Fresh-frozen Bone Research Articles

Fresh-frozen allogeneic bone blocks grafts for alveolar ridge augmentation: Biological and clinical aspects.

The possibilities for oral bone regeneration procedures vary depending on the type of bone defect to be treated, which in turn dictate the type of graft to be used. Atrophic alveolar ridges are non-contained defects and pose a challenging defect morphology for bone regeneration/augmentation. Successful results are regularly obtained with the use of particulate grafts in combination with barrier membranes. In cases of very narrow ridges with need of larger amount of bone augmentation, block grafts are often used. Fresh-frozen allogeneic bone block grafts have been proposed as an alternative to autogenous (AT) bone blocks. Based on a systematic appraisal of pre-clinical invivo studies and clinical trials including a direct comparison of fresh-frozen bone (FFB) blocks versus AT bone blocks it can be concluded that a FFB block graft: (a) cannot be considered as a reliable replacement of a AT bone block, and (b) should only be considered in cases where the amount of necessary augmentation-in a lateral direction-is relatively limited, so that the main portion of the body of the implant lies within the inner (i.e., the vital) aspect of the block.

Cost-effectiveness of decellularised bone allograft compared with fresh-frozen bone allograft for acetabular impaction bone grafting during a revision hip arthroplasty in the UK

ObjectivesFresh-frozen allograft is the gold-standard bone graft material used during revision hip arthroplasty. However, new technology has been developed to manufacture decellularised bone with potentially better graft incorporation. As these...

Comparing Fusion Rates Between Fresh-Frozen and Freeze-Dried Allografts in Anterior Cervical Discectomy and Fusion

ObjectiveThe objective of this retrospective study is to compare the fusion rates in anterior cervical discectomy and fusion surgery using freeze-dried versus fresh-frozen allografts.MethodsThe study comprised 79 patients. Fifty-one patients received freeze-dried allograft (106 total spinal levels) and 28 patients received fresh-frozen allograft (50 total spinal levels). Fusion was assessed through trabecular bridging on follow-up anterior-posterior/lateral radiographs. Trabecular bridging was assessed on the superior and inferior borders of each spinal level and given a fusion grade. Complete fusion is defined as >50% bridging between superior and inferior borders of the bone graft; union is complete fusion in <26 weeks; delayed union is complete fusion after 26 weeks; and fibrous union is <50% bridging at ≥1 borders over 52 weeks.ResultsAll spinal levels reached complete fusion for both graft types. Of the freeze-dried treated cervical spinal levels, 77.35% (82/106) reached union (adequate trabecular bridging within 6 months) without delay compared with 80% (35/50) for the fresh-frozen bone graft group (P = 0.85). There was no significant difference in time-to-fusion analysis and no significant association between delayed union and any patient factors. In assessing Neck Disability Index (NDI), freeze-dried allografts did show a significantly greater decrease in NDI scores at 6 months (P = 0.03). At the 1 year follow-up, improvements in NDI were consistent in both allografts (P = 0.9647).ConclusionsFrom this study, freeze-dried and fresh-frozen allografts showed comparable rates of union, and both allografts can be used interchangeably for anterior cervical discectomy and fusion.

High Spatial Resolution MALDI Imaging Mass Spectrometry of Fresh-Frozen Bone.

