Enhanced alveolar ridge preservation with hyaluronic acid-enriched allografts: a comparative study of granular allografts with and without hyaluronic acid addition.

PURPOSE: Ridge preservation is essential to restore alveolar ridge volume and to enhance esthetic and functional outcomes for dental implants. The addition of hyaluronic acid to allogeneic bone substitute materials might enhance these outcomes. This clinical study evaluated the efficacy of ridge preservation after tooth extraction using granular allografts with and without hyaluronic acid addition. METHODS: In this retrospective study, 40 patients with compromised extraction sockets were enrolled. Among them, 19 received particulate allogeneic bone substitutes (Allo), 21 received allogeneic bone substitutes with hyaluronic acid (AlloHya). Vertical and horizontal graft stability, graft shrinkage rate, and bone mineral density were assessed using radiographic measurements on CBCT scans conducted before tooth extraction, directly after ridge preservation and after four months. Patients were followed up 12 months post-implantation. RESULTS: Vertical height loss after 4 months was significantly greater in the Allo group (-0.82 ± 0.95 mm) compared to the AlloHya group (-0.19 ± 0.51 mm; p = 0.011). Graft shrinkage rate was 16.9 ± 11.5% (Allo) and 10.3 ± 7.7% (AlloHya) (p = 0.038). After four months, average bone density was significantly higher in the AlloHya compared to the Allo group (p = 0.004). Nearly all implants (39 out of 40) were classified as "Success" according to the ICOI scheme, with no differences in implant quality between the two study groups. CONCLUSIONS: Improved graft stability, reduced resorption, and increased bone density were observed in hyaluronic acid-enriched allografts compared to pure allografts. Adding hyaluronic acid to allogeneic bone grafts significantly enhanced outcomes in ridge preservation.

Single-Stage Lateral Sinus Floor Elevation Using Different Grafts: A Systematic Review of Controlled Clinical Trials.

PURPOSE: To assess histologic and imaging outcomes related to new bone formation around implants, inserted simultaneously with sinus augmentation, and compare different types of grafts. MATERIALS AND METHODS: This systematic review (SR) was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the Cochrane Handbook for Systematic Reviews of Interventions. LILACS/BVS, MEDLINE/PubMed, Cochrane Library, and Embase databases, including gray literature and manual investigations, were searched to identify clinical trials reporting specific requirements. The present study needed human histologic and imaging data of bone formation around implants inserted into the maxillary sinus simultaneously with elevation and augmentation procedures. Study selection, risk of bias (Rob 2.0 or ROBINS-I), quality of evidence (GRADE), and data collection were performed by two independent reviewers. RESULTS: Of the 1,101 potentially eligible articles, 44 were retrieved, 12 were assessed for eligibility, and 5 were included (4 randomized and 1 controlled clinical trial). As a result, 130 grafted sinuses with 179 placed implants in 103 patients were analyzed. The patients were aged between 24 and 79 years and followed up between 6 and 15 months. The heterogeneity between studies did not allow the data to be combined for meta-analysis. All graft materials proved to be viable options for the intervention. The use of biphasic calcium phosphate was related to higher bone-to-implant contact. CONCLUSIONS: All of the assessed grafts are viable options for the addressed intervention. The use of some material is justified to maintain the sinus volume and allow bone formation in the apical implant site under the sinus membrane. Longer chair time and donor site morbidity should be considered when choosing autogenous bone. Synthetic biphasic materials can be selected for this intervention due to superior bone-to-implant contact compared to deproteinized bovine bone.

