Microbial Shifts During Dental Biofilm Re-Development in the Absence of Oral Hygiene in Periodontal Health and Disease

Aim to monitor microbial shifts during dental biofilm re-development Methods Supra and subgingival plaque samples were taken separately from 28 teeth in 38 healthy and 17 periodontitis subjects at baseline and immediately after tooth cleaning. Samples were taken again from 7 teeth in randomly selected quadrants during 1, 2, 4 and 7 days of no oral hygiene. Samples were analyzed using checkerboard DNA-DNA hybridization. Species counts were averaged within subjects at each time point. Significant differences in counts between healthy and periodontitis subjects were sought using the Mann-Whitney test. Results Total supra and subgingival counts were significantly higher in periodontitis on entry and reached or exceeded baseline values after day 2. Supragingival counts of Veillonella parvula, Fusobacterium nucleatum ss vincentii and Neisseria mucosa increased from 2 to 7 days. Subgingival counts were greater for Actinomyces, green and orange complex species. Significant differences between groups in supragingival counts occurred for 17 of 41 species at entry, 0 at day 7; for subgingival plaque these values were 39/41 taxa at entry, 17/41 at day 7. Conclusions Supragingival plaque re-development was similar in periodontitis and health, but subgingival species recolonization was more marked in periodontitis

Early Microbial Succession in Re-Developing Dental Biofilms in Periodontal Health and Disease

Objective To determine the order of bacterial species succession in re-developing supra and subgingival biofilms. Methods Supra 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 7 teeth in randomly selected quadrants after 1, 2, 4 and 7 days of no oral hygiene and analyzed using checkerboard DNA-DNA hybridization. % DNA probe counts were averaged within subjects at each time point. Ecological succession was determined using a modified moving window analysis. Results Succession in supragingival biofilms from periodontitis and health was similar. At 1 day, Streptococcus mitis and Neisseria mucosa showed increased proportions, followed by Capnocytophaga gingivalis, Eikenella corrodens, Veillonella parvula and Streptococcus oralis at 1–4 days. At 4–7 days, Campylobacter rectus, Campylobacter showae, Prevotella melaninogenica and Prevotella nigrescens became elevated. Subgingival plaque redevelopment was slower and very different from supragingival. Increased proportions were first observed for S. mitis, followed by V. parvula and C. gingivalis and, at 7 days by Capnocytophaga sputigena and P. nigrescens. No significant increase in proportions of periodontal pathogens was observed in any of the clinical groups or locations. Conclusions There is a defined order in bacterial species succession in early supra and subgingival biofilm re-development after professional cleaning

Comparison of Microbial Changes in Early Re-Developing Biofilms on Natural Teeth and Dentures

Background and objective Surfaces and fluids can affect oral bacterial colonization. The aim of this study was to compare re-developing biofilms on natural teeth and dentures. Methods Supragingival plaque samples were taken from 55 dentate subjects and the denture teeth of 62 edentulous subjects before and after professional cleaning. Also, samples from 7 “teeth” in randomly selected quadrants were collected after 1, 2, 4 and 7 days of no oral hygiene. Samples were analyzed using checkerboard DNA-DNA hybridization. Counts and proportions of 41 bacterial taxa were determined at each time point and significant differences were sought using the Mann-Whitney test. Ecological succession was determined using a modified moving window analysis. Results Mean total DNA probe counts were similar pre-cleaning but were higher in dentate subjects at all post-cleaning visits (pStreptococcus mitis, Streptococcus oralisand Streptococcus mutans, whereas dentate subjects had higher proportions of Tannerella forsythia, Selenomonas noxia and Neisseria mucosa. By 2 days, mean counts of all taxa were higher in natural teeth and most remained higher at 7 days (pS. mitis and S. oralis by 1 day. N. mucosa, Veillonella parvula and Eikenella corrodens increased in both groups but later in edentate samples. Conclusions “Mature” natural and denture teeth biofilms have similar total numbers of bacteria but different species proportions. Post-cleaning biofilm re-development is more rapid and more complex on natural than denture teeth