Bone and bone marrow are vital to mammalian structure, movement, and immunity. These tissues are also commonly subjected to molecular alterations giving rise to debilitating diseases like rheumatoid arthritis and osteomyelitis. Technologies such as matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) facilitate the discovery of spatially resolved chemical information in biological tissue samples to help elucidate the complex molecular processes underlying pathology. Traditionally, preparation of osseous tissue for MALDI IMS has been difficult due to its mineralized composition and heterogeneous morphology, and compensation for these challenges with decalcification and fixation protocols can remove or delocalize molecular species. Here, sample preparation methods were advanced to enable multimodal MALDI IMS of undecalcified, fresh-frozen murine femurs, allowing the distribution of endogenous lipids to be linked to tissue structures and cell types. Adhesive-bound bone sections were mounted onto conductive glass slides with microscopy-compatible glue and freeze-dried to minimize artificial bone marrow damage. High spatial resolution (10 μm) MALDI IMS was employed to characterize lipid distributions, and use of complementary microscopy modalities aided tissue and cell assignments. For example, various phosphatidylcholines localize to the bone marrow, adipose tissue, marrow adipose tissue, and muscle. Further, sphingomyelin(42:1) was abundant in megakaryocytes, whereas sphingomyelin(42:2) was diminished in this cell type. These data reflect the vast molecular and cellular heterogeneity indicative of the bone marrow and the soft tissue surrounding the femur. Multimodal MALDI IMS has the potential to advance bone-related biomedical research by offering deep molecular coverage with spatial relevance in a preserved native bone microenvironment.

Implant stability and new bone microarchitecture in atrophic maxillae reconstructed with allogenic grafts: A pilot trial

ObjectiveRehabilitation of atrophic maxilla with allografts could be sometimes challenging in the choice. The present pilot clinical trial aimed to compare the change in stability over time of implants placed in particulate demineralized freeze-dried bone (DFDBA) or fresh-frozen bone (FFB) allografts in the posterior maxilla and to examine the microarchitecture of new bone formation. MethodsHealthy adult patients of both genders underwent bilateral maxillary sinus lifts. Only patients that presented with maxillary sinus pneumatization and who on tomographic examination were determined to have a residual bone height of less than 7 mm were eligible for inclusion. Each side was randomly grafted with DFDBA or FFB. Six to nine months after grafting, at the time of dental implant installation bone core biopsies, 10 mm in length, were obtained using a 2 mm short trephine drill. The bone biopsies were fixed in buffered formalin and randomly and blindly submitted to microcomputed tomography and histomorphological analysis. Implant stability was measured using resonance frequency equipment at three time points: immediately, 6, and 12 months after dental implant installment. ResultsA total of 10 patients were finally included. An increased bone volume was observed tomographically for all allografted regions. Implants placed in FFB show a significant enhanced stability after six months. Specially after one-year implant stability was significantly greater in FFB than in DFDBA grafts. Microtomographic analyses revealed that bone morphometric parameters were similar between allografts. ConclusionBoth allogenic grafts can be used to successfully rehabilitate the atrophic maxilla for implant placement.

Sinus augmentation - autograft vs. fresh frozen allograft: Bone density dynamics and implant stability

ObjectivesCompare bone density changes and initial implant stability following sinus augmentation with autogenous bone (AB) vs. fresh frozen bone (FFB). Materials and methodsRandomized, prospective, split mouth study. Sinus augmentation executed using either AB or FFB. Dental implants were inserted after 6 months of healing. Implant dimensions and insertion torques were recorded. Prostheses were delivered 6 months thereafter. All patients had computerized tomography (CT) scans 1 week (T1) and 6 months (T2) after initial bone grafting. Third CT (T3) was taken 12 months after prosthesis delivery. Data from CT scans was used to analyze bone density at each period. ResultsA total of 15 patients (8 males, 7 females) following bilateral sinus augmentation procedures, were included. Mean age was 54 ± 5 years (range 48–60 years). All patients had 3 CT examinations. The initial augmented AB density was higher than the initial FFB density. Nevertheless, density differences between the two groups were not statistically significant at any time frame. At T2 density of both grafts showed a statistically significant increase. A significant increase from T2 to T3 was noted only for the FFB group. Implant insertion torque was significantly higher in the FFB group. Insertion torque ≥32 N/cm was achieved in significantly more patients in the FFB group. ConclusionThe use of FFB for sinus augmentation is a reliable option of graft material. The newly formed bone quality performance, evaluated by CBCT density, is as good as AB, allowing predictable initial implant stability and osseointegration. Unnecessary morbidity associated with AB harvesting is thus avoided.