Use of bone pate and bioactive glass granules for mastoid obliteration in cholesteatoma surgery / Mastoidobliterációhoz használt csontpor és bioaktív üveggranulátum a cholesteatoma sebészetében

Introduction and objective: Mastoid obliteration technique combines the advantages of canal wall-up (CWU) and canal wall-down (CWD) approaches in the surgery of chronic suppurative otitis media with cholesteatoma. We aim to demonstrate our experience with mastoid obliteration technique using bone dust and BonAlive® (S53P4) bioactive glass granule in a comparative prospective clinical study. Patients and methods: Between 1st of March 2012 and 31st of November 2021, mastoid obliteration surgery was performed in 14 patients using bone dust (7 cases) and BonAlive® granule (7 cases). Prior to these interventions, the patients had undergone more than three ear surgeries (CWU and CWD) generally in both groups. Changes of complaints, audiological results, and changes in quality of life were analysed in both groups, postoperatively. Results: Having performed the mastoid obliteration technique, cochlear damage did not occur in either patient group. Long-term ear discharge and vertigo were occasionally observed after performing obliteration with bone dust. However, these complaints disappeared after a while. Complications were not reported in the case of obliteration with BonAlive®. Outstanding improvement was experienced in both groups. Conclusion: In our practice, mastoid obliteration surgery, using either bone dust or BonAlive® granule, has proved to

Efficacy of NHP66 Bioactive Cage on Patients with Cervical Spine Injury in Short-Track Speed Skating.

BACKGROUND: Short-track speed skating (STSS) is an extreme sport in pursuit of extreme speed and explosive force. In such a sport, once athletes fall down, they are susceptible to serious cervical spine injury (CSI) under the inertia of high-velocity movement. Nanohydroxyapatite/polyamide 66 (NHP66) bioactive cage is a high-tech product of nanotechnology in the medical field in recent years. With a structure similar to that of human cortical bone, NHP66 bioactive cage has extremely high toughness and strength, which tailors to the needs of STSS. OBJECTIVE: This study mainly analyzed the therapeutic effect of NHP66 on patients with CSI in STSS, aiming to provide new opportunities for the treatment of this patient population. METHODS: A total of 51 patients with CSI treated in our hospital were enrolled, including 19 cases of short-track speed skaters (observation group) and 32 cases of car accidents, falls from heights, or collision injuries (control group). The relevant surgical indicators (operation time, intraoperative blood loss, etc.), the incidence of adverse reactions, the Cobb angle of cervical lordosis before and after surgery, and the fusion segment height of the cage were observed and compared between the two groups. Postoperative pain was evaluated by the visual analog scale (VAS), improvement of spinal cord injury was assessed by the American Spinal Cord Injury Association (ASIA) Impairment Scale, and bone fusion, bone subsidence, and other motor functions were assessed by the Japanese Orthopaedic Association (JOA) score rating system. RESULTS: The operation time, intraoperative blood loss, and incidence of adverse reactions in the observation group were significantly lower than those in the control group. The Cobb angle of cervical lordosis and the fusion segment height of cage increased significantly higher in both groups after surgery. In addition, the VAS scores of the observation group 2 h and 3 d after operation were significantly lower than those of the control group. In terms of improvement of spinal cord injury, ASIA and JOA scores in the observation group were significantly higher than those before treatment and in the control group. There was no significant difference in bone fusion activity between the two groups. CONCLUSIONS: In this study, it is found through experiments that NHP66 has higher safety and application value than autogenous iliac bone, confirming that NHP66 can achieve significant results as a cage for anterior cervical decompression and iliac bone graft fusion and internal fixation in short-track speed skaters after CSI.

Systemic Administration of PTH Supports Vascularization in Segmental Bone Defects Filled with Ceramic-Based Bone Graft Substitute.

