Demineralized Bone Matrix Putty Research Articles

Alveolar Ridge Preservation with The Use of Demineralized Bone Matrix Putty: Clinical, Radiographic and Histological Observations in A Case Series

<p>Alveolar ridge preservation (ARP) can minimize alveolar ridge resorption following tooth ex¬traction and facilitate restorative-driven implant placement. Demineralized bone matrix (DBM) comprises a human allograft that is osteoinductive and osteoconductive. This report describes radiographic, histologic and clinical findings of ARP using DBM putty and non-resorbable high-density polytetrafluoroethylene (d-PTFE) membrane in three cases. </p> <p>Materials and Methods: From January 2018 to May 2018, three patients underwent the ARP procedure. The surgery involved atraumatic extraction, socket debridement, filling the socket with DBM putty, applying a d-PTFE membrane, and suturing with 5-0 nylon. After healing for 6–7 months, an implant was placed and biopsy specimens were collected simultaneously. Using the same customized surgical stent and computed tomography, the preoperative and postoperative alveolar ridge heights and widths were measured. Histological evaluations in¬cluding the percentage of newly formed bone, residual graft particles, and fibrous connective tissue were performed. </p> <p>Results: In all three cases, the health status of the hard and soft tissue improved (mean fol¬low-up: 54 months). Guided bone regeneration was not required during implant placement. Radiographically, the mean change was 0.5 mm in the alveolar ridge height and 1.2, 0.87, and 0.73 mm in the alveolar ridge width at 2, 4, and 6 mm apical to the initial vertical measure¬ment, respectively. Histologically, the mean percentage of new bone, residual graft particles, and fibrous connective tissue was 40.5±5.9%, 10.7±6.9%, and 48.8±9.6%, respectively, and the voids were not included in these calculations. </p> <p>Conclusion: This case series demonstrated the effectiveness of DBM putty as a biocompatible filler in extraction sockets for ridge preservation prior to implantation. Further longitudinal studies regarding the efficacy and stability of DBM putty in ridge preservation are required.</p> <p> </p>

Clinical and Radio Graphical Evaluation of Implants Placed in Ridge Preserved Sites versus Naturally Healed Sites

Introduction: Dental implant has proved to be a pioneer in prosthetic rehabilitation overcoming the disadvantage of a removable or a fixed partial denture. The aim of the study was to clinically and radiographically evaluate and compare changes of hard and soft tissues around the implants which will be placed in ridge preserved sites with implant placed in naturally healed extraction sites.
 Materials and Methods: In this study 10 Patients having tooth with hopeless prognosis requiring tooth extraction followed by implant placement were enrolled. These patients were randomly divided in to two groups. Group I: Socket preservation with demineralized bone matrix putty group. Group II: Naturally healed socket after extraction, followed by implant placement in both groups.
 Results: The results of the current study indicated that demineralisedbone matrix putty, when used in patients for dental augmentation in either mandibular or maxillary sites, resulted in replacement of the graft material with bone by as early as 4-6 months, there upon enabling implant placement and subsequent prosthetic reconstruction.
 Conclusion: Bucco lingual ridge width and width of keratinized gingiva can be preserved by ridge preservation after extraction. Short-term survival rates and clinical outcomes of both groups were similar and were comparable. Further clinical trials with longer duration follow up with larger sample size should be done to get more affirmative and conclusive results.

Authors' Comments—Long-Term Postoperative Cone-Beam Computed Tomography Analysis of Secondary Bone Grafting in 79 Patients With Unrepaired Alveolar Clefts

Authors' Comments—Long-Term Postoperative Cone-Beam Computed Tomography Analysis of Secondary Bone Grafting in 79 Patients With Unrepaired Alveolar Clefts

In-vivo Performance of Seven Commercially Available Demineralized Bone Matrix Fiber and Putty Products in a Rat Posterolateral Fusion Model.

