The Subgingival Microbiome Relationship to Periodontal Disease in Older Women.

Understanding of the oral microbiome in relation to periodontal disease in older adults is limited. The composition and diversity of the subgingival microflora and their oligotypes in health and levels of periodontal disease were investigated in this study on older postmenopausal women. The 16S rRNA gene was sequenced using the Illumina MiSeq platform in 1,206 women aged 53 to 81 y. Presence and severity of periodontal disease were defined by Centers for Disease Control and Prevention/American Academy of Periodontology criteria. Composition of the microbiome was determined by 16S rRNA amplicon sequencing and the abundance of taxa described by the centered log2-ratio (CLR) transformed operational taxonomic unit (OTU) values. Differences according to periodontal disease status were determined by analysis of variance with Bonferroni correction. Bacteria oligotypes associated with periodontal disease and health were determined by minimum entropy decomposition and their functions estimated in silico using PICRUSt. Prevalence of none/mild, moderate, and severe periodontal disease was 25.1%, 58.3%, and 16.6%, respectively. Alpha diversity of the microbiome differed significantly across the 3 periodontal disease categories. ß-Diversity differed between no/mild and severe periodontal disease, although considerable overlap was noted. Of the 267 bacterial species identified at ≥0.02% abundance, 56 (20.9%) differed significantly in abundance according to periodontal disease status. Significant linear correlations for pocket depth and clinical attachment level with bacterial amounts were observed for several taxa. Of the taxa differing in abundance according to periodontal disease status, 53% had multiple oligotypes appearing to differ between none/mild and severe periodontal disease. Among older women, taxonomic differences in subgingival microbiome composition and diversity were observed in relation to clinical periodontal disease measures. Potential differences in bacterial subspecies (oligotypes) and their function were also identified in periodontal disease compared with health.

Tannerella forsythia-produced methylglyoxal causes accumulation of advanced glycation endproducts to trigger cytokine secretion in human monocytes.

The periodontal pathogen Tannerella forsythia has the unique ability to produce methylglyoxal (MGO), an electrophilic compound which can covalently modify amino acid side chains and generate inflammatory adducts known as advanced glycation endproducts (AGEs). In periodontitis, concentrations of MGO in gingival-crevicular fluid are increased and are correlated with the T. forsythia load. However, the source of MGO and the extent to which MGO may contribute to periodontal inflammation has not been fully explored. In this study we identified a functional homolog of the enzyme methylglyoxal synthase (MgsA) involved in the production of MGO in T. forsythia. While wild-type T.forsythia produced a significant amount of MGO in the medium, a mutant lacking this homolog produced little to no MGO. Furthermore, compared with the spent medium of the T. forsythia parental strain, the spent medium of the T. forsythia mgsA-deletion strain induced significantly lower nuclear factor-kappa B activity as well as proinflammogenic and pro-osteoclastogenic cytokines from THP-1 monocytes. The ability of T. forsythia to induce protein glycation endproducts via MGO was confirmed by an electrophoresis-based collagen chain mobility shift assay. Together these data demonstrated that T. forsythia produces MGO, which may contribute to inflammation via the generation of AGEs and thus act as a potential virulence factor of the bacterium.

A Randomized Clinical Trial Evaluating rh-FGF-2/ß-TCP in Periodontal Defects.

