The effect of supragingival plaque control on the composition of the subgingival microbial flora in ligature-induced periodontitis in the monkey

Use of Nonhuman Primates in Periodontal Disease Research: Contribution of the Caribbean Primate Research Center and Cayo Santiago Rhesus Colony

This review article provides a historical summary regarding the use, value, and validity of the nonhuman primate model of periodontal disease. The information provided cites results regarding the features of naturally occurring periodontitis in various nonhuman primate species, as well as the implementation of a model of experimental periodontitis. Clinical similarities to human disease are discussed, as well as the use of these models to document physiological and pathophysiological tissue changes in the periodontium related to the initiation and progression of the disease. Additionally, the use of these analytics in examination of the tissue characteristics of the disease, and the utility of nonhuman primates in testing and describing various therapeutic modalities are described. As periodontitis represents a disease of an oral microbiome dysbiosis, features of the altered microbiome in the disease in nonhuman primates are related to similar findings in the human condition. The review then provides a summary of the features of local and systemic host responses to a periodontal infection in an array of nonhuman primate species. This includes attributes of innate immunity, acute and chronic inflammation, and adaptive immune responses. Finally, extensive information is presented regarding the role of Macaca mulatta derived from the Cayo Santiago community in evaluating critical biologic details of disease initiation, progression, and resolution. This unique resource afforded the capacity to relate risk and expression of disease and traits of the responses to age, sex, and matriline derivation (e.g., heritability) of the animals. The Cayo Santiago colony continues to provide a critical preclinical model for assessment of molecular aspects of the disease process that can lead to both new targets for therapeutics and consideration of vaccine approaches to preventing and/or treating this global disease.

Acquisition of oral microbes and associated systemic responses of newborn nonhuman primates

The acquisition and development of the complex oral microbiome remain ill defined. While selected species of oral bacteria have been examined in relation to their initial colonization in neonates, a more detailed understanding of the dynamics of the microbiome has been developed only in adults. The current investigation used a nonhuman primate model to document the kinetics of colonization of the oral cavities of newborns and infants by a range of oral commensals and pathogens. Differences in colonization were evaluated in newborns from mothers who were maintained on an oral hygiene regimen pre- and postparturition with those displaying naturally acquired gingivitis/periodontitis. The results demonstrate distinct profiles of acquisition of selected oral bacteria, with the transmission of targeted pathogens, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, being passed on primarily from mothers with gingivitis/periodontitis. This colonization resulted in defined patterns of systemic antibody responses in the infants. The significant relative risk measures for infection with the pathogens, as well as the relationship of oral infection and blood serum antibody levels, were consistent with those of the newborns from mothers with gingivitis/periodontitis. These findings indicate that the early acquisition of potentially pathogenic oral bacterial species might impact the development of mucosal responses in the gingiva and may provide an enhanced risk for the development of periodontitis later in life.

The effect of one session of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis

Supragingival plaque control is a requisite for the success of any periodontal procedure. However, little is know about the effect of this procedure alone on periodontitis. The aim of this study was to determine the effect of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis. Twenty-five subjects exhibiting at least 4 pockets > 5mm, non-smokers and with no relevant systemic diseases, were selected for the study. The clinical and biochemical assessments were done before and 21 days after removal of plaque retentive factors, extraction of affected teeth and instruction in oral hygiene. The statistical analysis was done with the Student paired t-test (p<0,05) and demonstrated a reduction on the percentage of sites with bleeding on probing from 42.72 ± 15.83 to 35.87 ± 13.30 (p=0.002). Reduction in probing depth was detected on anterior teeth (initial/final mean: 2.88 mm/2.78 mm; p=0.01) and interproximal sites (initial/final mean: 3.80 mm/3.65 mm; p=0.001). There was an increase from 66.81% to 68.65% in the number of sites with probing depth of 1 to 3mm and a decrease from 26.21% to 24.17% in those with probing depth of 4 to 6mm. The BAPNA results showed a decrease from 51.44 ± 20.78 to 38.64 ± 12.34 (p=0.04). This study demonstrated that supragingival plaque control provides a reduction in gingival inflammation and alterations in the subgingival microflora detected by the BAPNA test.

Involvement of toll-like receptor 4 in alveolar bone loss and glucose homeostasis in experimental periodontitis

BACKGROUND AND OBJECTIVE

There is general agreement that certain fatty acids and lipopolysaccharides (LPS) promote inflammation through toll-like receptor 4 (TLR4), and that inflammation promotes insulin resistance. We therefore hypothesized that mice with periodontitis and a TLR4 loss-of-function (LOF) mutation fed a high-fat (HF) diet would develop improved glucose homeostasis compared with wild-type (WT) animals with periodontitis fed a HF diet.

MATERIAL AND METHODS

Wild-type and TLR4 mutant mice fed a HF diet were divided into four groups (n = 6/group): WT; WT with periodontitis (WT/P); mutant (Mut); and mutant with periodontitis (Mut/P). Periodontitis was induced by placing LPS soaked ligatures around maxillary second molars. Fasting insulin and glucose levels were measured weekly for 10 wk. Glucose tolerance was evaluated at baseline (week 1) and at 9 wk. Insulin signaling (phosphorylation of Akt) and tumor necrosis factor-α (TNF-α) mRNA levels in liver were determined when the mice were killed at week 10.

