Percentage Of New Bone Formation Research Articles

Effects of vitamin K2 administration on guided bone regeneration in diabetic rats.

The present study aimed to investigate the histomorphometric and immunohistochemical impacts of vitamin K2 on guided bone regeneration (GBR) in calvarial critical-size defects (CSDs) in diabetic rats. A total of 30 rats were used in this study, comprising 12 non-diabetic (control) rats and 18 with streptozotocin-nicotinamide-induced experimental Diabetes mellitus (DM). In all rats, two calvarial CSDs were created: one defect was left empty (E), the other was treated with bovine-derived bone graft and collagen-based resorbable membrane (GM). Study groups were as follows: control rats administered saline (n = 6, C-E and C-GM groups) or vitamin K2 (n = 6, CK-E and CK-GM groups) and diabetic rats administered saline (n = 6, DM-E and DM-GM groups) or vitamin K2 (n = 6, DMK-E and DMK-GM groups). After 4 weeks of saline or vitamin K2 administration, the rats were euthanized. Bone defect healing and new bone formation were assessed histomorphometrically, and osteocalcin and osteopontin levels were examined immunohistochemically. Percentage of new bone formation was greater in CK-GM vs. CK-E and in DMK-GM vs. DMK-E [d = 3.86 (95% CI = 16.38-28.61), d = 1.86, (95% CI = 10.74-38.58), respectively, p < .05]. Bone defect healing scores were higher in CK-GM vs. CK-E and in DMK-GM vs. DMK-E [d = 2.69 (95% CI = -2.12 to -0.87), d = 3.28 (95% CI = 0.98-1.91), respectively, p < .05]. Osteocalcin expression levels were elevated in CK-GM vs. CK-E, in DMK-GM vs. DMK-E [d = 1.19 (95% CI = 0.08-1.41), d = 1.10 (95% CI = 0.02-1.22), respectively p < .05]. Vitamin K2 enhanced osteocalcin expression levels in DMK-E vs. DM-E [d = 2.78, (95% CI = 0.56-1.53), p < .05] and in DMK-GM vs. DM-GM [d = 2.43, (95% CI = 0.65-2.10), p < .05]. Osteopontin expression was enhanced in defects treated with GM vs. E defects [C-GM vs. C-E, d = 1.56 (95% CI = 0.38-2.01); CK-GM vs. CK-E, d = 1.91 (95% CI = 0.49-1.72); DM-GM vs. DM-E, d = 2.34 (95% CI = -1.12 to -0.50); DMK-GM vs. DMK-E, d = 2.00 (95% CI = 0.58-1.91), p < .05]. The research findings suggest that administering vitamin K2 in GBR for rats with DM favorably impacts bone healing in CSDs, presenting an adjunctive strategy for bone regeneration.

Does Varying Platelet-Rich Fibrin Centri̇fugati̇on Protocols Enhance New Bone Formati̇on in Extracti̇on Site?

Finding a protocol that could prevent bone resorption and be implemented in clinical practice would be crucial in providing sufficient bone to replace missing teeth with implants. The study aimed to determine the effectiveness of different centrifugation platelet-rich fibrin (PRF) protocols in new bone formation and bone regenerative markers. This randomized clinical trial was conducted at Izmir Katip Çelebi Research Hospital, a population-based facility in Izmir. Study subjects were composed of patients who required extraction of anterior teeth. Exclusion criteria included periodontal disease, resorption of alveolar bone, defects, smoking, alcoholism, and systemic diseases. The independent variable was the PRF protocol. The subjects were randomly assigned to one of three groups: Leukocyte Platelet-Rich Fibrin (L-PRF), Advanced Platelet-Rich Fibrin (A-PRF) and control groups (healing naturally). The primary outcome of interest was the percentage of new bone formation, determined by analyzing the staining intensity in histomorphometric assessments of bone samples collected 8weeks after extraction. The secondary outcomes were regenerative effects measured by the immunohistochemical expression of markers such as osteocalcin, alkaline phosphatase, and proliferating cell nuclear antigen. Potential benefits were evaluated by clinical observations of pain, swelling, membrane visibility and healing. Age, sex and health conditions. Histologic comparative staining intensities and biomarkers expression between groups were evaluated by one way analysis of variance. A difference of P<.05 was considered statistically significant. The study included 57 subjects, with a mean age of 45years (±5.6); 29 were male (51%) and 28 female (49%). The control group had a mean new bone formation of 32.68% (±2.5), the A-PRF group 61.37% (±3.0), and the L-PRF group 70.74% (±3.5) (P<.001). The A-PRF group showed significantly higher osteocalcin expression than the control group (P=.013). Alkaline phosphatase and proliferating cell nuclear antigen expression scores for PRF groups were significantly higher than the control group's (P=.001). Both groups demonstrated significantly lower pain scores, reduced gingival swelling, better membrane visibility, and healing compared to the control group. PRF enhanced bone formation rates, with L-PRF showing the most significant effect.