Use of homologous bone for alveolar crest reconstruction in 483 patients with 5\xa0years\u2019 outcomes post implantation

PurposeThe purpose of this study was to evaluate the clinical course of bone reconstruction of the alveolar crest using homologous fresh-frozen bone harvested from deceased donors.MethodsA retrospective survey was based on the Castelfranco Veneto Hospital database, in which 3264 clinical records with a primary or secondary diagnosis of alveolar atrophy were collected over a 10-year period. A random sample of 483 patients with at least 5 years’ follow-up was included in the survey. Patients were contacted by telephone and administered a questionnaire with specific questions to build a significant sample.ResultsOf the patients, 449 (93% of the sample) had an uneventful follow-up after surgery and 93.2% received at least one implant, with a mean of 3.4 implants per patient. At the time of the survey, 93% of the patients were wearing a dental prosthesis, 86.9% had not lost any implants, and 6.7% had lost at least one implant, while 6.4% still had implants but presented some clinical problems. Finally, patients were asked to provide an index score (1–10 points) on the therapy as a whole, i.e., bone graft, implants, and prostheses. A score of insufficient (up to 5 points) was given by 5.3% of patients, of sufficient (6 to 7 points) by 6.1%, and of good/very good (over 7) by 88.6%.ConclusionsHomologous bone for alveolar crest reconstruction can be a valid alternative to autologous grafting if specific tissue limitations are considered when planning therapy. Creeping substitution is partial and slower than in autologous grafts, especially in cases where cortical bone is thick or volume graft is very large. The quality of soft tissue coverage and mucosa lining is also important, possibly due to slower tissue revascularization, so future implants should predictably be positioned primarily within the original host bone.

Growth Dynamic of Allogeneic and Autogenous Bone Grafts in a Vertical Model.

Several techniques have been proposed for vertical bone regeneration, and many of them use bone autogenous and allogeneic grafts. The purpose of this study was to compare demineralised freeze-dried bone allografts (DFDBA), fresh-frozen (FF) allografts, autogenous bone grafts to find differences between volumetric and histological quantity of bone formation and vertical bone growth dynamic. A vertical tissue regeneration bone model was performed in rabbit calvarias under general anaesthesia. Four hollow cylinders of pure titanium were screwed onto external cortical bone calvarias in eight rabbits. Each one of the cylinders was randomly filled with one intervention: DFDBA, FF, autogenous bone, or left to be filled with blood clot (BC) as control. Allogeneic grafts were obtained from a ninth animal following international standardised protocols for the harvesting, processing, and cryopreservation of allografts. Autogenous graft was obtained from the host femur scraping before adapting hollow cylinders. Animals were euthanized at 13 weeks. Vertical volume was calculated after probe device measurements of the new formed tissue inside the cylinders and after titanium cylinders were removed. Histomorphometry and fluorochrome staining were used to analyse quantity and dynamic of bone formation, respectively. Results showed that DFDBA and fresh-frozen bone improved the velocity and the quantity of bone deposition in distant portions of the basal plane of grafting. Remaining material in allograft groups was more intense than in autogenous group. Both allografts can be indicated as reliable alternatives for volume gain and vertical bone augmentation.

Staged Minimally Invasive Surgical Approach in the Management of Glandular Odontogenic Cyst