RESULTS

Mut/P mice developed less alveolar bone loss compared with WT/P mice (p < 0.05). Fasting glucose levels were improved after 8 wk of feeding a HF diet (weeks 9 and 10) in Mut/P mice compared with Mut, WT and WT/P mice (p < 0.05). Glucose tolerance was impaired in all groups compared with baseline (p < 0.05), except for the Mut/P group. Insulin signaling was improved (p < 0.05), and expression of TNF-α was decreased (p < 0.05) in the liver of Mut/P mice compared with the liver of WT/P mice.

CONCLUSION

The TLR4 LOF mutation partially protects against alveolar bone loss and improves glucose homeostasis in mice with periodontitis fed a HF diet.

Comparison of the effects of cetylpyridinium chloride with an essential oil mouth rinse on dental plaque and gingivitis ? a six-month randomized controlled clinical trial

OBJECTIVE

To compare the effects of an experimental mouth rinse containing 0.07% cetylpyridinium chloride (CPC) (Crest Pro-Health) with those provided by a commercially available mouth rinse containing essential oils (EOs) (Listerine) on dental plaque accumulation and prevention of gingivitis in an unsupervised 6-month randomized clinical trial.

MATERIAL AND METHODS

This double-blind, 6-month, parallel group, positively controlled study involved 151 subjects balanced and randomly assigned to either positive control (EO) or experimental (CPC) mouth rinse treatment groups. At baseline, subjects received a dental prophylaxis procedure and began unsupervised rinsing twice a day with 20 ml of their assigned mouthwash for 30 s after brushing their teeth for 1 min. Subjects were assessed for gingivitis and gingival bleeding by the Gingival index (GI) of Löe & Silness (1963) and plaque by the Silness & Löe (1964) Plaque index at baseline and after 3 and 6 months of rinsing. At 3 and 6 months, oral soft tissue health was assessed. Microbiological samples were also taken for community profiling by the DNA checkerboard method.

RESULTS

Results show that after 3 and 6 months of rinsing, there were no significant differences (p=0.05) between the experimental (CPC) and the positive control mouth rinse treatment groups for overall gingivitis status, gingival bleeding, and plaque accumulation. At 6 months, the covariant (baseline) adjusted mean GI and bleeding sites percentages for the CPC and the EO rinses were 0.52 and 0.53 and 8.7 and 9.3, respectively. Both mouth rinses were well tolerated by the subjects. Microbiological community profiles were similar for the two treatment groups. Statistically, a significant greater reduction in bleeding sites was observed for the CPC rinse versus the EO rinse.

CONCLUSION

The essential findings of this study indicated that there was no statistically significant difference in the anti-plaque and anti-gingivitis benefits between the experimental CPC mouth rinse and the positive control EO mouth rinse over a 6-month period.

Supragingival plaque may modify the effects of subgingival bacteria on attachment loss

BACKGROUND

Bacterial interactions in response to local and systemic factors may explain important features of the pathogenesis of periodontal disease. This study evaluates the role of supragingival plaque level on the relationship between subgingival microorganisms and the risk of attachment loss.

METHODS

The study population consisted of 386 white women aged 45 years and older who had at least seven teeth. Subgingival plaque samples were taken from the mesio-buccal surface of six maxillary and six mandibular teeth using paper point technique. The samples were pooled, and immunofluorescence microscopy was performed to identify the following target microorganisms: Actinobacillus actinomycetemcomitans (Aa), Tannerella forsythensis (Tf), Campylobacter rectus (Cr), Prevotella intermedia (Pi), Capnocytophaga species (Cs), Porphyromonas gingivalis (Pg), Eubacterium saburreum (Es), and Fusobacterium nucleatum (Fn). The presence or absence of supragingival plaque and clinical attachment loss (CAL) were assessed at the same 12 sites where subgingival plaque samples were taken. The association of each microorganism with CAL was tested using multiple logistic regressions controlling for age, smoking status, and diabetes. Odds ratios (OR) and their 95% confidence intervals (CI) were calculated.

RESULTS

At low supragingival plaque levels, only the presence of Pg was significantly associated with CAL (OR: 6.41, 95% CI: 1.30 to 31.70); all remaining microorganisms were also associated with increased but non-significant risk of CAL. At high supragingival plaque levels, the presence of Tf (OR: 2.40, 95% CI: 1.42 to 4.04) and Pg (OR: 3.71, 95% CI: 1.63 to 8.42) was significantly associated with increased risk of attachment loss. By contrast, the presence of Cs (OR: 0.55, 95% CI: 0.30 to 1.01) and Es (OR: 0.35, 95% CI: 0.15 to 0.82) was associated with decreased risk of attachment loss. Fn, Pi, and Cr were not significantly associated with CAL at either low or high supragingival plaque levels.

CONCLUSIONS

This study suggests that the association of certain subgingival microorganisms with CAL changes in relation to supragingival plaque levels in older adult women. It also suggests that the overall effect of dental plaque is a function of the balance between pathogenic and other microorganisms that colonize this environment. Therefore, all microorganisms in the biofilm, including those with no apparent association with overt disease and those with negative associations, may play roles in the pathogenesis of periodontal diseases.

