Percentage Of New Bone Formation Research Articles

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.

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.

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.

Dimensional and histomorphometric evaluation of biomaterials used for alveolar ridge preservation: a systematic review and network meta-analysis.

This systematic review and network meta-analysis aimed to answer to the following questions: (a) In patients undergoing alveolar ridge preservation after tooth extraction, which grafting material best attenuates horizontal and vertical ridge resorption, as compared to spontaneous healing?, and (b) which material(s) promotes bone formation in the extraction socket? The MEDLINE, SCOPUS, CENTRAL, and EMBASE databases were screened in duplicate for RCTs up to March 2021. Two independent authors extracted the data and assessed the risk of bias of the included studies. Primary outcomes were ridge horizontal and vertical dimension changes and new bone formation into the socket. Both pairwise and network meta-analysis (NMA) were undertaken to obtain estimates for primary outcomes and compare different grafting materials. Eighty-eight RCTs were included, with a total of 2805 patients and 3073 sockets. Overall, a total of 1740 sockets underwent alveolar ridge preservation with different materials (1432 were covered by a membrane). Pairwise meta-analysis showed that, as compared to spontaneous healing, all materials statistically significantly reduced horizontal and vertical shrinkage. According to the multidimensional scale ranking of the NMA, xenografts (XG) and allografts (AG), alone or combined with bioactive agents (Bio + AG), were the most predictable materials for horizontal and vertical ridge dimension preservation, while platelet concentrates performed best in the percentage of new bone formation. Alveolar ridge preservation is effective in reducing both horizontal and vertical shrinkage, as compared to untreated sockets. NMA confirmed the consistency of XG for ridge dimension preservation, but several other materials and combinations like AG, Bio + AG, and AG + alloplasts, produced even better results than XG in clinical comparisons. Further evidence is needed to confirm the value of such alternatives to XG for alveolar ridge preservation. Bio + AG performed better than the other materials in preserving ridge dimension and platelet concentrates in new bone formation. However, alloplasts, xenografts, and AG + AP performed consistently good in majority of the clinical comparisons. XG and Bio + AG demonstrated significantly better performance in minimizing post-extraction horizontal and vertical ridge dimension changes as compared with other grafting materials or with spontaneous healing, even if they presented the worst histological outcomes. Allografts and other materials or combinations (AG + AP) presented similar performances while spontaneous healing ranked last.

Recombinant factors for periodontal intrabony defects: A systematic review and network meta-analysis of preclinical studies.

The use of bioactive agents combined with osteoconductive scaffolds for the regeneration of periodontal intrabony defects has been the subject of intensive research in the past 20years. Most studies reported that such agents, used in different concentrations, doses and combined with various scaffolds, might promote periodontal tissue regeneration, but evidence for the most effective combination of such agents is lacking. The objective of this study 13 was to rank the different combinations of recombinant human-derived growth and differentiation factors with/without scaffold biomaterial in the treatment of periodontal intrabony defects, through network meta-analysis of pre-clinical studies. The systematic review and network meta-analysis protocol was registered on the PROSPERO Systematic Review database with reference number: CRD42021213673. Relevant published articles were obtained after searching five electronic databases. A specific search strategy was followed by using keywords related to intrabony defects, regenerative materials, scaffolds and recombinant factors, and animal studies. All pre-clinical studies used for periodontal regeneration were included. The primary outcomes were: regeneration of junctional epithelium (mm), new cementum, connective tissue attachment, percentage of new bone formation (%), bone area (mm2 ), bone volume density (g/cm3 ) and bone height (mm) data was extracted. The analysis was carried out using network meta-analysis methods, that is illustrating network plots, contribution plots, predictive and confidence interval plot, surface under the cumulative ranking (SUCRA), multidimensional scale ranking and net funnel plots using STATA IC statistical software. An SYRCLE's tool for assessing risk of bias was used for reporting risk of bias among individual studies. A total of N=24 for qualitative and N=21 studies for quantitative analysis published till 2020 were included. The cumulative total number of animals included in the control and test groups were N=162 and N=339, respectively. The duration of the study was between 3 and 102weeks rhBMP-2 ranked higher in SUCRA as the agent associated with the best performance for bone volume density. rhGDF-5/TCP ranked best in the bone area (mm2), rhPDGF-BB/Equine ranked best in bone height (mm), rhBMP-2 ranked best in the percentage of new bone fill, rhBMP-2/ACS ranked best in new cementum formation, and rhGDF-5/b- TCP/PLGA ranked best in connective tissue attachment and junctional epithelium. There were no adverse effects identified in the literature that could affect the different outcomes for regeneration in intrabony defects. Various recombinant factors are effective in promoting the regeneration of both soft and hard tissue supporting structures of the periodontium. However, when considering different outcomes, different agents, associated or not with biomaterials, ranked best. Keeping into account the limited transferability of results from animal studies to the clinical setting, the choice of the most appropriate formulation of bioactive agents may depend on clinical needs and purpose.

