Periodontal health and gingival diseases and conditions on an intact and a reduced periodontium: Consensus report of workgroup 1 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.

Periodontal health is defined by absence of clinically detectable inflammation. There is a biological level of immune surveillance that is consistent with clinical gingival health and homeostasis. Clinical gingival health may be found in a periodontium that is intact, i.e. without clinical attachment loss or bone loss, and on a reduced periodontium in either a non-periodontitis patient (e.g. in patients with some form of gingival recession or following crown lengthening surgery) or in a patient with a history of periodontitis who is currently periodontally stable. Clinical gingival health can be restored following treatment of gingivitis and periodontitis. However, the treated and stable periodontitis patient with current gingival health remains at increased risk of recurrent periodontitis, and accordingly, must be closely monitored. Two broad categories of gingival diseases include non-dental plaque biofilm-induced gingival diseases and dental plaque-induced gingivitis. Non-dental plaque biofilm-induced gingival diseases include a variety of conditions that are not caused by plaque and usually do not resolve following plaque removal. Such lesions may be manifestations of a systemic condition or may be localized to the oral cavity. Dental plaque-induced gingivitis has a variety of clinical signs and symptoms, and both local predisposing factors and systemic modifying factors can affect its extent, severity, and progression. Dental plaque-induced gingivitis may arise on an intact periodontium or on a reduced periodontium in either a non-periodontitis patient or in a currently stable "periodontitis patient" i.e. successfully treated, in whom clinical inflammation has been eliminated (or substantially reduced). A periodontitis patient with gingival inflammation remains a periodontitis patient (Figure 1), and comprehensive risk assessment and management are imperative to ensure early prevention and/or treatment of recurrent/progressive periodontitis. Precision dental medicine defines a patient-centered approach to care, and therefore, creates differences in the way in which a "case" of gingival health or gingivitis is defined for clinical practice as opposed to epidemiologically in population prevalence surveys. Thus, case definitions of gingival health and gingivitis are presented for both purposes. While gingival health and gingivitis have many clinical features, case definitions are primarily predicated on presence or absence of bleeding on probing. Here we classify gingival health and gingival diseases/conditions, along with a summary table of diagnostic features for defining health and gingivitis in various clinical situations.

Matrix Metalloproteinase Response of Dendritic Cell, Gingival Epithelial Keratinocyte, and T-Cell Transwell Co-Cultures Treated with Porphyromonas gingivalis Hemagglutinin-B.

Matrix metalloproteinases (MMPs) are enzymes involved in periodontal tissue destruction. Hemagglutinin B (HagB) from the periodontal pathogen Porphyromonas gingivalis induces an elevated MMP response in dendritic cells, but responses from cultures of single-cell types do not reflect the local tissue environment. The objective of this study was to measure HagB-induced MMP responses in a transwell co-culture system containing dendritic cells, gingival epithelial (GE) keratinocytes, and CD4+ T-cells. Transwell co-cultures were assembled and treated with or without HagB. Immunoassays were used to determine production of MMP1, MMP7, MMP9, and MMP12 in response to HagB up to 64 h. Control responses were subtracted from HagB-induced responses. A two-way fixed effect ANOVA was fit to log-transformed concentrations and pairwise group comparisons were conducted (p < 0.05). At 64 h, dendritic cells produced elevated MMP1 and MMP9 responses, which were attenuated in the 3-cell co-culture (p < 0.05). There were also significant differences in MMP7 and MMP12 production between single-cell cultures and co-cultures. These results support the need to use multiple cell types in culture models to evaluate a more representative response to proinflammatory agonists. This three-cell transwell co-culture model may help us better understand the inflammatory process in periodontal disease and test novel therapeutic approaches.

Promise of Combining Antifungal Agents in Denture Adhesives to Fight Candida Species Infections.