Introduction: Demineralized bone matrix (DBM) is a widely used bone graft in spinal fusion. Most commercial DBMs are composed of demineralized bone particles (~125–800 microns) suspended in a carrier that provides improved handling but dilutes the osteoinductive component. DBM fibers (DBF) provide improved osteoconductivity and do not require a carrier. It has been suggested that 100% DBF may offer improved performance over particulate-based DBMs with carrier.Study Design: Seven commercially available DBM products were tested in an athymic rat posterolateral fusion model. There were four 100% DBFs, two DBFs containing a carrier, and one particulate-based DBM containing carrier.Objective: The study objectives were to evaluate the in vivo performance: (1) compare fusion rate and fusion maturity of six commercially available DBFs and one particulate-based DBM, and (2) assess the effect of carrier on fusion outcomes for DBFs in a posterolateral fusion model.Methods: The DBF/DBM products evaluated were: StrandTM Family, Propel® DBM Fibers, Vesuvius® Demineralized Fibers, Optium® DBM Putty, Grafton® DBF, Grafton Flex, and DBX® Putty. Single-level posterolateral fusion was performed in 69 athymic rats. Fusion was assessed bilaterally after 4 weeks by manual palpation, radiograph and CT for bridging bone. Fusion mass maturity was assessed with a CT maturity grading scale and by histology. Statistical analysis was performed using Fishers Exact Test for categorical data and Kruskal-Wallis Test for non-parametric data.Results: Strand Family achieved 100% fusion (18/18) by manual palpation, radiographic and CT evaluation, significantly higher than Propel Fibers, Vesuvius Fibers, Optium Putty, and DBX Putty, and not statistically higher than Grafton DBF and Grafton Flex. Strand Family provided the highest fusion maturity, with CT maturity grade of 2.3/3.0 and 89% mature fusion rate. Fusion results suggest a detrimental effect of carrier on fusion performance.Conclusions: There were large variations in fusion performance for seven commercially available DBM products in an established preclinical fusion model. There were even significant differences between different 100% DBF products, suggesting that composition alone does not guarantee in vivo performance. In the absence of definitive clinical evidence, surgeons should carefully consider available data in valid animal models when selecting demineralized allograft options.

Clinical and radiographic evaluation of amnion chorion membrane and demineralized bone matrix putty allograft for management of periodontal intrabony defects: a randomized clinical trial.

The aim of this trial was to compare the clinical and radiographic outcomes of amnion chorion membrane (ACM) with demineralized bone matrix (DBM) in a putty form in management of periodontal intrabony defects. Twenty-two participants with severe chronic periodontitis and intrabony defects, were randomly assigned in two equal parallel groups. Each group was treated with open flap debridement (OFD) and ACM or OFD and DBM putty. Plaque index, gingival index, pocket depth (PD), clinical attachment level (CAL) and radiographic measurement of bone defect area (BDA) were recorded at baseline, 3 and 6months postoperatively. Both ACM and DBM putty demonstrated significant improvement in all clinical and radiographic outcomes at 6months compared to baseline values. However, no significant difference was observed between the two treatment modalities when compared at different time intervals. Six months postoperatively, ACM showed 3.18 ± 0.85mm, PD reduction and 2.25 ± 0.75mm CAL gain, while DBM putty revealed 3.45 ± 1.08mm PD reduction and 2.73 ± 0.85mm CAL gain. Radiographic assessment showed that mean baseline BDA for ACM group was 10.39 ± 3.86mm2, which significantly reduced to 5.21 ± 2.38 after 6months. Mean BDA mm2 in DBM putty group also significantly improved after 6months, 5.35 ± 3.63mm2 when compared to baseline values 9.80 ± 5.77mm2. Both ACM barrier and DBM putty allograft provided significant improvement in clinical and radiographic outcomes after 6months, yet no significant differences were noticed between them. This trial implied that both biomaterials have a potential regenerative capacity in treating periodontal intrabony defects.

