Comparison of microbial changes in early redeveloping biofilms on natural teeth and dentures.

BACKGROUND: Surfaces and fluids can affect oral bacterial colonization. The aim of this study is to compare redeveloping biofilms on natural teeth and dentures. METHODS: Supragingival plaque samples were taken from 55 dentate individuals and the denture teeth of 62 edentulous individuals before and after professional cleaning. Also, samples from seven "teeth" (samples included dentures) 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 determined using the Mann-Whitney U test. Ecological succession was determined using a modified moving window analysis. RESULTS: Mean total DNA probe counts were similar precleaning but were higher in dentate individuals at all post-cleaning visits (P <0.01). Precleaning edentate biofilms had higher counts and proportions of Streptococcus mitis, Streptococcus oralis, and Streptococcus mutans, whereas dentate individuals had higher proportions of Tannerella forsythia, Selenomonas noxia, and Neisseria mucosa. By day 2, mean counts of all taxa were higher in natural teeth, and most remained higher at day 7 (P <0.01). Succession was more rapid and complex in dentate individuals. Both groups demonstrated increased proportions of S. mitis and S. oralis by day 1. N. mucosa, Veillonella parvula, and Eikenella corrodens increased in both groups, but later in samples from edentate individuals. CONCLUSIONS: "Mature" natural and denture teeth biofilms have similar total numbers of bacteria but different species proportions. Post-cleaning biofilm redevelopment is more rapid and more complex on natural teeth than on denture teeth.

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

BACKGROUND AND OBJECTIVE: 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. MATERIAL AND METHODS: 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. RESULTS: 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. CONCLUSION: There is a defined order in bacterial species succession in early supragingival and subgingival biofilm redevelopment after professional cleaning.

Clinical changes following four different periodontal therapies for the treatment of chronic periodontitis: 1-year results.

OBJECTIVE: To compare clinical changes occurring in chronic periodontitis subjects receiving SRP alone or with systemically administered azithromycin, metronidazole or a sub-antimicrobial dose of doxycycline. MATERIAL AND METHODS: 92 chronic periodontitis subjects were randomly assigned to receive SRP alone (N=23) or combined with 500 mg azithromycin per day for 3 days (N=25), 250 mg metronidazole tid for 14 days (N=24) or 20 mg doxycycline bid for 3 months (N=20). Gingival redness, bleeding on probing, suppuration, pocket depth and attachment level were measured at baseline and 3, 6 and 12 months post therapy. The significance of changes in clinical parameters within groups over time was sought using the Friedman test and among groups using ANCOVA or the Kruskal Wallis test. RESULTS: All groups showed clinical improvements at 12 months, with subjects receiving adjunctive agents showing a somewhat better response. Sites with initial pocket depth > 6 mm showed significantly greater pocket depth reduction and greater attachment gain in subjects receiving metronidazole or azithromycin than subjects in the other groups. Some subjects showed attachment loss at 12 months in each group ranging from 15% to 39% of subjects in the SDD and SRP only groups respectively. CONCLUSION: This study, demonstrated that periodontal therapy provides clinical benefits and that antibiotics provide a clinical benefit over SRP alone, particularly at initially deeper periodontal pockets.

Clinical and microbiological changes associated with the use of combined antimicrobial therapies to treat "refractory" periodontitis.

BACKGROUND: The present investigation examined clinical and microbial changes after a combined aggressive antimicrobial therapy in subjects identified as "refractory" to conventional periodontal therapy. METHOD: Fourteen subjects were identified as "refractory" based on full-mouth mean attachment loss and/or >3 sites with attachment loss > or =3 mm following scaling and root planing (SRP), periodontal surgery and systemic antibiotics. After baseline monitoring, subjects received SRP, locally delivered tetracycline at pockets > or =4 mm, systemically administered amoxicillin (500 mg, t.i.d. for 14 days)+metronidazole (250 mg, t.i.d. for 14 days) and professional removal of supragingival plaque weekly for 3 months. Subjects were monitored clinically every 3 months post-therapy for 2 years. Subgingival plaque samples were taken at the same time points from the mesial aspect of each tooth and the levels of 40 subgingival taxa were determined using checkerboard DNA-DNA hybridization. Mean levels of each species were averaged within a subject at each visit. Significance of changes in clinical and microbiological parameters over time were evaluated using the Friedman or Wilcoxon signed ranks test. RESULTS: On average, subjects showed significant improvements in all clinical parameters after therapy. Mean (+/-SEM) full-mouth pocket depth reduction was 0.83+/-0.13 mm and mean attachment level "gain" was 0.44+/-0.12 at 24 months. Clinical improvement was accompanied by major reductions in multiple subgingival species during the first 3 months of active therapy that were maintained for most species to the last monitoring visit. Reductions occurred for three Actinomyces species, "orange complex" species including Campylobacter showae, Eubacterium nodatum, three Fusobacterium nucleatum subspecies, Peptostreptococcus micros, Prevotella intermedia as well as the "Streptococcus milleri" group, Streptococcus anginosus, Streptococcus constellatus and Streptococcus intermedus. Subjects differed in their response to therapy; six modest response subjects exhibited less attachment level gain and were characterized by reductions in the microbiota from baseline to 3 months, but re-growth of many species thereafter. CONCLUSIONS: The combined antibacterial therapy was successful in controlling disease progression in 14 "refractory" periodontitis subjects for 2 years.