Non-unions continue to present a challenge to trauma surgeons, as current treatment options are limited, duration of treatment is long, and the outcome often unsatisfactory. Additionally, standard treatment with autologous bone grafts is associated with comorbidity at the donor site. Therefore, alternatives to autologous bone grafts and further therapeutic strategies to improve on the outcome and reduce cost for care providers are desirable. In this study in Sprague-Dawley rats we employed a recently established sequential defect model, which provides a platform to test new potential therapeutic strategies on non-unions while gaining mechanistic insight into their actions. The effects of a combinatorial treatment of a bone graft substitute (HACaS+G) implantation and systemic PTH administration was assessed by µ-CT, histological analysis, and bio-mechanical testing and compared to monotreatment and controls. Although neither PTH alone nor the combination of a bone graft substitute and PTH led to the formation of a stable union, our data demonstrate a clear osteoinductive and osteoconductive effect of the bone graft substitute. Additionally, PTH administration was shown to induce vascularization, both as a single adjuvant treatment and in combination with the bone graft substitute. Thus, systemic PTH administration is a potential synergistic co-treatment to bone graft substitutes.

Mesoporous Silica-Bioglass Composite Pellets as Bone Drug Delivery System with Mineralization Potential.

For decades, local bone drug delivery systems have been investigated in terms of their application in regenerative medicine. Among them, inorganic polymers based on amorphous silica have been widely explored. In this work, we combined two types of amorphous silica: bioglass and doxycycline-loaded mesoporous silica MCM-41 into the form of spherical granules (pellets) as a bifunctional bone drug delivery system. Both types of silica were obtained in a sol-gel method. The drug adsorption onto the MCM-41 was performed via adsorption from concentrated doxycycline hydrochloride solution. Pellets were obtained on a laboratory scale using the wet granulation-extrusion-spheronization method and investigated in terms of physical properties, drug release, antimicrobial activity against Staphylococcus aureus, mineralization properties in simulated body fluid, and cytotoxicity towards human osteoblasts. The obtained pellets were characterized by satisfactory mechanical properties which eliminated the risk of pellets cracking during further investigations. The biphasic drug release from pellets was observed: burst stage (44% of adsorbed drug released within the first day) followed by prolonged release with zero-order kinetics (estimated time of complete drug release was 19 days) with maintained antimicrobial activity. The progressive biomimetic apatite formation on the surface of the pellets was observed. No cytotoxic effect of pellets towards human osteoblasts was noticed.

Subchondroplasty for Bone Marrow Lesions in the Arthritic Knee Results in Pain Relief and Improvement in Function.

Subchondroplasty is a relatively new joint preserving procedure, which involves the localized injection of calcium pyrophosphate bone substitute into the bone marrow lesion. The advent of magnetic resonance imaging (MRI) has greatly facilitated the identification of these bone marrow lesions. We investigated the clinical efficacy of subchondroplasty in the treatment of symptomatic bone marrow lesions in the knee, including knees with preexisting osteoarthritis. This study comprised of 12 patients whose knees were evaluated with standard radiographs and MRI to identify and localize the bone marrow lesions. They then underwent subchondroplasty under intraoperative radiographic guidance. Preoperative and postoperative visual analog scale (VAS) pain scores, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, and Knee Injury and Arthritis Outcome Scores (KOOS) were obtained. VAS scores improved significantly from 7.5 ± 1.8 before surgery to 5.2 ± 2.7 after surgery. This further improved to 2.1 ± 2.4 at the one-year follow-up. KOOS scores improved significantly from 38.5 ± 17.0 before surgery to 73.2 ± 19.0 at the one-year follow-up. WOMAC scores improved significantly from 47.8 ± 20.5 before surgery to 14.3 ± 13.2 at the one-year follow-up. Subchondroplasty offers an effective way to treat subchondral bone marrow lesions in the arthritic knee, resulting in improvement in symptoms and early return to activity. Long-term studies are required to evaluate if these benefits can last. This is a Level II study.

Knee Intraosseous Injections: A Systematic Review of Clinical Evidence of Different Treatment Alternatives.