ABSTRACT Aim The aim of the study was to report a unique case of glandular odontogenic cyst (GOC) in an unusual location of anterior maxilla. Materials and methods Considering the age, sex, and location of the lesion, a minimally invasive surgical procedure was opted considering esthetics, such as decompression followed by enucleation and fresh frozen bone (FFB) grafting. To arrive at the diagnosis, cytokeratin (CK)-19 was employed to differentiate from suspected intraosseous mucoepidermoid carcinoma. Results With the evidence of pre- and post treatment histopathological changes, the lesion appeared less aggressive justifying the treatment executed. Conclusion Glandular odontogenic cyst is a locally aggressive jaw cyst, which has a high rate of cortical perforation and recurrence that poses both diagnostic and therapeutic challenges. Clinical significance Treatment of decompression, followed by enucleation may be considered as an effective option in comparison to aggressive surgical intervention. How to cite this article Kumari K, Sowmya SV, Vineeth K, Rao RS, Lalitha RM, Augustine D, Haragannavar VC, Nambiar S, Abraham M. Staged Minimally Invasive Surgical Approach in the Management of Glandular Odontogenic Cyst. World J Dent 2018;9(1):48-52.

Freeze-dried and irradiated allograft bone combined with fresh autologous coagula promotes angiogenesis in an ectopic bone allograft implantation model

ABSTRACTBackground: Freeze-dried and irradiated allograft bone (FIAB) is more easily impacted than fresh-frozen allograft bone (FAB), but has weaker incorporation efficiency. We combined FIAB with fresh autologous coagula to enhance donor-host incorporation after impaction during hip revision. Methods: Thirty adult male Sprague–Dawley (SD) rats were sacrificed for bone allograft harvesting, and nine male rats were subjected to ectopic bone allograft implantation. For each rat, the container on the left (study) side was filled with freeze-dried allograft bone powder and fresh autologous blood coagula, whereas the right (control) side was filled with freeze-dried allograft bone powder and physiological saline. The extent of angiogenesis (VEGFα) was investigated at postoperative weeks 1, 4, and 8. The deformability of the material was evaluated by performing a confined-impaction mechanical test. Results: At postoperative weeks 4 and 8, angiogenesis within FIAB on the left side was more pronounced than that on the right side. At postoperative week 1, the left side showed significantly higher VEGFα expression than that on the right side. The delta ratios of compression of the allografts were found to be influenced by bone height and impaction frequency, but not by stiffness or elastic modulus (EM). Conclusion: Supplementation with fresh autologous coagula promoted angiogenesis within the FIABs. Moreover, FIABs were equivalent to FABs in terms of deformability.

Atrophic Maxilla Reconstruction With Fresh Frozen Allograft Bone, Titanium Mesh, and Platelet-Rich Fibrin: Case Report

The purpose of this article was to report the clinical and radiographic findings about a case of a man affected by severely atrophic maxilla to demonstrate the clinical proceedings associated with alveolar reconstruction destined for dental implant rehabilitation. The 3-dimensional augmentation of the alveolar ridge with the use of fresh-frozen bone graft, platelet-rich fibrin membrane, and titanium mesh suggests potential benefits to the development of the bone formation physiology. The treatment combination may result in an optimal prognosis and represents an option for reconstruction of bone defects. At 8 months after surgery, no evidence of complications was observed; the clinical examination and computerized tomographic scan revealed bone formation and installed implant stability.

Bone grafts, bone graft extenders, substitutes and enhancers for acetabular reconstruction in revision total hip arthroplasty.

Acetabular bone loss is a relevant concern for surgeons dealing with a failed total hip arthroplasty.Since the femoral head is no longer available, allografts represent the first choice for most reconstructive solutions, either as a structural buttress or impacted bone chips.Even though fresh-frozen bone is firmly recommended for structural grafts, freeze-dried and/or irradiated bone may be used alternatively for impaction grafting. Indeed, there are some papers on freeze-dried or irradiated bone impaction grafting, but their number is limited, as is the number of cases.Xenografts do not represent a viable option based on the poor available evidence but bioactive bioceramics such as hydroxyapatite and biphasic calcium phosphates are suitable bone graft extenders or even substitutes for acetabular impaction grafting.Bone-marrow-derived mesenchymal stem cells and demineralised bone matrix seem to act as reliable bone graft enhancers, i.e. adjuvant therapies able to improve the biological performance of standard bone grafts or substitutes. Among these therapies, platelet-rich plasma and bone morphogenetic proteins need to be investigated further before any recommendations can be made.Cite this article: EFORT Open Rev 2016;1:431-439. DOI:10.1302/2058-5241.160025

Fresh-Frozen Bone Allografts in Maxillary Alveolar Augmentation: Analysis of Complications, Adverse Outcomes, and Implant Survival.