In vitro and in vivo evaluation of xenogeneic bone putty with the carrier of hydrogel derived from demineralized bone matrix.

The demineralized bone matrix (DBM) putty is a traditional bone graft utilized to facilitate the repair and reconstruction of bone. Recent studies indicated the DBM putties with the various carriers were different in bone repairing ability. In order to prepare a kind of DBM putty with a good biocompatibility and bioactivity, the DBM gel was processed from the DBM and the feasibility as a carrier for the DBM putty was evaluated. After the bovine DBM gel was prepared, the BMPs content as well as the ability to promote osteogenic differentiation of MC3T3-E1 cells in vitro were investigated. Then the DBM putty was prepared and filled into the rat calvarial defect model to evaluate the bone repairing ability by micro-CT and histology. The result showed there was 2.953 ± 0.054ng BMP contained in per gram of the DBM gel. And the ALP production of MC3T3-E1 cells in the DBM gels group increased with prolonged culturing, the mineralized nodules formed in MC3T3-E1 cells on 14th day after co-culture. The putty prepared by DBM gel was easy to handle without loss of DBM particles at room temperature. In the rat calvarial bone defect experiment, histological observation showed more mature bone formed in the DBM putty group than that in the type I collagen group at 12weeks, which indicated the bone putty prepared by DBM gel exhibited a better bone repair capability.

The Elution Kinetics of BMP-2, BMP-4, and BMP-7 From a Commercial Human Demineralized Bone Matrix Putty.

Bone morphogenetic proteins (BMPs) are associated with bone extracellular matrix and impart osteoinductive properties to demineralized bone matrix (DBM) grafts. The first step of the osteoinductive process is BMP release from DBM in situ; however, this has not been characterized for human DBM. The authors investigated the release of BMPs 2, 4, and 7 from a clinical human DBM putty (Bonus II DBM, Biomet Inc, Warsaw, IN). The DBM was placed in Sorensen buffer and the BMP concentrations in the Sorensen buffer and guanidine extracts of the DBM were measured concurrently by enzymelinked immunosorbant assay for up to 7 days. The baseline DBM concentrations were BMP-2: 28.1 ± 1.3 ng/g DBM, BMP-4: 0.577 ± 0.056 ng/g DBM, and BMP-7: 92.9 ± 7.5 ng/g DBM. Relative to baseline, the proportions released by 7 days were 11.1%, 3.9%, and 29.3%, respectively. The early (0-8 hour) and late (8-168 hours) elution rates were BMP-2: 0.16 ± 0.24 and 0.0089 ± 0.012 ng/(g DBM hr), and BMP-7: 1.29 ± 2.1 and 0.086 ± 0.039 ng/(g DBM hr), respectively. Little BMP-4 elution occurred over the first 24 hours, with the rate for the remaining interval being 0.00014 ± 0.00021 ng/(g DBM hr). The apparent DBM BMP profiles were counterintuitive in that the concentrations increased from baseline for some, or all, of the 7 days instead of monotonically decreasing. Similar behavior has previously been reported in bovine studies. This provides further evidence that BMPs are associated with at least 2 compartments in DBM differing by their affinity for BMPs and that guanidine extraction of BMPs is not 100% efficient.

Local effect of zoledronic acid on new bone formation in posterolateral spinal fusion with demineralized bone matrix in a murine model.

