Factors affecting human supragingival biofilm composition. I. Plaque mass

Background and Objective:  Little is known about the factors that affect the microbial composition of supragingival biofilms. This study was designed to examine the relationship between total DNA probe counts of supragingival biofilm samples, clinical parameters and supragingival biofilm composition.
Material and Methods:  Supragingival plaque samples were taken from 187 systemically healthy adult subjects ( n  = 4745 samples). All samples were individually analyzed for their content of 40 bacterial species using checkerboard DNA–DNA hybridization. The relationship between total DNA probe counts and microbial composition was examined by subsetting the data into 10 groups based on 10 percentile increments of the total DNA probe counts. Differences among groups in terms of species counts and proportions were sought, as well as relationships of total plaque DNA probe count and clinical parameters.
Results:  There was a wide distribution in mean total DNA probe counts among the 187 subjects. With increasing total plaque levels there was a change in the proportions of individual species and microbial complexes. 'Small plaques' were characterized by high proportions of species in the yellow, orange, purple and 'other' complexes; plaques of moderate mass were characterized by high proportions of Actinomyces and purple complex species, while 'large plaques' exhibited increased proportions of green and orange complex species. Measures of gingival inflammation, pocket depth and recession were significantly positively associated with total DNA probe counts. Increased plaque numbers were related to increased pocket depth irrespective of presence or absence of gingival inflammation.
Conclusion:  The proportions of individual species and microbial complexes in supragingival biofilms are influenced by the total numbers of organisms in the biofilm.     

Clinical and microbiological benefits of strict supragingival plaque control as part of the active phase of periodontal therapy

Aim: To compare the clinical and microbiological effects of scaling and root planing (SRP) alone or combined with mechanical [professional plaque control (PPC)] or chemical [chlorhexidine rinsing (CHX)] control of supragingival plaque in the treatment of chronic periodontitis.
Material and Methods: Sixty subjects were randomly assigned to receive SRP alone or combined with PPC (twice a week) or with CHX rinsing (twice a day). The adjunctive treatments began with SRP and were continued for 42 days. Clinical and microbiological examinations were performed at baseline, 2 and 6 months post-therapy. Subgingival plaque samples were analysed for 38 bacterial species by checkerboard DNA–DNA hybridization.
Results: The two test treatments were more effective in improving probing depth and clinical attachment level (CAL) than SRP alone, even in intermediate and deep sites. CAL gain was better maintained in the CHX group. The most beneficial microbiological changes were observed in CHX-treated subjects, who showed a significant reduction in the proportions of red and orange complexes, as well as an increase in the proportions of the host-compatible bacterial species.
Conclusion: Strict plaque control performed during and after SRP improves periodontal treatment outcomes. The greatest microbiological and clinical benefits were observed with the use of CHX rinsing.     

Microflora in oral ecosystems in subjects with radiation-induced hyposalivation

Aim:  To analyse the microbial flora in specific oral sites in 13 dentate subjects, 6–8 months after completed radiation therapy (RT group) and in 13 matched controls.
Material and methods:  The microflora on the tongue, buccal mucosa, vestibulum, supragingival plaque and subgingival region was analysed using duplicate sampling and cultivation technique. A clinical examination was also performed.
Results:  Candida albicans was found in one or more sites in 54% of the RT subjects and in 15% of the controls. In three RT subjects, C. albicans was found at all four sites analysed. An unexpected finding was that enterococci were found in all RT subjects and in high number in 38%. None of the controls harboured enterococci. In supragingival plaque, Lactobacillus spp. were detected in 92% of the RT subjects and the number and proportion of Lactobacillus spp. were extremely high compared with the controls. Mutans streptococci were detected in high numbers in 31% of the RT subjects, while they were not detected in 23%.
Conclusion:  The microbial results explain why some RT subjects have an increased susceptibility to oral diseases and stress that site-specific microbial analysis is an important diagnostic tool when planning oral health preventive care for RT subjects.     