Effect of Applying 1% Metformin on Guided Bone Regeneration Processes with Bovine-Derived Xenografts.

Background: Although xenografts have shown successful results in GBR procedures due to their osteoconductive properties, many authors have opted to add co-adjuvant drugs to favor osteogenesis and differentiate cells into an osteoblastic lineage. Metformin has been shown to have bone-protective properties, regulating osteoclast differentiation, as well as the ability to promote osteoblast mineralization and differentiation. The present study aimed to evaluate the effect of the local application of a 1% metformin solution on bone neoformation in the treatment of an experimental bone defect in a guided bone regeneration animal model with a particulated bovine hydroxyapatite xenograft with hyaluronate. Methods: With this purpose in mind, two critical defects with 8 mm diameter and 0.5 mm depth were created in eight male New Zealand rabbit calvarias. Titanium cylinders were fixed in each defect and filled with particulate hydroxyapatite of bovine origin and sodium hyaluronate, with sterile injectable saline added to the control group and sterile 1% metformin solution added to the test group. At 6 weeks, the animals were euthanized, and samples were obtained and prepared for histomorphometric analysis. Results: A higher percentage of new bone formation was observed in the metformin samples than in the control samples, both in the region closest to the animal's calvaria and in the most distal region analyzed. A higher average bone-biomaterial contact percentage was observed in the samples, with metformin in both the proximal and distal regions. There was no statistically significant difference in the mean value in either region in both parameters. Conclusion: The local application of a 1% metformin solution in an animal model of guided bone regeneration with particulate bovine hydroxyapatite and hyaluronate resulted in greater bone neoformation and xenograft osseointegration than in the control group.

Efficacy of autologous platelet concentrate products for alveolar preservation: A meta-analysis.

The purpose of the study was to systematically evaluate the efficacy of autologous platelet concentrate products in the preservation of the alveolar ridge after tooth extraction through meta-analysis and provide a theoretical basis for the clinical application of autologous platelet concentrates to reduce alveolar bone resorption. This study conducted a meta-analysis of clinical trials between 2013 and 2023, focusing on autologous platelet concentrate products (e.g., PRP, PRF, CGF, and PRCF) used for alveolar ridge preservation after tooth extraction. The analysis included 122 articles and 371 extraction sockets. All statistical analyses were performed using Review Manager version 5.4. Results indicate that these platelet concentrates effectively reduced changes in horizontal width 1 mm below the alveolar crest and vertical socket height. They also promoted a higher percentage of new bone formation in extraction sockets compared with control groups. However, they did not significantly prevent horizontal bone resorption at 3 and 5 mm below the alveolar crest. In conclusion, autologous platelet concentrates are useful for alveolar ridge preservation, but larger clinical studies are needed to confirm these findings due to the relatively small sample size in this study.

Comparison of the healing process of xenografts with three different sources in critical-size bone defects: An in vivo study.

Xenograft bone substitutes can be obtained from different animals and processed using various methods. The present in vivo study evaluated bone regeneration after using three types of xenografts with different sources in critical-sized bone defects in rabbit calvaria. Four 8-mm defects were created in calvaria of 14 New Zealand and white male rabbits. Three out of four defects were filled with xenografts of bovine, camel, and ostrich sources. The fourth defect was left unfilled as the control group. Seven rabbits were sacrificed after eight weeks and seven others after 12 weeks. Micro-CT imaging and histologic evaluation were further performed on dissected calvarias. After 8 and 12 weeks, the highest and lowest percentages of new bone formation were observed in the camel (27.71% and 41.92%) and control (11.33% and 15.96%) groups, respectively. In the case of residual material, the ostrich group had the most value after eight weeks (53%), while after 12 weeks, it was highest in the camel group (37%). Micro-CT findings were consistent with histologic results. Although all three xenografts can be good choices for treating bone defects, camel-sourced xenograft seemed to be better than the other two groups. The origin and processing procedures of xenografts affected their final characteristics, which should be considered for clinical use.