Posterolateral spinal fusion is a common orthopaedic surgery performed to treat degenerative and traumatic deformities of the spinal column. In posteriolateral spinal fusion, different osteoinductive demineralized bone matrix products have been previously investigated. We evaluated the effect of locally applied zoledronic acid in combination with commercially available demineralized bone matrix putty on new bone formation in posterolateral spinal fusion in a murine in vivo model. A posterolateral sacral spine fusion in murine model was used to evaluate the new bone formation. We used the sacral spine fusion model to model the clinical situation in which a bone graft or demineralized bone matrix is applied after dorsal instrumentation of the spine. In our study, group 1 received decortications only (n=10), group 2 received decortication, and absorbable collagen sponge carrier, group 3 received decortication and absorbable collagen sponge carrier with zoledronic acid in dose 10µg, group 4 received demineralized bone matrix putty (DBM putty) plus decortication (n=10), and group 5 received DBM putty, decortication and locally applied zoledronic acid in dose 10µg. Imaging was performed using MicroCT for new bone formation assessment. Also, murine spines were harvested for histopathological analysis 10weeks after surgery. The surgery performed through midline posterior approach was reproducible. In group with decortication alone there was no new bone formation. Application of demineralized bone matrix putty alone produced new bone formation which bridged the S1-S4 laminae. Local application of zoledronic acid to demineralized bone matrix putty resulted in significant increase of new bone formation as compared to demineralized bone matrix putty group alone. A single local application of zoledronic acid with DBM puttyduring posterolateral fusion in sacral murine spine model increased significantly new bone formation in situ in our model. Therefore, our results justify further investigations to potentially use local application of zoledronic acid in future clinical studies.

Laser Sintered Porous Ti-6Al-4V Implants Stimulate Vertical Bone Growth.

The objective of this study was to examine the ability of 3D implantswith trabecular-bone-inspired porosity and micro-/nano-rough surfacesto enhance vertical bone ingrowth. Porous Ti-6Al-4V constructs were fabricated via laser-sintering and processed to obtain micro-/nano-rough surfaces. Male and female human osteoblasts were seeded on constructs to analyze cell morphology and response. Implants were then placed on rat calvaria for 10weeks to assess vertical bone ingrowth, mechanical stability and osseointegration. All osteoblasts showed higher levels of osteocalcin, osteoprotegerin, vascular endothelial growth factor and bone morphogenetic protein 2 on porous constructs compared to solid laser-sintered controls. Porous implants placed in vivo resulted in an average of 3.1±0.6mm3 vertical bone growth and osseointegration within implant pores and had significantly higher pull-out strength values than solid implants. New bone formation and pull-out strength was not improved with the addition of demineralized bone matrix putty. Scanning electron images and histological results corroborated vertical bone growth. This study indicates that Ti-6Al-4V implants fabricated by additive manufacturing to have porosity based on trabecular bone and post-build processing to have micro-/nano-surface roughness can support vertical bone growth in vivo, and suggests that these implants may be used clinically to increase osseointegration in challenging patient cases.

Efficacy comparison of Accell Evo3 and Grafton demineralized bone matrix putties against autologous bone in a rat posterolateral spine fusion model