PURPOSE: Several complications may arise in patients wearing complete prosthetic appliances, including denture-associated infections and mucosal stomatitis due to Candida species. This study evaluated the activity of anti-Candida agents in denture adhesive and the cytotoxicities of these preparations for primary human gingival epithelial (GE) keratinocytes. MATERIALS AND METHODS: The anti-Candida activities of antimicrobial peptides, antimicrobial lipids, and antifungal agents against C. albicans ATCC 64124 or HMV4C were assessed in microdilution assays containing water or 1% denture adhesive. The minimal inhibitory concentrations (MIC) and the minimal bactericidal concentrations (MBC) were determined. The cytotoxicities of denture adhesive compounded with these agents were assessed in 1.0 × 105 primary GE keratinocytes in LGM-3 media with resazurin. RESULTS: Lactoferricin B, SMAP28, sphingosine, dihydrosphingosine, and phytosphingosine in 1% denture adhesive lost antimicrobial activity for C. albicans (p < 0.05). Amphotericin B, chlorhexidine dihydrochloride, chlorhexidine gluconate, fluconazole, and nystatin in 1% denture adhesive or compounded directly into denture adhesive and then diluted to 1% adhesive, did not lose antimicrobial activity. Compounded formulations were not cytotoxic (LD50 > 100.0 µg/ml) against primary human GE keratinocytes. CONCLUSIONS: Antimicrobial peptides and antimicrobial lipids had diminished activities in 1% adhesive, suggesting that components in adhesives may inactivate local innate immune factors in the oral cavity, possibly predisposing denture wearers to Candida species infections. More importantly, antifungal agents retained their anti-C. albicans activities in denture adhesive, strongly suggesting that antifungal agents could be candidates for inclusion in adhesive formulations and used as prescribed topical treatments for individuals with denture stomatitis.

Predicting PD-L1 expression on human cancer cells using next-generation sequencing information in computational simulation models.

PURPOSE: Interaction of the programmed death-1 (PD-1) co-receptor on T cells with the programmed death-ligand 1 (PD-L1) on tumor cells can lead to immunosuppression, a key event in the pathogenesis of many tumors. Thus, determining the amount of PD-L1 in tumors by immunohistochemistry (IHC) is important as both a diagnostic aid and a clinical predictor of immunotherapy treatment success. Because IHC reactivity can vary, we developed computational simulation models to accurately predict PD-L1 expression as a complementary assay to affirm IHC reactivity. METHODS: Multiple myeloma (MM) and oral squamous cell carcinoma (SCC) cell lines were modeled as examples of our approach. Non-transformed cell models were first simulated to establish non-tumorigenic control baselines. Cell line genomic aberration profiles, from next-generation sequencing (NGS) information for MM.1S, U266B1, SCC4, SCC15, and SCC25 cell lines, were introduced into the workflow to create cancer cell line-specific simulation models. Percentage changes of PD-L1 expression with respect to control baselines were determined and verified against observed PD-L1 expression by ELISA, IHC, and flow cytometry on the same cells grown in culture. RESULT: The observed PD-L1 expression matched the predicted PD-L1 expression for MM.1S, U266B1, SCC4, SCC15, and SCC25 cell lines and clearly demonstrated that cell genomics play an integral role by influencing cell signaling and downstream effects on PD-L1 expression. CONCLUSION: This concept can easily be extended to cancer patient cells where an accurate method to predict PD-L1 expression would affirm IHC results and improve its potential as a biomarker and a clinical predictor of treatment success.

Influence of smoking on gingival crevicular fluid cytokines in severe chronic periodontitis.