Correlation between patient satisfaction and dental clinic credibility in regular dental check-ups in Japan

The aim of this study was to investigate the relationship between dental clinic credibility and patient satisfaction with regular dental check-ups, to compare the level of satisfaction of patients who had regular check-ups with those who did not, and to identify factors associated with regular dental checkups. Thirty-nine private dental clinics in 17 prefectures throughout Japan participated in this study. A total of 9024 questionnaires were distributed to the patients at these clinics, and patients returned the questionnaires using a pre-paid envelope (response rate 56.8%). The questionnaires consisted of items related to patient demographics and 11 items concerning the level of patient satisfaction with the dental clinic. Using multiple logistic regression analysis, the strongest correlation was found between dental clinic credibility in regular checkups and the technical competence of the dentist. The responses to those items concerning making an appointment, and the cleanliness and neatness of the waiting room were different between patients who had regular check-ups and those who did not. To investigate the factors that encourage regular dental check-ups, correlation of factors with regular check up experience were analyzed. Multivariate-adjusted odds ratios indicated a strong association between regular dental check ups and both the technical competence of the dental hygienist and the cost of treatment.

Periodontal infection as a possible severity factor for rheumatoid arthritis

OBJECTIVE

Clinical effects of periodontal treatment on biochemical and clinical markers of disease severity in rheumatoid arthritis (RA) patients with periodontal disease were evaluated.

METHODS

Forty-two patients were assigned to two groups, G1 (n=16) and G2 (n=26). G1 patients were submitted to oral hygiene instruction and professional tooth cleaning and G2 patients additionally had full-mouth scaling and root planing (SRP). Clinical periodontal measurements were obtained at baseline and 3 months after periodontal treatment. A Health Assessment Questionnaire (HAQ) was used to evaluate their performance on daily living. Rheumatoid factor (RF), erythrocyte sedimentation rate (ESR) and drug therapy were assessed.

RESULTS

Both groups presented a full-mouth improvement in all periodontal clinical parameters (p<0.05), with the exception of clinical attachment level (CAL) and probing pocket depth (PPD) >6 mm for G1. G2 showed greater mean reductions on PPD >4 mm than G1 (p<0.001). HAQ analyses showed a reduction on the degree of disability of G2, but not statistically significant. ESR was significantly reduced for G2 after SRP although RF did not show statistical reductions.

CONCLUSION

The data suggest that periodontal treatment with SRP might have an effect on the ESR reduction.

Anti-gingivitis efficacy of a stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifrice. A controlled 6-month clinical trial

OBJECTIVE

Stannous fluoride is a broad-spectrum anti-microbial agent that has been used in dentistry as a chemical adjunct to prevent dental caries and gingivitis. The objective of this study was to assess the anti-gingivitis efficacy of a stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifrice relative to a negative control.

METHODS

This was a randomized, 6-month, double-blind, parallel-group gingivitis study conducted according to the guidelines for evaluating chemotherapeutic products for the control of gingivitis outlined by the American Dental Association. A stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifrice was tested against a commercially available negative control dentifrice. Following baseline measurements, subjects received a dental prophylaxis. Subjects were then instructed to brush twice daily for 60 s using their assigned product. Oral soft-hard-tissue examinations and clinical examinations using the Modified Gingival Index, Gingival Bleeding Index, and the Turesky modification of the Quigley-Hein Plaque Index were performed at baseline, 3 and 6 months post-treatment.

RESULTS

A total of 143 subjects were enrolled and 130 of them completed the 6-month study. After 6 months of product usage, the experimental group had 21.7% less gingivitis (p<0.001), 57.1% less bleeding (p<0.001), and 6.9% less plaque (p=0.01) on average compared with the negative control group. No adverse oral soft-hard-tissue effects or extrinsic tooth staining was observed in the study.

CONCLUSION

The results demonstrate that use of the stabilized 0.454% stannous fluoride/sodium hexametaphosphate dentifrice over a 6-month period provided statistically significant reductions in gingivitis, gingival bleeding, and plaque when compared with a negative control dentifrice.

Effects of short professional mechanical tooth-cleaning (PMTC) program in young adults with mental disabilities

We evaluated the usefulness of a short professional mechanical tooth-cleaning (PMTC) program to improve periodontal conditions and caries susceptibility in 10 young adult patients with mental and/or physical disabilities. The PMTC program was carried out once on each of 6 sextants of the full mouth during 6 visits at two-week intervals. Even one treatment with PMTC was found to be significantly effective in reducing the probing depth in eight of the 10 subjects. A reduction in the total number of bleeding sites on probing was also clearly observed in all subjects. Moreover, the debris index was reduced in nine subjects by the PMTC program. Although caries susceptibility was improved, albeit very slowly, by PMTC, the Cariostat pH values showed no consistent tendency. The effects lasted for more than 6 weeks. Analysis of these results suggests that the PMTC program can be effective in adults with mental disabilities, especially in reducing gingival inflammation.