Background ContextSpinal fusion procedures are intended to stabilize the spinal column for a multitude of disorders including abnormal curvature, traumatic instability, degenerative instability, and damage from infections or tumors. As an aid in the bone healing response, bone graft materials are used to bridge joints for arthrodesis and promote unions in pseudoarthrosis. Currently, the gold standard for stabilizing fusion masses in spinal procedures involves using the osteogenic, osteoinductive, and osteoconductive properties of autologous iliac crest corticocancellous bone. However, considerable morbidity is associated with harvesting the autologous graft. Donor site complications including infection, large hematomas, and pain have been reported at rates as high as 50% (Boden and Jeffrey, 1995). Biologically, the rate of bone repair dictates the rate at which the fusion mass will unite under autologous graft conditions. PurposeThe purpose of this study is to compare the quality and rate of fusion between Accell Evo3 and Grafton demineralized bone matrix (DBM), with the gold standard iliac crest bone graft (ICBG) as the control, in athymic rat posterolateral fusion. Study DesignThis study was a randomized, controlled study in a laboratory setting at the Hospital for Special Surgery in New York City. Blinded observations were made, which created an assessment of outcomes for successful fusions between each method. Patient SampleForty-eight (48) athymic rats were used in this study and underwent posterolateral lumbar fusion. They were assessed at either 3 weeks or 9 weeks to see the rate and efficacy of fusion. Outcome MeasuresOutcome measures will be the efficacy of the different bone grafts and their success rates of fusion in the rats. MethodsA comparison of the quality and rate of fusion between Accell Evo3® (DBM A) and Grafton (DBM B), with the gold standard iliac crest bone graft (ICBG) as the control, was performed using the established posterolateral intertransverse process on an athymic rat model. Materials were evaluated for fusion by several criteria, including manual palpation, standard and high-resolution radiographic imaging, micro-computed topography, and histologic analysis. Forty-eight (48) athymic rats received a bilateral intertransverse process fusion, using either bone from the iliac crest (control group), Accell Evo3, or Grafton. Twelve (12) rats (four from each group) were sacrificed at 3 weeks postoperatively, whereas the remaining thirty-six (36) were sacrificed at 9 weeks postoperatively. Three blinded observers examined the spines after the rats were euthanized, and they blindly assessed each rat for fusion success. ResultsManual palpation of the three different groups at 3 weeks postoperatively found successful fusion in 1 of 4 (25%) of the autologous bone graft (ABG) group and 4 of 4 (100%) of both DBM A and B groups. Manual palpation of the remaining animals that were sacrificed at 9 weeks postoperatively showed successful fusion in 4 of 12 (33%) of the ABG group, 8 of 12 (66%) of the DBM A group, and 12 of 12 (100%) of the DBM B group. Radiography found that 9 of 16 (56%) of the ABG group and 16 of 16 (100%) of both DBM Putty A and B groups had fused. Histologic analysis of the ABG group demonstrated less mature and less organized osteoid at both 3 and 9 weeks than the DBM Putty A and B groups. Nondestructive mechanical testing demonstrated increased stiffness in 4-point bending of both DBM A and B compared with ABG. ConclusionsBoth DBM-treated groups achieved a significantly higher rate of fusion than the ABG-treated group at 9 weeks in this model. Successful fusion was also demonstrated in the DBM-treated groups at 3 weeks.

Evaluation of Low Intensity Pulsed Ultrasound Effects on the Osteogenesis Potential of Demineralized Bone Matrix in Experimental Tibial Defect in Rabbits

Background: Many studies have assessed the effects of either low intensity pulsed ultrasound (LIPUS) or demineralized bone matrix (DBM) on bone repair; however, an evaluation of the combination of these modalities (LIPUS + DBM) has not yet been considered. Objectives: This study aimed to investigate combined effects of DBM and LIPUS on fracture healing. Methods: Bilateral 5-mm tibial defects were created in male Dutch rabbits (n = 30). Animals were divided to two groups of empty defect (A) and DBM group (B), in which commercial DBM putty was used in defects. In each animal left tibia was treated with LIPUS (intensity = 30 mW/cm2, I SATA, 1 MHz, 20 min/day, pulsed duty 1:4) and the contralateral limb was used as the control. Animals, after 14, 28 and 60 days, were submitted to radiographic or computerized tomography (CT) scanning analysis. Results: At two weeks, LIPUS had no substantial effect on bone formation. Slight increase of average rates in LIPUS group (A2) were seen compared to the empty defect group (A1) at day 21 and 28. In the DBM–treated group compared with the sham LIPUS, bone-healing rate was reduced at the end of the period (60 days) after surgery. The average healing rate in group B at the end of the 60-day period was less than group A after 21 days. Conclusions: The present study discusses systemic effect of LIPUS because of non-significant results between treated group and control group and is the first to demonstrate that LIPUS decreases bone formation induced by DBM.

The effect of temperature exposure during shipment on a commercially available demineralized bone matrix putty.