Effects of Photobiomodulation Using Low-Power Diode Laser Therapy and Nano-bone on Mandibular Bone Regeneration in Rats.

Introduction: Recently, the positive effects of photobiomodulation (PBM) and nano-bone on bone regeneration have garnered significant attention. The purpose of the research was to assess the impact of PBM and nano-bone on the process of mandibular bone repair in mice. Methods: A 4-mm diameter bone defect was created in the left mandibular angle of 24 mice separated into 4 equal groups: group I: control; group II: PBM by irradiation at 100 mW of a 980 nm diode laser for one minute (three sessions per week; day on and day off); group III: nano-bone; group IV: PBM with nano-bone. Every group was sectioned into 3 equal subgroups corresponding to the evaluation method period: (A) one week, (B) two weeks, and (C) four weeks. Histological examination was done with hematoxylin, eosin, and Masson's Trichrome after one, two and four weeks for inflammation, bone defect coverage, vascularization within the newly formed bone, and new bone formation. Statistical analysis of the data was done and presented as percentage values using chi-square. The significance level was set at P value≤0.05 within all tests. Results: In general, by histological examination of the mandibular bone defect of the rats, the intensity of inflammation was the least in group IV when compared with groups II and III and the control group at all evaluation periods (P<0.001). Also, group IV showed a high significant rise in the percentage of new bone formation following four weeks when compared with the control (P≤ 0.001) and groups II and III (P<0.001). Conclusion: The present research results confirmed that the combination of PBM and nano-bone can aid in the repair of mandibular bone abnormalities. This animal study suggests that the use of PBM and nano-bone should be investigated further in clinical studies.

Evaluation of Two Anorganic Bovine Xenogenous Grafts in Bone Healing of Critical Defect in Rats Calvaria.

The purpose of this study was to provide an evaluation of two different xenogeneic bone substitutes in bone healing of critical-sized bone defects (Ø =5mm) created in rats calvaria. Thirty animals were randomized into 3 groups with one of the following treatments. In the control group (n=10), the defects were filled with blood clots; BO group (n=10), the defects were filled with bovine medullary bone substitute (Bio-Oss®); BF group (n=10), the defects were filled with bovine cortical bone substitute (Bonefill®). All defects were covered with an absorbable membrane. Five animals from each group were euthanized at 30 and 45 days, subsequently histomorphometrical and immunohistochemical analyses were performed. The histomorphometry was used to measure the percentage of new bone formation in the total area of the defect while the immunohistochemistry evaluated the expression of bone immunomarkers for bone morphogenetic protein 2/4 (BMP2/4), osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP). Data was statistically analyzed with a 5% significance level. The results demonstrated that the BO group showed greater bone formation compared to the BF group at 30 days (P<0.05). However, there was no statistically significant difference between the control and BO groups at 30 days (P>0.05). The expression of BMP2/4 and OCN were higher in the BO group at 45 days compared to the BF at 30 and 45 days respectively (P<0.05). In conclusion, even with the higher expression of proteins related to bone formation, there was no difference in new bone formation at 45 days when both anorganic bovine xenogenous grafts were evaluated.

Enamel Matrix Derivatives as an Adjunct to Alveolar Ridge Preservation—A Systematic Review

To systematically assess the current evidence regarding the adjunctive application of enamel matrix derivatives (EMDs) during alveolar ridge preservation (ARP) following tooth extraction. A comprehensive literature search was conducted in MEDLINE, Cochrane Library, PsycINFO, Web of Science, Google Scholar, and Scopus to identify relevant randomized controlled clinical trials (RCTs). The primary outcome parameters of this systematic review were histomorphometric and radiographic data; secondary outcomes were the feasibility of implant placement after ARP as well as patient-related outcomes such as postoperative discomfort. The search identified 436 eligible articles published from 2011 to 2022, but only five were ultimately included for data extraction (146 patients). Given the substantial heterogeneity among the included studies, no meta-analysis could be performed. The authors' qualitative analysis showed marginally improved outcomes regarding an increased percentage of new bone formation after tooth extraction and a reduction in postoperative discomfort. Given the potential value of EMDs in other fields of regenerative dentistry, more consideration should be given to EMDs as an adjunctive treatment option in ARP. However, more well-controlled randomized clinical trials are necessary to evaluate the exact potential and impacts of EMDs.