Early-onset periodontitis associated with Down's syndrome--clinical interventional study

Individuals with Down's syndrome (DS) have an increased prevalence of periodontal disease compared with otherwise normal, age-matched control groups and other mentally handicapped patients of similar age distribution. The exaggerated immune-inflammatory response of the tissues cannot be explained by poor oral hygiene alone and might be the result of an impaired cell-mediated and humoral immunity and a deficient phagocytic system. As far as the progression and severity of destruction, the oral manifestations of DS patients are consistent with the juvenile periodontitis (JP) disease pattern. The purpose of the present study was 1) to assess the periodontal clinical and microbiological status of 10 DS patients aged 20 to 31 years (mean: 26.3 years) relative to that of 11 patients with cerebral palsy (CP) aged 23 to 53 years (mean: 36 years) without defective immunological functions, and 2) to determine the effect of supragingival plaque control and oral hygiene instruction in these patient groups. Subsequent to the initial examination and a professional tooth cleaning program, clinical and microbiological parameters were monitored over a period of 12 weeks. The clinical examination included the recording of plaque index (P1), gingival index (GI), probing depth (PD), and clinical attachment level (CAL). Subgingival plaque samples were always obtained from the same pocket with the highest disease activity (deepest bleeding site at baseline examination) in each subject for a morphotype analysis by dark field microscopy and for identification and quantitation of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Eikenella corrodens, Bacteroides forsythus, Fusobacterium nucleatum, Treponema denticola, and Campylobacter rectus by DNA probes. The results of the baseline examinations demonstrated that DS patients and patients with cerebral palsy had inflamed gingiva associated with a high amount of plaque. The mean probing depth and percentage of sites with probing depth> 4 mm corresponded to age and poor oral hygiene in CP patients. Deep pockets in DS patients demonstrated a high prevalence of periodontal disease compared with age-matched children with mental retardation and non-handicapped patients. Regarding the young age of onset, the severe destruction of periodontal tissues and pathogenesis of periodontitis in DS patients are consistent with the juvenile periodontitis disease pattern. The missing clinical benefit and alteration of the subgingival flora following supragingival plaque control in DS patients underlined the alteration in the immunological response.

Effect of triclosan on the subgingival microbiota of periodontitis-susceptible subjects

The present study evaluated the long-term effect of (i) meticulous self-performed, supragingival plaque control and (ii) the use of a triclosan/copolymer containing dentifrice in adult subjects susceptible to destructive periodontitis. 40 individuals were recruited into the trial. 3-5 years prior to the baseline examination, they had all been treated by nonsurgical means- for advanced periodontal disease. During the subsequent maintenance phase, all subjects had at different time intervals exhibited sites with recurrent periodontitis. At a baseline examination, 6 surfaces per tooth were examined regarding bleeding on probing, probing pocket depth, and probing attachment level. The deepest pocket site in each quadrant (i.e. 4 sites per subject) was selected and samples of the subgingival bacteria were taken. At baseline, all volunteers received detailed information on proper oral hygiene techniques. This information was repeated on an individual need basis during the course of the subsequent 36-months. No professional subgingival therapy was delivered between the baseline and the 36-month examinations. The subjects were randomly distributed into 2 equal groups of 20 individuals each, 1 test and 1 control group. The members of the test group were supplied with a fluoridated dentifrice containing triclosan/copolymer (Total, Colgate), while the controls received a corresponding dentifrice but without triclosan/copolymer. The findings demonstrated that in subjects with advanced and recurrent periodontitis, carefully practiced supragingival plaque control had some effects on the subgingival microbiota, but also that this was insufficient to prevent disease progression. In a corresponding group of subjects, however, who used a triclosan/copolymer dentifrice, the subgingival microbiota was reduced in both quantitative and qualitative terms and recurrent periodontitis was almost entirely prevented.

The effect of supragingival plaque control on the subgingival microflora in human periodontitis

The aim of the present trial was to study if carefully practiced supragingival plaque control influenced the subgingival microbiota at periodontal sites with suprabony, infrabony, or furcation pockets. 12 subjects, 5 males and 7 females aged 44 to 69 years (mean age 55 years) participated in the study. None of the participants had during the last 12 months received periodontal therapy, and none of the subjects had used antibiotics during a 3-month period preceding the study. Following a screening examination, 6 to 8 sites per subject were selected which had a probing depth of > or = 5 mm. Among these sites, 1-3 sites had a suprabony location, 1-3 sites had an infrabony location, and 1-3 sites were associated with a furcation defect. The selected sites were exposed to a baseline examination at which the following parameters were recorded: plaque, gingivitis, probing pocket depth and probing attachment level. A bacterial sample was obtained from each of the selected sites: 2 sterile paper points were inserted into the pocket and kept in place for 30 seconds. The paper point samples were removed, placed in a vial containing an anaerobically prepared transport medium, and processed using routine procedures. Following the baseline examination, each subject was given a case presentation, received thorough supragingival scaling and was instructed to practice proper plaque control with the use of toothbrush and dentifrice. During the subsequent 30 weeks they were recalled 2-3xper week for professional tooth cleaning. Each session was handled by a dental hygienist and required about 15 min. Re-examinations were performed after 30 weeks. The findings indicated that professionally delivered and frequently repeated supragingival tooth cleaning, combined with careful self-performed plaque control had a marked effect on the subgingival microbiota of moderate to deep periodontal pockets. Thus, at sites with suprabony and infrabony pockets, as well as at furcation sites, the meticulous and prolonged supragingival plaque removal reduced the total number of microorganisms that could be harvested, as well as the % of sites with P. gingivalis.