OBJECTIVE: To systematically review the available clinical evidence regarding the safety and efficacy of knee intraosseous injections for the treatment of bone marrow lesions in patients affected by knee osteoarthritis. DESIGN: A literature search was carried out on PubMed, Embase, and Google Scholar databases in January 2020. The following inclusion criteria were adopted: (1) studies of any level of evidence, dealing with subchondral injection of bone substitute materials and/or biologic agents; (2) studies with minimum 5 patients treated; and (3) studies with at least 6 months' follow-up evaluation. All relevant data concerning clinical outcomes, adverse events, and rate of conversion to arthroplasty were extracted. RESULTS: A total of 12 studies were identified: 7 dealt with calcium phosphate administration, 3 with platelet-rich plasma, and 2 with bone marrow concentrate injection. Only 2 studies were randomized controlled trials, whereas 6 studies were prospective and the remaining 4 were retrospective. Studies included a total of 459 patients treated with intraosseous injections. Overall, only a few patients experienced adverse events and clinical improvement was documented in the majority of trial. The lack of any comparative evaluation versus subchondral drilling alone is the main limitation of the available evidence. CONCLUSIONS: Knee intraosseous injections are a minimally invasive and safe procedure to address subchondral bone damage in osteoarthritic patients. They are able to provide beneficial effects at short-term evaluation. More high-quality evidence is needed to confirm their potential and to identify the best product to adopt in clinical practice.

Comparison of Freshly Isolated Adipose Tissue-derived Stromal Vascular Fraction and Bone Marrow Cells in a Posterolateral Lumbar Spinal Fusion Model.

STUDY DESIGN: Rat posterolateral lumbar fusion model. OBJECTIVE: The aim of this study was to compare the efficacy of freshly isolated adipose tissue-derived stromal vascular fraction (A-SVF) and bone marrow cells (BMCs) cells in achieving spinal fusion in a rat model. SUMMARY OF BACKGROUND DATA: Adipose tissue-derived stromal cells (ASCs) offer advantages as a clinical cell source compared to bone marrow-derived stromal cells (BMSCs), including larger available tissue volumes and reduced donor site morbidity. While pre-clinical studies have shown that ex vivo expanded ASCs can be successfully used in spinal fusion, the use of A-SVF cells better allows for clinical translation. METHODS: A-SVF cells were isolated from the inguinal fat pads, whereas BMCs were isolated from the long bones of syngeneic 6- to 8-week-old Lewis rats and combined with Vitoss (Stryker) bone graft substitute for subsequent transplantation. Posterolateral spinal fusion surgery at L4-L5 was performed on 36 female Lewis rats divided into three experimental groups: Vitoss bone graft substitute only (VO group); Vitoss + 2.5 × 106 A-SVF cells/side; and, Vitoss + 2.5 × 106 BMCs/side. Fusion was assessed 8 weeks post-surgery via manual palpation, micro-computed tomography (µCT) imaging, and histology. RESULTS: µCT imaging analyses revealed that fusion volumes and µCT fusion scores in the A-SVF group were significantly higher than in the VO group; however, they were not significantly different between the A-SVF group and the BMC group. The average manual palpation score was highest in the A-SVF group compared with the BMC and VO groups. Fusion masses arising from cell-seeded implants yielded better bone quality than nonseeded bone graft substitute. CONCLUSION: In a rat model, A-SVF cells yielded a comparable fusion mass volume and radiographic rate of fusion to BMCs when combined with a clinical-grade bone graft substitute. These results suggest the feasibility of using freshly isolated A-SVF cells in spinal fusion procedures.Level of Evidence: N/A.

Radiographic and clinical assessment of unidirectional porous hydroxyapatite to treat benign bone tumors.