Success of any bone augmentation procedure is dependent on several factors. Because complications occur in some cases, the aims of this study are to analyze adverse events associated with placement of fresh-frozen bone allografts (FFBAs) during alveolar ridge augmentation and to assess 1-year survival of dental implants placed in reconstructed sites. Fifty-eight consecutive patients (15 males and 43 females, aged 38 to 76 years; mean age: 58 ± 9.2 years) requiring maxillary bone reconstruction prior to implant placement were enrolled in this study. A total of 268 implants was subsequently placed in sites reconstructed with FFBAs. There were 22 posterior grafted sites, 19 anterior, and 17 full-arch sites. After a 4- to 6-month integration period, all patients received an implant-supported fixed prostheses. Complications occurring during treatment and the 12-month follow-up period were recorded and evaluated. Thirteen of 58 (22.41%) patients experienced some kind of complication in the receptor site. Infection occurred in six (10.34%) individuals, dehiscence in five (8.62%), and mucosal perforation in seven (12.07%). Adverse outcomes categorized as partial and total graft loss occurred in four (6.90%) and three (5.17%) patients, respectively. Implant failure rate was 16 (5.97%) of the 268 fixtures placed in 12 (20.70%) of 58 patients. Infection and suture dehiscence are significantly correlated with graft loss in a maxillary FFBA augmentation. Patients with full-arch grafting reconstructions lost significantly more implants. Early diagnosis and prompt management of adverse events seem to be of great importance in prevention of total graft loss.

Volumetric Stability of Fresh Frozen Bone Blocks in Atrophic Posterior Mandible Augmentation.

Fresh frozen bone allografts (FFB) have become an alternative for bone augmentation in the past decades, especially because of the absence of recent reports of disease transmission or immunologic reactions when it is used. The aim of this prospective controlled study is to evaluate volumetric changes of newly created bone following reconstruction of the atrophic posterior mandible. Twenty consecutive patients presenting for reconstruction of posterior mandibular alveolar bone ridge width ≤6.0 mm and/or height ≤6.0 who met all inclusion and exclusion criteria were included. FFB blocks were used. The main outcome variable investigated was bone volume dynamics. Vertical, horizontal, and 3-dimensional bone gain data were measured from computerized tomography scans. The main predictor variable was time evaluated at 3 points: immediately after surgery (T1), at implant placement (T2), and 1 year after functional loading (T3). Secondary outcome parameters evaluated were implant survival, histologic findings, and microtomographic morphometry. The study included 28 hemi-mandibles, 50 FFB bone blocks, and 15 female and 5 male patients (mean age, 51.8 years). Block and implant survival rates were 100% and 96%, respectively, after 31.75 months of follow-up. Vertical and horizontal bone gain at T2 was 5.15 and 6.42 mm, respectively. Volumetric resorption was 31% at T2, followed by an additional 10% reduction at T3. Histologic evaluation showed newly formed vital bone in intimate contact with the remaining FFB. Microtomography revealed 31.8% newly formed bone, 14.5% remaining grafted bone, and 53.7% connective tissue and bone marrow. Thus, FFB blocks may lead to new bone formation and consolidation, with satisfactory volumetric bone maintenance, allowing implant-supported rehabilitation with high success rates.