Histological and microbiological aspects of ligature-induced periodontitis in beagle dogs

This study was designed to investigate, using 6 beagle dogs, the levels of selected putative pathogens in healthy sites, in gingivitis sites, and in sites with histologically confirmed attachment loss. Levels of attachment loss increased with increasing periods of ligation and reached a maximum of 0.15 mm at 57 days. Both histological attachment level and histological pocket depth were found to vary significantly with health/disease status (p < 0.0001). Higher numbers of total colony-forming units were seen for ligated sites than for healthy and gingivitis sites. Levels of Porphyromonas gingivalis and Prevotella intermedia also changed significantly with health/disease status (p < 0.001). These organisms showed their greatest increases at the time of the most intense attachment loss. Higher levels of Fusobacterium nucleatum were seen in the gingivitis sites than in healthy or ligated sites. Low levels of Campylobacter rectus and Capnocytophaga spp. were detected throughout. The morphometric microbiological analysis revealed unexpectedly high %s of motile rods, while spirochetes were found in very low %s. The total number of bacterial cells detected using phase contrast microscopy was not found to vary significantly. None of the morphotypes were demonstrated as showing significant changes with health/disease status.

The influence of supragingival plaque control on clinical and microbial outcomes following the use of antibiotics for the treatment of periodontitis

Although supragingival plaque control is essential to successful periodontal therapy, the role of plaque control following systemic antibiotic use in periodontal disease has not been well defined. This study evaluated, following antibiotic use, which clinical and microbial parameters appeared to be influenced primarily by the antibiotics, independent of plaque control, and which outcomes appeared to be dependent on plaque control. Two hundred thirty-six patients (236) with moderate to severe periodontitis were clinically evaluated and microbial samples were taken by their private-practice periodontists. All patients were treated with scaling and root planing and a variety of systemic antibiotics, which were selected based on the microbial and clinical profile of the patient. Three months after therapy, patients were reevaluated and grouped by post-treatment plaque control, as either having very good oral hygiene (LoPl: N = 143; < or = 10% plaque-covered surfaces) or poor oral hygiene (HiPl: N = 93; > or = 25% plaque-covered surfaces). The two groups had different plaque and bleeding scores initially, but similar numbers of pockets probing > 5 mm and similar microbial patterns. Although the LoPl group had a significantly greater reduction in plaque than the HiPl group, bleeding scores and probing depths changed comparably in both groups after antibiotic therapy. Plaque control influenced outcomes significantly, but in a complex manner. The LoPl group exhibited a significantly greater reduction in certain bacteria, for example P. gingivalis. Interactions between plaque control and specific microbial parameters significantly affected clinical outcomes, although neither alone was sufficient to predict outcomes following antibiotic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of subgingival debridement on periodontal disease parameters and the subgingival microbiota

The aim of the present investigation was to analyse the effect of subgingival scaling and root planing in subjects who prior to treatment exercised meticulous supragingival plaque control. 300 subjects were examined at baseline and after 1 and 2 years without treatment. After the year 2 examination, 62 subjects were randomly selected for therapy. They were given detailed instruction in proper self-performed toothcleaning measures and were carefully monitored during the subsequent 2 years. Following the year-4 examination, 2 quadrants, 1 maxillary and 1 mandibular in each subject, were randomly selected for additional therapy. The teeth in the selected quadrants were exposed to subgingival scaling and root planing. The subgingival therapy was repeated until a site no longer bled on gentle probing. This basic therapy was completed within a 2-month period. All subjects were re-examined after another 12-month interval. The examinations at year 4 and 5 included assessment of plaque, gingivitis, probing pocket depth and analysis of samples obtained from the subgingival microbiota at 134 selected sites. The findings from the present study demonstrated: (i) that subgingival scaling and root planing were effective in eliminating subgingival plaque and gingivitis; (ii) that professional therapy resulted in a pronounced reduction of probing depth at sites which at year 4 had a probing depth > 3 mm; (iii) that in non-scaled quadrants, the extension of self-performed plaque control resulted in a continued improvement of the periodontal conditions at sites which at year 4 were < 5 mm deep.

The role of supragingival plaque in the control of progressive periodontal disease. A review

Levels of supragingival plaque and calculus have been related to progressive periodontal disease, and control of supragingival plaque in conjunction with professional tooth cleaning subgingivally forms the basis for the management of progressive periodontal disease. However, the contribution towards the management of progressive periodontal disease brought about by supragingival plaque control alone is not clear. There are studies which address, directly or indirectly, the contribution of supragingival plaque control alone towards the management of progressive periodontal disease. The effects of supragingival plaque control alone have been evaluated clinically, histologically and microbiologically, and taken together, the evaluations suggest that these effects may not be as marked as when professional subgingival tooth cleaning is also performed. These studies, however, given the patterns of periodontal disease found in adults in many communities, can form the basis for advocating high individual levels of supragingival plaque control as a community measure in the management of periodontal disease. Further long-term investigations into this approach may be warranted.