Relationship between periodontal pocket sulfide levels and subgingival species.

BACKGROUND: Many species implicated in the pathogenesis of periodontal disease produce volatile sulfur compounds (VSC). This investigation examined the relationship between levels of sulfide and subgingival bacterial species in the same periodontal pockets. MATERIAL AND METHODS: Twenty chronic periodontitis subjects were measured clinically at six sites per tooth for plaque, gingivitis, bleeding on probing, suppuration, pocket depth and attachment level. Subgingival plaque samples, taken from the mesial aspect of each tooth, were individually analyzed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization. Sulfide levels were measured at the same sites using a Diamond Probe/Perio 2000 system. Clinical and microbiological data were averaged for sulfide-positive and -negative sites separately in each subject and then averaged across subjects. Significance differences in clinical and microbial parameters between sulfide-positive and -negative sites were sought using the Wilcoxon signed ranks test. RESULTS: Mean total DNA probe counts (x10(5), +/-SEM) at sulfide-negative and -positive sites were 44.0 +/- 9.9 and 65.0 +/- 13.3, respectively (p < 0.01). Seventeen species were found at significantly higher levels in sulfide-positive than -negative sites. These included abundant producers of VSC such as members of the genera Fusobacterium, Campylobacter, Prevotella, Treponema and Eubacterium, and Bacteriodes forsythus, Selenomonas noxia and Propionibacterium acnes. Prevotella intermedia, Bacteriodes forsythus, Prevotella nigrescens, Fusobacterium nucleatum ss vincentii and Treponema denticola exhibited the greatest difference in mean counts between sulfide-negative and -positive sites. Orange and red complex species were at higher counts at shallow (< 4 mm) sulfide-positive than shallow sulfide-negative sites. Although not statistically significant, mean clinical parameters were somewhat higher at sulfide-positive than sulfide-negative sites. CONCLUSIONS: Intra-pocket sulfide levels reflect the levels of sulfide-producing species and may provide useful diagnostic information.

Efficacy of manual and powered toothbrushes (I). Effect on clinical parameters.

BACKGROUND/AIM: The purpose of the present investigation was to compare manual (Crest Complete) and powered toothbrushing (Braun Oral-B 3D Plaque Remover) for their ability to affect clinical parameters of periodontal diseases. METHODS: 48 periodontal maintenance subjects completed this single-blind 6-month longitudinal study. Subjects had a minimum of 20 natural teeth excluding third molars and >10% of sites (approximately 17 sites) with pocket depth > or =4 mm and/or >10% sites with attachment level >4 mm. At baseline, subjects received full mouth clinical measurements (168 sites) to determine mean Plaque Index, Gingival Index, pocket depth and attachment level and % of sites exhibiting BOP. Subjects were then randomly assigned to one of two groups. The control group (N=26) used a manual toothbrush while the test group (N=22) used a powered toothbrush. Subjects received instruction in oral hygiene and used their assigned toothbrush twice daily according to instruction. Follow-up clinical assessments were performed at 3 and 6 months. Significance of differences in clinical measures over time was determined using the Quade test and between brushing groups at each time point using the Mann-Whitney test. RESULTS: Mean pocket depth, mean plaque index and % of sites exhibiting BOP showed significant reductions from baseline to 3 and 6 months in both groups. Mean probing attachment level and mean Gingival Index were significantly reduced in the powered brushing group only. There was a significant positive correlation between plaque reduction and reduction in other clinical parameters in both brushing groups. The majority of subjects showed improvements in clinical parameters at 6 months, although a greater proportion of subjects in the powered group showed a reduction in Plaque Index (77% versus 65%) and in % sites exhibiting BOP (82% versus 69%). Mean pocket depth and mean attachment level showed significantly greater reductions between baseline and 6 months in lingual and mandibular areas in the powered group. CONCLUSIONS: Both manual and powered toothbrushes reduced pocket depth, plaque index and BOP. The powered toothbrush significantly reduced mean gingival index and probing attachment level. The greatest benefit of the powered brush was at mandibular and lingual surfaces.

Efficacy of manual and powered toothbrushes (II). Effect on microbiological parameters.