Biological mediators have been used to enhance periodontal regeneration. The aim of this prospective randomized controlled study was to evaluate the safety and effectiveness of 3 doses of fibroblast growth factor 2 (FGF-2) when combined with a ß-tricalcium phosphate (ß-TCP) scaffold carrier placed in vertical infrabony periodontal defects in adult patients. In this double-blinded, dose-verification, externally monitored clinical study, 88 patients who required surgical intervention to treat a qualifying infrabony periodontal defect were randomized to 1 of 4 treatment groups-ß-TCP alone (control) and 0.1% recombinant human FGF-2 (rh-FGF-2), 0.3% rh-FGF-2, and 0.4% rh-FGF-2 with ß-TCP-following scaling and root planing of the tooth prior to a surgical appointment. Flap surgery was performed with EDTA conditioning of the root prior to device implantation. There were no statistically significant differences in patient demographics and baseline characteristics among the 4 treatment groups. When a composite outcome of gain in clinical attachment of 1.5 mm was used with a linear bone growth of 2.5 mm, a dose response pattern detected a plateau in the 0.3% and 0.4% rh-FGF-2/ß-TCP groups with significant improvements over control and 0.1% rh-FGF-2/ß-TCP groups. The success rate at 6 mo was 71% in the 2 higher-concentration groups, as compared with 45% in the control and lowest treatment groups. Percentage bone fill in the 2 higher-concentration groups was 75% and 71%, compared with 63% and 61% in the control and lowest treatment group. No increases in specific antibody to rh-FGF-2 were detected, and no serious adverse events related to the products were reported. The results from this multicenter trial demonstrated that the treatment of infrabony vertical periodontal defects can be enhanced with the addition of rh-FGF-2/ß-TCP (ClinicalTrials.gov NCT01728844).

A tribute to Marty Taubman: the Earl of Sandwich, IgA, T-regs, and the Celtics.

This tribute to Marty Taubman is written on the occasion of his retirement from full-time faculty status at The Forsyth Institute and Harvard Dental School, and his stepping down as editor of the "Discovery!" section of the Journal of Dental Research. It recognizes his seminal contributions to oral immunology, his mentoring of a generation of new scientists, his key role as a leader in organized research as president of the American Association for Dental Research, as well as his editorship, which has recognized scores of his colleagues in science. He is a leader in our field and has made many lasting contributions to research, teaching, and our profession, for which we are very grateful.

Self-reported measures for surveillance of periodontitis.

The purpose of this study was to evaluate the performance of self-reported measures in predicting periodontitis in a representative US adult population, based on 2009-2010 National Health and Nutrition Examination Survey (NHANES) data. Self-reported gum health and treatment history, loose teeth, bone loss around teeth, tooth not looking right, and use of dental floss and mouthwash were obtained during in-home interviews and validated against full-mouth clinically assessed periodontitis in 3,743 US adults 30 years and older. All self-reported measures (> 95% item response rates) were associated with periodontitis, and bivariate correlations between responses to these questions were weak, indicating low redundancy. In multivariable logistic regression modeling, the combined effects of demographic measures and responses to 5 self-reported questions in predicting periodontitis of mild or greater severity were 85% sensitive and 58% specific and produced an 'area under the receiver operator characteristic curve' (AUROCC) of 0.81. Four questions were 95% sensitive and 30% specific, with an AUROCC of 0.82 in predicting prevalence of clinical attachment loss ≥ 3 mm at one or more sites. In conclusion, self-reported measures performed well in predicting periodontitis in US adults. Where preferred clinically based surveillance is unattainable, locally adapted variations of these self-reported measures may be a promising alternative for surveillance of periodontitis.

Prevalence of periodontitis in adults in the United States: 2009 and 2010.

This study estimated the prevalence, severity, and extent of periodontitis in the adult U.S. population, with data from the 2009 and 2010 National Health and Nutrition Examination Survey (NHANES) cycle. Estimates were derived from a sample of 3,742 adults aged 30 years and older, of the civilian non-institutionalized population, having 1 or more natural teeth. Attachment loss (AL) and probing depth (PD) were measured at 6 sites per tooth on all teeth (except the third molars). Over 47% of the sample, representing 64.7 million adults, had periodontitis, distributed as 8.7%, 30.0%, and 8.5% with mild, moderate, and severe periodontitis, respectively. For adults aged 65 years and older, 64% had either moderate or severe periodontitis. Eighty-six and 40.9% had 1 or more teeth with AL ≥ 3 mm and PD ≥ 4 mm, respectively. With respect to extent of disease, 56% and 18% of the adult population had 5% or more periodontal sites with ≥ 3 mm AL and ≥ 4 mm PD, respectively. Periodontitis was highest in men, Mexican Americans, adults with less than a high school education, adults below 100% Federal Poverty Levels (FPL), and current smokers. This survey has provided direct evidence for a high burden of periodontitis in the adult U.S. population.