The effect of supragingival plaque control on the composition of the subgingival flora in periodontal pockets

The effect of mechanical supragingival plaque control on the composition of the subgingival microflora in untreated 4-6 mm deep periodontal pockets was investigated. 13 subjects with chronic periodontitis were recruited for the study. Periodontally-diseased sites were subjected to professional plaque control 3 x weekly for a period of 3 weeks. Contralateral sites received no prophylaxis and served as controls. No instructions in oral hygiene procedures were given to the patients who maintained their habitual oral hygiene regime during the observation period. Clinical examination and darkfield microscopic analysis of bacterial samples were performed every week. The PlI scores for the experimental sites were reduced markedly, while those for the control sites remained stable throughout the observation period. No changes in the other clinical parameters were detected during the study. The composition of the subgingival microflora at the control sites did not change during the experimental period. In contrast, at the test sites, the proportion of spirochetes+motile rods decreased continuously. This decrease reached statistical significance at the end of the experiment. The results indicate that at periodontally diseased sites with an established subgingival ecosystem, supragingival plaque removal may influence the composition of the subgingival microflora.

The effect of supragingival plaque control on the subgingival microbiota in subjects with periodontal disease

The present investigation was performed to study the effect on the subgingival microbiota, of a plaque control program which included meticulous oral hygiene instruction, supragingival scaling and professional monitoring during a 2 year period. 300 subjects were examined for periodontal disease and monitored for 2 years without treatment. After the 2 year examination, 80 subjects were invited to participate in a treatment program intended to improve the standard of their self-performed plaque control. 40 of the invitees had a gingivitis and only minor attachment loss, while 40 subjects had moderate signs of periodontitis. 62 subjects volunteered for this treatment. 23 of the volunteers (Group AB) had several sites with deep pockets (> 4 mm). 39 of the volunteers had gingivitis but shallow pockets only (Group C). Group AB contributed 31 shallow pocket sites (A-sites) and 40 deep pocket sites (B-sites), while Group C contributed 63 shallow sites (C-sites). After the clinical examination, samples of the subgingival microbiota were harvested from the 134 A, B and C sites. The 62 subjects were enrolled in a supervised oral hygiene program. Supragingival scaling was carried out. Oral hygiene instruction was provided and repeated on an individual need basis so that all subjects reached and maintained a supragingival plaque score which was < 20%. 24 months after the year 2 examination, the 62 subjects were examined again using both clinical and microbiological examination procedures. The findings demonstrated that carefully performed supragingival plaque control changed the quantity and the composition of the supragingival microbiota.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of partial denture connectors on gingival health

The effect on the gingiva of a variety of relationships of a removable partial denture connector to the gingival margin was investigated in 10 subjects. Acrylic resin baseplates were designed incorporating a variety of relationships of the connector to the gingival margin. The appliances were worn for a 12 hour period daily, for 21 days. At baseline and at days 7, 21 and 49, plaque index, gingival index and probing pocket depth measurements were recorded, and subgingival plaque samples were examined using darkfield microscopy. No increase in plaque accumulation was detected in any area at any time interval. There was a significant increase in gingival index at day 21 in areas where the appliance covered the gingival margin. Small increases in probing pocket depth were recorded at day 21, there being no difference between any of the test areas. Baseline values were re-established by day 49. No significant differences were detected in the percentage of motile organisms or spirochaetes counted in the subgingival plaque samples collected from any area. It was concluded that deterioration in gingival health occurred rapidly following the insertion of a removable appliance, and that coverage of the gingival margin, irrespective of the degree of gingival relief, had a detrimental effect.

Clinical and light microscopic observations of gingivitis and early ligature-induced periodontitis in the cynomolgus monkey

Clinical and histological observations were made on gingivitis and ligature-induced periodontitis in 4 adult female cynomolgus monkeys (Macaca fascicularis) to define the changes occurring in the early periodontitis lesion. Silk ligatures were tied around selected posterior teeth and replaced weekly for 4 weeks. The changes from gingivitis to periodontitis induced by ligation, and back to a state of clinical health after ligature removal, scaling and polishing, were characterized by Plaque Index, Gingival Index, probing pocket depth, attachment loss, and histologic evaluation. A mild, chronic marginal gingivitis was the normal finding in the gingiva of posterior teeth. The inflammatory infiltrate in the connective tissue contained primarily lymphocytes. Hygienic measures once a week reduced the amount of infiltrate and the epithelial proliferation, but did not eliminate it. Placement of silk ligatures rapidly changed the clinical picture to a moderate or severe gingivitis, which presented an almost bizarre response of sulcular and oral epithelium, with an increase in polymorphonuclear neutrophil infiltration. Within 2 weeks there was significant probing attachment loss. The clinical response on removal of ligatures and plaque was almost as rapid as the onset. The animal model is useful for manipulating variables in ways not possible in the study of human periodontitis.