Comparison of bioresorbable bone substitutes, carbonate apatite and β‐tricalcium phosphate, for alveolar bone augmentation with simultaneous implant placement

AbstractAimThis study histologically compared two bioresorbable bone substitutes with different composition, carbonate apatite (CO3Ap) and beta‐tricalcium phosphate (β‐TCP), through alveolar bone augmentation with simultaneous titanium implant placement in beagle dogs.MethodsBone defects (length 7 mm, width 2 mm, and depth 6 mm) were created bilaterally at mandibular premolar sites and augmented with either CO3Ap or β‐TCP granules after titanium implant installation. The specimens with the surrounding tissue were harvested from the mandible at 4, 12, and 24 weeks postoperatively, and histological evaluation was performed.ResultsMost β‐TCP granules dissolved in early stages postoperatively, resulting in a lower volume of alveolar bone surrounding the titanium implant. By contrast, in the case of CO3Ap group, the alveolar ridge was reconstructed without reducing the alveolar bone height, and almost all implant threads were covered with new bone by at least 12 weeks postoperatively. Quantitatively, the CO3Ap group showed a significantly higher percentage of new bone formation in the alveolar ridge portion at all follow‐ups. Additionally, it demonstrated a significantly higher bone‐to‐implant contact ratio than that of the β‐TCP group at 12 and 24 weeks after implantation (70.8 ± 5.6% vs. 29.3 ± 16.4% and 54.8 ± 6.9% vs. 41.8 ± 2.2%, respectively).ConclusionIn conclusion, based on the superior outcomes noted in this study, CO3Ap is useful for clinical use in alveolar bone augmentation with simultaneous implant placement.

Optimization of Fluorapatite/Bioactive Glass Nanocomposite Foams as Bone Tissue Scaffold: An in Vivo Study.

The present study investigated the suitability of nanocomposite foams of fluorapatite and bioactive glass (FA /BG) in different weight ratios as scaffolds for bone tissue in rat tibia regeneration to determine the optimal composition. FA and BG nano powders with a weight ratio of 25% FA/75% BG (compound 1) and 75% FA/25% BG (compound 2) were used as precursors for gel casting to produce nanocomposite foams. Thirty rats were randomly divided into two equal groups. Disk-shaped samples of each compound were implanted into the tibias of 15 rats. After 15, 30, or 60 days, five rats from each group were sacrificed and subjected to radiological, histopathological, and histomorphometrical examination. Data were analyzed using SPSS software. No foreign body reaction was observed in either group at all intervals, and the bone-biomaterial junction was direct. Overall, the inflammation rate, and the number of blood vessels, osteoblasts, and osteoclasts decreased over time in both groups. However, the number of osteocytes, trabecular bone thickness, and the percentage of new bone formation increased, in contrast to the remaining biomaterial percentage. Most of the changes in the group implanted with compound 2 were significantly more significant and faster than in the other group. Although the composite with the higher percentage of FA was superior to the composite with the higher percentage of BG, considering the results of our previous similar studies, the composite with the same percentage of FA and BG is more favorable to be used as a substitute for bone tissue in the body.

Effect of Injectable platelet-rich fibrin (i-PRF) on new bone formation in surgical expansion with mini-screw assisted rapid palatal expander: A dog model study

The objective of the study is to test whether the local injection of i-PRF may affect osteoblast, blood vessels and new bone formation in surgically expanded mid palatal suture using maxillary skeletal expander.Eighteen adult male local breed dogs were divided randomly into three groups: group I (control), includes the expansion with maxillary skeletal expander that was done without corticotomy and i-PRF. Group II, involves the expansion that was done with mid palatal corticotomy but without i-PRF injection. Group III, has the expansion that was done with mid palatal corticotomy and has injection with 2 ml of i-PRF. Each group consisted of 6 dogs which were subdivided into 3 dogs. Three dogs were sacrificed after 15 days and the other 3 dogs were sacrificed after 45 days. The number of osteoblast, blood vessels and new bone formation percentage were statistically analyzed using Sigma plot platform. Mean and standard error, ANOVA and Duncan were performed among the different groups. Values of P ≤ 0.05 were considered significant.After expansion, the i-PRF group demonstrated a considerable increase in the amount of new bone in the mid-palatal suture at 15 and 45 days compared with other 2 groups which were indicated by highest percentages of new bone formation (29.30% of 15 days and 76.55% at 45 days) if compared to control group which were (7.72% at 15 days and 22.30% at 45 days). The corticotomy groups were in between, 15.33% and 46.84% respectively. Moreover the number of osteoblasts was higher in corticotomy with i-PRF group on 15 days and decreased on 45 days than the other two groups, while the blood vessels were highest in this group than the other two groups both on 15 and 45 days.I-PRF enhanced the production of osteoblast, blood vessels, and new bone in the surgically expanded mid palatal suture.