Single nucleotide polymorphisms of pattern recognition receptors and chronic periodontitis.

BACKGROUND AND OBJECTIVE: Periodontitis is a multifactorial disease influenced partly by genetics. Activation of pattern recognition receptors (PRRs) can lead to the up-regulation of inflammatory pathways, resulting in periodontal tissue destruction. Hence, functional polymorphisms located in PRRs can explain differences in host susceptibility to periodontitis. This study investigated single nucleotide polymorphisms of PRRs including toll-like receptor (TLR)2 (G2408A), TLR4 (A896G), TLR9 (T1486C), TLR9 (T1237C) and CD14 (C260T) in patients with chronic periodontitis and in periodontally healthy subjects. METHODS: One-hundred and fourteen patients with chronic periodontitis and 77 periodontally healthy subjects were genotyped using TaqMan® allelic discrimination assays. Fisher's exact test and chi-square analyses were performed to compare genotype and allele frequencies. RESULTS: The frequency of subjects with the CC genotype of CD14 (C260T) (24.6% in the chronic periodontitis group vs. 13% in the periodontally healthy group) and those expressing the T allele of CD14 (C260T) (CT and TT) (75.4% in the chronic periodontitis group vs. 87% in the periodontally healthy group) was statistically different among groups (p = 0.04). Homozygocity for the C allele of the CD14 (C260T) polymorphism (CC) was associated with a two--fold increased susceptibility to periodontitis (p = 0.04; odds ratio, 2.49; 95% confidence interval, 1.06-6.26). Individuals with the CC genotype of TLR9 (T1486C) (14.9% in the chronic periodontitis group vs. 28.6% in the periodontally healthy group) and those expressing the T allele of TLR9 (T1486C) (CT and TT) (85.1% in the chronic periodontitis group vs. 71.4% in the periodontally healthy group) were also significantly differently distributed between groups without adjustment (p = 0.03). Further analysis of nonsmokers revealed a significant difference in the distribution of genotypes between groups for TLR9 (T1486C; p = 0.017) and CD14 (C260T; p = 0.03), polymorphisms again without adjustment. CONCLUSION: The CC genotype of CD14 (C260T) is related to susceptibility to chronic periodontitis in Caucasians. In addition, differences observed in the distribution of TLR9 (T1486C) genotypes between groups warrant further investigation.

Osteoporosis and oral infection: independent risk factors for oral bone loss.

Studies have suggested that oral bone loss is independently influenced by local and systemic factors, including osteoporosis. This cross-sectional study of 1256 post-menopausal women, recruited from the Buffalo center of the Women's Health Initiative Observational Study, evaluated the influence of oral infection and age on the associations between osteoporosis and oral bone loss. Systemic bone density was measured by dual-energy x-ray absorptiometry. Alveolar crestal height was measured from standardized dental radiographs. Oral infection was assessed from subgingival plaque samples. Total forearm density [beta (SE)= -0.931 (0.447), p=0.038] and presence of Tannerella forsythensis [beta (SE)=0.125 (0.051), p=0.015] were independently associated with mean alveolar height among women aged <70 years after confounder adjustment. Women aged 70+ years had worse oral bone loss, in general, but neither bone density nor oral infection was significantly associated with mean alveolar height in this age group. Systemic bone density and oral infection independently influenced oral bone loss in post-menopausal women aged <70 years.

Periodontal infections contribute to elevated systemic C-reactive protein level.

