Double layer graft technique for horizontal alveolar ridge augmentation with staged implant placement: radiographic histological and implant stability analysis-a case report.

INTRODUCTION: Horizontal ridge augmentation of a deficient alveolar bone site is performed either simultaneously with implant placement or in a staged approach prior to implant insertion. There are several available strategies for the augmentation of alveolar ridge deficiencies, including guided bone regeneration (GBR) through the use of barrier membranes. The success of the GBR approach mainly depends on the exclusion of soft tissue cells during bone remodeling. CASE PRESENTATION: A healthy 25-year-old male patient presented with a missing upper left central incisor after clinical and radiographic examination, the site showed a class III defect horizontal atrophy. The procedure performed was the horizontal alveolar ridge augmentation using resorbable pericardium membrane with double layer graft technique (DLT) where autogenous bone placed as a first layer of the graft followed by xenograft as a second layer, the membrane was fixed with titanium pins. A cone beam computed tomography (CBCT) was performed before, immediately and 6 month following the surgery. After 6 months during implant placement, a core biopsy specimen was retrieved, stored and prepared for histological evaluation, with assessment of primary implant stability. The radiographic analysis showed a horizontal width gain of about 4 mm, at 6 month following implant placement, the implant was successfully osteointegrated with stability assessment also done after 6 months from placement. CONCLUSION: DLT was successfully used for horizontal alveolar ridge augmentation, thus allowing a prosthetically driven implant placement. More cases assessing implant survival and success are needed to confirm the results of this case report.

Volumetric assessment of volume stable collagen matrix in maxillary single implant site development: A randomized controlled clinical trial.

INTRODUCTION: The stability of soft tissue volume around dental implants is an important factor for the final esthetic outcome. The main objective of this study was to compare volume stable collagen matrix (VCMX) versus connective tissue graft (CTG) in the augmentation of soft tissue profiles in single implant sites with a class I Siebert ridge defect. MATERIALS AND METHODS: Twenty patients (14 females and 6 males) were enrolled in the present study. After implant placement and augmentation of the buccal defect by VCMX or CTG, post-operative evaluation of the volumetric changes at the augmented implant site was carried out at 3, 6, and 9 months as primary outcome, clinical and radiographic soft tissue thickness were carried out at baseline and 9-month intervals, visual analog scale (VAS) and oral health impact profile-14 (OHIP14) were recorded 2 weeks after the surgery. RESULTS: A statistically significant difference in soft tissue volume was found between baseline and 3, 6, and 9 months postoperatively in both groups with the highest value at 9 months (136.33 ± 86.80) (mm3) in VCMX and (186.38 ± 57.52) (mm3) in CTG. Soft tissue thickness was significantly increased in both groups at 9 months in comparison to baseline. However, there was a significantly higher increase in soft tissue thickness at 9 months in CTG (3.87 ± 0.91) than in VCMX (2.94 ± 0.31). Regarding the radiographic soft tissue thickness, there was a statistically significant increase in both groups at 9 months in comparison to baseline. However, there was a statistically higher increase in the radiographic soft tissue thickness at 9 months in CTG (3.08 ± 0.97) than in VCMX (2.37 ± 0.29). VAS showed a statistically lower value in VCMX (0.4 ± 0.7) than CTG (2.8 ± 1.48). The OHIP recorded lower values in the VCMX group than the CTG group with no statistical significance. In addition, there was no difference in the PES between the two groups. CONCLUSION: The present study showed that CTG and VCMX were both effective in soft tissue augmentation around implants in the esthetic zone. However, CTG proved more efficient in increasing peri-implant soft tissue volume and mucosal thickness around single implants at a 9-month follow-up period. VCMX was associated with less pain or discomfort and reduced patient morbidity, as reflected by the significantly reduced VAS value in the VCMX group.

Treatment of class I Sibert alveolar ridge defects with volume stable collagen matrix. A case report.

