Biological evaluation of critical bone defect regeneration using hydroxyapatite/ alginate composite granules.

PURPOSE: to evaluate biocompatibility and osteogenic potential of hydroxyapatite/alginate composite after its implantation on rat calvarian critical bone defect. METHODS: thirty adults male Wistar rats were randomly distributed into two groups: GHA - critical bone defect filled with hydroxyapatite/alginate composite granules (HA/Alg) and CG - critical bone defect without biomaterial; evaluated at biological points of 15, 45 and 120 days. RESULTS: the histomorphometrically analyses for GHA showed osteoid matrix deposition (OM) among the granules and towards the center of the defect in centripetal direction throughout the study, with evident new bone formation at 120 days, resulting in filling 4/5 of the initial bone defect. For CG, this finding was restricted to the edges of the bone margins and formation of connective tissue on the residual area was found in all biological points. Inflammatory response on GHA was chronic granulomatous type, discrete and regressive for all biological points. Throughout the study, the CG presented mononuclear inflammatory infiltrate diffuse and regressive. Histomorphometry analyses showed that OM percentage was evident for GHA group when compared to CG group in all analyzed periods (p > 0.05). CONCLUSIONS: the biomaterial evaluated at this study showed to be biocompatible, bioactive, osteoconductive and biodegradable synchronously with bone formation.

A new hydroxyapatite-alginate-gelatin biocomposite favor bone regeneration in a critical-sized calvarial defect model.

This study aimed to evaluate the osteogenic potential of hydroxyapatite (HA), Alginate (Alg), and Gelatine (Gel) composite in a critical-size defect model in rats. Twenty-four male rats were divided into three groups: a negative control with no treatment (Control group), a positive control treated with deproteinized bovine bone mineral (DBBM group), and the experimental group treated with the new HA-Alg-Gel composite (HA-Alg-Gel group). A critical size defect (8.5mm) was made in the rat's calvaria, and the bone formation was evaluated by in vivo microcomputed tomography analysis (µCT) after 1, 15, 45, and 90 days. After 90 days, the animals were euthanized and histological and histomorphometric analyses were performed. A higher proportion of mineralized tissue/biomaterial was observed in the DBBM group when compared to the HA-Alg-Gel and Control groups in the µCT analysis during all analysis periods. However, no differences were observed in the mineralized tissue/biomaterial proportion observed on day 1 (immediate postoperative) in comparison to later periods of analysis in all groups. In the histomorphometric analysis, the HA-Alg-Gel and Control groups showed higher bone formation than the DBBM group. Moreover, in histological analysis, five samples of the HA-Alg-Gal group exhibited formed bone spicules adjacent to the graft granules against only two of eight samples in the DBBM group. Both graft materials ensured the maintenance of defect bone thickness, while a tissue thickness reduction was observed in the control group. In conclusion, this study demonstrated the osteoconductive potential of HA-Alg-Gel bone graft by supporting new bone formation around its particles.

Partial Cranial Reconstruction Using Titanium Mesh after Craniectomy: An Antiadhesive and Protective Barrier with Improved Aesthetic Outcomes.

OBJECTIVE: Describe a new, safe, technique that uses titanium mesh to partially cover skull defects immediately after decompressive craniectomy (DC). METHODS: This study is a retrospective review of 8 patients who underwent DC and placement of a titanium mesh. The mesh partially covered the defect and was placed between the temporalis muscle and the dura graft. The muscle was sutured to the mesh. All patients underwent cranioplasty at a later time. The study recorded and analyzed demographic information, time between surgeries, extra-axial fluid collections, postoperative infections, need for reoperation, cortical hemorrhages, and functional and aesthetic outcomes. RESULTS: After craniectomy, all patients underwent cranioplasty within an average of 112.5 days (30-240 days). One patient reported temporalis muscle atrophy, which was the only complication observed. During the cranioplasties, no adhesions were found between temporalis muscle, titanium mesh, and underlying dura. None of the patients showed complications in the follow-up computerized tomography scans. All patients had favorable aesthetic and functional results. CONCLUSIONS: Placing a titanium mesh as an extra step during DC could have antiadhesive and protective properties, facilitating subsequent cranioplasty by preventing adhesions and providing a clear surgical plane between the temporalis muscle and intracranial tissues. This technique also helps preserve the temporalis muscle and enhances functional and aesthetic outcomes postcranioplasty. Therefore, it represents a safe alternative to other synthetic anti-adhesive materials. Further studies are necessary to draw definitive conclusions and elucidate long-term outcomes, however, the results obtained hold great promise for the safety and efficacy of this technique.