Favorable Early Results of Impaction Bone Grafting With Reinforcement Mesh for the Treatment of Paprosky 3B Acetabular Defects

BackgroundWe present the early institutional experience with the use of impaction bone grafting, mesh augmentation, and cement fixation of an all-polyethylene cup for the treatment of Paprosky 3B acetabular defects during revision total hip arthroplasty. MethodsBetween 2005 and 2014, 21 patients (9 men, 12 women) with Paprosky 3B acetabular defects who underwent revision total hip arthroplasty using this technique were reviewed clinically and radiographically. Average age and body mass index were 72.4 (range, 48-91) years and 24.5 (range, 18.9-31) kg/m2, respectively. All patients underwent revision for aseptic loosening. Surgical technique included the use of a peripheral mesh to contain the defect, followed by impaction of morselized fresh-frozen bone graft and cement fixation of a polyethylene cup. ResultsComplications occurred in 6 patients (29%) including limp (2), sciatic nerve palsy that resolved (1), limb length discrepancy (1), and greater trochanteric fracture (1). After an average follow-up of 47 months (range, 13-128 months), the average Hospital for Special Surgery hip score was 35.5 (range, 20-40). Radiographic assessment revealed cephalad cup migration of 2.29 mm (range, 0-20 mm) and medial migration of 1.57 mm (range, 0-6 mm). One patient has radiographic loosening and no symptoms 120 months postoperatively. No patient returned to the operating room for a related reason or is scheduled to undergo acetabular re-revision surgery. ConclusionImpaction bone grafting is a reliable technique for the treatment of Paprosky 3B acetabular defects. It restores bone stock like no other available for addressing these defects. Longer follow-up is required to assess potential deterioration of fixation.

Long-Term Retrospective Evaluation of Dental Implants Placed in Resorbed Jaws Reconstructed With Appositional Fresh-Frozen Bone Allografts.

The aim of this study was to evaluate the outcome of fresh-frozen bone allografts in preprosthetic surgery for implant placement purposes. The cohort comprised 45 patients treated with fresh-frozen bone block grafts and dental implants. Clinical and radiological evaluations were performed to evaluate the survival rate. The data were statistically analyzed with the Kaplan-Meier estimator to assess the influence of possible predictors of implant failure on survival. Overall, 262 implants were retrospectively analyzed. The survival rate was 90.84% over a mean follow-up of 50 months. Comparing the donor site and the position of the implants, no statistically significant differences could be detected (P = 0.7194 and P = 0.2901, respectively), whereas sex resulted in a marginally statistically significant difference (P = 0.0581). When considering age categorized on the median value (≤55/>55 years), age resulted in a statistically significant difference (P = 0.0340), with higher failures found in older people. Implant loss was strictly related to the lack of primary osseointegration. Female sex and old age were found to be risk factors, which could negatively influence implant survival.

A positive bacterial culture from allograft bone at implantation does not correlate with subsequent surgical site infection.

Fresh-frozen allograft bone is frequently used in orthopaedic surgery. We investigated the incidence of allograft-related infection and analysed the outcomes of recipients of bacterial culture-positive allografts from our single-institute bone bank during bone transplantation. The fresh-frozen allografts were harvested in a strict sterile environment during total joint arthroplasty surgery and immediately stored in a freezer at -78º to -68º C after packing. Between January 2007 and December 2012, 2024 patients received 2083 allografts with a minimum of 12 months of follow-up. The overall allograft-associated infection rate was 1.2% (24/2024). Swab cultures of 2083 allografts taken before implantation revealed 21 (1.0%) positive findings. The 21 recipients were given various antibiotics at the individual orthopaedic surgeon's discretion. At the latest follow-up, none of these 21 recipients displayed clinical signs of infection following treatment. Based on these findings, we conclude that an incidental positive culture finding for allografts does not correlate with subsequent surgical site infection. Additional prolonged post-operative antibiotic therapy may not be necessary for recipients of fresh-frozen bone allograft with positive culture findings.