AIM: The aim of this study was to compare the expression of 22 chemokines and cytokines in gingival crevicular fluid (GCF) from smokers and non-smokers with periodontitis and periodontally healthy control subjects. MATERIALS AND METHODS: Forty subjects with generalized severe chronic periodontitis (20 smokers and 20 non-smokers) and 12 periodontally healthy control subjects participated in this study. Four diseased and two healthy sites were selected from each of the periodontitis subjects. GCF samples were collected and cytokines analysed utilizing a multiplexed immunoassay (Luminex(®) ). Statistical analyses employed non-parametric tests including the Mann-Whitney and Wilcoxon matched-pairs signed-rank tests. RESULTS: Compared with healthy control subjects, GCF in subjects with chronic periodontitis contained significantly higher amounts of interleukin (IL)-1α, IL-1ß, IL-6, IL-12(p40) (pro-inflammatory cytokines); IL-8, macrophage chemotactic protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, regulated on activation normal T-cell expressed and secreted (RANTES) (chemokines); IL-2, IFN-γ, IL-3, IL-4 (Th1/Th2 cytokines); IL-15 [regulator of T-cells and natural killer (NK) cells]. Smokers displayed decreased amounts of pro-inflammatory cytokines [IL-1α, IL-6, IL-12(p40)], chemokines (IL-8, MCP-1, MIP-1, RANTES), and regulators of T-cells and NK cells (IL-7, IL-15). CONCLUSIONS: Periodontitis subjects had significantly elevated cytokine and chemokine profiles. Smokers exhibited a decrease in several pro-inflammatory cytokines and chemokines and certain regulators of T-cells and NK-cells. This reflects the immunosuppressant effects of smoking which may contribute to an enhanced susceptibility to periodontitis.

PD-L1 correlates with chemokines and cytokines in gingival crevicular fluid from healthy and diseased sites in subjects with periodontitis.

OBJECTIVE: PD-L1 is an immune checkpoint molecule that regulates immune and inflammatory responses. While cells of periodontal tissues express PD-L1, its presence in GCF is not known. The purpose of this study was to measure the PD-L1 values in GCF and correlate values with the presence of chemokine and cytokine values from periodontally diseased subjects and periodontally healthy subjects. RESULTS: PD-L1 values (pg/30 s), determined in triplicate using a fluorescent microparticle-based immunoassay ranged from 0.04-31.65 pg/30 s. PD-L1 correlated with 15 out of 22 chemokine and cytokine responses. In 85 healthy sites in 31 subjects, PD-L1 values were negatively correlated with IL6, CXCL8, IL10, and CCL3 values. In 53 diseased sites in 20 subjects, PD-L1 values were positively correlated with CCL11, CSF2, IFNG, IL1A, IL1B, IL2, IL7, IL15, and CCL5 values and negatively correlated with IL12A and IL5 values. Gene ontology (GO) annotations identified roles of PD-L1 in Th1 and Th2 activation and T-cell exhaustion signaling canonical pathways. PD-L1 values were correlated with the expression of chemokines and cytokines, which likely regulates immune cell trafficking and protects the periodontium from uncontrolled immune responses to pathogens and inflammation-induced tissue damage.

Dataset on the chemokine and cytokine responses of multi-cell cultures treated with Porphyromonas gingivalis hemagglutinin B.

Chemokines and cytokines produced in gingival tissues exposed to microorganisms and microbial products in dental plaque lead to local inflammation and tissue damage seen in periodontal disease. Bates et al. 2018 [1] reported that Porphyromonas gingivalis hemagglutinin B (HagB)-induced matrix metalloproteinase (MMP) responses of single cell cultures containing dendritic cells, gingival epithelial (GE) keratinocytes, or T cells were significantly different from the MMP responses of these same cells grown in multi-cell cultures. Here we report the concentrations (pg/ml) of HagB-induced IL1α, IL6, IL8, IL12(p40), GM-CSF, MIP1α, MIP1ß, RANTES, TNFα, and VEGF produced by dendritic cells, GE keratinocytes, or T cells in single cell cultures, two-cell cultures, or three-cell cultures.

Computational Models Accurately Predict Multi-Cell Biomarker Profiles in Inflammation and Cancer.