Azithromycin as an adjunctive treatment of aggressive periodontitis: 12-months randomized clinical trial

Aim: To assess the effect of systemic azithromycin as a supplement to scaling and root planing (SRP) in the treatment of aggressive periodontitis (AgP).
Material and Methods: Twenty-four individuals (13–26 years old) underwent a plaque control program, and then were treated with SRP. Subjects were assigned randomly into two groups; the test group used 500 mg azithromycin once a day for 3 days, whereas the control group used a placebo. Clinical variables were assessed at baseline, 3, 6, 9, and 12 months. The periodontal status at baseline and 12 months was compared using the Wald test, and adjusting for the effect of clustering of teeth within subjects.
Results: There were no significant differences in visible plaque, gingival bleeding, and supragingival calculus between groups throughout the study. Periodontal probing depth (PPD) and clinical attachment level improved significantly from baseline to 12 months in both groups, with the test group showing significantly more reduction in mean PPD compared with controls (2.88 mm versus 1.85 mm, respectively, p =0.025). Subjects administering azithromycin showed a higher percentage of teeth with attachment gain 1 mm (81.34 versus 63.63, p =0.037), whereas the controls had higher percentage of teeth with attachment loss 1 mm (11.57 versus 2.24, p =0.015).
Conclusions: The adjunctive use of azithromycin has the potential to improve periodontal health of young patients with AgP.     

Comparison between polymerase chain reaction-based and checkerboard DNA hybridization techniques for microbial assessment of subgingival plaque samples

Aim: To compare polymerase chain reaction (PCR) with subsequent reverse hybridization (micro-IDent test) and checkerboard DNA–DNA hybridization for the identification of 13 bacterial species in subgingival plaque samples.
Material and Methods: Subgingival plaque samples were taken using paper points and curettes from two sites each with pocket depth <4, 4–6 and >6 mm at baseline and 3 months in 25 periodontitis subjects and two sites in 25 periodontally healthy subjects. Samples were analysed for their content of 13 bacterial species using both assays. Similarities for each species between techniques were determined using regression analysis. Differences between health and periodontitis were determined using the Mann–Whitney test.
Results: Three hundred and fifty samples were evaluated using both techniques. Regression analysis indicated that 10/13 test species showed significant positive correlations between the counts determined by checkerboard analysis and levels determined by the PCR-based test after adjusting for 13 comparisons. The highest rank correlations of 0.58, 0.49 and 0.46 were seen for Treponema denticola, Fusobacterium nucleatum and Eubacterium nodatum , respectively ( p <0.0001). Both tests could distinguish samples from healthy and periodontitis subjects.
Conclusion: Detection patterns of 10/13 test species in subgingival plaque samples from periodontitis and healthy subjects were similar using the two molecular techniques.     

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.     

Scaling and root planing, systemic metronidazole and professional plaque removal in the treatment of chronic periodontitis in a Brazilian population II--microbiological results

OBJECTIVE: The current investigation evaluated changes in levels and proportions of 39 bacterial species in subgingival plaque samples after scaling and root planing (SRP) alone or in combination with systemic metronidazole and/or professional cleaning in subjects with chronic periodontitis. METHODS: Forty-four adult subjects (mean age 45+/-6 years) with periodontitis were randomly assigned in four treatment groups, a control (C, n=10) that received SRP and placebo and three test groups treated as follows: T1 (n=12): SRP and metronidazole (M, 400 mg tid) for 10 days; T2 (n=12): SRP, weekly professional supragingival plaque removal for 3 months (PC) and placebo; and T3 (n=10): SRP, M and PC. Subgingival plaque samples were taken from seven sites per subject at baseline and 90 days post-therapy. Counts of 39 subgingival species were determined using checkerboard DNA-DNA hybridization. Significance of differences over time was determined using the Wilcoxon signed ranks test and among groups using ancova. RESULTS: The mean counts of the majority of the species were reduced post-therapy in the 4 treatment groups. Counts (x 10(5)+/-SEM) of Porphyromonas gingivalis, Tannerella forsythensis and Treponema denticola were significantly reduced in groups T2 and T3. Levels of beneficial species, such as some Actinomyces species, Veillonella parvula, Streptococcus sanguis, Streptococcus oralis and Streptococcus gordonii were minimally affected in levels when the combined therapy was applied (T3). Mean proportions of red complex species decreased from 18.4% at baseline to 3% at 90 days post-therapy in group T3 (p<0.01), from 25.8% to 2.3% in group T2 (p<0.01), from 17.7% to 5.6% in group T1 (p<0.05) and from 19.4% to 8.8% in group C (NS). Proportions of the suspected periodontal pathogens from the orange complex were also markedly reduced in groups T2 and T3. CONCLUSIONS: All treatments reduced counts and proportions of red complex species. Adjunctive therapy appeared to have a greater effect and also affected members of the orange complex.     