Platelet-rich fibrin improves the osteoneogenesis in non-critical defects in calvaria: a histological and histometric study.

PURPOSE: The aim of this study was to evaluate the effect of platelet-rich fibrin (PRF) and autograft on non-critical bone repair. METHODS: Four bone defects (8.3 × 2 mm) were produced on the calvarium of 15 rabbits. The surgical defects were treated with either autograft, autograft associated to PRF, PRF alone, and sham. Animals were euthanized on the second, fourth or sixth posteoperative week. Histological analyses for presence of bone development on deffect was evaluated comparing the groups treated with autograft and without the autograft separately within the same period. Mann-Whitney's tests were used to compare the percentage of bone repair in each post-operative period for autograft × autograft + PRF groups and also for control × PRF groups (α = 5%). RESULTS: No differences were observed between the groups that received autograft and autograft associated to PRF on the second and fourth postoperative week, but areas treated with PRF demonstrated significant osteogenesis when compared to sham group on the fourth and sixth weeks. The groups that received PRF (with autograft or alone) demonstrated an enlarged bone deposition when compared to their control group. CONCLUSIONS: The use of PRF may influence bone repair and improve the bone deposition in late period of repair demonstrating osteoconductive and osteogenic properties.

Effect of the pulsed electromagnetic field in the repair of a calvaria critical bone defect in rats: cone beam computed tomographic and histomorphometric analysis.: PEMF in the repair of a calvaria critical bone defect: CBCT analyses.

INTRODUCTION: The present study evaluated the effect of two protocols of Pulsed Electromagnetic Field (PEMF) therapy on bone neoformation on calvaria critical defects in rats. MATERIAL & METHODS: 96 rats were randomly divided into 3 groups: Control Group (CG; n=32); Test Group - PEMF 1 hour (TG1h; n=32) and Test Group - PEMF 3 hour (TG3h; n=32). A Critical-size Bone Defect (CSD) was surgically created in the calvaria of rats. The animals in the test groups were exposure to PEMF for 5 days a week. The animals were euthanized at 14, 21, 45 and 60 days. The specimens were processed for volume and texture (TAn) analysis, by Cone Beam Computed Tomography (CBCT) and histomorphometric analysis, RESULTS: Histomorphometric and volume analyses revealed that there was no statistically significant difference in the repair of bone defects between groups receiving PEMF therapy and CG. TAn revealed a statistically significant difference between the groups only for the entropy parameter, in which TG1h group presented a higher value compared to CG on 21 days. TG1h and TG3h did not accelerate bone repair in calvarial critical size defect and the parameters of PEMF should be considered. DISCUSSION: This study showed that PEMF application on CSD in rats does not accelerate bone repair. Although literature showed a positive association in biostimulation on bone tissue with the parameters applied, studies with other PEMF parameters are essential to verify improving this study design.

In vivo evaluation of a collagen membrane in bone neoformation: A morphological and histomorphometric study.