BACKGROUND: Periodontitis is a local inflammatory process mediating destruction of periodontal tissues triggered by bacterial insult. However, this disease is also characterized by systemic inflammatory host responses that may contribute, in part, to the recently reported higher risk for cardiovascular disease (CVD) among patients with periodontitis. Moderate elevation of C-reactive protein (CRP) has been found to be a predictor of increased risk for CVD. Elevated CRP levels in periodontal patients have been reported by several groups. In this study, we examined whether CRP plasma levels are increased in periodontitis and if there is a relation to severity of periodontal disease and to the periodontal microflora. METHODS: CRP serum levels were assessed using radial immunodiffusion assay in 174 subjects, 59 with moderate mean clinical attachment loss (AL) (2.39+/-0.29 mm) and 50 with high AL (3.79+/-0.86 mm) as compared to 65 periodontally healthy controls (AL, 1.74+/-0.18 mm). Clinical attachment loss, probing depths, and percentage of periodontal pocket sites > or =5 mm were measured. The presence of periodontal pathogens Porphyromonas gingivalis (P.g.), Prevotella intermedia (P.i.), Campylobacter recta (C.r.), and Bacteroides forsythus (B.f.) in subgingival plaque samples was measured by immunofluorescence microscopy. RESULTS: Statistically significant increases in CRP levels were observed in subjects with periodontal disease when compared to healthy controls (P= 0.036). Subjects with high levels of mean clinical attachment loss had significantly higher mean CRP levels (4.06+/-5.55 mg/l) than controls (1.70+/-1.91 mg/l), P= 0.011. The CRP levels were adjusted for factors known to be associated with elevated CRP, including age, smoking, body mass index (BMI), triglycerides, and cholesterol. Age and BMI were found to be significant covariates. The reported range for CRP as a risk factor for CVD, peripheral vascular diseases, or stroke is 1.34 mg/l to 6.45 mg/l and the mean of this range is 3 mg/l. The percentage of subjects with elevated levels of CRP > or = 3 mm was significantly higher in the high clinical AL group (38%; 95% Cl: 26.7%, 49.3%) when compared to the control group (16.9%; 95% CI: 9.25%, 24.5%), P= 0.011. The presence of periodontal pathogens P.g., P.i., C.r., and B.f. in subgingival samples was positively associated with elevated CRP levels (P= 0.029). CONCLUSIONS: The extent of increase in CRP levels in periodontitis patients depends on the severity of the disease after adjusting for age, smoking, body mass index, triglycerides, and cholesterol. Also, there are elevated levels of CRP associated with infection with subgingival organisms often associated with periodontal disease, including P.g., P.i., C.r., and B.f. Recent investigations emphasized the role of moderate elevated CRP plasma levels as a risk factor for CVD. The positive correlation between CRP and periodontal disease might be a possible underlying pathway in the association between periodontal disease and the observed higher risk for CVD in these patients.

Development of a gene inactivation system for Bacteroides forsythus: construction and characterization of a BspA mutant.

Bacteroides forsythus is a gram-negative anaerobic bacterium associated with periodontitis. The bspA gene encoding a cell surface associated leucine-rich repeat protein (BspA) involved in adhesion to fibronectin and fibrinogen was recently cloned from this bacterium in our laboratory. We now describe the construction of a BspA-defective mutant of B. forsythus. This is the first report describing the generation of a specific gene knockout mutant of B. forsythus, and this procedure should be useful in establishing the identity of virulence-associated factors in these organisms.

The effect of alcohol consumption on periodontal disease.