INTRODUCTION AND IMPORTANCE: The soft tissue volume and its stability around dental implants are important for the final aesthetic outcome. CASE PRESENTATION: A 39-year-old female was referred for dental implant placement for her missing tooth. Following attachment of the cover screw VCMX was used to simultaneously augment buccal ridge defect. Patient was seen 2 weeks after surgery for follow up where sutures were removed. After 3 months, patient received her final crown and been on follow up for 9 months where a successful well-functioning restoration with clinically healthy soft tissue and optimal profilometric outcome were maintained. CLINICAL DISCUSSION: This approach is relatively simple, less invasive and time saving as it eliminates the need for another surgical donor site to manage the defect. CONCLUSIONS: The present report showed that VCMX was effective in soft tissue augmentation at implant sites in aesthetic zone. CLINICAL RELEVANCE: Within the limits of this study, the positive results suggest that the volume stable collagen matrix (VCMX) may be a reliable option in treatment of siebert class I ridge defects. VCMX was associated with less amount of pain or discomfort and reduced patient morbidity.

Injectable platelet rich fibrin versus hyaluronic acid with bovine derived xenograft for alveolar ridge preservation. A randomized controlled clinical trial with histomorphometric analysis.

BACKGROUND: Alveolar ridge preservation (ARP) is a technique that aims to maintain bone volume and minimize resorption after tooth extraction. OBJECTIVE: This study aimed to compare the effectiveness of injectable platelet-rich fibrin (I-PRF) versus hyaluronic acid (HA) in combination with xenografts for ARP. METHODS: This randomized controlled trial included 36 patients (20 females and 16 males) who required implant placement in the upper arch. The patients were randomly allocated to one of three groups (n = 12 each): I-PRF with xenografts, HA with xenografts, or xenografts alone. All patients underwent ARP, and the extraction sockets were sealed with a free gingival graft harvested from the palate, a total of 36 implants were inserted. Cone-beam CT scans were performed before and 4 months postoperatively to measure radiographic bone gain as the primary outcome. Clinical parameters, including soft tissue thickness and clinical bone width, were evaluated preoperatively, and at 4 months and 1 year postoperatively. Additionally, histological assessment of core bone biopsies was performed 4 months postoperatively using histomorphometric analysis to determine the percentages of newly formed bone, mature bone, and residual grafts. RESULTS: Regarding the radiographic bone gain 4 months postoperative the HA group exhibited the highest value (9.78 ± 0.87), which was significantly greater than the values observed in the I-PRF and control groups (8.60 ± 1.27 and 7.99 ± 0.89, respectively) (one-way ANOVA, p = 0.007). Crestal bone loss was significantly higher in the control group (-0.98 ± 0.18) than in the I-PRF group (-0.53 ± 0.11) and HA group (-0.33 ± 0.15) groups (one-way ANOVA, p < 0.001). In the histomorphometric analysis, the mean area fraction of newly formed bone trabeculae was significantly higher in the HA group (56.66 ± 7.35) than in the I-PRF group (28.74 ± 5.15) and the control group (24.05 ± 3.64) (repeated measures ANOVA, p < 0.001). Additionally, the mean area fraction of residual graft material was higher in the I-PRF group (6.76 ± 2.59), followed by the control group (2.71 ± 1.24), while the HA group had the lowest value (2.63 ± 1.27) (Repeated measures ANOVA, p < 0.001). CONCLUSION: The combination of HA with xenografts yielded better radiographic and histological outcomes in terms of new bone formation and degree of bone maturation than the I-PRF and control groups. Furthermore, I-PRF improved soft tissue thickness. Please note that clinical trial registration was not completed prior to participant recruitment and randomization. The registration link for this trial is https://clinicaltrials.gov/ct2/show/NCT05781529.

Osteogenic Effect of a Bioactive Calcium Alkali Phosphate Bone Substitute in Humans.