OBJECTIVE: Guided bone regeneration (GBR) is a technique that involves the placement of mechanical barriers to protect the blood clot, and create an isolated space to prevent competition from epithelial and connective tissues in bone augmentation treatments. Collagen membranes stand out from other materials available for performing regenerative surgeries, and are widely used because of their ability to promote cell adhesion and homeostasis, and their biocompatibility, ease of handling, and low immunogenicity. In this context, researchers have investigated xenogenic membranes/barriers that cost less and have slower resorption rates. The current study aimed to assess the osteogenic potential induced by a crosslinked, synthesized xenogenic membrane 100 µm thick when applied in vivo to critical defects in rat calvaria. MATERIAL AND METHODS: Critical size defects were created in the calvaria of thirty male Wistar rats, and randomly divided into the following two groups: G1 - clot covered with a commercial xenogenic membrane (Lumina-Coat®, Criteria, Brazil), and G2 - clot covered with a synthesized xenogenic membrane. The animals were euthanized after 7, 15 and 30 days, and samples of calvaria were processed to perform morphometric evaluations to measure bone neoformation in the defect region. In addition, ultrastructural characterization of the collagen membranes was performed by scanning electron microscope. The quantitative analyses were carried out by adopting a significance level of 5%. RESULTS: The ultrastructural characterization revealed that the synthesized membrane had thicker collagen fibers and a more cohesive surface, compared with the Lumina-Coat® collagen membrane (G1). There was no significant difference in bone neoformation between the membranes (p>0.05), at any of the time periods analyzed. The bone quantification area increased significantly over time for both membranes (p<0.05). CONCLUSION: The synthesized membrane exhibited morphological characteristics similar to those of the commercial membrane evaluated, allowed potentially active participation in the bone neoformation process, and served as a low-cost alternative for GBR procedures.

Effect of ozone therapy on the modulation of inflammation and on new bone formation in critical defects of rat calvaria filled with autogenous graft.

OBJECTIVE: The aim of this study was to evaluate the effect of ozone therapy on new bone formation and inflammation modulation in defects of rat calvaria filled with autogenous bone. MATERIAL AND METHODS: Critical size defects were created in the calvaria of 24 male Wistar rats. The animals were randomly divided into four groups according to the treatment: G1: clot; G2: clot and covered with xenogenic membrane; G3: particulate autogenous bone graft; G4: autogenous bone graft and application of 3 mL O2/O3 gas mixture (10 µg/ml). The defects were filled immediately after surgery with a bilateral retroauricular application, in the region immediately above the incision. After 21 days, the animals were euthanized, and the samples were processed for morphometric evaluations designed to measure both the intensity of the inflammatory infiltrate, and the presence of new bone formation in the defect. RESULTS: The results showed a lower inflammation score and higher mean of newly formed bone in the region of the defect for the group associated with ozone therapy (G4). The bone formed in the region of the defect could be observed as being more lamellar and mineralized in the case of associated ozone therapy. CONCLUSION: Ozone therapy represents a promising adjuvant therapy to accelerate tissue regeneration.

Comparative study of the effect of different temperatures on bovine bone used for bone repair of critical calvaria defects in rats.

To evaluate the osteoconductive potential of inorganic biomaterials of bovine origin submitted to different temperatures in the bone repair of critical defects in rat calvaria. Forty-eight rats were divided into four groups according to the material used to fill the defect: control group (GC), the defect was filled only with blood clot (n = 12); GBO, defect filled with Bio-Oss®, deproteinzed at 300°C (n = 12); GOX, defect filled with Inorganic GenOx®, deproteinzed from 850 to 1200°C (n = 12) and G700, defect filled with Inorganic GenOx 700, deproteinzed at 700°C (n = 12). In each animal's calvaria, a trephine bur with 5 mm internal diameter was used to produce a 6 mm-diameter central defect. Gen Derm® resorbable bovine membrane was superimposed over all defects. Subsequently, animals were euthanized at 30 and 60 days after surgery. The pieces were sent for histological and histometric analysis to evaluate the following variables: bone neoformation, presence of biomaterial, mononuclear and polymorphonuclear leukocytes, presence of other tissues (granulation and medullary) and maturation of collagen fibers. The most representative group for bone neoformation was GC. At 30 days, there was a higher mean of mature bone tissue (75.8). At 60 days, there was no statistical difference between the GC (64.9), GBO (32.9), GOX (45.3), and G700 (26.6) groups. GBO presented the highest amount of biomaterial after 30 days (115.9) and 60 days (118.5). All bovine biomaterials were biocompatible and osteoconductive. GOX promoted the best bone repair of the studied materials.