BACKGROUND: Alcohol consumption, like smoking, may be related to periodontal disease independently of oral hygiene status. This study assessed the relationship between alcohol consumption and severity of periodontal disease. METHODS: A cross-sectional study of 1,371 subjects ages 25 to 74 in the Erie County, NY population was performed. Alcohol intake was assessed by means of previously validated self-reported questionnaires. Outcome variables were gingival bleeding, clinical attachment loss, alveolar bone loss, and presence of subgingival microorganisms. RESULTS: Logistic regression analyses adjusting for age, gender, race, education, income, smoking, diabetes mellitus, dental plaque, and presence of any of 8 subgingival microorganisms showed that those consuming > or =5 drinks/week had an odds ratio (OR) of 1.65 (95% CI: 1.22 to 2.23) of having higher gingival bleeding, and OR of 1.36 (95% CI: 1.02 to 1.80) of having more severe clinical attachment loss compared to those consuming <5 drinks/week. Those consuming > or =10 drinks/week had an odds ratio (OR) of 1.62 (95% CI: 1.12 to 2.33) of having higher gingival bleeding and OR of 1.44 (95% CI: 1.04 to 2.00) of having more severe clinical attachment loss compared to those consuming <10 drinks/week. Alcohol consumption was not significantly related to alveolar bone loss nor to any of the subgingival microorganisms. CONCLUSIONS: The results suggest that alcohol consumption is associated with moderately increased severity of periodontal disease. Longitudinal studies are needed to determine whether alcohol is a true risk factor for periodontal disease.

Oral immunization with recombinant Streptococcus gordonii expressing porphyromonas gingivalis FimA domains.

Porphyromonas gingivalis, a gram-negative anaerobe, is implicated in the etiology of adult periodontitis. P. gingivalis fimbriae are one of several critical surface virulence factors involved in both bacterial adherence and inflammation. P. gingivalis fimbrillin (FimA), the major subunit protein of fimbriae, is considered an important antigen for vaccine development against P. gingivalis-associated periodontitis. We have previously shown that biologically active domains of P. gingivalis fimbrillin can be expressed on the surface of the human commensal bacterium Streptococcus gordonii. In this study, we examined the effects of oral coimmunization of germfree rats with two S. gordonii recombinants expressing N (residues 55 to 145)- and C (residues 226 to 337)-terminal epitopes of P. gingivalis FimA to elicit FimA-specific immune responses. The effectiveness of immunization in protecting against alveolar bone loss following P. gingivalis infection was also evaluated. The results of this study show that the oral delivery of P. gingivalis FimA epitopes via S. gordonii vectors resulted in the induction of FimA-specific serum (immunoglobulin G [IgG] and IgA) and salivary (IgA) antibody responses and that the immune responses were protective against subsequent P. gingivalis-induced alveolar bone loss. These results support the potential usefulness of the S. gordonii vectors expressing P. gingivalis fimbrillin as a mucosal vaccine against adult periodontitis.

An economic evaluation of a chlorhexidine chip for treating chronic periodontitis: the CHIP (chlorhexidine in periodontitis) study.

BACKGROUND: The authors previously suggested that an adjunctive, controlled-release chlorhexidine, or CHX, chip may reduce periodontal surgical needs at little additional cost. This article presents an economic analysis of the CHX chip in general dental practice. METHODS: In a one-year prospective clinical trial, 484 chronic periodontitis patients in 52 general practices across the United States were treated with either scaling and root planing, or SRP, plus any therapy prescribed by treating, unblinded dentists; or SRP plus other therapy as above but including the CHX chip. Economic data were collected from bills, case report forms and 12-month treatment recommendations from blinded periodontist evaluators. RESULTS: Total dental charges were higher for SRP + CHX chip patients vs. SRP patients when CHX chip costs were included (P = .027) but lower when CHX chip costs were excluded (P = .012). About one-half of the CHX chip acquisition cost was offset by savings in other charges. SRP + CHX chip patients were about 50 percent less likely to undergo surgical procedures than were SRP patients (P = .021). At the end of the trial, periodontist evaluators recommended similar additional procedures for both groups: SRP, about 46 percent; maintenance, about 37 percent; surgery, 56 percent for SRP alone and 63 percent for SRP + CHX chip. CONCLUSIONS: Adjunctive CHX chip use for general-practice patients with periodontitis increased costs but reduced surgeries over one year. At study's end, periodontists recommended similar additional surgical treatment for both groups. CLINICAL IMPLICATIONS: In general practice, routine use of the CHX chip suggests that costs will be partially offset by reduced surgery over at least one year.

Overview of risk factors for periodontal disease and implications for diabetes and cardiovascular disease.

