Clinical, Microbiological and Immunological Responses to Two Non-Surgical Periodontal Treatment Modalities

The current study compared the clinical, microbiological and immunological parameters of chronic periodontitis patients that received two different treatment strategies: one-day full-mouth scaling and root planing (FM-SRP) versus quadrant scaling and root planing at two-weekly intervals (Q-SRP). In addition, the effects of smoking on the periodontal status, subgingival microflora and humoral immune response were examined. Clinical measurements, subgingival plaque samples, gingival crevicular fluid (GCF) and sera were collected from 42 patients with moderate to advanced chronic periodontitis before and after treatment over a period of six months. Patients were randomly allocated into two treatment groups and received FM-SRP or Q-SRP. Polymerase chain reaction (PCR) was used to determine the presence of P. gingivalis, A. actinomycetemcomitans, P. intermedia, T denticola and B. forsythus in plaque. Enzyme-linked immunosorbent assay (ELISA) was used to examine systemic and local antibody titres to these bacteria and thiocyanate disassociation was used to determine antibody avidity. Q-SRP and FM-SRP were found to be equally efficacious periodontal treatments. Therefore, the clinician should decide which treatment strategy to choose on a practical basis. No evidence emerged from this study to document a strong immunological reaction elicited by FM-SRP, as was speculated by Quirynen et al. (1995). In fact, during therapy the host responses of patients in both treatment groups followed a similar pattern. In general, both treatments resulted in significant clinical improvement and reduced titres of antibodies, but which were of similar avidity for the majority of the tested organisms. These changes paralleled marked reductions in the site and subject prevalence of putative periodontopathogens. In addition the present data do not support the hypothesis that, during the active phase of quadrant root planing therapy, the treated sites are re-infected with organisms that are possibly transmitted from the remaining untreated pockets and from other intra-oral niches (Quirynen et al. 1995). In contrast, the commencement of quadrant root planing and meticulous oral hygiene measures had a significant positive effect on the periodontal conditions of the remaining untreated quadrants. Nevertheless, this clinical improvement was smaller compared to changes seen after the completion of mechanical debridement. Despite the fact that FM-SRP resulted in significantly higher pain scores and more patients taking analgesics compared to Q-SRP, it still seemed to be well tolerated by patients. Smoking had a significant adverse effect on the inflammatory response to the bacterial challenge and on the treatment outcome. The outcome of each treatment strategy (Q-SRP and FM-SRP) was affected significantly by smoking over the course of treatment, having a significant impact on pocket depth (PD) and relative attachment level (RAL) of selected sites. A smaller PD reduction and less gain in RAL were noted after both treatment strategies at selected sites of smokers compared with those of non-smokers. Smoking appeared to modify both local and systemic host responses by producing lower levels of GCF and serum antibodies, respectively, but appeared to have no significant effect on the subgingival microflora. This study associated systemic antibody levels with the presence of homologous organisms in subgingival plaque. Furthermore, the present study showed that subjects with less severe disease and a better clinical outcome retained higher levels of serum antibodies compared to patients who had more advanced disease and a moderate clinical outcome. These findings confirm the suggestions from other studies that antibodies are protective against the progression of periodontal disease. GCF antibody titres were low compared to serum antibody levels, which agrees with previous findings and a large site-to-site variability was evident, making interpretation of the results difficult. Nevertheless, it was apparent that deep pockets and sites that harboured a bacterial species gave rise to higher levels of GCF antibodies for that species

Characterization of the soft-tissue wall lining residual periodontal pockets and implications in periodontal wound healing