Cranioplasty with cryopreserved autologous bone in craniectomized patients due to brain trauma, a current and safe option: Experience of 97 cases.

BACKGROUND: Cranioplasty is the used method in neurosurgery for repairing cranial bone defects. In our environment, the most widely used material is cryopreserved autologous bone (ABCp). OBJECTIVE: A retrospective observational study was proposed in order to analyze complications in patients who underwent decompressive craniectomy for brain trauma, with subsequent cranioplasty with ABCp. METHOD: Patients who underwent cranioplasties with consecutive ABCp performed at our institution over a four-year period (2016-2019) with subsequent follow-up were included, collecting multiple variables in relation to the appearance of complications. RESULTS: 113 cranioplasties were performed, of which 85.8% (n = 97) were performed with ABCp. Mainly with frontotemporoparietal bone defect (94.84%) performed late (> 3 months) in 91.76%. The complication rate was 16.49%, the most significant being the infection of the surgical site (n = 8, 8.24%), the presence of intracranial hematoma (n = 3, 3.09%) and the reabsorption of the autologous bone (n = 2, 2.06%), meriting surgical management in nine of them (9.27%). CONCLUSIONS: ABCp is a valid and safe option, which meets the basic characteristics to consider it the ideal material, with an acceptable rate of complications, biocompatible, with osteogenic potential, adequate protection of the brain and decrease in surgery costs.

ANTECEDENTES: La craneoplastia es el método utilizado en neurocirugía para reparar los defectos óseos craneanos. En nuestro medio, el material utilizado mayormente es el hueso autólogo criopreservado (HACp). OBJETIVO: Realizamos un estudio retrospectivo observacional para analizar las complicaciones en pacientes sometidos a craniectomía descompresiva por trauma craneoencefálico y realización de craneoplastia con HACp. MÉTODO: Se incluyeron pacientes que fueron sometidos a craneoplastias con HACp consecutivas realizadas en un periodo de 4 años (2016-2019) con seguimiento posterior, recabando múltiples variables en relación con la aparición de complicaciones. RESULTADOS: Se realizaron 113 craneoplastias, de las cuales el 85.8% (n = 97) fueron realizadas con HACp, principalmente con defecto óseo frontotemporoparietal (94.84%), realizadas de forma tardía (> 3 meses) en el 91.76%. El índice de complicaciones fue del 16.49%, siendo las más significativas la infección del sitio quirúrgico (n = 8, 8.24%), la presencia de hematoma endocraneano (n = 3, 3.09%) y la reabsorción del hueso autólogo (n = 2, 2.06%), ameritando manejo quirúrgico en nueve ocasiones (9.27%). CONCLUSIONES: El HACp es una opción válida y segura, la cual cumple con las características para considerarlo el material ideal, con un aceptable índice de complicaciones, biocompatible, con potencial osteogénico, adecuada protección encefálica y disminución de los costos de la cirugía.

Laddec® versus Bio-Oss®: The effect on the healing of critical-sized defect - Calvaria rabbit model.

The aim of this study was to evaluate the in vivo performance of two different deproteinized bovine bone (DBB) grafting materials: DBBB (Bio-Oss®) and DBBL (Laddec®), for the regeneration of critically sized (8 mm) defects in rabbit's calvaria. Three round-shaped defects were surgically created in the calvaria of 13 New Zealand White rabbits proximal to the coronal suture in the parietal bone. Two of the defects were filled with one of the grafting materials while a third was left empty to serve as a negative control. Bone regeneration properties were evaluated at 4- and 8-weeks after implantation by means of histological and histomorphometrical analyses. Statistical analyses were performed through a mixed model analysis with fixed factors of time and material. Histological evaluation of the control group evidenced a lack of bridging bone formation across the defect sites at both evaluation time points. For the experimental groups, new bone formation was observed around the defect periphery and to progress radially inwards to the center of the defect site, regardless of the grafting material. Histomorphometric analyses at 4 weeks demonstrated higher amount of bone formation through the defect for DBBB group. However, at 8 weeks, DBBL and DBBB demonstrated osteoconductivity and low resorption rates with evidence of statistically similar bone regeneration through the complete boney defect. Finally, DBBB presented lower soft tissue migration within the defect when compared to DBBL at both evaluation time points. DBBB and DBBL presented similar bone regeneration performance and slow resorption rates. Although both materials promoted bone regeneration through the complete defect, DBBB presented lower soft tissue migration within the defects at 4- and 8-weeks.