Effect of commercially pure titanium implant coated with calcium carbonate and nanohydroxyapatite mixture on osseointegration.

In this research, rabbit femurs were implanted with CP Ti screws coated with a combination of CaCO3 and nanohydroxyapatite, and the effect on osseointegration was assessed using histological and histomorphometric examination at 2 and 6 weeks. CaCO3 and nanohydroxyapatite were combined with the EPD to coat the surfaces of the CP Ti screws. The femurs of five male rabbits were implanted with coated and uncoated implant screws. Healing time was divided into two groups (2 and 6 weeks). After 2 and 6 weeks of implantation, the histological examination revealed an increase in the growth of bone cells for coated screws, and the histomorphometric analysis revealed an increase in the percentage of new bone formation (after 6 weeks, 5.08% for coated implants and 3.66% for uncoated implants). In addition, the uncoated implant, the CP Ti implant coated with a combination of CaCO3 and nanohydroxyapatite, stimulated early bone development after two weeks and mineralization and maturation after six weeks.

Comparing the effect of demineralized versus hybrid dentin matrices on inducing bone regeneration in New Zealand white rabbits' Mandibular defect

ObjectivesThe aim of this study was to compare the effect of using demineralized dentin matrix (DDM) versus hybrid dentin matrices; Demineralized and undemineralized dentin particles (DDM +UDDM) on inducing bone regeneration in mandibular defects. DesignThe study was conducted on fifty adult New Zealand rabbits, twenty for preparation of experimental materials and thirty for surgical procedures. They were randomly assigned into 3 equal groups as follow one control group: no treatment and two experimental groups including demineralized group: treated with DDM only; and hybrid group: treated with a hybrid of (50% DDM+50% UDD). A rounded critical size defect (10 mm in diameter- 5 mm in depth) was created in the body of mandible. After 3- and 6-weeks post-surgery, the bone regeneration was evaluated by light microscope, scanning electron microscope and histomorphometry. ResultsHistological, histomorphometrical observation and SEM revealed that both dentin matrices had largely resorbed and induced new bone formation at both experimental groups compared to the control group, with statistically higher percentage of new bone formation in the hybrid group. ConclusionWe concluded that although both dentin matrices induced new bone formation; however, hybrid dentin matrix yielded better results compared to DDM group.

Evaluation of the Effects of Dual Antiplatelet Therapy on Guided Bone Regeneration in Peri-Implant Bone Defect.

In this study, the authors aim to investigate the effect of dual antiplatelet agents on peri-implant-guided bone regeneraation by studying a sample of rats with titanium implants in their tibias. The rats were randomly divided into 5 groups: acetylsalicylic acid (ASA) (n=10), treated with 20mg/kg of ASA; ASA+CLPD (Clopidogrel): (n=10), treated with 20mg/kg of ASA and 30mg/kg of clopidogrel; ASA+PRSG (Prasugrel): (n=10), treated with 20mg/kg of ASA and 15mg/kg of prasugrel; ASA+TCGR (Ticagrelor): (n=10), treated with 20mg/kg of ASA and 300mg/kg of ticagrelor; and a control group (n=10) received no further treatment after implant surgery. Bone defects created half of the implant length circumferencial after implant insertion and defects filled with bone grafts. After 8 weeks experimental period, the rats sacrified and implants with surrounding bone tissues were collected to histologic analysis; bone filling ratios of defects (%) and blood samples collected to biochemical analysis (urea, creatinine, aspartate aminotransferase, alanine aminotransferase, phosphorus, magnesium, alkaline phosphatase, calcium, and parathormone). A statistically significant difference was not detected between the groups for all parameters ( P >0.05). When the percentage of new bone formation was examined, it was found that there was no statistically significant difference between the groups ( P >0.05). Antiplatelet therapy may not adversely affect guided bone regeneration in peri-implant bone defects.

The efficacy of vancomycin-loaded biphasic calcium phosphate bone substitute in the promotion of new bone growth and the prevention of postoperative infection.