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.     

Distribution of selected cariogenic bacteria in five different intra-oral habitats in young children

Background.  Knowledge of the colonization patterns and composition of the oral microbiota can lead to a better understanding of disease initiation.
Aim.  The aim of this study was to examine the distribution of selected cariogenic bacteria in samples from five different oral habitats in young Greek children.
Design.  Ninety-three children 3–12 years old (mean + SD 7.9 ± 2.5) (60.2% male, 39.8% female) participated and split into three different age groups: primary (3–6 years), early mixed (6–9 years), and mixed dentition (9–12 years). Samples for bacterial enumeration were taken from saliva, supragingival and subgingival plaque, tongue dorsum, and soft tissues from each child, and were further analysed using checkerboard DNA–DNA hybridization.
Results.  Mean counts and proportions of all the test bacteria differed significantly among sample locations. Cariogenic bacteria were present in almost all healthy children. Mean proportions of Streptococcus mutans isolated from soft tissue and Streptococcus sanguinis from soft tissue, subgingival and saliva samples increased significantly with age, whereas the opposite was seen for Lactobacillus acidophilus .
Conclusions.  Cariogenic bacteria were present in almost all young children. Soft tissues, saliva, and tongue were more often colonized by cariogenic streptococcal species than teeth. These surfaces may serve as reservoirs for oral pathogens, requiring attention during preventive interventions.     

The effects of a 0.3% triclosan-containing dentifrice on the microbial composition of supragingival plaque

Abstract. 144 subjects completed a 6-month, double-blind study which examined the effects of a 0.3% triclosan/2% copolymer/0.243% sodium fluoride dentifrice on the microflora of supragingival dental plaque. The subjects were randomly assigned to use, in an oral hygiene program, either the triclosan/copolymer/fluoride test dentifrice or a control dentifrice. The latter had the same formulation as the test dentifrice except it did not contain triclosan. Supragingival plaque was collected from the buccal and lingual surfaces of 4 teeth at baseline, 3 months, and 6 months, and microbiological examined by darkfield microscopy, gram stain morphology', immunofluorescence, and selective and non-selective media. Antimicrobial susceptibilities were determined by agar dilution and whole plaque susceptibility methodologies on plaque samples from 136 subjects at each of the above sample periods and at 6-week intervals for an additional 6 months post-therapy. Both dentifrices resulted in highly statistically significant reductions in the total cultivable flora obtained at both the 3 and 6-month samples relative to baseline as well as at 6 months relative to the 3-month sample. The relative decrease in total anaerobic counts and in strict anaerobes, while not statistically significant, was more pronounced at both the 3- and 6-month sample periods in subjects receiving the triclosan dentifrice than for the controls. Neither dentifrice resulted in detrimental shifts in the microbial composition of the normal flora nor led to the emergence of periodontal or opportunistic pathogens. There was no difference in the relative proportions of the microflora resistance to triclosan or in the number of subjects harboring triclosan-resistant micro-organisms regardless of whether the subjects received the triclosan dentifrice or the control. The proportion of the cultivable flora resistant to triclosan was higher at baseline than at any other sample period. This study demonstrates that the extended use of the 03% triclosan/2% copolymer/fluoride dentifrice does not disrupt the normal microflora associated with supragingival plaque, favor the growth or colonization of periodontal or opportunistic pathogens, or promote the acquisition of microbial resistance.     