Unidirectional porous hydroxyapatite (UDPHAp) was developed as an excellent scaffold with unidirectional pores oriented in the horizontal direction with interpore connections. The purpose of this study was to assess radiographic changes and clinical outcomes and complications following UDPHAp implantation to treat benign bone tumors. We retrospectively analyzed 44 patients treated with intralesional resection and UDPHAp implantation for benign bone tumors between 2010 and 2015. Clinical and radiographic findings were evaluated postoperatively at regular follow-up visits. The mean follow-up was 49 months. Radiographic changes were classified into five stages based on bone formation in the implanted UDPHAp according to Tamai's classification. All patients showed excellent bone formation inside and around implanted UDPHAp. Absorption of UDPHAp and bone marrow cavity remodeling was identified in 20 patients at a mean of 17 months postoperatively, and was significantly more common in young patients. Preoperative cortical thinning was completely regenerated in 26 of 31 patients on average 10 months after surgery. There were no cases of delayed wound healing, postoperative infection, or allergic reaction related to implanted UDPHAp. UDPHAp is a useful bone-filling substitute for treating benign bone tumor, and the use of this material has a low complication rate.

A Novel Resorbable Composite Material Containing Poly(ester-co-urethane) and Precipitated Calcium Carbonate Spherulites for Bone Augmentation-Development and Preclinical Pilot Trials.

Polyurethanes have the potential to impart cell-relevant properties like excellent biocompatibility, high and interconnecting porosity and controlled degradability into biomaterials in a relatively simple way. In this context, a biodegradable composite material made of an isocyanate-terminated co-oligoester prepolymer and precipitated calcium carbonated spherulites (up to 60% w/w) was synthesized and investigated with regard to an application as bone substitute in dental and orthodontic application. After foaming the composite material, a predominantly interconnecting porous structure is obtained, which can be easily machined. The compressive strength of the foamed composites increases with raising calcium carbonate content and decreasing calcium carbonate particle size. When stored in an aqueous medium, there is a decrease in pressure stability of the composite, but this decrease is smaller the higher the proportion of the calcium carbonate component is. In vitro cytocompatibility studies of the foamed composites on MC3T3-E1 pre-osteoblasts revealed an excellent cytocompatibility. The in vitro degradation behaviour of foamed composite is characterised by a continuous loss of mass, which is slower with higher calcium carbonate contents. In a first pre-clinical pilot trial the foamed composite bone substitute material (fcm) was successfully evaluated in a model of vertical augmentation in an established animal model on the calvaria and on the lateral mandible of pigs.

Cement-augmented screw fixation for calcaneal fracture treatment: a biomechanical study comparing two injectable bone substitutes.

BACKGROUND: The role of cement-augmented screw fixation for calcaneal fracture treatment remains unclear. Therefore, this study was performed to biomechanically analyze screw osteosynthesis by reinforcement with either a calcium phosphate (CP)-based or polymethylmethacrylate (PMMA)-based injectable bone cement. METHODS: A calcaneal fracture (Sanders type IIA) including a central cancellous bone defect was generated in 27 synthetic bones, and the specimens were assigned to 3 groups. The first group was fixed with four screws (3.5 mm and 6.5 mm), the second group with screws and CP-based cement (Graftys® QuickSet; Graftys, Aix-en-Provence, France), and the third group with screws and PMMA-based cement (Traumacem™ V+; DePuy Synthes, Warsaw, IN, USA). Biomechanical testing was conducted to analyze peak-to-peak displacement, total displacement, and stiffness in following a standardized protocol. RESULTS: The peak-to-peak displacement under a 200-N load was not significantly different among the groups; however, peak-to-peak displacement under a 600- and 1000-N load as well as total displacement exhibited better stability in PMMA-augmented screw osteosynthesis compared to screw fixation without augmentation. The stiffness of the construct was increased by both CP- and PMMA-based cements. CONCLUSION: Addition of an injectable bone cement to screw osteosynthesis is able to increase fixation strength in a biomechanical calcaneal fracture model with synthetic bones. In such cases, PMMA-based cements are more effective than CP-based cements because of their inherently higher compressive strength. However, whether this high strength is required in the clinical setting for early weight-bearing remains controversial, and the non-degradable properties of PMMA might cause difficulties during subsequent interventions in younger patients.

Synergistic use of biomaterials and licensed therapeutics to manipulate bone remodelling and promote non-union fracture repair.