AIM To characterize the soft-tissue wall of remaining periodontal pockets for wound healing-related parameters versus healthy gingival crevices in the same individuals. MATERIALS AND METHODS Gingival tissues collected from the diseased interface of pockets (GT biopsies) and from healthy gingival crevices (G biopsies) were subjected to RT$^{2}$-profiler PCR Array for wound healing-related markers and network analysis of differentially expressed genes. Lymphangiogenesis-related gene expression was determined by qRT-PCR. The migration potential of mesenchymal stem cells isolated from GT biopsies (GT-MSCs) and G biopsies (G-MSCs) was evaluated by the scratch- and the transwell migration assays. The total collagen protein content was determined in GT-MSCs and G-MSCs homogenates. RESULTS Gene-ontology analysis on significantly upregulated genes expressed in GT biopsies revealed enrichment of several genes involved in processes related to matrix remodeling, collagen deposition, and integrin signaling. No significantly expressed genes were seen in G biopsies. Regarding lymphangiogenesis-related genes, GT biopsies demonstrated greater expression for PROX1 than G biopsies (p = 0.05). Lower migration potential (p < 0.001), yet greater production of collagen protein (p = 0.05), was found for GT-MSCs over G-MSCs. CONCLUSION Differential expression patterns of various molecular pathways in biopsies and cell cultures of diseased versus healthy gingival tissues indicate a potential of the former for tissue remodeling and repair. CLINICAL RELEVANCE In the course of periodontitis, granulation tissue is formed within a periodontal defect in an attempt to reconstruct the site. Following treatment procedures periodontal granulation tissue remains inflamed but appears to retain healing potential

Erratum to: Smoking, Porphyromonas gingivalis and the immune response to citrullinated autoantigens before the clinical onset of rheumatoid arthritis in a Southern European nested case–control study

No abstract available

Understanding the microbial components of periodontal diseases and periodontal treatment-induced microbiological shifts

In the mid-1960s the microbial aetiology of periodontal diseases was introduced based on classical experimental gingivitis studies . Since then, numerous studies have addressed the fundamental role that oral microbiota plays in the initiation and progression of periodontal diseases. Recent advances in laboratory identification techniques have contributed to a better understanding of the complexity of the oral microbiome in both health and disease. Modern culture-independent methods such as human oral microbial identification microarray and next-generation sequencing have been used to identify a wide variety of microbial taxa residing in the gingival sulcus and the periodontal pocket. The first theory of the ‘non-specific plaque’ hypothesis gave rise to the ‘ecological plaque’ hypothesis and more recently to the ‘polymicrobial synergy and dysbiosis hypothesis’. Periodontitis is now considered to be a multimicrobial inflammatory disease in which the various bacterial species within the dental biofilm are in a dysbiotic state and this imbalance favours the establishment of chronic inflammatory conditions and ultimately the destruction of tooth-supporting tissues. Apart from the known putative periodontal pathogens, the whole biofilm community is now considered to play a role in the establishment of inflammation and the initiation and progression of periodontitis in a susceptible host. Treatment is unlikely to eliminate putative pathogens but, when it is thoroughly performed it has the potential to establish a healthy ecosystem by altering the microbial community in numbers and composition and also contribute to the maturation of the host immune response

Microbiome of peri-implantitis affected and healthy dental sites in patients with a history of chronic periodontitis.

To determine the composition of the microbiome of peri-implantitis sites and corresponding dental sites in subjects with a history of chronic periodontitis. Clinical and radiographic examination assessed the periodontal/peri-implant disease status. Plaque samples were collected from one diseased implant with peri-implantitis, functional for at least two years and healthy sites in ten non-smokers who had received periodontal treatment prior to implant placement. Following DNA extraction, the bacteria present in each sample were determined by high-throughput sequencing of V3-V4 region of the 16S rRNA gene using the Illumina MiSeq platform. OTUs were picked using QIIME. Differences between dental and implant sites were determined using linear discriminant analysis, effect size and diversity analyses were conducted using PAST v3.02. The microbiomes of healthy samples were more diverse than those found in disease, although disease was associated with a higher abundance of taxa relative to health. The genera Actinobacillus and Streptococcus were most closely associated with health, whereas Prevotella and Porphyromonas were most discriminative for disease. Synergistetes were highly associated with peri-implantitis. In patients with a history of periodontitis, putative periodontal pathogens prevailed in the microbiome of diseased implants. Diseased implants and corresponding healthy sites appear to have distinct microbiological ecosystems

Microbiome associated with peri-implantitis versus periodontal health in individuals with a history of periodontal disease