During August and September of 2013, temperature data loggers were shipped to and from an AATB accredited and FDA registered allograft tissue processing facility in Belgrade, MT (Bacterin International, Inc.) to five warm climate cities (Dallas, TX, El Paso, TX, New Orleans, LA, Phoenix, AZ, and Tampa, FL). Shipping data acquired from 72 independent shipments were analyzed to generate an assessment of temperature exposure, shipment times, and shipping event durations experienced during routine distribution. Overall the packages experienced an average temperature of 26.2 ± 2.3 °C which mirrored the average external ambient temperature of 25.8 ± 3.0 °C. However, temperature spikes above 40 °C were frequently observed. The data from the model shipments were extrapolated to provide a worst-case high temperature spike of 52.9 °C for 12 h and 14 min. Multiple lots of a commercially available demineralized bone matrix (DBM) putty (OsteoSelect® DBM Putty) were subjected to continuous heating at 50 °C, to multiple worst-case temperature spikes, and to multiple freeze–thaw cycles to assess the effects of these temperature extremes on the handling and osteoinductivity of the allograft tissue. Five weeks of continuous exposure to 50 °C and 12 simulated worst-case one-way shipments did not adversely affect the handling characteristics or the in vivo osteoinductivity of the product.

3D Ti-6Al-4V constructs produced by additive manufacturing induce osteoblast differentiation in vitro and regenerate bone in vivo without exogenous factors

3D Ti-6Al-4V constructs produced by additive manufacturing induce osteoblast differentiation in vitro and regenerate bone in vivo without exogenous factors

Complications of Anterior Cervical Fusion using a Low-dose Recombinant Human Bone Morphogenetic Protein-2.

ObjectiveThere are several reports, which documented a high incidence of complications following the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior cervical fusions (ACFs). The objective of this study is to share our experience with low-dose rhBMP-2 in anterior cervical spine.MethodsWe performed a retrospective analysis of 197 patients who underwent anterior cervical fusion (ACF) with the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) during 2007-2012. A low-dose rhBMP-2 (0.7mg/level) sponge was placed exclusively within the cage. In 102 patients demineralized bone matrix (DBM) was filled around the BMP sponge. Incidence and severity of dysphagia was determined by 5 points SWAL-QOL scale.ResultsTwo patients had prolonged hospitalization due to BMP unrelated causes. Following the discharge, 13.2%(n=26) patients developed dysphagia and 8.6%(n=17) patients complained of neck swelling. More than half of the patients (52.9%, n=9) with neck swelling also had associated dysphagia; however, only 2 of these patients necessitated readmission. Both of these patients responded well to the intravenous dexamethasone. The use of DBM did not affect the incidence and severity of complications (p>0.05). Clinico-radiological evidence of fusion was not observed in 2 patients.ConclusionA low-dose rhBMP-2 in ACFs is not without risk. However, the incidence and severity of complications seem to be lower with low-dose BMP placed exclusively inside the cage. Packing DBM putty around the BMP sponge does not affect the safety profile of rhBMP-2 in ACFs.

Demineralized bone matrix for alveolar cleft management.

The aim of this article is to describe the results of the use of demineralized bone matrix putty in alveolar cleft of patients with cleft lip and palate. We performed a prospective, descriptive case series study, in which we evaluated the results of the management of alveolar clefts with demineralized bone matrix. Surgery was performed in 10 patients aged between 7 and 26 years (mean 13 years), involving a total of 13 clefts in the 10 patients. A preoperative cone beam computed tomography (CBCT) was taken to the patients in whom the width of the cleft was measured from each edge of the cleft reporting values between 5.76 and 16.93 mm (average, 11.18 mm). The densities of the clefts were measured with a CBCT, 6 months postoperative to assess bone formation. The results showed a register of gray values of 1,148 to 1,396 (mean, 1,270). The follow-up was conducted for 15 to 33 months (mean, 28.2 months). The results did not show satisfactory bone formation in the cleft of patients with the use of demineralized bone matrix.

