Anti-Inflammatory Activity of a Demineralized Bone Matrix: An In Vitro Pilot Study

Demineralized bone matrix (DBM) is commonly used for the reconstruction of bone defects. Early graft consolidation involves a transient inflammatory process. It is, however, unclear whether DBM can modulate this process. To test this possibility, we prepared acid lysates of demineralized ground cortical (DGC) and moldable demineralized fibers (MDF). Murine RAW 264.7 and primary bone marrow macrophages were exposed to acid lysates of DGC and MFD prior to provoking an inflammatory response with lipopolysaccharide (LPS). Similarly, murine ST2 mesenchymal cells were exposed to DGC and MFD with and without interleukin 1β (IL1) and TNFα. We show here that acid lysates of DGC and MFD reduced the expression of IL1 and IL6 in RAW 264.7 macrophages, as determined by RT-PCR and, for IL6, by immunoassay. This response was confirmed with primary macrophages. Likewise, desalted acid lysates exert anti-inflammatory properties on RAW 264.7 cells and in ST2 cells, the forced expression of IL6, inducible nitric oxide synthase (iNOS) and chemokine ligand 5 (CCL5) was reduced. These in vitro findings suggest that DGC and MFD lower the inflammation-induced expression of inflammatory mediators in murine cell-based bioassays.

Effectiveness of platelet rich fibrin versus demineralized bone xenograft in periodontally accelerated osteogenic orthodontics: A pilot comparative clinical study

ABSTRACT Objectives To compare the rate of extraction space closure between periodontally accelerated osteogenic orthodontics (PAOO) using platelet-rich fibrin (PRF) (Group 1) and PAOO using demineralized bone xenograft (DMBM) (Group 2) and to compare the level of wound healing between the PRF group vs the DMBM group after PAOO. Materials and Methods A two-arm prospective single blind pilot study with a split-mouth design was used in which 14 patients requiring premolar extraction were divided into two groups: PRF and DMBM. En-masse space closure was carried out with using mini implants after the PAOO procedure. The amount of space closure was measured at five time points with 2-week intervals within 2 months. The gingival healing levels were assessed using early wound healing scores on the first postoperative day. Results The rate of extraction space closure was faster in the experimental quadrant at all time points (T1-T4) in the PRF group and at time points (T3, T4) in the DMBM group. Comparison between experimental quadrants showed a significant increase in the rate of space closure in the PRF group T1 to T3 (P < .05). The PRF group showed higher total early healing scores than the DMBM group. Conclusions PRF, when used in the PAOO procedure, produces a faster rate of space closure with better early wound healing than DMBM.

Preliminary outcomes of the combination of demineralized bone matrix and platelet Rich plasma in the treatment of long bone non-unions

Background A variety of bone graft substitutes have been introduced into the treatment of bone non-unions. However, clinical outcomes from current evidences are various and conflicting. This study aimed to present the preliminary outcomes of a treatment protocol in which the combination of demineralized bone matrix (DBM) and platelet rich plasma (PRP) was used as a bone graft substitute for long bone non-unions. Methods Data of this retrospective study were reviewed and collected from a consecutive case series involving 43 patients who presented with a long bone non-union and were treated in our department from October 2018 to May 2019. The combination of DMB and PRP was applied as a bone defect filler in 16 patients, whilst the other 27 patients were treated with iliac bone autografting. Patients’ demographics, postoperative complications and the result of bone union were compared and evaluated. Results The demographic data between the two groups were comparable. No significant difference was found with regard to the incidence of postoperative complications. No graft rejection, heterotopic ossification or other complications were noted. The distribution of bony healing time was rather scattered but did not differ significantly between the groups (7.533 ± 3.357 months vs. 6.625 ± 2.516 months; P=0.341). Union was identified radiographically in 15 of 16 patients in the DBM+PRP group and in 24 of 27 patients in autograft group. Conclusions The present study identified that low incidence of postoperative complications and satisfactory bony healing rate could be achieved in the treatment of long bone non-unions augmented with the combination of DBM and PRP. Although these findings might indicate the promising future of this treatment protocol, larger and higher quality studies should also be executed to assess its routine use.

Preparation and Characterization of Moldable Demineralized Bone Matrix/Calcium Sulfate Composite Bone Graft Materials

Demineralized bone matrix (DBM) is a decalcified allo/xenograft retaining collagen and noncollagenous proteins, which has been extensively used because of its osteoconductive and osteoinductive properties. Calcium sulfate (CaSO4, CS) is a synthetic bone substitute used in bone healing with biocompatible, nontoxic, bioabsorbable, osteoconductive, and good mechanical characteristics. This study aims to prepare a DBM/CS composite bone graft material in a moldable putty form without compromising the peculiar properties of DBM and CS. For this purpose, firstly, porcine femur was defatted using chloroform/methanol and extracted by acid for demineralization, then freeze-dried and milled/sieved to obtain DBM powder. Secondly, the α-form and β-form of calcium sulfate hemihydrate (CaSO4 •0.5H2O, CSH) were produced by heating gypsum (CaSO4 •2H2O). The morphology and particle sizes of α- and β-CSH were obtained by SEM, and their chemical properties were confirmed by EDS, FTIR and XRD. Furthermore, the DBM-based graft was mixed with α- or β-CSH at a ratio of 9:1, and glycerol/4% HPMC was added as a carrier to produce a putty. DBM/CSH putty possesses a low washout rate, good mechanical strength and biocompatibility. In conclusion, we believe that the moldable DBM/CSH composite putty developed in this study could be a promising substitute for the currently available bone grafts, and might have practical application in the orthopedics field as a potential bone void filler.