Supragingival cleaning 3 times a week. The microbiological effects in moderately deep pockets

It is generally believed that supragingival plaque control has little effect on the subgingival microflora of deep periodontal pockets. However, this may not be true for moderately deep pockets (4-5 mm), which may represent a pathological state between gingivitis and marginal periodontitis. In 6 patients with poor oral hygiene and severe gingival inflammation, 4 matched sites (1 in each quadrant), were chosen which demonstrated at least 20% spirochetes and 15% black-pigmented Gram-negative bacilli. During the first 12 weeks (phase 1), supragingival calculus was removed from the right half of the mouth and then the teeth were professionally cleaned three times a week. At the beginning of phase 2, supragingival calculus was also removed from the left quadrants and the entire mouth was subjected to the same protocol used in phase 1. At no time did patients receive oral hygiene instructions. Clinical parameters were assessed and microbiological samples were taken at 3-week intervals. Samples were submitted to darkfield microscopy and anaerobic culturing. Analysis by multiple linear regression and the Wilcoxon signed-rank test revealed significant changes in the composition of the subgingival microbiota at cleaned sites. While Gram-positive organisms increased proportionally, a number of putative periodontal pathogens, such as P. gingivalis and spirochetes decreased.

Current concepts of periodontal maintenance

Changing concepts and a more complete understanding of the aetiology of chronic marginal periodontitis allow a more rational approach to the treatment of patients with periodontal diseases. A sequence of treatment steps of increasing complexity is presented for the prevention of recurrence of chronic marginal periodontitis during the maintenance phase of treatment.

Effect of periodontal status of rotary electric toothbrushes vs. manual toothbrushes during periodontal maintenance. II. Microbiological results

We compared the use of a rotary electric toothbrush with conventional toothbrushing for their effectiveness in modulating the subgingival microbiota. Forty subjects who had received periodontal treatment for moderate to advanced periodontitis and were on 3-month periodontal maintenance were divided into two equal groups matched for age and sex. One group used only the rotary tooth cleaner and the other group used conventional toothbrushing, dental floss, and toothpicks for 12 months. Subgingival plaque samples (two sites per patient) were taken from 10 subjects per group at baseline, 6 months, and 12 months and analyzed for percentage of obligate anaerobes and colony-forming units of black-pigmented Bacteroides, Fusobacterium, Actinomyces, Streptococcus, and Veillonella spp. The percentage of spirochetes and motile rods was determined by darkfield microscopy. Results showed that levels of obligate anaerobes, Fusobacterium, and Actinomyces and percentage of spirochetes and motile rods decreased significantly (P less than 0.05), while levels of Streptococcus spp. increased (P less than 0.05) for both groups. However, there was no significant difference between the two groups, indicating that the rotary tooth cleaner and conventional toothbrushing are equally effective in controlling gingivitis and fostering a less pathogenic microflora.

Clinical effects of local application of collagen film-immobilized tetracycline

Tetracycline-containing cross-linked collagen film (TC film), or tetracycline-free placebo film, were locally applied 4 times, at 1-week intervals, to 33 teeth with periodontal pockets larger than 4 mm, in 11 patients with periodontal disease. The clinical and microbiological effects are summarized, as follows. In the group treated with the TC film, (1) the clinical indices were significantly decreased at the 4th and 7th weeks in comparison with those at the beginning of treatment. In particular, this group showed a significant decrease in the incidence of bleeding as compared with the placebo group at the 4th week. (2) Total counts of bacteria in the periodontal pockets showed an obvious tendency to decrease with time. The proportion of black-pigmented bacteroides was significantly decreased at the 4th and 7th weeks when compared with the pretreatment value. The extent of decrease in the proportion of spirochetes at both the 4th and 7th weeks was significant compared with the placebo group and the pretreatment value.

Combined antibiotic (metronidazole) and mechanical treatment effects on the subgingival bacterial flora of sites with recurrent periodontal disease

5 patients in maintenance, 1-3 years after periodontal therapy who showed sites with reinfected pockets and bleeding despite regular recall visits were selected. Darkfield microscopy from 3 sites in each patient showed an average of 41% spirochetes and 21% motile rods. Probing depths ranged from 7 to 9 mm and loss of clinical attachment from 6 to 13 mm in these sites. The patients were given 3 times 250 mg/day of metronidazole (Flagyl) for 10 days. Darkfield microscopy and microbiological cultures of the subgingival plaque were performed twice prior to the study, at the end of the medication and after 3 weeks, 3 and 6 months. The plaque and gingival indices, probing depth and loss of clinical attachment were recorded. During the medication and at 3 and 6 months, the teeth were scaled and root planed. The samples were obtained with 3 paper points and cultured anaerobically in the glove box on non-selective and selective media and representative bacterial colonies identified by aerobic growth, gram stain and rapid biochemical tests. Presumptive pathogenic micro-organisms including Bacteroides were identified. The % of spirochetes, motile rods and non-motile bacteria were enumerated by darkfield microscopy. The clinical results show that administration of metronidazole and repeated root planing significantly decreased gingival inflammation, probing depth and loss of clinical attachment in reinfected sites. After treatment, these sites harbored significantly less spirochetes and more non-motile bacteria, while motile rods tended to return to baseline levels with time. The combined antibiotic and mechanical therapy resulted in a statistically significant decrease of gram-negative rods, Fusobacteria and Bacteroides gingivalis over 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of supragingival plaque control on the composition of the subgingival microflora in human periodontitis