(1) Background: The desire to avoid autograft harvesting in implant dentistry has prompted an ever-increasing quest for bioceramic bone substitutes, which stimulate osteogenesis while resorbing in a timely fashion. Consequently, a highly bioactive silicon containing calcium alkali orthophosphate (Si-CAP) material was created, which previously was shown to induce greater bone cell maturation and bone neo-formation than ß-tricalcium phosphate (ß-TCP) in vivo as well as in vitro. Our study tested the hypothesis that the enhanced effect on bone cell function in vitro and in sheep in vivo would lead to more copious bone neoformation in patients following sinus floor augmentation (SFA) employing Si-CAP when compared to ß-TCP. (2) Methods: The effects of Si-CAP on osteogenesis and Si-CAP resorbability were evaluated in biopsies harvested from 38 patients six months after SFA in comparison to ß-TCP employing undecalcified histology, histomorphometry, and immunohistochemical analysis of osteogenic marker expression. (3) Results: Si-CAP as well as ß-TCP supported matrix mineralization and bone formation. Apically furthest away from the original bone tissue, Si-CAP induced significantly higher bone formation, bone-bonding (bone-bioceramic contact), and granule resorption than ß-TCP. This was in conjunction with a higher expression of osteogenic markers. (4) Conclusions: Si-CAP induced higher and more advanced bone formation and resorbability than ß-TCP, while ß-TCP's remarkable osteoconductivity has been widely demonstrated. Hence, Si-CAP constitutes a well-suited bioactive graft choice for SFA in the clinical arena.

Adjunctive effect of collagen membrane coverage to L-PRF in the treatment of periodontal intrabony defects: a randomized controlled clinical trial with biochemical assessment.

BACKGROUND: The innovation of leukocyte platelet-rich fibrin (L-PRF) has added enormous impact on wound healing dynamics especially the field of periodontal regeneration. The release of growth factors (GF) is thought to improve the clinical outcomes in infrabony defects. The aim of this study was to evaluate the clinical effect of covering L-PRF contained infrabony defects with collagen membranes (CM), and to compare their GF release profile to uncovered L-PRF defects and open flap debridement (OFD). METHODS: Thirty non- smoking patients with infrabony pockets participated to be randomly assigned to OFD group (n = 10), L-PRF group (n = 10), or L-PRF protected CM group (n = 10). Plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment level (CAL) and the radiographic defect base fill (DBF) were measured at baseline and at 6 month following surgical intervention. Gingival crevicular fluid samples were obtained on days 1, 3, 5, 7, 14, 21 and 30 days following surgery for the Platelet Derived Growth Factor-BB (PDGF-BB) and Vascular Endothelial Growth Factors (VEGF) release profile evaluation. RESULTS: For all patients, a statistically significant (P ≤ 0.05) reduction in PI, GI, PD and CAL were reported throughout the study period. Differences between the three treatment modalities were not statistically significant. PRF + CM showed a statistically significant DBF compared to OFD and L-PRF groups at follow up. Quantitative analysis of PDGF-BB and VEGF levels demonstrated a statistically significant (P < 0.001) decline between measurement intervals for all groups with no statistically significant differences between the three groups. CONCLUSION: Within the limitations of this study, L-PRF coverage with CM may augment defect base fill through its mechanical protective effect without enhancement in the release profile of VEGF and PDGF. The non-significant intergroup differences question the validity of the claimed extra physiologic concentration of GF offered by L-PRF harvests. TRIAL REGISTRATION: The present study was registered at ClinicalTrials.gov (NCT05496608), (11/08/2022).

A tissue engineered 3D printed calcium alkali phosphate bioceramic bone graft enables vascularization and regeneration of critical-size discontinuity bony defects in vivo.