The vaginal microflora in relation to gingivitis

<p>Abstract</p> <p>Background</p> <p>Gingivitis has been linked to adverse pregnancy outcome (APO). Bacterial vaginosis (BV) has been associated with APO. We assessed if bacterial counts in BV is associated with gingivitis suggesting a systemic infectious susceptibilty.</p> <p>Methods</p> <p>Vaginal samples were collected from 180 women (mean age 29.4 years, SD ± 6.8, range: 18 to 46), and at least six months after delivery, and assessed by semi-quantitative DNA-DNA checkerboard hybridization assay (74 bacterial species). BV was defined by Gram stain (Nugent criteria). Gingivitis was defined as bleeding on probing at ≥ 20% of tooth sites.</p> <p>Results</p> <p>A Nugent score of 0–3 (normal vaginal microflora) was found in 83 women (46.1%), and a score of > 7 (BV) in 49 women (27.2%). Gingivitis was diagnosed in 114 women (63.3%). Women with a diagnosis of BV were more likely to have gingivitis (p = 0.01). Independent of gingival conditions, vaginal bacterial counts were higher (p < 0.001) for 38/74 species in BV+ in comparison to BV- women. Counts of four lactobacilli species were higher in BV- women (p < 0.001). Independent of BV diagnosis, women with gingivitis had higher counts of <it>Prevotella bivia </it>(p < 0.001), and <it>Prevotella disiens </it>(p < 0.001). <it>P. bivia, P. disiens, M. curtisii </it>and <it>M. mulieris </it>(all at the p < 0.01 level) were found at higher levels in the BV+/G+ group than in the BV+/G- group. The sum of bacterial load (74 species) was higher in the BV+/G+ group than in the BV+/G- group (p < 0.05). The highest odds ratio for the presence of bacteria in vaginal samples (> 1.0 × 10⁴cells) and a diagnosis of gingivitis was 3.9 for <it>P. bivia </it>(95% CI 1.5–5.7, p < 0.001) and 3.6 for <it>P. disiens </it>(95%CI: 1.8–7.5, p < 0.001), and a diagnosis of BV for <it>P. bivia </it>(odds ratio: 5.3, 95%CI: 2.6 to 10.4, p < 0.001) and <it>P. disiens </it>(odds ratio: 4.4, 95% CI: 2.2 to 8.8, p < 0.001).</p> <p>Conclusion</p> <p>Higher vaginal bacterial counts can be found in women with BV and gingivitis in comparison to women with BV but not gingivitis. <it>P. bivia </it>and <it>P. disiens </it>may be of specific significance in a relationship between vaginal and gingival infections.</p

Efficacy of Chlorhexidine Varnish for the Prevention of Adult Caries: A Randomized Trial

The Prevention of Adult Caries Study, an NIDCR-funded multicenter, double-blind, randomized clinical trial, enrolled 983 adults (aged 18-80 yrs) at high risk for developing caries (20 or more intact teeth and 2 or more lesions at screening) to test the efficacy of a chlorhexidine diacetate 10% weight per volume (w/v) dental coating (CHX). We excluded participants for whom the study treatment was contraindicated or whose health might affect outcomes or ability to complete the study. Participants were randomly assigned to receive either the CHX coating (n = 490) or a placebo control (n = 493). Coatings were applied weekly for 4 weeks and a fifth time 6 months later. The primary outcome (total net D1-2FS increment) was the sum of weighted counts of changes in tooth surface status over 13 months. We observed no significant difference between the two treatment arms in either the intention-to-treat or per-protocol analyses. Analysis of 3 protocol-specified secondary outcomes produced similar findings. This trial failed to find that 10% (w/v) chlorhexidine diacetate coating was superior to placebo coating for the prevention of new caries (Clinicaltrials.gov registration number NCT00357877)

The short-term treatment effects on the microbiota at the dorsum of the tongue in intra-oral halitosis patients-a randomized clinical trial

<p>This study aims to assess the effects of rinsing with zinc- and chlorhexidine-containing mouth rinse with or without adjunct tongue scraping on volatile sulfur compounds (VSCs) in breath air, and the microbiota at the dorsum of the tongue.</p><p>A randomized single-masked controlled clinical trial with a cross-over study design over 14 days including 21 subjects was performed. Bacterial samples from the dorsum of the tongue were assayed by checkerboard DNA-DNA hybridization.</p><p>No halitosis (identified by VSC assessments) at day 14 was identified in 12/21 subjects with active rinse alone, in 10/21with adjunct use of tongue scraper, in 1/21 for negative control rinse alone, and in 3/21 in the control and tongue scraping sequence. At day 14, significantly lower counts were identified only in the active rinse sequence (p <0.001) for 15/78 species including, Fusobacterium sp., Porphyromonas gingivalis, Pseudomonas aeruginosa, Staphylococcus aureus, and Tannerella forsythia. A decrease in bacteria from baseline to day 14 was found in successfully treated subjects for 9/74 species including: P. gingivalis, Prevotella melaninogenica, S. aureus, and Treponema denticola. Baseline VSC scores were correlated with several bacterial species. The use of a tongue scraper combined with active rinse did not change the levels of VSC compared to rinsing alone.</p><p>VSC scores were not associated with bacterial counts in samples taken from the dorsum of the tongue. The active rinse alone containing zinc and chlorhexidine had effects on intra-oral halitosis and reduced bacterial counts of species associated with malodor. Tongue scraping provided no beneficial effects on the microbiota studied.</p><p>Periodontally healthy subjects with intra-oral halitosis benefit from daily rinsing with zinc- and chlorhexidine-containing mouth rinse.</p>