BACKGROUND/AIM: The purpose of the present investigation was to determine the effect of self-performed supragingival plaque removal using either manual (Crest Complete) or power (Braun 3D Plaque Remover) toothbrushing on supra and subgingival plaque composition. METHODS: 47 periodontal maintenance subjects completed this single-blind 6 month longitudinal study. At baseline, samples of supra and separately subgingival plaque were taken from the mesial aspect of each tooth in each subject using sterile curettes and individually analyzed for their content of 18 bacterial taxa using checkerboard DNA-DNA hybridization. After random assignment to groups receiving either a manual (n=25) or power toothbrush (n=22), subjects received instruction in oral hygiene and used their assigned toothbrush 2x daily for 6 months. Clinical monitoring and microbiological sampling were repeated at 3 and 6 months. Significant differences in microbiological measures over time were sought using the Quade test and between brushing groups at each time point using the Mann-Whitney test. RESULTS: Mean total counts were significantly reduced for supra- and subgingival plaque samples in the manual group and subgingival samples in the powered brushing group. Actinomyces naeslundii and Actinomyces israelii/gerencseriae were the most numerous organisms detected at baseline and showed the greatest reductions in counts in both brushing groups. Streptococcus constellatus/intermedius was significantly reduced in both groups, while Streptococcus mitis/oralis/sanguis was significantly reduced in the manual toothbrushing group. Mean counts of species were more markedly altered in subgingival plaque. Major reductions occurred in both groups for A. naeslundii, A. israelii/gerencseriae, Peptostreptococcus micros, Veillonella parvula, Prevotella intermedia/nigrescens, S. mitis/oralis/sanguis and S. constellatus/intermedius. All taxa examined were reduced in prevalence (% of sites colonized) in the subgingival plaque samples for both brushing groups. The reductions in prevalence were greater for A. naeslundii, S. constellatus/intermedius, V. parvula, A. israelii/gerencseriae, S. mitis/oralis/sanguis, P. micros, Streptococcus mutans and P. intermedia/nigrescens. Mean prevalence was decreased more for Porphyromonas gingivalis, Campylobacter rectus/showae, Treponema denticola and Bacteroides forsythus in supragingival plaque than subgingival plaque. CONCLUSIONS: The major finding was the effect of supragingival plaque removal on the composition of the subgingival microbiota. Counts and prevalence of most taxa examined were markedly decreased in both toothbrushing groups. This reduction should translate to a decreased risk of periodontal disease initiation or recurrence. Further, the decreased prevalence of periodontal pathogens in supragingival plaque lowers potential reservoirs of these species.

The effect of repeated professional supragingival plaque removal on the composition of the supra- and subgingival microbiota.

BACKGROUND, AIMS: The purpose of the present investigation was to determine the effect of weekly professionally administered supragingival plaque removal on the composition of the supra and subgingival microbiota. METHODS: 18 adult subjects with periodontitis who had been treated and were in a maintenance phase of therapy were clinically and microbiologically monitored at baseline, 3, 6 and 12 months. After the baseline visit, the subjects received scaling and root planing followed by professional supragingival plaque removal every week for 3 months. Clinical measures of plaque accumulation, bleeding on probing (BOP), gingival redness, suppuration, pocket depth and attachment level were made at 6 sites per tooth at each visit. Separate supra (N = 1804) and subgingival (N = 1804) plaque samples were taken from the mesial aspect of all teeth excluding third molars in each subject at each time point and evaluated for their content of 40 bacterial taxa using checkerboard DNA-DNA hybridization. Significance of changes in mean counts, prevalence and proportions of bacterial species over time in both supra and subgingival samples were determined using the Quade test and adjusted for multiple comparisons. RESULTS: Mean % of sites exhibiting plaque, gingival redness and BOP were significantly reduced during the course of the study. Significant decreases in mean counts were observed in both supra and subgingival samples. Mean total DNA probe counts (x10(5), +/-SEM) at baseline, 3, 6 and 12 months were: 133+/-19, 95+/-25, 66+/-6, 41+/-6 (p<0.001) for supragingival samples and 105+/-22, 40+/-10, 19+/-4, 13+/-3 (p<0.001) for subgingival samples. Mean counts of 22 of 40 and 34 of 40 species tested were significantly reduced in the supra and subgingival samples respectively over the monitoring period. For example, mean counts of Porphyromonas gingivalis x10(5) at baseline, 3, 6 and 12 months in the subgingival plaque samples were 2.0+/-0.4, 0.5+/-0.2, 0.6+/-0.3, 0.3+/-0.1 (p<0.001); Bacteroides forsythus 2.0+/-0.6, 0.4+/-0.1, 0.4+/-0.2, 0.1+/-0.2 (p<0.001); Treponema denticola 3.4+/-1.1, 0.8+/-0.3, 0.4+/-0.2, 0.3+/-0.3 (p<0.01). Similar reductions were seen in supragingival plaque samples. While counts were markedly reduced by professional plaque removal, the proportion and prevalence of the 40 test species were marginally affected. CONCLUSIONS: Weekly professional supragingival plaque removal profoundly diminished counts of both supra- and subgingival species creating a microbial profile comparable to that observed in periodontal health. This profile was maintained at the final monitoring visit, 9 months after completion of therapy.