Introduction: Recently, efforts towards the development of patient-specific 3D printed scaffolds for bone tissue engineering from bioactive ceramics have continuously intensified. For reconstruction of segmental defects after subtotal mandibulectomy a suitable tissue engineered bioceramic bone graft needs to be endowed with homogenously distributed osteoblasts in order to mimic the advantageous features of vascularized autologous fibula grafts, which represent the standard of care, contain osteogenic cells and are transplanted with the respective blood vessel. Consequently, inducing vascularization early on is pivotal for bone tissue engineering. The current study explored an advanced bone tissue engineering approach combining an advanced 3D printing technique for bioactive resorbable ceramic scaffolds with a perfusion cell culture technique for pre-colonization with mesenchymal stem cells, and with an intrinsic angiogenesis technique for regenerating critical size, segmental discontinuity defects in vivo applying a rat model. To this end, the effect of differing Si-CAOP (silica containing calcium alkali orthophosphate) scaffold microarchitecture arising from 3D powder bed printing (RP) or the Schwarzwalder Somers (SSM) replica fabrication technique on vascularization and bone regeneration was analyzed in vivo. In 80 rats 6-mm segmental discontinuity defects were created in the left femur. Methods: Embryonic mesenchymal stem cells were cultured on RP and SSM scaffolds for 7d under perfusion to create Si-CAOP grafts with terminally differentiated osteoblasts and mineralizing bone matrix. These scaffolds were implanted into the segmental defects in combination with an arteriovenous bundle (AVB). Native scaffolds without cells or AVB served as controls. After 3 and 6 months, femurs were processed for angio-µCT or hard tissue histology, histomorphometric and immunohistochemical analysis of angiogenic and osteogenic marker expression. Results: At 3 and 6 months, defects reconstructed with RP scaffolds, cells and AVB displayed a statistically significant higher bone area fraction, blood vessel volume%, blood vessel surface/volume, blood vessel thickness, density and linear density than defects treated with the other scaffold configurations. Discussion: Taken together, this study demonstrated that the AVB technique is well suited for inducing adequate vascularization of the tissue engineered scaffold graft in segmental defects after 3 and 6 months, and that our tissue engineering approach employing 3D powder bed printed scaffolds facilitated segmental defect repair.

Evaluation of soft tissue and labial plate of bone stability with immediate implant in direct contact versus gap with socket shield: A randomized clinical trial with 1 year follow-up.

OBJECTIVE: In the anterior region, the resorption of the buccal plate of bone after tooth extraction leads to contraction of the overlying soft tissues, resulting in an esthetic problem. In the socket shield technique, the buccal root section of the tooth is maintained, to preserve the buccal bone for immediate implant placement. The aim of this randomized clinical trial was to investigate the effect of leaving a gap or not between implant and retained root fragment on bone dimensions and soft tissue esthetics. METHODS: This was a two armed parallel group randomized clinical trial with allocation ratio 1:1. Patients were eligible in case they needed immediate implant replacing teeth in esthetic zone with sufficient buccal bone support. CBCT was performed immediately after the intervention and 12 months later. RESULTS: Forty six patients (26 females and 20 males) were enrolled in the study with 23 of them placed in contact with shield and 23 were placed palatal leaving a gap to graft with a xenograft. After 12 months, excellent soft tissue stability was reported (mean pink esthetic score at placement group A: 12.00 ± 1.60 after 12 months 12.90 ± 1.69, group B 12.62 ± 2.07 and after 12 months 12.38 ± 2.20) Using both surgical techniques. Radiographic crestal bone level changes mean for group A was -0.26 ± 0.52 and for group B -0.34 ± 0.31. There was a strong positive correlation between clinical and radiographic bone width values which was statistically significant (r = 0.782, p < 0.001). Width and thickness of keratinized gingiva showed no significant difference between values measured in both groups. Nonsignificant difference between studied groups according to the labial plate of bone clinical and radiographic changes after immediate implantation. CONCLUSION: Within the limitations of this study, the present data seem to support that the clinical outcome of the socket shield technique with immediate implant placement placed in contact or leaving a gap gave excellent esthetic results.