Short-term clinical effects of commercially available gel containing Acacia arabica: a randomized controlled clinical trial

Background:  Certain plants used in folk medicine serve as a source of therapeutic agent by having antimicrobial and other multi-potential effects. This prospective, randomized, placebo and positively controlled clinical trial was designed to evaluate the short-term clinical effects of a commercially available gel containing Acacia arabica in the reduction of plaque and gingival inflammation in subjects with gingivitis.
Methods:  Ninety subjects diagnosed with chronic generalized gingivitis were selected and randomly divided into three groups: Group I – placebo gel, Group II – gumtone gel and Group III – 1% chlorhexidine gel. Clinical evaluation was undertaken using the gingival index of Loe and Silness and the plaque index at baseline, 2 weeks, 4 weeks and 6 weeks. A subjective evaluation was undertaken by questionnaire.
Results:  Gumtone gel showed significant clinical improvement in gingival and plaque index scores as compared to a placebo gel. This improvement was comparable to 1% chlorhexidine gel. Unlike chlorhexidine gel, gumtone gel was not associated with any discolouration of teeth or unpleasant taste.
Conclusions:  Gumtone gel may be a useful herbal formulation for chemical plaque control agent and improvement in plaque and gingival status.     

Molecular identification of bacteria on the tongue dorsum of subjects with and without halitosis

Aim:  Compare the microbial profiles on the tongue dorsum in patients with halitosis and control subjects in a UK population using culture-independent techniques.
Materials and methods:  Halitosis patients were screened according to our recently developed recruitment protocol. Scrapings from the tongue dorsum were obtained for 12 control subjects and 20 halitosis patients. Bacteria were identified by PCR amplification, cloning and sequencing of 16S rRNA genes.
Results:  The predominant species found in the control samples were Lysobacter -type species, Streptococcus salivarius , Veillonella dispar , unidentified oral bacterium, Actinomyces odontolyticus , Atopobium parvulum and Veillonella atypica . In the halitosis samples, Lysobacter -type species, S. salivarius , Prevotella melaninogenica , unidentified oral bacterium, Prevotella veroralis and Prevotella pallens were the most commonly found species. For the control samples, 13–16 (4.7–5.8%) of 276 clones represented uncultured species, whereas in the halitosis samples, this proportion increased to 6.5–9.6% (36–53 of 553 clones). In the control samples, 22 (8.0%) of 276 clones represented potentially novel phylotypes, and in the halitosis samples, this figure was 39 (7.1%) of 553 clones.
Conclusions:  The microflora associated with the tongue dorsum is complex in both the control and halitosis groups, but several key species predominate in both groups.     

Prevalence and molecular diversity of Archaea in subgingival pockets of periodontitis patients

Introduction:  The aim of this study was to investigate the prevalence and molecular diversity of Archaea in the subgingival crevices of patients with chronic periodontitis.
Methods:  Subgingival plaque was collected from 41 patients with chronic periodontitis and 15 healthy subjects. The prevalence of Archaea in those plaque samples was tested by polymerase chain reaction with two broad-range archaeal primer sets. Amplicons from eight Archaea -positive plaque samples were cloned and sequenced for molecular diversity analysis using one of these two primer sets and a novel third primer set.
Results:  Archaea were detected in the subgingival plaque of patients with chronic periodontitis at a prevalence of 70.7–73.2%, but were not detected in healthy subjects. Using one primer set, all sequences of the archaeal amplicons were identified as Methanobrevibacter oralis -like species. With another primer set, the amplicons were also found to be identical to the uncultured M. oralis -like species except one phylotype was found to belong to the class Thermoplasmata .
Conclusion:  Archaea might be correlated with periodontal diseases. The diversity of Archaea associated with periodontitis was limited. Almost all sequenced amplicons fell into the genus Methanobrevibacter of the Euryarcheota phylum. M. oralis -like species was the predominant but non-exclusive archaeon in the subgingival dental plaque of patients with periodontitis.     