Comparison of the Osteogenic Potential of OsteoSelect Demineralized Bone Matrix Putty to NovaBone Calcium-Phosphosilicate Synthetic Putty in a Cranial Defect Model

The purpose of this study was to compare the osteogenic potential of a synthetic and a demineralized bone matrix (DBM) putty using a cranial defect model in New Zealand white rabbits. Paired, bilateral critical-size defects (10 mm) were prepared in the frontal bones of 12 rabbits and filled with either OsteoSelect DBM Putty or NovaBone calcium-phosphosilicate putty. At days 43 and 91, 6 rabbits were killed and examined via semiquantitative histology and quantitative histomorphometry. Defects filled with the DBM putty were histologically associated with less inflammation and fibrous tissue in the defect and more new bone than the synthetic counterpart at both time points. Histomorphometric analysis revealed that the defects filled with DBM putty were associated with significantly more bone formation at day 43 (70.7% vs 40.7%, P = 0.043) and at day 91 (70.4% vs 39.9%, P = 0.0044). The amount of residual implant was similar for both test groups at each time point.

Evaluation of a new formulation of demineralized bone matrix putty in a rabbit posterolateral spinal fusion model

Background contextAlternatives to autologous bone graft (ABG) with osteoconductive, osteoinductive, and osteogenic potential continue to prove elusive. Demineralized bone matrix (DBM) however, with its osteoconductive and osteoinductive potential remains a viable option to ABG in posterolateral spine fusion. PurposeTo compare the efficacy of a new formulation of DBM putty with that of ABG in a rabbit posterolateral spinal fusion model. Study designEfficacy of a new formulation of DBM was studied in an experimental animal posterolateral spinal fusion model. MethodsTwenty-four male New Zealand White rabbits underwent bilateral posterolateral spine arthrodesis of the L5–L6 intertransverse processes, using either ABG (control group, n=12) or DBM (DBM made from rabbit bone) putty (test group, n=12). The animals were killed 12 weeks after surgery and the lumbar spines were excised. Fusion success was evaluated by manual palpation, high resolution X-rays, microcomputed tomography imaging, biomechanical four-point bending tests, and histology. ResultsTwo animals were lost because of anesthetic related issues. Manual palpation to assess fusion success in the explanted lumbar spines showed no statistical significant difference in successful fusion in 81.8% (9/11) of DBM group and 72.7% (8/11) of ABG group (p=.99). Reliability of these assessments was measured between three independent observers and found near perfect agreement (intraclass correlation cofficient: 0.92 and 0.94, respectively). Fusion using high resolution X-rays was solid in 10 of the DBM group and 9 of the ABG group (p=.59). Biomechanical testing showed no significant difference in stiffness between the control and test groups on flexion, extension, and left lateral and right lateral bends, with p values accounting for .79, .42, .75, and .52, respectively. The bone volume/total volume was greater than 85% in the DBM treated fusion masses. Histologic evaluation revealed endochondral ossification in both groups, but the fusion masses were more mature in the DBM group. ConclusionsThe DBM putty achieved comparable fusion rates to ABG in the rabbit posterolateral spinal fusion model.

A Clinical Investigation of Demineralized Bone Matrix Putty for Treatment of Periodontal Bony Defects in Humans

The goal of this study was to evaluate the effectiveness of demineralized bone matrix (DBM) putty, consisting of demineralized human bone allograft matrix in a carrier of bovine collagen and alginate, for the treatment of periodontal defects in humans. Twenty subjects with at least one site having a probing depth ≥ 6 mm and radiographic evidence of bony defect depth > 3 mm were included. The infrabony defects were grafted with DBM putty bone graft. The following clinical parameters were assessed at baseline and 6 months posttreatment: probing depth (PD), gingival recession (GR), and clinical attachment level (CAL). Bone fill was evaluated using transgingival probing and standardized radiographs taken at baseline and 6 months posttreatment. The 6-month evaluation showed a significant PD reduction of 3.27 ± 1.67 mm and clinical attachment gain of 2.27 ± 1.74 mm. Bone sounding measurements showed a mean clinical bone defect fill of 2.93 ± 1.87 mm and a mean radiographic bone fill of 2.55 ± 2.31 mm. The use of DBM putty was effective for treatment of periodontal bony defects in humans. Significant improvement in CAL, PD, and bone fill was observed at 6 months compared to baseline.