Autogenous dentin block versus bone block for horizontal alveolar ridge augmentation and staged implant placement: A randomized controlled clinical trial including histologic assessment.

OBJECTIVES: This study aimed to compare the dentin block (D-group) harvested from impacted wisdom teeth with autogenous ramus bone block (A-group) for horizontal alveolar ridge augmentation. MATERIALS AND METHODS: Forty-two patients with anterior missing teeth and horizontal ridge defect were randomly assigned to two groups (n = 21 per group) to receive either dentin block group or autogenous bone block. Six months after the augmentation, dental implants were placed in all patients, and a core biopsy was performed for histological evaluation in addition to clinical and radiographic evaluation using cone beam computed tomography. The primary outcome was the mean overall clinical ridge width gain (CRWG) after 6 months of augmentation. Secondary outcomes were the overall radiographic ridge width gain (RRWG) after 6 months of augmentation and descriptive histological analysis with histomorphometric assessment of bone fraction %. RESULTS: All sites healed uneventfully, and the mean overall CRWG 6 months after augmentation was 3.52 ± 0.56 mm and 2.24 ± 0.86 mm in the D and A groups, respectively, with statistically significant difference between them (P ≤ .001). The overall mean RRWG was 3.61 ± 0.61 mm and 3.41 ± 1.15 mm in D and A groups, respectively, without any statistically significant difference between them (p = .062). The histomorphometric analysis of the bone area fraction was 42.6% and 41.3% in D and A groups, respectively, without any statistically significant difference between the two values (p = .89, Student's t-test). Histological evaluation in the D-group revealed new bone formation, viable cells, and matrix formation on the dentin block periphery, in addition to well-organized woven bone that suggests dentin block remodeling and supports new bone deposition. CONCLUSION: The present clinical study revealed that dentin block may serve as an alternative graft to support horizontal alveolar ridge augmentation. Dentin blocks showed less resorption than autogenous bone blocks.

Autogenous Dentin Block of a Non-Restorable Wisdom Tooth for Localized Horizontal Ridge Augmentation: Radiographic and Histological Analysis - A Preliminary Case Report.

INTRODUCTION: Tooth roots proved in different studies clinically and radiographically to be an alternative to autogenous bone. However, the histological evaluation of the tooth block following ridge augmentation is still missing. The aim of this case report was to evaluate histologically and radiographically the effect of autogenous dentin block (DB) to restore a horizontal ridge deficiency at a single tooth gap. CASE PRESENTATION: A healthy 36-year-old female patient presented with a missing lower first molar (30), after clinical and radiographic examination, the site showed a class III defect horizontal atrophy. The procedure performed was the surgical removal of the wisdom tooth (32), shaping and fixation of a separated DB at the defect site using an osteosynthesis screw. A cone beam computed tomography was performed immediately and 6 month following the surgery. During implant placement, a core biopsy specimen was retrieved, stored and prepared for histological evaluation. The radiographic analysis showed a horizontal width gain of about 4 mm. The histologic assessment revealed cortical bone formation at the buccal and lingual aspects between the tooth and the bone. During implant placement, the core biopsy exhibited a slight separation upon removal from the grafted side, at 6 month following implant placement, the implant was successfully osteointegrated. CONCLUSION: DB was successfully used for horizontal alveolar ridge augmentation, thus allowing a prosthetically driven implant placement. More cases assessing implant survival and success are needed to confirm the results of this case report.

Porphyromonas gingivalis induced up-regulation of PD-L1 in colon carcinoma cells.