Disrupted bone metabolism can lead to delayed fracture healing or non-union, often requiring intervention to correct. Although the current clinical gold standard bone graft implants and commercial bone graft substitutes are effective, they possess inherent drawbacks and are limited in their therapeutic capacity for delayed union and non-union repair. Research into advanced biomaterials and therapeutic biomolecules has shown great potential for driving bone regeneration, although few have achieved commercial success or clinical translation. There are a number of therapeutics, which influence bone remodelling, currently licensed for clinical use. Providing an alternative local delivery context for these therapies, can enhance their efficacy and is an emerging trend in bone regenerative therapeutic strategies. This review aims to provide an overview of how biomaterial design has advanced from currently available commercial bone graft substitutes to accommodate previously licensed therapeutics that target local bone restoration and healing in a synergistic manner, and the challenges faced in progressing this research towards clinical reality.

Effect of bone morphogenetic protein-2/hydroxyapatite on ankle fusion with bone defect in a rabbit model: a pilot study.

BACKGROUND: Revision ankle-fusion surgery after a failure of total ankle arthroplasty has a problem with bone-defect management by implant removal. For the reconstruction of bone defects, autogenous bone often causes minor and major complications. Recombinant human-bone morphogenetic protein-2 (rhBMP-2) plays essential roles in bone regeneration strategies, and hydroxyapatite (HA) is beneficial as the rhBMP-2 carrier. In this study, we evaluate whether rhBMP-2/HA can replace autogenous bone in a rabbit ankle-fusion model with distal tibia bone defect. METHODS: The bone defect was created in the distal tibia. The ankle fusion was performed by a cannulated screw from lateral malleolus and various treatments on bone defect. Thirty male white New Zealand rabbits were divided into three groups of 10 animals on each group dependent on treatment methods as control group (no treatment into defect), auto-bone group (autogenous bone treatment), and rhBMP-2/HA group (40 µL of 1 µg/mL rhBMP-2/100 µL HA). Bone formation on defect and the union of the ankle joint were evaluated by X-ray, micro-CT, and histological analysis at 8 weeks and 12 weeks, postoperatively. RESULTS: Radiographic assessment found the control and auto-bone groups still had the bone defect present, but rhBMP-2/HA group showed complete replacement of the defect with newly formed bone at 12 weeks. Micro-CT showed significantly higher new bone formation within the defect in the rhBMP-2/HA group than in the auto-bone and control groups at 8 weeks (p > 0.05 and p < 0.01, respectively) and 12 weeks (p < 0.05, p < 0.001, respectively). Fusion rate (%) analysis of micro-CT showed a higher percentage of union in the rhBMP-2/HA group than in the auto bone and control groups at 8 weeks (p > 0.05, p < 0.001, respectively) and 12 weeks (p < 0.001 and p < 0.001, respectively). The histological showed the highest osteointegration between distal tibia and talus in the rhBMP-2/HA group at 12 weeks. CONCLUSIONS: This study indicated that rhBMP-2/HA showed much better bone fusion than did the autogenous bone graft and was effective in promoting fusion rate and improving the quality of the ankle joint fusion.

Bioactive glass granules S53P4 in osteotomy Le Fort I.

We evaluated bioactive glass graft (S53P4) in patients undergoing Le Fort I osteotomy, with non-grafted patients as controls. Computed tomography facial scans of the 25 patients submitted for Le Fort I were divided into two groups: Group 1-S53P4 group and Group 2-without grafting. CT scans were analyzed in the immediate postoperative period (T1) and 6 months later (T2), for linear bone gap measurements, tomographic radiodensity and behavior of the maxillary sinus. A Kruskal-Wallis test on bone gap data adopted α significance levels (p ≤ 0.05). The Friedman test (p ≤ 0.05) was used to evaluate sinus reaction cores. For gap measurements, we observed a decrease in median data between T1 and T2 in both groups, with statistical significances observed between groups in T0; G1 presented statistical difference in its two studied times (p ≤ 0.0001). For bone density, the studied data behaved inversely. G1's bone density decreased from T1 to T2, whereas in G2 there was an increase from T1 to T2. S53P4 did not elicit increased reactions and/or sinus infections in the G1 group (p ≥ 1.00). S53P4 did not impact on Le Fort I osteotomies as a coadjuvant and a favorable factor in bone formation, and appeared innocuous in the maxillary sinus.