Individual computational models of single myeloid, lymphoid, epithelial, and cancer cells were created and combined into multi-cell computational models and used to predict the collective chemokine, cytokine, and cellular biomarker profiles often seen in inflamed or cancerous tissues. Predicted chemokine and cytokine output profiles from multi-cell computational models of gingival epithelial keratinocytes (GE KER), dendritic cells (DC), and helper T lymphocytes (HTL) exposed to lipopolysaccharide (LPS) or synthetic triacylated lipopeptide (Pam3CSK4) as well as multi-cell computational models of multiple myeloma (MM) and DC were validated using the observed chemokine and cytokine responses from the same cell type combinations grown in laboratory multi-cell cultures with accuracy. Predicted and observed chemokine and cytokine responses of GE KER + DC + HTL exposed to LPS and Pam3CSK4 matched 75% (15/20, p = 0.02069) and 80% (16/20, P = 0.005909), respectively. Multi-cell computational models became 'personalized' when cell line-specific genomic data were included into simulations, again validated with the same cell lines grown in laboratory multi-cell cultures. Here, predicted and observed chemokine and cytokine responses of MM cells lines MM.1S and U266B1 matched 75% (3/4) and MM.1S and U266B1 inhibition of DC marker expression in co-culture matched 100% (6/6). Multi-cell computational models have the potential to identify approaches altering the predicted disease-associated output profiles, particularly as high throughput screening tools for anti-inflammatory or immuno-oncology treatments of inflamed multi-cellular tissues and the tumor microenvironment.

Comparison of two different surgical approaches to increase peri-implant mucosal thickness: A randomized controlled clinical trial.

BACKGROUND: Current evidence supports the positive effect of adequate peri-implant mucosal thickness (PMT) on both marginal bone level stability and esthetic outcomes. While the subepithelial connective tissue graft (sCTG) has been traditionally considered as the gold standard for peri-implant mucosal augmentation, acellular dermal matrix (ADM) may be a valid alternative. The primary aim of this randomized clinical trial was to determine the clinical efficacy of ADM in the augmentation of PMT as compared to an autologous sCTG. METHODS: Patients who could benefit from peri-implant mucosal augmentation at the time of implant placement were recruited. Participants were randomized to the control (simultaneous sCTG) or test (simultaneous ADM) group. The primary outcome in this study was changes in PMT between baseline and 16 weeks later. Keratinized mucosal width (KMW) changes, modified wound healing index (MWHI) variations and patient-reported outcome measures (PROMs) were recorded, as well. RESULTS: A total of 20 participants were recruited per an a priori power analysis. There were no statistically significant differences between groups at baseline for any of the parameters analyzed. The gain in PMT at 1 mm, 3 mm, and 5 mm from the expected mucosal margin was 0.44 ± 2.04 mm, 1.20 ± 1.48 mm, and 1.20 ± 0.89 mm in the sCTG group, and 0.05 ± 1.57 mm, 0.85 ± 1.29 mm, and 1.45 ± 1.17 mm in the ADM group. No statistically significant differences in terms of PMT, KMW, and MWHI changes were observed between groups. The perceived discomfort was higher at 2 and 4 weeks for patients in the sCTG group. CONCLUSION: ADM produces similar outcomes to sCTG in terms of mucosal augmentation at the time of implant placement.

Periodontal health and gingival diseases and conditions on an intact and a reduced periodontium: Consensus report of workgroup 1 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions.

Periodontal health is defined by absence of clinically detectable inflammation. There is a biological level of immune surveillance that is consistent with clinical gingival health and homeostasis. Clinical gingival health may be found in a periodontium that is intact, i.e. without clinical attachment loss or bone loss, and on a reduced periodontium in either a non-periodontitis patient (e.g. in patients with some form of gingival recession or following crown lengthening surgery) or in a patient with a history of periodontitis who is currently periodontally stable. Clinical gingival health can be restored following treatment of gingivitis and periodontitis. However, the treated and stable periodontitis patient with current gingival health remains at increased risk of recurrent periodontitis, and accordingly, must be closely monitored. Two broad categories of gingival diseases include non-dental plaque biofilm-induced gingival diseases and dental plaque-induced gingivitis. Non-dental plaque biofilm-induced gingival diseases include a variety of conditions that are not caused by plaque and usually do not resolve following plaque removal. Such lesions may be manifestations of a systemic condition or may be localized to the oral cavity. Dental plaque-induced gingivitis has a variety of clinical signs and symptoms, and both local predisposing factors and systemic modifying factors can affect its extent, severity, and progression. Dental plaque-induced gingivitis may arise on an intact periodontium or on a reduced periodontium in either a non-periodontitis patient or in a currently stable "periodontitis patient" i.e. successfully treated, in whom clinical inflammation has been eliminated (or substantially reduced). A periodontitis patient with gingival inflammation remains a periodontitis patient (Figure 1), and comprehensive risk assessment and management are imperative to ensure early prevention and/or treatment of recurrent/progressive periodontitis. Precision dental medicine defines a patient-centered approach to care, and therefore, creates differences in the way in which a "case" of gingival health or gingivitis is defined for clinical practice as opposed to epidemiologically in population prevalence surveys. Thus, case definitions of gingival health and gingivitis are presented for both purposes. While gingival health and gingivitis have many clinical features, case definitions are primarily predicated on presence or absence of bleeding on probing. Here we classify gingival health and gingival diseases/conditions, along with a summary table of diagnostic features for defining health and gingivitis in various clinical situations.