Background: Due to the increasing need for suitable alternatives to bone grafts, artificial bones made of biphasic calcium phosphate (BCP) are currently being extensively researched. These porous bone substitutes have also demonstrated considerable incorporation with the host bone, and new bone is able to grow within the porous structure. They therefore offer a potential therapeutic approach for bone defects. Methods: Vancomycin-loaded Bicera™, a BCP bone substitute, was investigated in order to prevent implant-associated osteomyelitis and postoperative infection after orthopedic surgery. The loading capacity of Bicera™ was measured to understand its potential antibiotic adsorption volume. An antibiotic susceptibility test was also carried out to analyze the effect of Bicera™ loaded with different concentrations of vancomycin on the growth inhibition of methicillin-resistant Staphylococcus aureus (MRSA). Vancomycin-loaded Bicera™ was implanted into rabbits with bone defects, and general gross, radiographic, and histological evaluation was undertaken at 4, 12, and 24weeks after implantation. Results: The maximum loading capacity of vancomycin-loaded Bicera™ was 0.9ml of liquid regardless of the vancomycin concentration. Antibiotic susceptibility tests showed that vancomycin-loaded Bicera™ inhibited the growth of MRSA for 6weeks. In addition, animal studies revealed that new bone grew into the vancomycin-loaded Bicera™. The percentage of new bone formation from 4 to 24weeks after implantation increased from 17% to 36%. Conclusion: Vancomycin-loaded Bicera™ could effectively inhibit the growth of MRSA in vitro. It was found to incorporate into the host bone well, and new bone was able to grow within the bone substitute. The results of this study indicate that vancomycin-loaded Bicera™ is a potential bone substitute that can prevent implant-associated osteomyelitis and postoperative infection.

Effect of Diclofenac and Simvastatin on Bone Defect Healing-An In Vivo Animal Study.

Non-steroidal, anti-inflammatory drugs and statins are two widely prescribed drug classes that affect bone formation. The aim of this study was to elucidate the effect of diclofenac and simvastatin in artificial bone defect healing. One hundred and forty-four male Wistar rats were used, and the specimens were divided into groups, with respect to the route of drug administration and the type of defect healing (with or without collagen membrane), and subgroups, with respect to the study duration (2, 4 or 8 weeks). Diclofenac was intramuscularly administered while simvastatin was administered both systemically and locally. Animals were euthanized and specimens were histomorphometrically analyzed to evaluate the percentage of new bone formation (%). Bone healing that occurred without any intervention developed more steadily than that of all other groups. Diclofenac exerted a clear, direct inhibitory effect on bone healing and its systemic administration should be avoided. The systemic administration of simvastatin was related to severe myopathy, while the solvent for the local administration of simvastatin seemed to play significant role in bone growth, as simvastatin, when it is administered intraperitoneally in a DMSO solution, appeared to promote bone healing. Local administration may have a significant impact on bone healing and it should be further investigated with the type of solvent or carrier that is used, which both may play a significant role in bone repair induction.

Octacalcium Phosphate/Gelatin Composite (OCP/Gel) Enhances Bone Repair in a Critical-sized Transcortical Femoral Defect Rat Model.