The aim of this study was to evaluate the effect of supragingival plaque control on the composition of the subgingival microflora. 8 subjects with moderate to severe periodontitis were chosen for the study. Sites with periodontal destruction (GI greater than 2; probing depth greater than 6.5 mm; vertical alveolar bone loss on radiographs) were submitted to professional plaque control 3 X a week for 3 weeks. Contralateral sites received no prophylaxis and served as controls. Patients maintained usual oral hygiene during the observation period: it consisted exclusively of tooth brushing once or twice a day with no use of interdental cleaning aids. Clinical examination and bacterial sampling were performed every week. At the end of the study, PlI scores for the experimental sites showed a marked diminution compared with the control sites. No variations were observed in GI or probing depth in test or control sites during the study. The composition of subgingival plaque in both groups showed no significant variations during that period.

Effects of subgingival chlorhexidine irrigation in chronic moderate periodontitis

The clinical and microbiological effects of once daily subgingival irrigations with 1 ml of 0.2% chlorhexidine gluconate (CH) during 14 days were evaluated in 23 patients with 4 to 6 mm contralateral pockets. On Days 0, 14 and 28, evaluations were made of the plaque index, the gingival index, gingival bleeding on probing pocket depth and of microbiological variables (phase-contrast microscopy). Supragingival scaling was carried out but no oral hygiene instructions were given to patients at the start of the trial. Twenty-three test sites (subgingival CH) and 23 control sites (subgingival distilled water + supragingival CH) were studied. The clinical results showed a significant reduction of the gingival index (P less than 0.05) in the test group with respect to the control group on Day 14. No other clinically significant differences could be observed in the test group with respect to the control group. A significant reduction in the proportions of spirochetes (P less than 0.05) and a significant increase in the proportions of cocci (P less than 0.005) were observed in the test group on Day 14. CH irrigation as a subgingival monotherapy yielded transient microbiological and limited clinical effects.

Effects of an immunomodulating agent on peripheral blood lymphocytes and subgingival microflora in ligature-induced periodontitis

The peripheral blood lymphocyte populations and the subgingival levels of black-pigmented Bacteroides species were monitored during the conversion of chronic gingivitis to progressing periodontitis in cynomolgus monkeys. In addition, the effects of an immunomodulating agent, the pentapeptide of thymopoietin (TP5), were determined. After the induction of active periodontitis, proportions of helper T-cells (OKT-4 positive) decreased from 31.5 to 26.4%, and proportions of B-cells (surface immunoglobulin positive) increased from 44.5 to 51.8%. Proportions of suppressor T-cells (OKT-8 positive) remained unchanged, but the numbers of OKT-8-positive cells increased. During this same time period the total cultivable subgingival flora increased from 1.5 X 10(6) to 3.5 X 10(6) per sample, with Bacteroides gingivalis increasing from 5.3 to 16.6% of the total cultivable subgingival flora. After 10 weeks of active periodontitis, animals were treated with either TP5 or placebo. Treatment with TP5 produced an increase in helper T-cells but had no effect on B-cells. The OKT-4/OKT-8 cell ratio, which decreased from 1.3 to 0.8 with disease induction, was increased to 1.1 after TP5 treatment but remained at 0.9 in placebo-treated animals. TP5 had no effect on the total cultivable subgingival flora but significantly decreased the subgingival proportions of B. gingivalis and other black-pigmented Bacteroides species. In this model system, active periodontitis was associated with an increase in B. gingivalis, a decreased helper/suppressor T-cell ratio, and increased levels of B-cells. Treatment with TP5 increased the helper/suppressor T-cell ratio and decreased B. gingivalis levels, suggesting that lymphocyte subsets have the potential to influence subgingival levels of potential periodontal pathogens.

Efficacy of plaque-removal using interdental brushes and waxed dental floss

The plaque-removing efficacy when using waxed dental floss and three interdental brushes was compared in an intraindividual clinical trial. Nine adult patients treated for periodontal disease, with a reduced but healthy periodontium and large interdental spaces were subjects in the study. Each subject tested the four interdental cleaning aids in random sequence over a 2-wk period. The duration of the study was 8 wk. The results indicated that the use of interdental brushes is preferable to that of dental floss in cleaning interdental areas where the papilla is missing. No difference in achieved cleanliness was noted after use of the different interdental brushes tested. No gingival damage or damage to the hard tissue of the teeth was observed after use of interdental brushes or dental floss.

The effect of supragingival plaque removal on anaerobic bacteria deep periodontal pockets

A study was made to determine if the numbers of subgingival anaerobes in deep periodontal pockets can be controlled by removal of only supragingival plaque. The study was based on the premises that the subgingival flora is dependent on the supragingival plaque for its source of organisms as well as for its perpetuation. Daily professional removal of only supragingival plaque produced a statistically significant reduction per sample in subgingival facultative and obligatory anaerobes.