounding native maxillary bone. CONCLUSION: Based on our clinical experience, we believe that the use of platelet rich plasma in combination with deproteinated bovine bone is effective for maxillary sinus augmentation with simultaneous insertion of endosseous dental implants in severely resorbed posterior maxillae.     

A clinical study of the outcomes and complications associated with maxillary sinus augmentation

PURPOSE: The aim of this study was to evaluate the rate of complications in maxillary sinus augmentation surgery and the impact of complications on subsequent implant treatment in a patient population with severe maxillary atrophy scheduled for treatment under general anesthesia. MATERIALS AND METHODS: The study population consisted of 70 patients (124 sinuses) with severe maxillary atrophy who underwent maxillary sinus augmentation. Sixteen patients were scheduled to have a unilateral procedure and 54 patients a bilateral procedure. Sinus augmentation was performed with autogenous bone alone in 93 sinuses; in 31 sinuses, a 1:1 mixture of autogenous bone and corticocancellous pig bone particles was used. Twenty-six of 124 procedures involved both sinus augmentation and autogenous block grafting for the treatment of severely atrophic maxillae. RESULTS: The most common intraoperative complication was the perforation of the sinus membrane, which was observed in 31 sinuses (25%). Seven (5.6%) sinuses in 7 patients exhibited suppuration of the maxillary sinus. Five of the 7 patients with sinus infection were smokers, showing a prevalence of complications significantly greater in smokers compared to nonsmokers. Moreover, the use of an onlay bone graft in conjunction with sinus augmentation appeared to significantly increase the rate of infective complications. Infections were treated by drainage and the administration of systemic antibiotics. Two clinical cases showing persistent signs of infection required an endoscopic inspection of the maxillary sinus. DISCUSSION AND CONCLUSION: In the present study sinus membrane perforation was not shown to be a significant factor in the rate of implant complications. However, the combination of smoking and onlay bone grafting could significantly increase the rate of postoperative infection following sinus grafting.