Factors affecting human supragingival biofilm composition. II. Tooth position

Background and Objective: Little is known regarding the factors that affect the microbial composition of supragingival biofilms. This study was designed to test the hypothesis that tooth location affects the microbial composition of supragingival plaque beyond the effect due to plaque mass as reflected by total DNA probe count. Material and Methods: Supragingival plaque samples were taken from the mesiobuccal aspect of each tooth in 187 subjects (n = 4745 samples). All samples were individually analyzed for their content of 40 bacterial species using checkerboard DNA–DNA hybridization. Significance of differences in mean species counts and proportions were determined among tooth surfaces and six tooth type categories: molars, bicuspids, incisors/canines in the mandible and maxilla separately using the Kruskal–Wallis test. Stepwise multiple linear regression was employed to examine the relationship between species proportions and total DNA probe count, tooth location, periodontal and smoking status, age and sex. Results: All species differed significantly among tooth types and among the six tooth categories. Higher plaque levels were seen on molars and lower incisors. Some differences observed between tooth types could be partly explained by the level of plaque. Teeth with high plaque mass exhibited high levels of Capnocytophaga gingivalis, Actinomyces naeslundii genospecies 2, Campylobacter rectus and Campylobacter showae. However, certain species, such as Veillonella parvula and Streptococcus sanguinis, differed significantly at different tooth locations despite similarities in plaque mass. Twenty of the test species exhibited a significant association with tooth location after adjusting for total DNA probe count and subject level factors. Conclusion: While plaque mass was associated with differences in proportions of many species in supragingival biofilms, tooth location also was strongly associated with species proportions in both univariate and multivariate analyses.     

The effect of scaling and root planing on the clinical and microbiological parameters of periodontal diseases: 12-month results

BACKGROUND/AIMS: Previously, we reported that SRP resulted in a decrease in mean pocket depth and attachment level and reduced prevalence and levels of Bacteroidesforsythus, Porphyromonas gingivalis, and Treponema denticola at 3 and 6 months post-SRP in 57 subjects with adult periodontitis. 32 of the 57 subjects were monitored at 9 and 12 months. Thus, the purpose of the present investigation was to evaluate the microbial and clinical effects of SRP in 32 (mean age 48+/-11) subjects over a 12-month period. METHOD: Clinical assessments of plaque, gingival redness, suppuration, bleeding on probing, pocket depth and attachment level were made prior to SRP and at 3, 6, 9, and 12 months post-therapy. Subgingival plaque samples were taken at each visit and analyzed using the checkerboard DNA-DNA hybridization technique for the presence and levels of 40 subgingival species. Each subject also received maintenance scaling at each of the subsequent monitoring visits. Differences in clinical parameters and prevalence and levels of bacterial species were analyzed pre- and post-therapy using the Wilcoxon signed ranks test. The Quade test for related samples was used for analysis of multiple visits. RESULTS: Mean pocket depth (mm+/-SEM) decreased from 3.2+/-0.3 at baseline to 2.9+/-0.3 at 12 months (p<0.01). Mean attachment level showed significant reduction at 6 months, but did not diminish further. Bleeding on probing and plaque were significantly reduced at 12 months (p<0.001, p<0.05, respectively). P. gingivalis, B. forsythus and T. denticola decreased in prevalence and levels up to the 6-month visit and remained at these lower levels at 9 and 12 months. Significant increases in levels and prevalence were noted at 12 months for Actinomyces naeslundii genospecies 2, Actinomyces odontolyticus, Fusobacterium nucleatum ss polymorphum, Streptococcus mitis, Capnocytophaga sp, and Veillonella parvula. CONCLUSIONS: The data suggest that the maintenance phase of therapy may be essential in consolidating clinical and microbiological improvements achieved as a result of initial therapy.     

