Oral Microbiome in Relation to Periodontitis Severity and Systemic Inflammation

Systemic inflammation induced by periodontitis is suggested to be the link between periodontitis and cardiovascular disease. The aim of this work was to explore the oral microbiome in periodontitis in relation to disease severity and systemic inflammation. The saliva and subgingival microbiome from periodontal pocket samples of patients with severe (n = 12) and mild periodontitis (n = 13) were analyzed using metagenomic shotgun sequencing. The taxa and pathways abundances were quantified. The diversity was assessed and the abundances to phenotype associations were performed using ANCOM and linear regression. A panel of inflammatory markers was measured in blood and was associated with taxa abundance. The microbial diversity and species richness did not differ between severe and mild periodontitis in either saliva or periodontal pockets. However, there were significant differences in the microbial composition between severe and mild periodontitis in the subgingival microbiome (i.e., pocket samples) and, in a lower grade, in saliva, and this is positively associated with systemic inflammatory markers. The “red complex” and “cluster B” abundances in periodontal pockets were strongly associated with inflammatory markers interleukin-6 and the white blood cell count. Our data suggest that systemic inflammation in severe periodontitis may be driven by the oral microbiome and may support the indirect (inflammatory) mechanism for the association between periodontitis and cardiovascular disease

Platelet autologous growth factors decrease the osteochondral regeneration capability of a collagen-hydroxyapatite scaffold in a sheep model

Background: Current research aims to develop innovative approaches to improve chondral and osteochondral regeneration. The objective of this study was to investigate the regenerative potential of platelet-rich plasma (PRP) to enhance the repair process of a collagen-hydroxyapatite scaffold in osteochondral defects in a sheep model. Methods: PRP was added to a new, multi-layer gradient, nanocomposite scaffold that was obtained by nucleating collagen fibrils with hydroxyapatite nanoparticles. Twenty-four osteochondral lesions were created in sheep femoral condyles. The animals were randomised to three treatment groups: scaffold, scaffold loaded with autologous PRP, and empty defect (control). The animals were sacrificed and evaluated six months after surgery. Results: Gross evaluation and histology of the specimens showed good integration of the chondral surface in both treatment groups. Significantly better bone regeneration and cartilage surface reconstruction were observed in the group treated with the scaffold alone. Incomplete bone regeneration and irregular cartilage surface integration were observed in the group treated with the scaffold where PRP was added. In the control group, no bone and cartilage defect healing occurred; defects were filled with fibrous tissue. Quantitative macroscopic and histological score evaluations confirmed the qualitative trends observed. Conclusions: The hydroxyapatite-collagen scaffold enhanced osteochondral lesion repair, but the combination with platelet growth factors did not have an additive effect; on the contrary, PRP administration had a negative effect on the results obtained by disturbing the regenerative process. In the scaffold + PRP group, highly amorphous cartilaginous repair tissue and poorly spatially organised underlying bone tissue were found

Effects of platelet rich plasma (PRP) on human gingival fibroblast, osteoblast and periodontal ligament cell behaviour

The use of platelet rich plasma (PRP, GLO) has been used as an adjunct to various regenerative dental procedures. The aim of the present study was to characterize the influence of PRP on human gingival fibroblasts, periodontal ligament (PDL) cells and osteoblast cell behavior in vitro

Bone regeneration and stem cells.

?  Introduction ?  Bone fracture healing and healing problems ?  Biomaterial scaffolds and tissue engineering in bone formation -  Bone tissue engineering -  Biomaterial scaffolds -  Synthetic scaffolds -  Micro- and nanostructural properties of scaffolds -  Conclusion ?  Mesenchymal stem cells and osteogenesis -  Bone tissue -  Origin of osteoblasts -  Isolation and characterization of bone marrow derived MSC -  In vitro differentiation of MSC into osteoblast lineage cells -  In vivo differentiation of MSC into bone -  Factors and pathways controlling osteoblast differentiation of hMSC -  Defining the relationship between osteoblast and adipocyte differentiation from MSC -  MSC and sex hormones -  Effect of aging on osteoblastogenesis -  Conclusion ?  Embryonic, foetal and adult stem cells in osteogenesis -  Cell-based therapies for bone -  Specific features of bone cells needed to be advantageous for clinical use -  Development of therapeutic biological agents -  Clinical application concerns -  Conclusion ?  Platelet-rich plasma (PRP), growth factors and osteogenesis -  PRP effects in vitro on the cells involved in bone repair -  PRP effects on osteoblasts -  PRP effects on osteoclasts -  PRP effects on endothelial cells -  PRP effects in vivo on experimental animals -  The clinical use of PRP for bone repair -  Non-union -  Distraction osteogenesis -  Spinal fusion -  Foot and ankle surgery -  Total knee arthroplasty -  Odontostomatology and maxillofacial surgery -  Conclusion ?  Molecular control of osteogenesis -  TGF-β signalling -  FGF signalling -  IGF signalling -  PDGF signalling -  MAPK signalling pathway -  Wnt signalling pathway -  Hedgehog signalling -  Notch signalling -  Ephrin signalling -  Transcription factors regulating osteoblast differentiation -  Conclusion ?  Summary This invited review covers research areas of central importance for orthopaedic and maxillofacial bone tissue repair, including normal fracture healing and healing problems, biomaterial scaffolds for tissue engineering, mesenchymal and foetal stem cells, effects of sex steroids on mesenchymal stem cells, use of platelet-rich plasma for tissue repair, osteogenesis and its molecular markers. A variety of cells in addition to stem cells, as well as advances in materials science to meet specific requirements for bone and soft tissue regeneration by addition of bioactive molecules, are discussed