Impact of Different Platelet Concentrates Application on Bone Regeneration. An Experimental Study

Purpose: This experimental study was to evaluate and compare bone regeneration capacity of experimental bone defects filled with different autologous platelet concentrates (APCs) as a bone graft material in the rabbit’s tibiae. Material and methods: A total of forty-two adult rabbits were included in this study. After creation of bone defects, the animals were randomly assigned to three groups. In control group, no bone graft was used (Group A, n=14), in one test group Plasma Rich in Growth Factors (PRGF) was used as bone graft material (Group B, n=14), and in the other test group Injectable Platelet Rich Fibrin (i-PRF) was used as bone graft material (Group C, n=14). After implantation, each group was further divided into two subgroups, where rabbits were sacrificed 2 and 4 weeks postoperatively and the defects were evaluated with histologic and histomorphometric analysis. Results: Both test groups (Group B and Group C) treated with APCs (PRGF: 10.92±0.85 & 41.53±2.55and i-PRF: 13.13±0.68 &57.27±1.66 at 2 and 4 weeks respectively) demonstrated higher percentages of new bone formation than the control group (5.11±1.15 & 30.31±1.29 at 2 and 4 weeks respectively) (P < 0.001). Significant difference was found between the two test groups and control group (P < 0.001). On the other hand, significant difference was found between test groups (P < 0.001). Conclusions: Within the limitation of this animal study, the adjunct implication of either i-PRF or PRGF in endodontic surgery may be of great significance as it dramatically improves bone regeneration.

Assessment of cell phone effect on dental socket healing in rat.

Electromagnetic waves can cause biological effects on repair process. Due to the proximity of the jawbone and the soft tissue around it in a part of the face with which it has the closest contact during the cell phone use, this study aims to investigate the effect of mobile waves on socket healing after tooth extraction in rats. This experimental study was conducted on 32 rats. The case group was exposed to a 900 MHz frequency electromagnetic field for 30 min/d. Sacrificed eight rats from the case group and 7 rats from the control group on day 14, and 8 rats from the case group and 7 rats from the control group were sacrificed on day 28 at the end of the radiation period and CBCT and microscopic examinations on the maxillary bones and soft tissue were performed. According to the findings, the healing process was significantly different in two groups in terms of the percentage of new bone formation on day 14 after the end of radiation (P=0.014). The other measured parameters including the degree of inflammation, thickness of the formed bone, number of osteoblasts and Gray Scale had no significant difference between the two groups in any of the 14-day and 28-day intervals. The results of this study showed that intermittent exposure to high frequency electromagnetic fields over a period of 20 hours has no significant effect on the healing process of alveolar socket after tooth extraction in rats.

Effect of Different Bone Grafting Materials and Mesenchymal Stem Cells on Bone Regeneration: A Micro-Computed Tomography and Histomorphometric Study in a Rabbit Calvarial Defect Model.

This study evaluated the new bone formation potential of micro–macro biphasic calcium phosphate (MBCP) and Bio-Oss grafting materials with and without dental pulp-derived mesenchymal stem cells (DPSCs) and bone marrow-derived mesenchymal stem cells (BMSCs) in a rabbit calvarial bone defect model. The surface structure of the grafting materials was evaluated using a scanning electron microscope (SEM). The multipotent differentiation characteristics of the DPSCs and BMSCs were assessed. Four circular bone defects were created in the calvarium of 24 rabbits and randomly allocated to eight experimental groups: empty control, MBCP, MBCP+DPSCs, MBCP+BMSCs, Bio-Oss+DPSCs, Bio-Oss+BMSCs, and autogenous bone. A three-dimensional analysis of the new bone formation was performed using micro-computed tomography (micro-CT) and a histological study after 2, 4, and 8 weeks of healing. Homogenously porous structures were observed in both grafting materials. The BMSCs revealed higher osteogenic differentiation capacities, whereas the DPSCs exhibited higher colony-forming units. The micro-CT and histological analysis findings for the new bone formation were consistent. In general, the empty control showed the lowest bone regeneration capacity throughout the experimental period. By contrast, the percentage of new bone formation was the highest in the autogenous bone group after 2 (39.4% ± 4.7%) and 4 weeks (49.7% ± 1.5%) of healing (p < 0.05). MBCP and Bio-Oss could provide osteoconductive support and prevent the collapse of the defect space for new bone formation. In addition, more osteoblastic cells lining the surface of the newly formed bone and bone grafting materials were observed after incorporating the DPSCs and BMSCs. After 8 weeks of healing, the autogenous bone group (54.9% ± 6.1%) showed a higher percentage of new bone formation than the empty control (35.3% ± 0.5%), MBCP (38.3% ± 6.0%), MBCP+DPSC (39.8% ± 5.7%), Bio-Oss (41.3% ± 3.5%), and Bio-Oss+DPSC (42.1% ± 2.7%) groups. Nevertheless, the percentage of new bone formation did not significantly differ between the MBCP+BMSC (47.2% ± 8.3%) and Bio-Oss+BMSC (51.2% ± 9.9%) groups and the autogenous bone group. Our study results demonstrated that autogenous bone is the gold standard. Both the DPSCs and BMSCs enhanced the osteoconductive capacities of MBCP and Bio-Oss. In addition, the efficiency of the BMSCs combined with MBCP and Bio-Oss was comparable to that of the autogenous bone after 8 weeks of healing. These findings provide effective strategies for the improvement of biomaterials and MSC-based bone tissue regeneration.