Intravenous bisphosphonate-associated osteonecrosis of the jaw.

BACKGROUND: Bisphosphonates have received attention in the dental and medical scientific literature because of spontaneous necrosis of the jaw subsequent to their use. As the population ages, the use of these medications is increasing; the medical benefits seem to outweigh the risk for osteonecrosis of the jaw (ONJ). METHODS: A 71-year-old white male with a history of multiple myeloma, for which he was receiving intravenous (IV) zoledronic acid, presented for routine periodontal maintenance therapy. Intraoral observation revealed a 9x4-mm area of exposed bone on the lingual aspect of tooth #31. Initially, the site was treated conservatively with topical 0.12% chlorhexidine gluconate application. Over a 12-month period, the area of exposed bone increased in size to 20x9 mm and became symptomatic. RESULTS: The osseous necrosis progressed, ultimately resulting in a pathologic fracture of the right posterior mandible that was managed by reduction and stabilization. At 5 months post-surgery, bone exposure persisted in the region, and a new site of osteonecrosis developed on the contralateral side of the jaw. CONCLUSIONS: ONJ associated with IV bisphosphonate therapy is extremely difficult to manage. Dental treatment of ONJ should be conservative and provide relief to the patient. Patients with cancer who are candidates for IV bisphosphonate therapy should be informed of the potential risks and be referred for dental evaluation. Dentists should collaborate with physicians to minimize the risk for ONJ.

Correlation between beta-defensin expression and induction profiles in gingival keratinocytes.

Human beta-defensins are antimicrobial peptides produced by epithelial cells. To date, 28 beta-defensins have been described and the expression of a select few has been classified as constitutive or inducible. Most studies have evaluated expression and regulation using a limited number of primary cell cultures or immortalized cell lines. The goal of this study was to quantitatively assess the in vitro expression and inducibility profiles of human beta-defensins, HBD-1, HBD-2, and HBD-3 across a number of primary gingival keratinocyte cultures. Cultured cells from 14 human subjects were stimulated with interleukin-1 beta (IL-1beta), IL-2, IL-6, IL-8, IL-12, tumor necrosis factor alpha (TNF-alpha), gamma interferon (IFN-gamma) or Escherichia coli lipopolysaccharide (LPS) and analyzed by reverse transcription (RT)-PCR. A subset of cultures were quantitatively assessed by real-time PCR. HBD-1 presented the highest and most heterogeneous expression at the basal level (non-stimulated) as compared to expression of HBD-2 and HBD-3, which was significantly lower and homogeneous. IFN-gamma was a primary inducer for HBD-1 and HBD-3, while IL-1beta and TNF-alpha were primary inducers for HBD-2. Sporadic induction was seen for IL-2, IL-6 and LPS. Synergistic expression was seen when various cytokines were combined. Interestingly, the induction potential of each beta-defensin was directly correlated to its basal expression. An inhibitor of JAK2 kinase (Janus kinase), down-regulated IFN-gamma-induced HBD-1 and HBD-3 expression, suggesting a role for the JAK/signal transducer and activator of transcription (STAT) signaling pathway in their expression. HBD-2 protein expression of supernatants and cell lysates paralleled mRNA expression. The results suggest that beta-defensin expression and induction in gingival keratinocytes is similar to that seen in other tissue. However, the novel finding of considerable variation among induction levels and the correlation of the induction with basal expression suggests that these innate response elements may play a key role in susceptibility or resistance to disease in the oral cavity.