Development and characterization of poultry collagen-based hybrid hydrogels for bone regeneration.

PURPOSE: Poultry by-products can contribute as an innovative natural source for the development of composites based on polymers and minerals aiming at bone regeneration. The objective of this study was the physicochemical and biological characterization of collagen-based hydrogels crosslinked with ultraviolet (UV)-riboflavin. METHODS: Pure hydrogels of 100% collagen (G1) or hybrid hydrogels, 90% collagen:10% apatite (G2), 90% collagen:10% nanokeratin (G3), and 90% collagen:5% apatite:5% nanokeratin (G4) were characterized by scanning electron microscope, Fourier-transform infrared spectroscopy, differential scanning calorimetry, swelling degree and quali-quantitative histological analysis. Ectopic implantation in subcutaneous tissue in mice at one, three and nine weeks allowed to assess the inflammation (neutrophils, lymphocytes, macrophages, and giant cells) and repair (neovascularization, and connective tissue) to determine biocompatibility and the integrity of biomaterials to score their biodegradability. Histomorphometry on critical size defects in rat calvaria at one and three months evaluated the percentage of bone, connective tissue, and biomaterials in all groups. RESULTS: The hydrogels presented porous microstructure, water absorption and physicochemical characteristics compatible with their polymeric and/or mineral composition. All materials exhibited biocompatibility, biodegradability, and low osteoconductivity. G2 showed greater density of new bone and biomaterial than the G1, G3 and G4. CONCLUSIONS: The collagen-apatite group formulation suggests potential for development as osteopromoting membrane.

Comparison of the effects of platelet concentrates produced by high and low-speed centrifugation protocols on the healing of critical-size defects in rat calvaria: a microtomographic and histomorphometric study.

The current study evaluated the healing of critical-size defects (CSD) created in rat calvaria treated with platelet concentrates produced by high-speed (Leukocyte- and Platelet-Rich Fibrin - L-PRF) and low-speed (Advanced Platelet-Rich Fibrin - A-PRF) protocols of centrifugation. Twenty-four rats were distributed into three groups: Control, L-PRF, and A-PRF. Five mm diameter CSD were created on the animals' calvaria. The defects of the L-PRF and A-PRF groups were filled with 0.01 ml of L-PRF and A-PRF, respectively. The control group defects were filled with a blood clot only. All animals were euthanized on the 35th postoperative day. Histomorphometric and microtomographic analyses were then performed. The L-PRF and A-PRF groups had significantly higher bone volume and neoformed bone area than those of the control group and lowered bone porosity values (p < .05). No significant differences were observed between A-PRF and L-PRF groups for the analyzed parameters. Therefore, it can be concluded that i) L-PRF and A-PRF potentiated the healing of CSD in rat calvaria; ii) high and low-speed centrifugation protocols did not produce PRF matrices with different biological impacts on the amount of bone neoformation.

Utility of Preoperative Helmet Molding Therapy in Patients With Isolated Sagittal Craniosynostosis.