Bone Marrow Edema, Clinical Significance, and Treatment Options: A Review.

Bone marrow edema (BME) is a descriptive term used to describe high-signal intensity changes detected on magnetic resonance fluid-sensitive sequences that could be attributed to a number of underlying pathologies. Regardless of the cause, physiologic remodeling of the subchondral bone can be limited because of ongoing joint forces, increased focalization of stress, and reduced healing capacity of the subchondral bone. BME is a known prognostic factor associated with pain, dysfunction, and progressive cartilage damage. This review summarizes the current known causes of BMEs, theories related to histopathological changes, and current treatment options including novel biologic surgical options.

Augmentation of Bone Regeneration by Depletion of Stress-Induced Senescent Cells Using Catechin and Senolytics.

Despite advances in bone regenerative medicine, the relationship between stress-induced premature senescence (SIPS) in cells and bone regeneration remains largely unknown. Herein, we demonstrated that the implantation of a lipopolysaccharide (LPS) sustained-release gelatin sponge (LS-G) increases the number of SIPS cells and that the elimination of these cells promotes bone formation in critical-sized bone defects in the rat calvaria. Histological (hematoxylin-eosin and SA-ß-gal) and immunohistological (p16 and p21 for analyzing cellular senescence and 4-HNE for oxidation) staining was used to identify SIPS cells and elucidate the underlying mechanism. Bone formation in defects were analyzed using microcomputed tomography, one and four weeks after surgery. Parallel to LS-G implantation, local epigallocatechin gallate (EGCG) administration, and systemic senolytic (dasatinib and quercetin: D+Q) administration were used to eliminate SIPS cells. After LS-G implantation, SA-ß-gal-, p16-, and p21-positive cells (SIPS cells) accumulated in the defects. However, treatment with LS-G+EGCG and LS-G+D+Q resulted in lower numbers of SIPS cells than that with LS-G in the defects, resulting in an augmentation of newly formed bone. We demonstrated that SIPS cells induced by sustained stimulation by LPS may play a deleterious role in bone formation. Controlling these cell numbers is a promising strategy to increase bone regeneration.

Implant stability in patients treated with platelet-rich fibrin and bovine bone substitute for alveolar ridge preservation is associated with peripheral blood cells and coagulation factors.

AIMS: The aim of the present study was to assess the association between dental implant stability and peripheral blood cell composition and levels of coagulation factors in patients treated with alveolar ridge preservation with platelet-rich fibrin (PRF) and bovine bone substitute. MATERIALS AND METHODS: Fifty patients were included between 2015 and 2017. PRF was prepared from autologous blood, in which blood cells and coagulation factor levels were measured. PRF and bovine bone were placed in the socket, followed by closure with PRF membrane. Implants were placed 14 (±2.5) weeks postextraction. The implant stability quotient was measured at t = 0, t = 10 days, t = 7 weeks, and t = 17 weeks by resonance frequency analysis. RESULTS: Erythrocyte count was inversely associated with PRF membrane length, but not with implant stability. Conversely, platelet count did not correlate with membrane size but inversely correlated with implant stability at 7 and 17 weeks. In addition, implant stability was directly correlated with levels FXIII (t = 0, p < .01), active von Willebrand factor (VWF; t = 0 and 7 weeks, p < .05), and total VWF (t = 7 weeks, p = .012). CONCLUSION: Implant stability following alveolar ridge preservation with PRF and bovine bone substitute is associated with circulating blood cells and coagulation factors. In particular, fibrin structure, VWF, and FXIII may be important modulators of implant stability.