The microbiome of peri-implantitis sites and healthy dental sites was determined in subjects with a history of periodontitis. Ten systemically healthy non-smokers received periodontal treatment before implant placement. Plaque samples were collected from four sites of one implant with peri-implantitis (bone loss ≥2mm; PPD ≥6mm; BOP/suppuration; >1year loading) and from one dental site per quadrant with periodontal health (PPD ≤3mm, CAL <4mm, absence of BOP and bone loss). Following DNA extraction, the bacteria present in each sample were determined by high-throughput sequencing of the V3-V4 region of the 16S-rRNA gene using the Illumina-MiSeq platform. OTUs were picked using QIIME. Differences between dental and implant sites were determined using linear discriminant analysis, effect size and diversity analyses were conducted using PAST v3.02. The microbiomes of diseased samples were less diverse than those found in health, although disease was associated with a higher abundance of taxa relative to health. The genera Actinobacillus and Streptococcus were most closely associated with health, whereas Prevotella and Porphyromonas were most discriminative for disease. Other disease associated genera were Peptostreptococcus, Tannerella, Treponema, TG5 and Atopobium. Diseased peri-implant and healthy periodontal tissues in the same individual appear to harbour distinct microbiological ecosystems with putative periodontal pathogens predominating in the peri-implantitis-associated microbiome

Isolation and prolonged expansion of oral mesenchymal stem cells under clinical-grade, GMP-compliant conditions differentially affects “stemness” properties

Abstract Background Development of clinical-grade cell preparations is central to meeting the regulatory requirements for cellular therapies under good manufacturing practice-compliant (cGMP) conditions. Since addition of animal serum in culture media may compromise safe and efficient expansion of mesenchymal stem cells (MSCs) for clinical use, this study aimed to investigate the potential of two serum/xeno-free, cGMP culture systems to maintain long-term “stemness” of oral MSCs (dental pulp stem cells (DPSCs) and alveolar bone marrow MSCs (aBMMSCs)), compared to conventional serum-based expansion. Methods DPSC and aBMMSC cultures (n = 6/cell type) were established from pulp and alveolar osseous biopsies respectively. Three culture systems were used: StemPro_MSC/SFM_XenoFree (Life Technologies); StemMacs_MSC/XF (Miltenyi Biotek); and α-MEM (Life Technologies) with 15% fetal bovine serum. Growth (population doublings (PDs)), immunophenotypic (flow cytometric analysis of MSC markers) and senescence (β-galactosidase (SA-β-gal) activity; telomere length) characteristics were determined during prolonged expansion. Gene expression patterns of osteogenic (ALP, BMP-2), adipogenic (LPL, PPAR-γ) and chondrogenic (ACAN, SOX-9) markers and maintenance of multilineage differentiation potential were determined by real-time PCR. Results Similar isolation efficiency and stable growth dynamics up to passage 10 were observed for DPSCs under all expansion conditions. aBMMSCs showed lower cumulative PDs compared to DPSCs, and when StemMacs was used substantial delays in cell proliferation were noted after passages 6–7. Serum/xeno-free expansion produced cultures with homogeneous spindle-shaped phenotypes, while serum-based expansion preserved differential heterogeneous characteristics of each MSC population. Prolonged expansion of both MSC types but in particular the serum/xeno-free-expanded aBMMSCs was associated with downregulation of CD146, CD105, Stro-1, SSEA-1 and SSEA-4, but not CD90, CD73 and CD49f, in parallel with an increase of SA-gal-positive cells, cell size and granularity and a decrease in telomere length. Expansion under both serum-free systems resulted in “osteogenic pre-disposition”, evidenced by upregulation of osteogenic markers and elimination of chondrogenic and adipogenic markers, while serum-based expansion produced only minor changes. DPSCs retained a diminishing (CCM, StemPro) or increasing (StemMacs) mineralization potential with passaging, while aBMMSCs lost this potential after passages 6–7 under all expansion conditions. Conclusions These findings indicate there is still a vacant role for development of qualified protocols for clinical-grade expansion of oral MSCs; a key milestone achievement for translation of research from the bench to clinics

Additional file 1: of Isolation and prolonged expansion of oral mesenchymal stem cells under clinical-grade, GMP-compliant conditions differentially affects “stemness” properties

is representative flow cytometry diagrams showing alterations in MSC marker expression in DPSCs during long-term expansion with CCM, StemMacs and StemPro (green line, unstained control; red line, marker of interest). Similar trends were observed for all DPSC and aBMMSC donors (PDF 418 kb