Proportions Of Periodontal Pathogens Research Articles

Interplay between vitamin D receptor FokI polymorphism and smoking influences Porphyromonas gingivalis proportions in subgingival plaque.

This cross-sectional study investigated the effect of the vitamin D receptor (VDR) FokI polymorphism and its interactions with smoking/drinking on the proportions of periodontal pathogens and periodontitis severity. FokI genotyping and bacterial quantification were performed using real-time polymerase chain reaction. Periodontitis severity was determined using mean clinical attachment level (CAL). Regression analyses examined the associations between the FokI polymorphism (rs2228570) and bacterial proportions or periodontitis severity. Effect modification by smoking or drinking was assessed. The study population comprised 1,460 individuals, aged 39-66years. After multivariable adjustment, the FokI risk genotypes (CC+CT) were associated with elevated Porphyromonas gingivalis proportions (regression coefficient (β) =0.294±0.139; p=.034) and increased mean CAL (β=0.130±0.048; p=.007). The effect of the FokI polymorphism on P.gingivalis proportions was greater in smokers (β=0.897±0.328; p=.006) compared to non-smokers (β=0.164±0.153; p=.282) and in drinkers (β=0.668±0.242; p=.006) compared to non-drinkers (β=0.114±0.169; p=.500). The genotype*smoking interaction for P.gingivalis proportions was significant (p=.043), whereas the genotype*drinking interaction was not (p=.061). Similar results were found for the effect of the genotype*smoking/drinking interaction on mean CAL. These findings suggest that the interplay between the host genotype and smoking is important in determining the subgingival microbial composition and periodontitis severity.

Does obesity influence the subgingival microbiota composition in periodontal health and disease?

To evaluate whether obesity affects the subgingival microbial composition of patients with periodontal health or chronic periodontitis (CP). Based on periodontal parameters, body mass index and waist-hip ratio, 166 patients were allocated into one of the following groups: Normal weight (NW) patients with periodontal health (n=44), NW patients with CP (n=40), obese patients with periodontal health (n=40) and obese patients withCP (n=42). Six subgingival biofilm samples per patient were analysed fortheircontent of 40 bacterial species using checkerboard DNA-DNA hybridization. Obese patients with CP harboured higher levels and/or higher proportions of several periodontal pathogens than those with NW and CP, including Aggregatibacter actinomycetemcomitans, Eubacterium nodatum, Fusobacterium nucleatum ss vincentii, Parvimonas micra, Prevotella intermedia, Tannerella forsythia, Prevotella melaninogenica and Treponema socranskii. The proportions of most of these pathogens, as well Campylobacter rectus and Eikenella corrodens, were more increased in the diseased sites of the obese patients than in those with NW. Furthermore, the healthy sites of the obese patients, presenting or not CP, also exhibited higher proportions of some of the pathogens than patients with NW. Obesity is associated with increased levels and proportions of periodontal pathogens, especially in patients with CP.

Early microbial succession in redeveloping dental biofilms in periodontal health and disease

The development of dental biofilms after professional plaque removal is very rapid. However, it is not clear whether most bacterial species return at similar rates in periodontally healthy and periodontitis subjects or if there are differences in bacterial recolonization between supragingival and subgingival biofilms in periodontal health and disease. Supragingival and subgingival plaque samples were taken separately from 28 teeth in 38 healthy and 17 periodontitis subjects immediately after professional cleaning. Samples were taken again from seven teeth in randomly selected quadrants after 1, 2, 4 and 7 d of no oral hygiene and analyzed using checkerboard DNA-DNA hybridization. The percentage of DNA probe counts were averaged within subjects at each time-point. Ecological succession was determined using a modified moving-window analysis. Succession in supragingival biofilms from subjects with periodontitis and from healthy individuals was similar. At 1 d, Streptococcus mitis and Neisseria mucosa showed increased proportions, followed by Capnocytophaga gingivalis, Eikenella corrodens, Veillonella parvula and Streptococcus oralis at 1-4 d. At 4-7 d, Campylobacter rectus, Campylobacter showae, Prevotella melaninogenica and Prevotella nigrescens became elevated. Subgingival plaque redevelopment was slower and very different from supragingival plaque redevelopment. Increased proportions were first observed for S. mitis, followed by V. parvula and C. gingivalis and, at 7 d, by Capnocytophaga sputigena and P. nigrescens. No significant increase in the proportions of periodontal pathogens was observed in any of the clinical groups or locations. There is a defined order in bacterial species succession in early supragingival and subgingival biofilm redevelopment after professional cleaning.