ABSTRACT: The purpose of this study was to review our institution's experience using helmet molding therapy in children with isolated non-syndromic sagittal craniosynostosis before placement of cranial springs and provide objective measurements of craniometric changes to help determine its role in treatment.Patients who underwent preoperative helmet molding therapy for sagittal craniosynostosis were retrospectively reviewed. Three-dimensional surface tomography scans were used to measure head circumference, cranial width, cranial length, cranial index (CI), and cranial vault asymmetry.Seventeen patients underwent orthotic helmeting therapy before spring mediated cranial vault expansion. Patients spent a median of 48 days (interquartile range [IQR] 32, 57) in preoperative orthotic helmeting therapy. There were increases in both cranial width and length post-helmeting (median: 107.5 mm [IQR 104.8, 110.4] versus 115.6 mm [IQR 114.5, 119.3]; P < 0.001) (median: 152.8 mm [IQR 149.2, 154.9] versus 156.8 mm [IQR 155.0, 161.5]; P < 0.001), respectively. There was a greater increase in cranial width (P = 0.015). Consequently, patients' CI improved after preoperative helmeting (median: 0.702 [IQR 0.693, 0.717] versus 0.739 [0.711, 0.752]; P < 0.001). There was no evidence of growth restriction from helmeting (pre-helmeting Head circumference [HC]: median 96.8 percentile [IQR 90.6, 99.9] versus post-helmeting HC: 98.7 percentile [IQR 94.7, 99.8]; P = 0.109).Preoperative helmeting in patients with non-syndromic isolated sagittal craniosynostosis can be used to improve CI before surgical correction. Significant benefits can be achieved in shorter preoperative helmeting durations than previously reported with no evidence of cranial growth restriction, which supports its feasibility and utility in children undergoing spring mediated cranial vault expansion.

Single sagittal craniosynostosis surgical treatment with the "Peau d́ours" technique. Single-center experience in Mexico.

Scaphocephaly (SC) is defined as an elongation of the anteroposterior axis of the skull resulting from the abnormal fusion of the sagittal suture. This study describes the "Peau d'ours" technique and results for correcting SC. We conducted a consecutive and retrospective analysis of patients treated from 2011 to 2016. We evaluated the gender, age, and surgical outcomes. A total of 53 patients were enrolled with a mean age of 19 months old. The advantages of this technique are healthy coronal and lambdoid suture preservation and symmetrical parietal bone flap opening. This technique is safe and simple to reproduce, allowing good surgical outcomes with a low incidence of secondary craniosynostosis. This technique is ideal for patients older than six months old.

Treatment of Sagittal Craniosynostosis Using Osteoplastic Parietal Craniotomy Flap With Distraction Osteogenesis: A Variation on Technique.

ABSTRACT: Late presentation sagittal craniosynostosis presents a unique challenge due to the decreased ability of the skull to repair the bony defects created by standard of care techniques. Distraction osteogenesis is a viable strategy to correct this defect in late presenting cases. The authors describe a variation in technique in which the temporalis muscle origin is retained, creating an osteoplastic bone flap with retained vascularity through the tem-poralis muscle. This may improve postoperative bony healing of bony defects in this compromised population. The authors present two patients who presented to them late with sagittal synostosis who were treated with distraction osteogenesis in which vascular continuity to the parietal bones is preserved through the temporalis muscle.

Forces Exerted in Craniofacial Distraction Osteogenesis.

BACKGROUND: The purpose of this study was to develop a methodology for quantifying linear forces of distraction osteogenesis, and thereafter apply this methodology to measure and compare distraction force magnitudes between cranial vault distraction osteogenesis (CVDO) and mandibular distraction osteogenesis (MDO). METHODS: Patients undergoing CVDO or MDO as inpatients had distraction forces acquired with a digital torque-measuring screwdriver. Torque measurements were then converted into linear distraction force values, which were then compared across distraction types and protocols with appropriate statistics. RESULTS: CVDO was performed on 7 patients (41.2%), and MDO was performed on 10 patients (58.8%). Across the entire cohort, the average maximum force per activation was 27.0 N, and the average elastic force was 10.7 N. Maximum force (CVDO: 52.9 N versus MDO: 12.9 N; P < 0.001) and elastic force (CVDO: 22.0 N versus MDO: 4.5 N; P < 0.001) were significantly higher in patients undergoing CVDO than MDO. Multivariate regression demonstrated that maximum activation force was significantly associated with sequential days of distraction (B= + 1.1 N/day; P < 0.001), distraction rate (B= + 8.9 N/mm/day; P = 0.016), distractor hardware failure (B= + 10.3 N if failure; P = 0.004), and distraction type (B= + 41.4 N if CVDO; P < 0.001). CONCLUSIONS: Cranial vault distraction requires significantly more linear distraction force than mandibular distraction. Maximum forces increase with each day of distraction, as well as with increased distraction rates. Linear distraction force methodology from this study may provide the foundation for future development of optimized procedure-specific or patient-specific distraction protocols.