Programmed death-ligand-1 (PD-L1) is a ligand for programmed death receptor (PD-1) that plays a major role in cell-mediated immune response; it regulates T-cell activation and regulates survival and functions of activated T cells. Expression of PD-L1 can induce chronic inflammation and activate mechanisms of immune evasion. PD-L1 is expressed in most of human carcinomas. Porphyromonas gingivalis (P. gingivalis) is a major keystone pathogen in periodontitis that invade host cells and disposes a variety of virulence factors. The aim of the present study was to clarify the signaling pathway of P. gingivalis molecules that induce PD-L1 up-regulation in colon carcinoma cells. Additionally, it was investigated which components of P. gingivalis are responsible for PD-L1 induction. Colon cancer cells (CL-11) were stimulated with total membrane (TM) fractions, peptidoglycans (PDGs) and viable P. gingivalis bacteria. Seven signaling molecule inhibitors were used: receptor-interacting serine/threonine-protein kinase 2 (RIP2) tyrosine kinase inhibitor, nucleotide-binding oligomerization domain (NOD)-like receptor 1&2 inhibitor, NOD-like receptor, nuclear factor kappa B inhibitor, c-Jun N-terminal kinases inhibitor, mitogen-activated protein/extracellular signal-regulated kinase inhibitor, mitogen activated kinase (MAPK) inhibitor. PD-L1 protein expression was examined by western blot analysis and quantitative real time PCR. It was demonstrated that the TM fraction and PDG induced up-regulation of PD-L1 expression in colon cancer cells. In conclusion, the results of this study suggest that PDG of P. gingivalis plays a major role in PD-L1 up-regulation in colon cancer cells. In addition, the mechanism of PD-L1 up-regulation depends on NOD 1 and NOD 2 and involves activation of RIP2 and MAPK signaling pathways.

Evaluation of the FDI Chairside Guide for Assessment of Periodontal Conditions: A Multicentre Observational Study.

OBJECTIVE: There is a need to develop easy-to-use tools to screen for periodontal conditions in daily practice. This study aimed to evaluate the FDI World Dental Federation "Chairside Guide" (FDI-CG) developed by the Task Team of the FDI Global Periodontal Health Project (GPHP) as a potential tool for screening. METHODS: Databases from 3 centres in Germany, Hong Kong, and Spain (n = 519) were used to evaluate the association of the FDI-CG and its individual items with the periodontitis case definitions proposed by the Centers for Disease Control and Prevention (CDC) and the American Academy of Periodontology (AAP) for population-based surveillance of periodontitis. RESULTS: Statistically significant differences were observed among the databases for the prevalence of periodontitis and the items included in the FDI-CG. The FDI-CG score and its individual components were significantly associated with the periodontal status in the individual databases and the total sample, with bleeding on probing showing the strongest association with severe periodontitis (odds ratio [OR] = 12.9, 95% CI [5.9; 28.0], P < .001, for those presenting bleeding on probing >50%), followed by age (OR = 4.8, 95% CI [1.7; 4.2], P = .004, for those older than 65 years of age). Those subjects with a FDI-CG score >10 had an OR of 54.0 (95% CI [23.5; 124.2], P < .001) and presented with severe periodontitis. A significant correlation was found between the different FDI-CG scoring categories (mild, moderate, and severe) and the categories for mild, moderate, and severe periodontitis using the Centers for Disease Control and Prevention and the American Academy of Periodontology criteria (r = 0.57, Spearman rank correlation test, P < .001). CONCLUSION: The FDI Chairside Guide may represent a suitable tool for screening the periodontal condition by general practitioners in daily dental practice.

Bone regeneration and graft material resorption in extraction sockets grafted with bioactive silica-calcium phosphate composite (SCPC) versus non-grafted sockets: clinical, radiographic, and histological findings.