3D-printed titanium implant-coated polydopamine for repairing femoral condyle defects in rabbits.

BACKGROUND: Large segmental bone defects are still one of the challenges for orthopaedic surgeons. Although 3D-printed porous titanium is a potential bone substitute material because of its porous structure simulating natural bone, the titanium surface has low bioactivity, integrates with bone tissue through the simple mechanical interlock. The study aims to investigate the capability and osteogenesis of 3D-printed porous titanium (3D PPT)-coated polydopamine (PDA) for repairing bone defects. METHODS: Fifteen 6-month New Zealand white rabbits were implanted with PDA-3D PPT to repair 6 mm × 10 mm defects on the femoral condyle compared with the group of 3D PPT and comparing with the blank group. After 6 weeks and 12 weeks, micro-CT and histological examination were performed to observe bone growth. RESULTS: All the PDA-3D PPT group, the 3D PPT group and the blank group recovered in good condition. The images showed that the boundaries between the implant area and the surrounding area were obscure in the three groups. The results of micro-CT demonstrated that at 6 weeks and 12 weeks, the bone volume (BV) values of PDA-3D PPT implants group were significantly higher than those of the 3D PPT implants group and blank group (P < 0.05), the BV/tissue volume (TV) and the trabecular number (Tb.N) of PDA-3D PPT implants were significantly higher than those of the 3D PPT group and blank group (P < 0.05). The results of un-decalcified bone slicing showed that ore new bone appeared to form around the PDA-3D PPT than that of 3D PPT and blank group. The bone-implant contact (BIC) of PDA-3D PPT was better (P < 0.05) than that of 3D PPT group. CONCLUSION: PDA-3D PPT could improve the bioactivity and promote the growth and healing of bone tissue and can be a promising repairing material.

Implantation of an Injectable Bone Substitute Material Enables Integration Following the Principles of Guided Bone Regeneration.

BACKGROUND/AIM: The present study investigates the in vivo tissue reaction and the integration behavior of an injectable bone substitute material (IBS) composed of a water-based gel combined with nano hydroxyapatite particles and biphasic calcium phosphate granules. The results of the IBS were compared to biphasic bone substitute granules (BBSM) of the same chemical composition. MATERIALS AND METHODS: The subcutaneous implantation model in 40 female 5-week-old CD-1 mice up to 60 days after implantation was used for conduction of the in vivo experiments. Moreover, established histological, histopathological and histomorphometrical methods were applied. RESULTS: The results showed that the IBS was gradually invaded by cells and complex tissue elements. Thus, the implant bed could be distinguished in two areas, i.e. an outer and inner region. While the outer region started to interact with the peri-implant tissue by evoking multinucleated giant cells and at earlier time points by undergoing a continuous high vascularization, the inner part was free of peri-implant cells for at least 30 days, starting to undergo a similar tissue reaction at a later time point. The bone substitute granules allowed for a fast tissue influx between the interspaces of the granules starting at day 10. While the vessel density did not differ in both groups up to the end of the study, the amount of vascularization was significantly higher over the entire observation period in the BBSM group. Moreover, the amount of biomaterial-associated multinucleated giant cells (BMGCs) was significantly higher in the IBS group in the period of between 15 to 30 days after implantation, while comparable BMGC numbers were found in both groups towards the end of the study. CONCLUSION: IBS can build a barrier-like structure that is able to control the soft tissue influx into the central regions of the implantation bed, which could not be observed in other bone substitute granules of the same chemical composition. This directed integration behavior is assumed to be in accordance with the concept of Guided Bone Regeneration (GBR). Furthermore, BMGCs can significantly influence the process of angiogenesis within an implant bed of a biomaterial but not the maturity of blood vessels.