Correlation between Primary, Secondary Stability, Bone Density, Percentage of Vital Bone Formation and Implant Size.

Background: This study aims to evaluate whether there is a correlation between implant stability, bone density, vital bone formation and implant diameter and length. Methods: Ninety patients were enrolled in this study. They underwent a socket preservation procedure with allograft or PRF and after 4 months, a total of 90 implants were placed. CBCT scans were assigned prior to implant placement in order to assess the bone density. During the surgical re-entry, a bone biopsy was harvested with a trephine drill. Immediately after implant insertion, the primary stability was measured. The secondary stability was measured 4 months after implant placement. Results: Primary stability showed a significant positive linear correlation with bone density (r = 0.471, p < 0.001) as well as with percentage of new bone formation (r = 0.567, p < 0.001). An average significant association of secondary stability with bone density (rs = 0.498, p < 0.001) and percentage of newly formed bone (r = 0.477, p < 0.001) was revealed. The mean values of primary stability in all three implant sizes, regarding the diameter of the implants, were similar (narrow 67.75; standard 66.78; wide 71.21) with no significant difference (p = 0.262). The same tendency was observed for secondary stability (narrow 73.83; standard 75.25; wide 74.93), with no significant difference (p = 0.277). Conclusions: The study revealed a high correlation between primary and secondary implant stability, and bone density, as well as with the percentage of vital bone formation. Implant length and diameter revealed no linear correlation with the implant stability.

The use of solvent-preserved human and bovine cancellous bone blocks for lateral defect augmentation - an experimental controlled study in vivo

BackgroundThe aim of this study was to compare new bone formation, resorbed bone matrix, and fibrous enclosed residual bone substitute material in laterally augmented alveolar bone defects using allogeneic, pre-treated and cleaned human bone blocks (tested in dogs, therefore considered to be xenogeneic), and pre-treated and cleaned bovine cancellous bone blocks, both with and without a collagen membrane in order to evaluate their augmentative potential.MethodsThirty-two critical size horizontal defects were prepared in the mandible of 4 adult foxhound dogs (8 per dog, 4 on each side). After 3 months of healing, the defects were laterally augmented in a split-mouth-design with either human (HXB) or bovine solvent-preserved bone blocks (BXB). Afterwards, defects were randomly covered with a bovine collagenous membrane (HXB + M, BXB + M). After a healing interval of 6 months, percentages of new bone formation, resorbed bone matrix, and fibrous enclosed residual bone substitute material were compared.ResultsResults showed little new bone formation of up to 3.7 % in human bone blocks (HXB 3.7 % ± 10.2, HXB + M 0.3 %± 0.4, BXB, 0.1 % ± 0.8, BXB + M 2.6 % ± 3.2, p = > 0.05). Percentages of fibrous encapsulation were higher in human bone blocks than in bovine bone blocks (HXB 71.2 % ± 8.6, HXB + M 73.71 % ± 10.6, BXB, 60.5 % ± 27.4, BXB + M 52.5 % ± 28.4, p = > 0.05). Resorption rates differed from 44.8 % in bovine bone blocks covered with a membrane to 17.4 % in human bone blocks (HXB 17.4 % ± 7.4, HXB + M 25.9 % ± 10.7, BXB, 38.4 % ± 27.2, BXB + M 44.8 % ± 29.6, p = > 0.05). The use of additional membranes did not significantly affect results.ConclusionsWithin its limitations, results of this study suggest that solvent-preserved xenogenic human and bovine bone blocks are not suitable for lateral bone augmentation in dogs. Furthermore, defect coverage with a membrane does not positively affect the outcome.