Bone grafting is widely used to treat large bone defects. A porous composite of a bioactive octacalcium phosphate material with gelatin sponge (OCP/Gel) has been shown to biodegrade promptly and be replaced with new bone both in animal models of a membranous bone defect and a long bone defect. However, it is unclear whether OCP/Gel can regenerate bone in more severe bone defects, such as a critical-size transcortical defect. Using an in vivo rat femur model of a standardized, transcortical, critical-size bone defect, we asked: Compared with a Gel control, does OCP/Gel result in more newly formed bone as determined by (1) micro-CT evaluation, (2) histologic and histomorphometric measures, and (3) osteocalcin staining and tartrate-resistant acid phosphatase staining? Thirty-four 12-week-old male Sprague-Dawley rats (weight 356 ± 25.6 g) were used. Gel and OCP/Gel composites were prepared in our laboratory. Porous cylinders 3 mm in diameter and 4 mm in height were manufactured from both materials. The OCP/Gel and Gel cylinders were implanted into a 3-mm-diameter transcortical critical-size bone defect model in the left rat femur. The OCP/Gel and Gel were randomly assigned, and the cylinders were implanted. The biological responses of the defect regions were evaluated radiologically and histologically. At 4 and 8 weeks after implantation, CT evaluation, histological examination of decalcified samples, and immunostaining were quantitatively performed to evaluate new bone formation and remaining bone graft substitutes and activity of osteoblasts and osteoclast-like cells (n = 24). Qualitative histological evaluation was performed on undecalcified samples at 3 weeks postimplantation (n = 10). CT and decalcified tissue analysis was not performed blinded, but an analysis of undecalcified specimens was performed under blinded conditions. Radiologic analysis revealed that the OCP/Gel group showed radiopaque regions around the OCP granules and at the edge of the defect margin 4 weeks after implantation, suggesting that new bone formation occurred in two ways. In contrast, the rat femurs in the Gel group had a limited radiopaque zone at the edge of the defect region. The amount of new bone volume analyzed by micro-CT was higher in the OCP/Gel group than in the Gel group at 4 and 8 weeks after implantation (​​4 weeks after implantation: OCP/Gel versus Gel: 6.1 ± 1.6 mm 3 versus 3.4 ± 0.7 mm 3 , mean difference 2.7 [95% confidence interval (CI) 0.9 to 4.5]; p = 0.002; intraclass correlation coefficient [ICC] 0.72 [95% CI 0.29 to 0.91]; 8 weeks after implantation: OCP/Gel versus Gel: 3.9 ± 0.7 mm 3 versus 1.4 ± 1.1 mm 3 , mean difference 2.5 [95% CI 0.8 to 4.3]; p = 0.004; ICC 0.81 [95% CI 0.47 to 0.94]). Histologic evaluation also showed there was a higher percentage of new bone formation in the OCP/Gel group at 4 and 8 weeks after implantation (​​4 weeks after implantation: OCP/Gel versus Gel: 31.2% ± 5.3% versus 13.6% ± 4.0%, mean difference 17.6% [95% CI 14.2% to 29.2%]; p < 0.001; ICC 0.83 [95% CI 0.53 to 0.95]; 8 weeks after implantation: OCP/Gel versus Gel: 28.3% ± 6.2% versus 9.5% ± 1.9%, mean difference 18.8% [95% CI 11.3% to 26.3%]; p < 0.001; ICC 0.90 [95% CI 0.69 to 0.97]). Bridging of the defect area started earlier in the OCP/Gel group than in the Gel group at 4 weeks after implantation. Osteocalcin immunostaining showed that the number of mature osteoblasts was higher in the OCP/Gel group than in the Gel group at 4 weeks (OCP/Gel versus Gel: 42.1 ± 6.5/mm 2 versus 17.4 ± 5.4/mm 2 , mean difference 24.7 [95% CI 16.2 to 33.2]; p < 0.001; ICC 0.99 [95% CI 0.97 to 0.99]). At 4 weeks, the number of osteoclast-like cells was higher in the OCP/Gel composite group than in the Gel group (OCP/Gel versus Gel: 3.2 ± 0.6/mm 2 versus 0.9 ± 0.4/mm 2 , mean difference 2.3 [95% CI 1.3 to 3.5]; p < 0.001; ICC 0.79 [95% CI 0.35 to 0.94]). OCP/Gel composites induced early bone remodeling and cortical bone repair in less time than did the Gel control in a rat critical-size, transcortical femoral defect, suggesting that OCP/Gel could be used as a bone replacement material to treat severe bone defects. In a transcortical bone defect model of critical size in the rat femur, the OCP/Gel composite demonstrated successful bone regeneration. Several future studies are needed to evaluate the clinical application of this interesting bone graft substitute, including bone formation capacity in refractory fracture and spinal fusion models and the comparison of bone strength after repair with OCP/Gel composite to that of autologous bone.

Lateral Ridge Augmentation Using Cross-Linked or Non-Cross-Linked Collagen Membrane: A Pilot Randomized Clinical Trial

Purpose: The aim of this investigation is to test, in a lateral ridge augmentation model without simultaneous implant placement, the effect of using a cross-linked collagen membrane and a non-cross-linked collagen membrane on guided bone regeneration. Material and Methods: Edentulous alveolar ridges of less than 5 mm width were treated with guided bone regeneration using a glutaraldehyde cross-linked collagen membrane (CL) or a non-cross-linked collagen membrane (NonCL). In all treated cases the bone graft used was a combination of autogenous bone scrapings and deproteinized bovine bone mixed in a 1:3 ratio. Ridge measurements were recorded clinically (during augmentation surgery and during implant placement surgery) and radiographically on the CBCT scans (pre-op, 1 week post-op and at implant placement). All ridge measurements were recorded at 1, 3 and 5 mm from the ridge crest. Soft tissue healing was assessed during the follow-up visits at 1, 2, 4, 8, 12, 16, 20 and 24 weeks post-op. A histological analysis was performed on core biopsies retrieved axially from implant or pontic sites. Results: Four patients were recruited and randomly allocated to treatment groups. Ridge width gain (RWgain) was significantly better for the CL group as assessed clinically. At 1, 3 and 5 mm from ridge crest, the clinically assessed gain was respectively 5.50 mm ± 2.121, 5.40 mm ± 2.074, 5.60 mm ± 1.140 for the CL group and -1.33 mm ± 0.577, 1.33 mm ± 2.517 and 2.00 mm ± 1.000 for the NonCL group. Graft volume resorption was significantly higher in the NonCL group (62%) in comparison to the CL group (10.9%). No soft tissue complications occurred during follow-ups in neither group. Histologically, both groups showed signs of bone remodeling and vital bone formation. New bone formation in the NonCL group was 23.64 % ± 0.64 and in the CL group was 15.75% ± 8.73. Conclusion: Despite the limitations of this pilot study, The CL membrane showed better performance than the NonCL membrane in terms of ridge width gain and in terms of graft volume consolidation as assessed clinically and radiographically. Although no statistical comparison was possible, the NonCL group presented a higher percentage of new bone formation than the CL group.