Cytotoxicity of HBD3 for dendritic cells, normal human epidermal keratinocytes, hTERT keratinocytes, and primary oral gingival epithelial keratinocytes in cell culture conditions.

Human ß-defensin 3 (HBD3) is a prominent host defense peptide. In our recent work, we observed that HBD3 modulates pro-inflammatory agonist-induced chemokine and cytokine responses in human myeloid dendritic cells (DCs), often at 20.0 µM concentrations. Since HBD3 can be cytotoxic in some circumstances, it is necessary to assess its cytotoxicity for DCs, normal human epidermal keratinocytes (NHEKs), human telomerase reverse transcriptase (hTERT) keratinocytes, and primary oral gingival epithelial (GE) keratinocytes in different cell culture conditions. Cells, in serum free media with resazurin and in complete media with 10% fetal bovine serum and resazurin, were incubated with 5, 10, 20, and 40 µM HBD3. Cytotoxicity was determined by measuring metabolic conversion of resazurin to resorufin. The lethal dose 50 (LD50, mean µM±Std Err) values were determined from the median fluorescent intensities of test concentrations compared to live and killed cell controls. The LD50 value range of HBD3 was 18.2-35.9 µM in serum-free media for DCs, NHEKs, hTERT keratinocytes, and GE keratinocytes, and >40.0 µM in complete media. Thus, HBD3 was cytotoxic at higher concentrations, which must be considered in future studies of HBD3-modulated chemokine and cytokine responses in vitro.

Differential cytotoxicity of long-chain bases for human oral gingival epithelial keratinocytes, oral fibroblasts, and dendritic cells.

Long-chain bases are present in the oral cavity. Previously we determined that sphingosine, dihydrosphingosine, and phytosphingosine have potent antimicrobial activity against oral pathogens. Here, we determined the cytotoxicities of long-chain bases for oral cells, an important step in considering their potential as antimicrobial agents for oral infections. This information would clearly help in establishing prophylactic or therapeutic doses. To assess this, human oral gingival epithelial (GE) keratinocytes, oral gingival fibroblasts (GF), and dendritic cells (DC) were exposed to 10.0-640.0 µM long-chain bases and glycerol monolaurate (GML). The effects of long-chain bases on cell metabolism (conversion of resazurin to resorufin), membrane permeability (uptake of propidium iodide or SYTOX-Green), release of cellular contents (LDH), and cell morphology (confocal microscopy) were all determined. GE keratinocytes were more resistant to long-chain bases as compared to GF and DC, which were more susceptible. For DC, 0.2-10.0 µM long-chain bases and GML were not cytotoxic; 40.0-80.0 µM long-chain bases, but not GML, were cytotoxic; and 80.0 µM long-chain bases induced cellular damage and death in less than 20 min. The LD50 of long-chain bases for GE keratinocytes, GF, and DC were considerably higher than their minimal inhibitory concentrations for oral pathogens, a finding important to pursuing their future potential in treating periodontal and oral infections.

Differential cytotoxicity of long-chain bases for human oral gingival epithelial keratinocytes, oral fibroblasts, and dendritic cells.

Long-chain bases, found in the oral cavity, have potent antimicrobial activity against oral pathogens. In an article associated with this dataset, Poulson and colleagues determined the cytotoxicities of long-chain bases (sphingosine, dihydrosphingosine, and phytosphingosine) for human oral gingival epithelial (GE) keratinocytes, oral gingival fibroblasts (GF), dendritic cells (DC), and squamous cell carcinoma (SCC) cell lines [1]. Poulson and colleagues found that GE keratinocytes were more resistant to long-chain bases as compared to GF, DC, and SCC cell lines [1]. In this study, we assess the susceptibility of DC to lower concentrations of long chain bases. 0.2-10.0 µM long-chain bases and GML were not cytotoxic to DC; 40.0-80.0 µM long-chain bases, but not GML, were cytotoxic for DC; and 80.0 µM long-chain bases were cytotoxic to DC and induced cellular damage and death in less than 20 mins. Overall, the LD50 of long-chain bases for GE keratinocytes, GF, and DC were considerably higher than their minimal inhibitory concentrations for oral pathogens, a finding important to pursuing their future potential in treating periodontal and oral infections.