PURPOSE: The purpose of the present study was to evaluate the effect of silica-calcium phosphate composite (SCPC) granules on bone regeneration in extraction sockets. METHODS: Ten patients were selected for a split-model study. In each patient, bone healing in SCPC-grafted and control ungrafted sockets was analyzed through clinical, radiographic, histomorphometric, and immunohistochemical assessments 6 months postoperatively. RESULTS: A radiographic assessment using cone-beam computed tomography showed minimal ridge dimension changes in SCPC-grafted sockets, with 0.39 mm and 1.79 mm decreases in height and width, respectively. Core bone biopsy samples were obtained 6 months post-extraction during implant placement and analyzed. The average percent areas occupied by mature bone, woven bone, and remnant particles in the SCPC-grafted sockets were 41.3%±12%, 20.1%±9.5%, and 5.3%±4.4%, respectively. The percent areas of mature bone and woven bone formed in the control ungrafted sockets at the same time point were 31%±14% and 24.1%±9.4%, respectively. Histochemical and immunohistochemical analyses showed dense mineralized bundles of type I collagen with high osteopontin expression intensity in the grafted sockets. The newly formed bone was well vascularized, with numerous active osteoblasts, Haversian systems, and osteocytes indicating maturation. In contrast, the new bone in the control ungrafted sockets was immature, rich in type III collagen, and had a low osteocyte density. CONCLUSIONS: The resorption of SCPC granules in 6 months was coordinated with better new bone formation than was observed in untreated sockets. SCPC is a resorbable bone graft material that enhances bone formation and maturation through its stimulatory effect on bone cell function. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03897010.

Effect of silicon-doped calcium phosphate bone grafting materials on bone regeneration and osteogenic marker expression after implantation in the ovine scapula.

Compared to the currently clinically available bone grafting materials for alveolar ridge augmentation, there is a great demand for bioactive bone substitutes with higher resorbability, which enhance osteogenesis at the same time. This has prompted the development of a silicon-doped rapidly resorbable calcium alkali orthophosphate (Si-CAOP) and silicon-doped ß-tricalcium phosphate (Si-TCP). This study evaluated the effect of these two particulate graft materials as compared to the currently clinically used ß-TCP on bone formation and osteogenic marker expression after 2 weeks, 1, 3, 6, 12, and 18 months of implantation in critical size defects in the sheep scapula. Immunohistochemical analysis of collagen type I, alkaline phosphatase, and osteocalcin expression was performed on resin embedded sections. The bone and particle area fraction and the bone-biomaterial contact were determined histomorphometrically. After 2 weeks and 1 month defects grafted with Si-CAOP displayed a significantly greater bone area fraction, bone-particle-contact, osteogenic marker expression and significantly lower particle area fraction than defects grafted with Si-TCP and TCP. By 3 and 6 months all materials studied mediated excellent defect regeneration with further bone remodeling at 12 and 18 months. Taken together, Si-CAOP induced the most expeditious bone regeneration of critical size defects in the sheep scapula. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 594-614, 2019.

Development of a synthetic tissue engineered three-dimensional printed bioceramic-based bone graft with homogenously distributed osteoblasts and mineralizing bone matrix in vitro.

Over the last decade there have been increasing efforts to develop three-dimensional (3D) scaffolds for bone tissue engineering from bioactive ceramics with 3D printing emerging as a promising technology. The overall objective of the present study was to generate a tissue engineered synthetic bone graft with homogenously distributed osteoblasts and mineralizing bone matrix in vitro, thereby mimicking the advantageous properties of autogenous bone grafts and facilitating usage for reconstructing segmental discontinuity defects in vivo. To this end, 3D scaffolds were developed from a silica-containing calcium alkali orthophosphate, using, first, a replica technique - the Schwartzwalder-Somers method - and, second, 3D printing, (i.e. rapid prototyping). The mechanical and physical scaffold properties and their potential to facilitate homogenous colonization by osteogenic cells and extracellular bone matrix formation throughout the porous scaffold architecture were examined. Osteoblastic cells were dynamically cultured for 7 days on both scaffold types with two different concentrations of 1.5 and 3 × 109 cells/l. The amount of cells and bone matrix formed and osteogenic marker expression were evaluated using hard tissue histology, immunohistochemical and histomorphometric analysis. 3D-printed scaffolds (RPS) exhibited more micropores, greater compressive strength and silica release. RPS seeded with 3 × 109 cells/l displayed greatest cell and extracellular matrix formation, mineralization and osteocalcin expression. In conclusion, RPS displayed superior mechanical and biological properties and facilitated generating a tissue engineered synthetic bone graft in vitro, which mimics the advantageous properties of autogenous bone grafts, by containing homogenously distributed terminally differentiated osteoblasts and mineralizing bone matrix and therefore is suitable for subsequent in vivo implantation for regenerating segmental discontinuity bone defects. Copyright © 2016 John Wiley & Sons, Ltd.