Scaling and root planing, systemic metronidazole and professional plaque removal in the treatment of chronic periodontitis in a Brazilian population. I. clinical results

OBJECTIVE: The current investigation evaluated the clinical effects of scaling and root planing (SRP) alone or in combination with systemic metronidazole and/or repeated professional removal of supragingival plaque in subjects with chronic periodontitis. METHODS: Fourty-four adult subjects (mean age: 45+/-6 years) with periodontitis were randomly assigned to four treatment groups; a control (C, n=10) that received SRP and placebo and three test groups treated as follows: Test 1 (T1) (n=12) received SRP and metronidazole (400 mg t.i.d., M) for 10 days; Test 2 (T2) (n=12) received SRP, weekly professional supragingival plaque removal for three months (professional cleaning (PC)) and placebo; and Test 3 (T3) (n=10) received SRP, M and PC. Pocket depth (PD), attachment level (AL), bleeding on probing (BOP) and presence of visible plaque and suppuration were measured at six sites per tooth at baseline and at 90 days post-therapy. Significance of differences over time was determined using the Wilcoxon test, and among groups using ancova. RESULTS: A reduction in full-mouth mean clinical parameters was observed at 90 days after all therapies. Sites with baseline PD<4 mm showed an increase in mean PD in the control group and in mean AL in all treatment groups. Sites with baseline PD of 4-6 mm in subjects who received PC as part of therapy (T2, T3) showed a marked reduction in PD, AL and in the % of sites with BOP. Subjects who received metronidazole (T1 and T3) showed the best clinical response at sites with an initial PD of >6 mm. The major clinical benefit occurred when the combination of SRP, M and PC was used. Group T3 showed the least attachment loss in initially shallow pockets. This group also exhibited the greatest reduction in the % of sites with BOP and suppuration as well as in mean PD and AL at sites with baseline PD>4 mm. CONCLUSION: The data suggest a significant clinical benefit in combining SRP, systemic metronidazole and weekly professional supragingival plaque removal for the treatment of chronic periodontitis.     

Controlling the plaque biofilm

Aim : To examine the effect of supragingival plaque removal in conjunction with different periodontal therapies on subgingival plaque composition in different subject populations. Method : Four different studies are presented which examined the effect of repeated removal of supragingival plaque performed by professionals or by tooth brushing on subgingival plaque composition. The studies were performed in different populations including chronic periodontitis, periodontal maintenance and refractory subjects. For all studies, each subject was examined for clinical parameters at up to 168 sites and subgingival plaque samples were taken from the mesial aspect of each tooth and examined for their content of specific bacterial species using checkerboard DNA‐DNA hybridisation techniques. Results : Repeated supragingival plaque removal used in conjunction with scaling and root planing only or combined with other periodontal therapies resulted in improvements in clinical parameters as well as significant decreases in the counts of subgingival species, including those associated with periodontal disease aetiology. Meticulous tooth brushing provided similar clinical and microbial improvements. Conclusions : Meticulous removal of supragingival plaque has beneficial effects on clinical parameters of periodontal disease and on the nature of the microbiota that colonises both above and below the gingival margin and appropriately has been a major focus in the prevention and control of dental diseases, particularly periodontal disease.     