Cigarette smoking and the periodontal patient.

Evidence from cross-sectional and case-control studies in various populations demonstrates that adult smokers are approximately three times as likely as non-smokers to have periodontitis. The association between smoking and attachment loss is even stronger when the definition of periodontitis is restricted to the most severely affected subjects. Smokers have a diminished response to periodontal therapy and show approximately half as much improvement in probing depths and clinical attachment levels following non-surgical and various surgical modalities of therapy. Implant failures in smokers are twice those of non-smokers, with a higher failure rate in the maxillary arch accounting for the majority of the difference. Tobacco-induced alterations in microbial and host factors contribute to these deleterious effects of smoking on the periodontium. In longitudinal studies, the rate of periodontal disease progression is increased in smokers, but decreases to that of a non-smoker following tobacco cessation. Likewise, recent non-smokers respond to periodontal therapy in a manner similar to patients who have never smoked. Data regarding the impact of smoking on periodontal status included in this review will be helpful to dental health professionals as they counsel their patients regarding tobacco use. The role of dental health professionals in tobacco cessation is discussed, including the use of the five A's: ask--identify tobacco users; advise--advise them to quit; assess--evaluate the patient's readiness to quit; assist--offer assistance in cessation; and arrange--follow up on the patient's cessation efforts. The addition of pharmacotherapy to behavioral therapy, including nicotine replacement therapy and bupropion, can increase cessation rates. The most popular form of nicotine replacement therapy is the patch, and its use has been shown to double cessation rates compared to behavioral therapy alone. Use of bupropion in combination with nicotine replacement therapy may be particularly helpful for heavy smokers or smokers who have experienced multiple failed attempts at cessation. The American Academy of Periodontology Parameters of Care include tobacco cessation as a part of periodontal therapy, and the 2000 Surgeon General's Report on Oral Health in America encourages dental professionals to become more active in tobacco cessation counseling. Doing so will have far-reaching positive effects on our patients' oral and general health.

Body fat indices and biomarkers of inflammation: a cross-sectional study with implications for obesity and peri-implant oral health.

PURPOSE: To examine the relationships between three measures of body fat-body mass index (BMI), waist circumference (WC), and total body fat percent-and markers of inflammation around dental implants in stable periodontal maintenance patients. MATERIALS AND METHODS: Seventy-three subjects were enrolled in this cross-sectional assessment. The study visit consisted of a physical examination that included anthropologic measurements of body composition (BMI, WC, body fat %); intraoral assessments were performed (full-mouth plaque index, periodontal and peri-implant comprehensive examinations) and peri-implant sulcular fluid (PISF) was collected on the study implants. Levels of interleukin (IL)-1α, IL-1ß, IL-6, IL-8, IL-10, IL-12, IL-17, tumor necrosis factor-α, C-reactive protein, osteoprotegerin, leptin, and adiponectin in the PISF were measured using multiplex proteomic immunoassays. Correlation analysis with body fat measures was then performed using appropriate statistical methods. RESULTS: After adjustments for covariates, regression analyses revealed statistically significant correlation between IL-1ß in PISF and WC (R = 0.33; P = .0047). CONCLUSION: In this study in stable periodontal maintenance patients, a modest but statistically significant positive correlation was observed between the levels of IL-1ß, a major proinflammatory cytokine in PISF, and WC, a reliable measure of central obesity.

The enhancement of bone regeneration by gene activated matrix encoding for platelet derived growth factor.