Effect of a Particulate and a Putty-Like Tricalcium Phosphate-Based Bone-grafting Material on Bone Formation, Volume Stability and Osteogenic Marker Expression after Bilateral Sinus Floor Augmentation in Humans.

This study examines the effect of a hyaluronic acid (HyAc) containing tricalcium phosphate putty scaffold material (TCP-P) and of a particulate tricalcium phosphate (TCP-G) graft on bone formation, volume stability and osteogenic marker expression in biopsies sampled 6 months after bilateral sinus floor augmentation (SFA) in 7 patients applying a split-mouth design. 10% autogenous bone chips were added to the grafting material during surgery. The grain size of the TCP granules was 700 to 1400 µm for TCP-G and 125 to 250 µm and 500 to 700 µm (ratio 1:1) for TCP-P. Biopsies were processed for immunohistochemical analysis of resin-embedded sections. Sections were stained for collagen type I (Col I), alkaline phosphatase (ALP), osteocalcin (OC) and bone sialoprotein (BSP). Furthermore, the bone area and biomaterial area fraction were determined histomorphometrically. Cone-beam CT data recorded after SFA and 6 months later were used for calculating the graft volume at these two time points. TCP-P displayed more advantageous surgical handling properties and a significantly greater bone area fraction and smaller biomaterial area fraction. This was accompanied by significantly greater expression of Col I and BSP and in osteoblasts and osteoid and a less pronounced reduction in grafting volume with TCP-P. SFA using both types of materials resulted in formation of sufficient bone volume for facilitating stable dental implant placement with all dental implants having been in function without any complications for 6 years. Since TCP-P displayed superior surgical handling properties and greater bone formation than TCP-G, without the HyAc hydrogel matrix having any adverse effect on bone formation or graft volume stability, TCP-P can be regarded as excellent grafting material for SFA in a clinical setting. The greater bone formation observed with TCP-P may be related to the difference in grain size of the TCP granules and/or the addition of the HyAc.

Effect of sex-hormone levels, sex, body mass index and other host factors on human craniofacial bone regeneration with bioactive tricalcium phosphate grafts.

Little is known regarding the associations between sex-hormone levels, sex, body mass index (BMI), age, other host factors and biomaterial stimulated bone regeneration in the human craniofacial skeleton. The aim of this study was to elucidate the associations between these factors and bone formation after sinus floor augmentation procedures (SFA) utilizing a bioactive tricalcium phosphate (TCP) bone grafting material. We conducted a prospective study in a human population in which 60 male and 60 female participants underwent SFA and dental implant placement using a staged approach. BMI as well as levels of serum estradiol (E2), total testosterone (TT), and the free androgen index (FAI) were measured by radioimmunoassay and electrochemoluminescent-immunoassay. At implant placement, 6 months after SFA, bone biopsy specimens were harvested for hard tissue histology, the amount of bone formation was evaluated by histomorphometry and immunohistochemical analysis of osteogenic marker expression. The Wilcoxon rank-sum U test, Spearman correlations and linear regression analysis were used to explore the association between bone formation and BMI, hormonal and other host factors. BMI and log E2 were significantly positively associated with bone formation in male individuals (p < 0.05). Histomorphometry revealed trends toward greater bone formation and osteogenic marker expression with non-smokers compared to smokers. In male patients, higher E2 levels and higher BMI enhanced TCP stimulated craniofacial i.e. intramembranous bone repair.