The stability analysis of implants installed in osteotomies with different types of controlled bone defects

The stability parameters of implants (ITV, ISQ & PTV) according to different sizes of controlled bone defects made in implant osteotomies were analyzed and the correlation among the three kinds of implant stability parameters was tested in this study. 45 tapped screw-type dental implants were inserted in three types of implant osteotomies made in 8 fresh-frozen pig femoral bones: Type1 — without coronal bone defect, Type2 — with 3 mm coronal bone defects, and Type3 — with 6 mm coronal bone defects. The insertion torque values, ISQ & PTV of implants were measured and analyzed statistically. It is concluded that the circumferential coronal bone defects statistically influence the primary stability of implants; ITV, ISQ and PTV are suitable and available to detect the peri-implant coronal bone defects in 3 mm increments, and ITV and PTV are more sensitive to coronal cortical bone loss. There was a strong correlation between ITV and ISQ.

Histological and clinical analysis of fresh-frozen allogeneic vs autogenic bone grafts for 3D alveolar bone reconstruction

Reconstruction of atrophic alveolar bone can be made with many grafting materi- als. Autogenous bone, from intra- or extraoral donor sites, represents the best doc- umented material in terms of number of patients and follow-up; allogeneic freshfrozen bone (FFB), from dead bodies has been suggested as an alternative to overcome problems related to autogenous bone collection (1, 2). The aim of this work is to histologically and histomorphometrically compare bone biopsies obtained during dental implant placement in reconstructed jaws with either FFB or autologous iliac crest bone blocks using the same surgical grafting procedure. All samples were processed for ground sections and then underwent a histomorphometrical evaluation using a stereologic method. Twenty edentulous patients were treated with either FFB (14 patients, group A) or with autografts (6 patients, group B) iliac crest grafts. Five to 9 months later, dental implants were placed in the reconstructed jaws and bone biopsies were harvested. Reconstructive procedure was uneventful in 9 patients of group A and in all patients of group B. In 5 patients of group A, bone sequestra were obtained and processed for ground sections. These specimens showed the typical findings of a bone necrosis. All other samples from both groups presented the same values in terms of proportion of lamellar, newly formed bone and bone marrow. In group A, the decreasing proportion of blood vessels from apical to coronal, the larger amount of osteocytic lacunae in the apical portion and the fewer vessels in the coro- nal portion compared to group B, evoke an effort of the host bone to “integrate” the graft from the apical portion. FFB cannot be considered as successful and safe in alve olar bone reconstruction as autogenous bone grafting.

Effect of autogenous and fresh-frozen bone grafts on osteoblast differentiation

ObjectiveFresh-frozen bone allograft (FFBA) is an alternative to autogenous bone (AB) for reconstructing maxillary bone. Despite the promising clinical results, cell responses to FFBA and AB were not evaluated. Thus, our aim was to compare cells harvested from maxillary reconstructed sites with either AB or FFBA in terms of osteoblast differentiation and to evaluate the effect of culturing cells in contact with FFBA. MethodsCells harvested from three patients submitted to bilateral maxillary reconstruction with AB and FFBA were cultured to evaluate: proliferation, alkaline phosphatase activity, extracellular matrix mineralization and gene expression of osteoblastic markers. The effect of FFBA on osteoblast differentiation was studied by culturing cells harvested from AB in contact with FFBA and evaluating the same parameters. Data were compared using either two-way ANOVA followed by Tukey-b test or Student's t test (p≤0.05). ResultsCell proliferation was higher in cultures from AB grafted sites and extracellular matrix mineralization was higher in cultures derived from FFBA grafted sites. The gene expression of alkaline phosphatase, RUNX2, bone sialoprotein and osteocalcin was higher in cells derived from FFBA compared with cells from AB grafted sites. However, the exposure of cells derived from AB to FFBA particles did not have any remarkable effect on osteoblast differentiation. ConclusionsThese results indicate the higher osteogenic activity of cells derived from FFBA compared with AB reconstructed sites, offering an explanation at cellular level of why FFBA could be a suitable alternative to AB for reconstructing maxillary bone defects.