Gene therapy using non-viral vectors that are safe and efficient in transfecting target cells is an effective approach to overcome the shortcomings of protein delivery of growth factors. The objective of this study was to develop and test a non-viral gene delivery system for bone regeneration utilizing a collagen scaffold to deliver polyethylenimine (PEI)-plasmid DNA (pDNA) [encoding platelet derived growth factor-B (PDGF-B)] complexes. The PEI-pPDGF-B complexes were fabricated at amine (N) to phosphate (P) ratio of 10 and characterized for size, surface charge, and in vitro cytotoxicity and transfection efficacy in human bone marrow stromal cells (BMSCs). The influence of the complex-loaded collagen scaffold on cellular attachment and recruitment was evaluated in vitro using microscopy techniques. The in vivo regenerative capacity of the gene delivery system was assessed in 5 mm diameter critical-sized calvarial defects in Fisher 344 rats. The complexes were ~100 nm in size with a positive surface charge. Complexes prepared at an N/P ratio of 10 displayed low cytotoxicity as assessed by a cell viability assay. Confocal microscopy revealed significant proliferation of BMSCs on complex-loaded collagen scaffolds compared to empty scaffolds. In vivo studies showed significantly higher new bone volume/total volume (BV/TV) % in calvarial defects treated with the complex-activated scaffolds following 4 weeks of implantation (14- and 44-fold higher) when compared to empty defects or empty scaffolds, respectively. Together, these findings suggest that non-viral PDGF-B gene-activated scaffolds are effective for bone regeneration and are an attractive gene delivery system with significant potential for clinical translation.

Quality assessment of systematic reviews on periodontal regeneration in humans.

BACKGROUND: Systematic reviews represent the highest form of evidence in the current hierarchy of evidence-based dentistry. Critical analysis of published systematic reviews may help to analyze their strengths and weaknesses and to identify areas that need future improvement. The aim of this overview is to determine and compare the quality of systematic reviews published in the field of periodontal regeneration using established checklists, such as the Assessment of Multiple Systematic Reviews (AMSTAR) guidelines. METHODS: A systematic search was conducted to retrieve reviews on periodontal regeneration in humans. A total of 14 systematic reviews were selected using a set of inclusion and exclusion criteria. Two independent reviewers appraised the quality of the selected reviews using AMSTAR guidelines. Each article was given an AMSTAR total score, based on the number of AMSTAR criteria that were fulfilled. The quality of included reviews was further assessed using a checklist proposed in 2003. RESULTS: Only one of the selected systematic reviews satisfied all the AMSTAR guidelines, whereas two reviews satisfied just two of the 11 items. This study shows that published systematic reviews on periodontal regeneration exhibit significant structural and methodologic variability. Quality assessment using the additional checklist further confirmed the variability in the way systematic reviews were conducted and/or reported. CONCLUSION: Consideration of guidelines for quality assessment, such as AMSTAR, when designing and conducting systematic reviews may increase the validity and clinical applicability of future reviews.

The association between periodontitis and coronary heart disease: a quality assessment of systematic reviews.

BACKGROUND: The existence of an association between periodontitis and cardiovascular disease has been proposed by investigators in several clinical studies and further confirmed by the results of several systematic reviews. The aim of the authors' study was to assess the quality of published systematic reviews focused on the association between periodontitis and coronary heart disease (CHD) by using established systematic review assessment checklists. METHODS: Two reviewers conducted a search for systematic reviews focusing on the association between periodontitis and CHD. Three independent reviewers appraised the quality of the selected 13 reviews by using an established and validated assessment tool for systematic reviews and another checklist. They gave each article a total score according to the number of criteria on each checklist that the article fulfilled. RESULTS: Nine reviews satisfied six or more items on the assessment tool, whereas two reviews each satisfied only one item. This assessment shows that published systematic reviews of the periodontitis-CHD association exhibit significant structural and methodological variation, which the authors further confirmed by using the second checklist. CONCLUSION: Systematic reviews of the association between periodontitis and CHD exhibited significant differences in their methodological quality. PRACTICAL IMPLICATIONS: Clinicians should be aware that not all systematic reviews of the periodontitis-CHD association are conducted in a rigorous manner and should be capable of differentiating well-conducted reviews from poorly conducted ones.