Histological Evaluation of Bone Regeneration Using Hydroxyapatite Based Bone Substitute Derived from Antler: An Animal Study.

Guided bone regeneration (GBR) is considered as a prerequisite in some cases of implant dentistry. For this purpose, bone materials are commonly used. Calcium compounds and Ca-P based materials like hydroxyapatite (HA, Ca10 (PO4)6(OH)2), due to their similarity with the human bone, can be used as graft materials for bone regeneration. This study aimed to evaluate biocompatibility of antler xenograft and compare the osteoconduction effects of antler xenograft with Cerabone in regeneration of calvarium bony defects of rabbits. Five defects with a diameter of 6 mm and a depth of 3 mm were prepared in the calvarium of four rabbits. Thereafter, two defects were randomly grafted with antler xenograft, two defects were filled with Cerabone, and one defect remained as the untreated group. Histological evaluations, including measuring percentage of new regenerated bone and the amounts of osteoblast, osteoclast, and osteocyte cells, were also performed. To do statistical analyses, paired t-test, chi-square, and Fisher tests were applied. The percentage of new bone formation was significantly higher in antler xenograft (73.33%) and in Cerabone (48.91%) compared to the untreated group (18.91%). The amounts of osteocytes and osteoblasts were obtained as 3.52 ± 0.17 and 2.41 ± 0.24 in the Antler xenograft and as 2.57 ± 0.29 and 2.31 ± 0.32 in the Cerabone group, respectively. Bone marrow formation were significantly higher in antler xenograft (6.66 ± 5.34) and Cerabone (1.99 ± 3.17) compared to the untreated group. According to this pilot study, results of using antler xenograft as an osteoconductive materials in regeneration of rabbit calvarial defects are comparable with Cerabone. Although more clinical studies are needed.

Histological evaluation of gelatin/beta-tricalcium phosphate sponges with or without concentrated growth factor in localized class II gingival recession

ObjectivesThe aim of this study was to evaluate, histologically, the effectiveness of using gelatin sponge loaded with β-tricalcium phosphate with or without concentrated growth factor (CGF) (groups I and III) versus collagen with CGF (group II) in the treatment of Miller class II gingival recession in experimentally created bony defects in Egyptian Baladi dogs.Materials and MethodsTwenty-four Miller class II gingival recession experimentally created defects in three Egyptian Baladi dogs were used in the present study. Six identical recession defects in three quadrants were created in upper and lower canines and premolars. Each quadrant received one of the three treatment modalities which were to be evaluated. The remaining two sites served as the control with a total of six control sites. Three dogs were euthanized after 12 weeks, and samples were collected for histological and histomorphometric analysis.ResultsExperimental defects of all groups showed distinct types of new attachment with variable degree of regeneration and repair of new cementum, bone, and periodontal fibers. The control group exhibited attachment with a long junctional epithelium. In group I, four defects showed new attachment with periodontal ligament (PDL)-like tissue whereas two defects healed with long junctional epithelium. Five defects in group II displayed new attachment with PDL-like tissue whereas the last defect demonstrated attachment with long junctional epithelium. While in group III, all defects showed new attachment with PDL-like tissues. The histomorphometrical analysis revealed a highly significant increase in the percentage of new bone formation in group III when compared to the other groups, followed by group II then group I, with the least bone formation in the control group.ConclusionThe results of the present study indicated that, gelatin sponge loaded with β-tricalcium phosphate with or without CGF (groups I and III) and collagen with CGF (group II), all led to favorable histological outcomes. It was therefore postulated that, the addition of CGF may have been a potentiating material, which could have enhanced periodontal tissue repair.