Recent studies have shown that there is a definite relationship between diseases of the oral cavity, especially periodontal infections, and systematic diseases. Periodontal disease may also produce systemic effects in the body, including an association with cardiovascular disease. This article discusses the risk factors for periodontal disease, the pathogenesis and risk factors for cardiovascular disease, the relationship between periodontal infection and cardiovascular disease, and the need for future studies to further define the relationship between periodontal disease and cardiovascular disease.

Position paper: sonic and ultrasonic scalers in periodontics. Research, Science and Therapy Committee of the American Academy of Periodontology.

Ultrasonic and sonic scalers appear to attain similar results as hand instruments for removing plaque, calculus, and endotoxin. Ultrasonic scalers used at medium power seem to produce less root surface damage than hand or sonic scalers. Due to instrument width, furcations may be more accessible using ultrasonic or sonic scalers than manual scalers. It is not clear whether root surface roughness is more or less pronounced following power-driven scalers or manual scalers. It is also unclear if root surface roughness affects long-term wound healing. Periodontal scaling and root planing includes thorough calculus removal, but complete cementum removal should not be a goal of periodontal therapy. Studies have established that endotoxin is weakly adsorbed to the root surface, and can be easily removed with light, overlapping strokes with an ultrasonic scaler. A significant disadvantage of power-driven scalers is the production of contaminated aerosols. Because ultrasonics and sonics produce aerosols, additional care is required to achieve and maintain good infection control when incorporating these instrumentation techniques into dental practice. Preliminary evidence suggests that the addition of certain antimicrobials to the lavage during ultrasonic instrumentation may be of minimal clinical benefit. However, more randomized controlled clinical trials need to be conducted over longer periods of time to better understand the long-term benefits of ultrasonic and sonic debridement.

Identification of periodontal pathogens in atheromatous plaques.

BACKGROUND: Recent studies suggest that chronic infections including those associated with periodontitis increase the risk for coronary vascular disease (CVD) and stroke. We hypothesize that oral microorganisms including periodontal bacterial pathogens enter the blood stream during transient bacteremias where they may play a role in the development and progression of atherosclerosis leading to CVD. METHODS: To test this hypothesis, 50 human specimens obtained during carotid endarterectomy were examined for the presence of Chlamydia pneumoniae, human cytomegalovirus, and bacterial 16S ribosomal RNA using specific oligonucleotide primers in polymerase chain reaction (PCR) assays. Approximately 100 ng of chromosomal DNA was extracted from each specimen and then amplified using standard conditions (30 cycles of 30 seconds at 95 degrees C, 30 seconds at 55 degrees C, and 30 seconds at 72 degrees C). Bacterial 16S rDNA was amplified using 2 synthetic oligonucleotide primers specific for eubacteria. The PCR product generated with the eubacterial primers was transferred to a charged nylon membrane and probed with digoxigenin-labeled synthetic oligonucleotides specific for Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis, and Prevotella intermedia. RESULTS: Eighty percent of the 50 endarterectomy specimens were positive in 1 or more of the PCR assays. Thirty-eight percent were positive for HCMV and 18% percent were positive for C. pneumoniae. PCR assays for bacterial 16S rDNA also indicated the presence of bacteria in 72% of the surgical specimens. Subsequent hybridization of the bacterial 16S rDNA positive specimens with species-specific oligonucleotide probes revealed that 44% of the 50 atheromas were positive for at least one of the target periodontal pathogens. Thirty percent of the surgical specimens were positive for B. forsythus, 26% were positive for P. gingivalis, 18% were positive for A. actinomycetemcomitans, and 14% were positive for P. intermedia. In the surgical specimens positive for periodontal pathogens, more than 1 species was most often detected. Thirteen (59%) of the 22 periodontal pathogen-positive surgical specimens were positive for 2 or more of the target species. CONCLUSIONS: Periodontal pathogens are present in atherosclerotic plaques where, like other infectious microorganisms such as C. pneumoniae, they may play a role in the development and progression of atherosclerosis leading to coronary vascular disease and other clinical sequelae.