Effect of platelet-rich plasma on bone regeneration in dentistry: a systematic review.

OBJECTIVE: To review systematically the reported effects of platelet-rich plasma (PRP) on bone regeneration. MATERIAL AND METHODS: Up to June 2006, MEDLINE and Cochrane databases were explored with different combinations of three search terms: 'PRP', 'bone regeneration', 'dentistry' and their synonyms. Inclusion criteria: human controlled clinical trials designed to treat maxillofacial bony defects with application of PRP (test) or without PRP (control), including at least five patients with a follow-up period of more than 3 months and using clinical assessment, radiography, histology and/or histomorphometry for evaluation. Literature search, selection of eligible articles and data extraction were carried out independently by two readers. RESULTS: The literature search revealed 108 references, of which 17 were selected for further analysis. Finally, nine articles fulfilling the inclusion criteria were selected for systematically review. Owing the substantial heterogeneity of the studies it was not possible to analyze the data statistically. An attempt was made to compare results from studies that used similar outcome measures by calculating and adding confidence intervals to the data presented in the original papers. Differences in treatment effects for periodontal defects in terms of clinical attachment level (CAL) were significant (ranging from 0.8 to 3.2 mm). The reported effects of PRP in sinus elevation (compared with their controls) were <10%. CONCLUSION: We found evidence for beneficial effects of PRP in the treatment of periodontal defects. Evidence for beneficial effects of PRP in sinus elevation appeared to be weak. No conclusions can be drawn about other applications of PRP in dentistry

Early effect of platelet-rich plasma on bone healing in combination with an osteoconductive material in rat cranial defects.

OBJECTIVE: The early effect of platelet-rich plasma (PRP) on bone regeneration in combination with dense biphasic hydroxyl apatite (HA)/beta-tricalcium phosphate (TCP) particles (ratio 60%/40%) was evaluated in rat cranial defects with a diameter of 6.2 mm. We hypothesize that PRP exerts its beneficial effect on bone regeneration within the first and second week after application in a bone defect combined with an osteoconductive material. MATERIALS AND METHODS: Forty-five rats were used in the study, in which always one cranial defect was created. The defects were filled with HA/beta-TCP particles and HA/beta-TCP particles combined with PRP gel. Some defects were also left unfilled as control. One and two weeks after surgery specimens were retrieved for light microscopy [hematoxylin-eosin, trichrome staining (Masson modification Goldner) and basic fuchsin-methylene blue] and micro-CT analysis to evaluate bone formation and neovascularization. One-way analysis of variance was performed on the raw data obtained from micro-CT analyses. RESULTS: The histological evaluation showed no effect of PRP on bone formation and neovascularization for both implantation times. In the first week, the defect closure was evaluated subjectively to be between 10% and 50% in all samples, whereas no difference among the groups appeared to occur. After 2 weeks, complete bridging of the original bone defect was observed for most of the empty defects, as well as for the defects that contained HA/beta-TCP particles. The trichrome staining revealed no difference in the number of blood vessels between the PRP and non-PRP groups for both implantation times. The osteoconductive nature of dense HA/beta-TCP particles was confirmed, as the bone formation was guided by their outer surfaces and resulted in a larger amount of newly formed bone in comparison with the empty defects. The quantitative micro-CT analysis demonstrated a statistically significant difference in new bone formation between the empty defects and defects filled with particles after 1 week of implantation, but there was no difference between the non-PRP and PRP groups. In at the second week, no difference in bone formation among all groups was observed, whereas even the non-filled control defects were almost completely closed. CONCLUSIONS: A 6.2 mm cranial defect is not a critical-sized defect in rats. Rat PRP had no effect on the early stages of bone healing in addition to an osteoconductive material. Dense HA/beta-TCP particles showed a beneficial effect on bone formation already after 1 and 2 weeks of implantation in non-critical-sized cranial defects in rats