Human oral mucosa-derived neural crest-like stem cells differentiate into functional osteoprogenitors that contribute to regeneration of critical size calvaria defects.

BACKGROUND AND OBJECTIVE: Regeneration of large bony defects is an unmet medical need. The therapeutic effect of fully developed bony constructs engineered in vitro from mineralized scaffold and adult stem cells is hampered by deficient long-term graft integration. The purpose of the present study was to investigate the regenerative capacity of a bony primordial construct consisting of human oral mucosa stem cells (hOMSC)-derived osteoprogenitors and absorbable Gelfoam® sponges. METHODS: Gingiva and alveolar mucosa-derived hOMSC were differentiated into osteoprogenitors (Runx2 and osterix positive) and loaded into Gelfoam® sponges to generate primordial hOMSC constructs. These were implanted into critical size calvaria defects in the rat. Defects treated with human dermal fibroblasts (HDF) constructs; Gelfoam® sponges and untreated defects served as controls. RESULTS: After 120-day post-implantation defects treated with hOMSC constructs, HDF constructs and gelatin and untreated defects exhibited 86%, 30%, 21%, and 9% of new bone formation, respectively. Immunofluorescence analysis for human nuclear antigen (HNA), bone sialoprotein (BSP), and osteocalcin (OCN) revealed viable hOMSC-derived osteoblasts and osteocytes that formed most of the cell population of the newly formed bone at 30 and 120 days post surgery. Few HNA-positive HDF that were negative for BSP and OCN were identified together with inflammatory cells in the soft tissue adjacent to new bone formation only at 30 days post implantation. CONCLUSION: Collectively, the results demonstrate that primordial in vitro engineered constructs consisting of hOMSC-derived osteoprogenitors and absorbable gelatin almost completely regenerate critical size defects in an immunocompetent xenogeneic animal by differentiating into functional osteoblasts that retain the immunomodulatory ability of naïve hOMSC.

The effectiveness of hydroxyapatite-beta tricalcium phosphate incorporated into stem cells from human exfoliated deciduous teeth for reconstruction of rat calvarial bone defects.

OBJECTIVE: To investigate the effects of stem cells from the pulp of human exfoliated deciduous teeth (SHED) on biphasic calcium phosphate granules (BCP) to repair rat calvarial defects as compared to autogenous bone grafting. MATERIALS AND METHODS: A defect with a 6-mm diameter was produced on the calvaria of 50 rats. BCP granules were incorporated into SHED cultures grown for 7 days in conventional (CM) or osteogenic (OM) culture media. The animals were allocated into 5 groups of 10, namely: clot, autogenous bone, BCP, BCP+SHED in CM (BCP-CM), and BCP+SHED in OM (BCP-OM). The presence of newly formed bone and residual biomaterial particles was assessed by histometric analysis after 4 and 8 weeks. RESULTS: The autogenous group showed the largest newly formed bone area at week 8 and in the entire experimental period, with a significant difference in relation to the other groups (P < 0.05). At week 8, BCP-CM and BCP-OM groups showed homogeneous new bone formation (P = 0.13). When considering the entire experimental period, the BCP group had the highest percentage of residual particle area, with no significant difference from the BCP-CM group (P = 0.06) and with a significant difference from the BCP-OM group (P = 0.01). BCP-CM and BCP-OM groups were homogeneous throughout the experimental period (P = 0.59). CONCLUSIONS: BCP incorporated into SHED cultures showed promising outcomes, albeit less pronounced than autogenous grafting, for the repair of rat calvarial defects. CLINICAL RELEVANCE: BCP incorporated into SHED cultures showed to be an alternative in view of the disadvantages to obtain autogenous bone graft.