The effect of mesenchymal stem cells, demineralized bone graft and platelet-rich plasma on osteogenesis in rat tibia defects

Aim: Deformities of the jaw and face are often caused by infection, inflammation, and cystic and neoplastic pathological conditions. Defects with various aetiologies should be repaired promptly using the most appropriate approach to reconstruct the anatomical form. To treat defects, bone grafts with various combinations have been used. In particular, combinations including cellular products to enhance osteogenic properties have been implemented. In this study, we aimed to investigate the effects of different materials and cells on bone defects by using mesenchymal stem cells (MSCs), which are thought to have a positive effect on healing, demineralized bone graft (DMB) and platelet-rich plasma (PRP). Methodology: We used 55 female rats weighing between 200-250 g, four of which were used to obtain platelet-rich plasma. The remaining animals were divided into five groups. Group I (n = 6) was the operative control group, Group II (n = 24) was given DMB, Group III (n = 24) was given DMB+PRP, Group IV (n = 24) was given MSC+DBG and Group V (n = 24) was given DMB+PRP+MSC applied to rat tibial defects (10 mm x 3 mm x 2 mm). Results: Statistically significant differences were observed in bone osteoblastic activity in tibia defects among the groups (p<0.05). Conclusion: Bone regeneration was significantly improved in groups where MSCs were used in combination with DMB and PRP. How to cite this article: Erdoğmuş Z, Gülsün B. The effect of mesenchymal stem cells, demıneralızed bone graft and platelet-rıch plasma on osteogenesıs ın rat tıbıa defects. Int Dent Res 2021;11(Suppl.1):47-55. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.8 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Histopathological and Radiographical Evaluation of Caprine Demineralized Bone Matrix in a Critical Ulnar Defect in a Rabbit Model

Background: Caprine species satisfy the conditions of an ideal donor animal when compared to bovine species that has been extensively studied and commercialized for bone xenograft. Histopathological and radiological evaluations of caprine demineralized bone matrix (CDBM) were therefore carried out for fracture healing properties for its possible use in bone grafting procedures. Materials and Methods: Twenty-four rabbits were used for this study and were divided randomly into three groups of eight (n=8) rabbits each. Critical bone defect was created on the ulnar diaphysis under xylazine-ketamine anaesthesia for autogenous bone graft (ABG) group, CDBM group and the last group was left unfilled as negative control (NC). Immediate post-grafting radiograph was taken and repeated on days 14, 28, 42 and 56 to monitor the evidence of radiographic healing. The animals were euthanized on day 56 and defect sites were harvested for histopathology. Results: There was a progressive evidence of radiographic healing and bone formation in all the groups with significance difference (P=0.0064). When compared with ABG, NC differ significantly (P<0.0001) whereas the CDBM did not differ significantly (P=0.6765). The histopathology sections of ABG and CDBM showed normal bone tissue while the NC section was predominated by fibrous connective tissue. There was therefore an overall significant difference (P=0.0001) in which CDBM did not differ from ABG (P=0.2946) while NC did (P=0.0005). Conclusion: The ABG and CDBM groups showed a similar healing effect in the critical bone defect. Therefore, CDBM could be used as an effective alternative to ABG in orthopaedics to circumvent the limitations and complications associated with it. Level of Evidence: Not applicable.

Regenerating effect of hyaluronic acid on circumferential bone defects in Wistar albino rats.

Objective: To determine the regenerating effect of hyaluronic acid on circumferential bone defects in albino Wistar rats. Material and Methods: An experimental type study was designed and carried out with 15 albino male Wistar rats, 4 months old and weighing between 250 and 350 grams. Two circumferential bone defects 3mm in diameter and 0.8mm deep were created in the calvaria of the parietal bone (on both sides of the midline). One defect was filled with a demineralized bone matrix (control group); while the other defect was filled with the combination of a demineralized bone matrix plus hyaluronic acid (experimental group). Five experimental rats were euthanized at 30, 60 and 90 days after surgery and they were histologically evaluated following the parameters proposed by Heiple. Results: The experimental group presented a better degree of bone regeneration at 30 and 60 postoperative days. Conclusion: Hyaluronic acid is effective in bone regeneration of circumferential bone defects.