Human perivascular stem cells show enhanced osteogenesis and vasculogenesis with Nel-like molecule I protein.

An ideal mesenchymal stem cell (MSC) source for bone tissue engineering has yet to be identified. Such an MSC population would be easily harvested in abundance, with minimal morbidity and with high purity. Our laboratories have identified perivascular stem cells (PSCs) as a candidate cell source. PSCs are readily isolatable through fluorescent-activated cell sorting from adipose tissue and have been previously shown to be indistinguishable from MSCs in the phenotype and differentiation potential. PSCs consist of two distinct cell populations: (1) pericytes (CD146+, CD34-, and CD45-), which surround capillaries and microvessels, and (2) adventitial cells (CD146-, CD34+, and CD45-), found within the tunica adventitia of large arteries and veins. We previously demonstrated the osteogenic potential of pericytes by examining pericytes derived from the human fetal pancreas, and illustrated their in vivo trophic and angiogenic effects. In the present study, we used an intramuscular ectopic bone model to develop the translational potential of our original findings using PSCs (as a combination of pericytes and adventitial cells) from human white adipose tissue. We evaluated human PSC (hPSC)-mediated bone formation and vascularization in vivo. We also examined the effects of hPSCs when combined with the novel craniosynostosis-associated protein, Nel-like molecule I (NELL-1). Implants consisting of the demineralized bone matrix putty combined with NELL-1 (3 μg/μL), hPSC (2.5×10(5) cells), or hPSC+NELL-1, were inserted in the bicep femoris of SCID mice. Bone growth was evaluated using microcomputed tomography, histology, and immunohistochemistry over 4 weeks. Results demonstrated the osteogenic potential of hPSCs and the additive effect of hPSC+NELL-1 on bone formation and vasculogenesis. Comparable osteogenesis was observed with NELL-1 as compared to the more commonly used bone morphogenetic protein-2. Next, hPSCs induced greater implant vascularization than the unsorted stromal vascular fraction from patient-matched samples. Finally, we observed an additive effect on implant vascularization with hPSC+NELL-1 by histomorphometry and immunohistochemistry, accompanied by in vitro elaboration of vasculogenic growth factors. These findings hold significant implications for the cell/protein combination therapy hPSC+NELL-1 in the development of strategies for vascularized bone regeneration.

Management of Retrograde Peri‐Implantitis by Apical Resection and Guided Bone Regeneration in Adjacent Maxillary Implants

Introduction: Retrograde peri‐implantitis (RPI) is defined as a clinically symptomatic periapical lesion that develops shortly after implant insertion while the coronal portion of the implant sustains a normal bone‐to‐implant interface. The etiology of RPI is unclear and may be attributed to several causes. Regardless of etiology, the management of RPI has been attempted by either resective or regenerative techniques.Case Presentation: A 61‐year‐old male was screened and evaluated for three maxillary anterior implants placed 10 years previously. Evaluation included a thorough periodontal and dental exam, radiographs, and cone‐beam computed tomography. Probing depths around all implants ranged from 2 to 4 mm with no bleeding on probing/mobility. The apices of implants #8 and #9 exhibited radiolucencies, and a draining fistula was associated with implant #8. Treatment consisted of sectioning and removal of the affected portion of the implants and collection of a specimen for histopathologic examination. Demineralized bone matrix putty was placed in the residual bony defects and covered with a collagen barrier. At 1 year, radiographs revealed both lesions around implants #8 and #9 appeared to be resolving. The lesion associated with implant #9 had a more remarkable radiographic change, because it was smaller than the lesion around implant #8. Both implants continued to function with no recurrence of fistula formation. Histopathologic analysis was consistent with the diagnosis of a periapical granuloma.Conclusion: Resection of the apical portion of implants is a viable treatment modality in the management of RPI.