Progression of chronic periodontitis can be predicted by the levels of Porphyromonas gingivalis and Treponema denticola in subgingival plaque

Introduction:  Chronic periodontitis is an inflammatory disease of the supporting tissues of the teeth associated with bacteria. Diagnosis is achieved retrospectively by clinical observation of attachment loss. Predicting disease progression would allow for targeted preventive therapy. The aim of this study was to monitor disease progression in patients on a maintenance program and determine the levels of specific bacteria in subgingival plaque samples and then examine the ability of the clinical parameters of disease and levels of specific bacteria in the plaque samples to predict disease progression.
Methods:  During a 12-month longitudinal study of 41 subjects, 25 sites in 21 subjects experienced disease progression indicated by at least 2 mm of clinical attachment loss. Real-time polymerase chain reaction was used to determine the levels of Porphyromonas gingivalis , Treponema denticola , Tannerella forsythia , Fusobacterium nucleatum , and Prevotella intermedia in subgingival plaque samples.
Results:  No clinical parameters were able to predict periodontal disease progression. In sites undergoing imminent periodontal disease progression within the next 3 months, significant partial correlations were found between P. gingivalis and T. forsythia ( r  = 0.55, P  < 0.001) and T. denticola and T. forsythia ( r  = 0.43, P  = 0.04). The odds of a site undergoing imminent periodontal disease progression increased with increasing levels of P. gingivalis and T. denticola .
Conclusion:  Monitoring the proportions of P. gingivalis and T. denticola in subgingival plaque has the potential to help identify sites at significant risk for progression of periodontitis, which would assist in the targeted treatment of disease.     

Helicobacter pylori in the oral cavity is associated with gastroesophageal disease

Background:  In Mexico, more than 80% of the population is infected with Helicobacter pylori . The frequency of H. pylori detection in the oral cavity is unknown, as its relationship with gastroesophageal pathology.
Aim:  To detect the presence of H. pylori in the oral cavity in Mexican population by PCR and to determine its association with gastroesophageal disease.
Methods:  Patients were divided into two groups with different clinic conditions from whom gastric biopsy, dental plaque, and saliva samples were taken and analyzed. The first group comprised of hospitalized patients, the majority of whom were diagnosed with gastroesophageal disease, while the second group was selected from a dental clinic (ambulatory population) the majority of whom appeared to be healthy subjects.
Results:  H. pylori was detected in gastric biopsy, dental plaque and saliva samples by PCR using a set of specific primers for the signal sequence of the vacuolating cytotoxin gene; detection of H. pylori in general was higher in gastric biopsy and dental plaque samples than in saliva samples. Detection of H. pylori in the oral cavity is significantly ( P  = 0.0001) associated with patients presenting gastroesophageal disease, while healthy subjects and those with other non-gastric disease do not present with H. pylori in their oral cavity.
Conclusions:  H. pylori detection in the oral cavity is associated to gastroesophageal disease. In addition, it is suggested that all patients presenting gastric symptoms and H. pylori detection in the oral cavity would begin bacterial treatment immediately.     

Immediate loading of implants in the edentulous maxilla: use of an interim fixed prosthesis followed by a permanent fixed prosthesis: a 32-month prospective radiological and clinical study

Purpose: The aim of this study was to prospectively evaluate the survival rate of splinted and immediately loaded Straumann sandblasted, large-grit, acid-etched, solid-screw dental implants in the edentulous maxilla after 32 months of loading.
Materials and Methods: Twenty-eight patients (mean age 63 years) with edentulous maxillae received 168 implants (six each) and an implant-supported fixed interim prosthesis within 24 hours after surgery. After a mean healing time of 15 weeks, the patients received permanent screw-retained prostheses. Clinical and radiological examinations were made at implant placement and after 8, 20, and 32 months of loading. All permanent prostheses were removed at the 32-month follow-up; implant stability was checked with a torque device, and the implant stability quotient was determined with resonance frequency analysis.
Results: Mean marginal bone loss from baseline to 8 months after loading was 1.6 mm (SD 1.16; p  = .094), from 8 to 20 months 0.41 mm (SD 0.63; p  = .094), and from 20 to 32 months 0.08 mm (SD 0.49; p  = .039). The 32-month cumulative survival rate was 98.2%.
Conclusions: The 32-month survival of solid-screw implants – immediately loaded within 24 hours after placement – was similar to survival rates reported for solid-screw implants with conventional loading. Immediate loading and splinting of implants in the edentulous maxilla is a viable treatment alternative.