Clinical responses to mechanical periodontal treatment in Chinese chronic periodontitis patients with and without Actinobacillus actinomycetemcomitans

BACKGROUND: The purpose of this study was to compare 12-month clinical responses to mechanical periodontal treatment in Chinese chronic periodontitis patients at sites with and without Actinobacillus actinomycetemcomitans at baseline, and to investigate the ability of mechanical periodontal treatment to eliminate A. actinomycetemcomitans. METHODS: Nineteen patients and a total of 76 selected sites with a mean probing depth (PD) of > or = 7 mm were studied. Whole mouth presence or absence of supragingival plaque (PI%), bleeding on probing (BOP%), probing depth (PD), and probing attachment level (PAL) were recorded at six sites per tooth at baseline and after 3, 9, and 12 months. Baseline subgingival plaque samples were taken from the deepest PD site in each quadrant using sterile paper points and were cultured on TSBV plates for 5 days in a 5% CO2-air incubator. All sites received mechanical periodontal treatment, which included oral hygiene instructions and supragingival and subgingival instrumentation with or without surgical access, with maintenance care being provided once every 3 months thereafter. RESULTS: At baseline, A. actinomycetemcomitans was isolated in 13 of the 19 subjects (68%) and in 29 out of the 76 sampled sites (38%). At the end of 12 months, in three of the initially A. actinomycetemcomitans-positive subjects, A. actinomycetemcomitans was not detected in the sampled sites, while one subject, in whom A. actinomycetemcomitans was not initially found at the sampled sites was A. actinomycetemcomitans-positive at 12 months. Multi-level variance component models showed there was no statistically significant difference in all clinical parameters between A. actinomycetemcomitans-positive and -negative subjects (P > 0.05). In the sampled sites of the initially A. actinomycetemcomitans-positive subjects, the mean PD was reduced from 7.6 +/- 1.6 mm to 3.2 +/- 1.8 mm, the mean PAL gain was 1.4 +/- 2.0 mm, and the mean recession was 3.0 +/- 2.3 mm. The corresponding figures in the sampled sites of the initially A. actinomycetemcomitans-negative subjects were 7.5 +/- 1.6 mm to 2.7 +/- 1.0 mm, 2.3 +/- 2.6 mm and 2.4 +/- 2.2 mm for mean PD changes, PAL gain, and mean recession, respectively. CONCLUSIONS: Favorable clinical responses to mechanical periodontal therapy may occur in Chinese chronic periodontitis patients at sites infected with A. actinomycetemcomitans. The mere detection of subgignival A. actinomycetemcomitans does not necessarily imply poorer treatment outcomes in the control of chronic periodontitis.     

Site-specific association between supragingival plaque and bleeding upon probing in young adults

The aim of the present study was to consider supragingival plaque as a risk factor for gingivitis in a group of young adults without destructive periodontal disease. A total of 127 subjects, 17 to 30 years of age, participated. Periodontal probing depth, clinical attachment level as well as bleeding upon probing and supragingival plaque was assessed at 6 sites of every tooth present. The individual odds ratios between plaque and bleeding ranged between 0.237 and 66.6. 23% volunteers had an odds ratio of below 1.2. Only 15% individuals presented with an attributable risk of supragingival plaque for bleeding upon probing of 50% or more. Overall, the odds of bleeding, adjusted for periodontal probing depth, was increased by 67% in the presence of plaque. Large differences were observed at different teeth with the highest odds ratio at mandibular premolars with 2.557 (95% confidence interval 2.033–3.216) and the lowest at maxillary molars with 1.355 (1.161–1.732). It was concluded that there was high interindividual and intraindividual variation of the relative risk for bleeding in the presence of plaque. The observed low overall relative risk has important consequences in educational and health care programmes since the risk of supragingival plaque which is actually attributable for the observed bleeding on probing may be rather small. Received: 29 February 2000 / Accepted: 13 June 2000     

Supragingival and subgingival microbiota of adult patients with Down''s syndrome. Changes after periodontal treatment

In this longitudinal study, five adult Down's syndrome patients with periodontitis were placed on a frequent recall visit schedule (every 6 weeks) after treatment, in order to investigate: 1) the microbiological status, both supragingivally and subgingivally, and the changes that occurred after treatment and 2) the effect of frequent professional supragingival plaque control on the subgingival microbiota and clinical variables in these patients. The clinical variables recorded were probing pocket depth, probing attachment level, bleeding on probing and presence of plaque (full mouth, six surfaces per tooth). Microbiological examination was performed separately for supragingival and subgingival samples from the same site for 14 species, using whole genomic DNA probes and the "checkerboard" DNA-DNA hybridization technique. The findings indicate that, although a reduction of periodontal indices was noticed, plaque levels remained high (60%) even at the end of the experimental period. Periodontal pathogens including Porphyromonas gingivalis, Bacteroides forsythus and Actinobacillus actinomycetemcomitans were frequently detected both supragingivally and subgingivally (>30%). The presence of a species supragingivally and the presence at the same time points subgingivally were correlated. This finding suggested that supragingival plaque acts as a reservoir for reinfection of treated sites. A reduction of the percentages of detection of these species was noticed 1 month after an oral hygiene period as well as at 3 and 6 months after treatment. Inadequate oral hygiene as performed by these patients probably affected supragingival, and consequently subgingival, plaque composition.     

Clinical alterations in relation to the morphological composition of the subgingival microflora following scaling and root planning

The aim of the present study was to relate shifts in the composition of subgingival plaque in periodontal pockets to alterations of the clinical periodontal conditions following a single course of subgingival scaling and root planing during a period of professional supragingival plaque control. For this purpose, 36 pairs of contralateral periodontal pockets in 10 subjects with moderately advanced periodontitis were assessed for the degree of gingival inflammation, probing pocket depths, bleeding on probing, attachment levels and the amount of supragingival plaque. In addition, samples of subgingival plaque were analyzed morphologically by dark-field microscopy. All patients received detailed information about proper oral hygiene and every 1-2 weeks, professional removal of supragingivally located deposits. When the oral hygiene standard had been sufficiently improved, 1 course of subgingival scaling on 1 side of each jaw only (test side) was carried out. Clinical and microbiological examinations were repeated after the scaling as well as after 2 and 6 months, while patients were recalled for supragingival prophylaxis every 2nd to 4th week. Our data showed that a single course of subgingival scaling and root planing resulted in reduced probing depths, a gain in clinical attachment and a shift in the composition of the subgingival microflora to a composition found in relatively healthy periodontal conditions. In relatively shallow pockets, however, a possible influence of repeated sampling on the subgingival microflora could not be ruled out. Bleeding on gentle probing was a reliable parameter for predicting a subgingival microflora where motile bacteria hold an increased portion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Distribution of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in an Australian population

BACKGROUND, AIM: The present study describes (i) the natural distribution of the three putative periodontopathogens Porphyromonas gingivalis, Prevotella intermedia and Actinobacillus actinomycetemcomitans in an Australian population and (ii) the relationship between these organisms, pocket depths and supragingival plaque scores. METHODS: Subgingival plaque was collected from the shallowest and deepest probing site in each sextant of the dentition. In total, 6030 subgingival plaque samples were collected from 504 subjects. An ELISA utilising pathogen-specific monoclonal antibodies was used to quantitate bacterial numbers. RESULTS:: A. actinomycetemcomitans was the most frequently detected organism (22.8% of subjects) followed by P. gingivalis and P. intermedia (14.7% and 9.5% of subjects respectively). The majority of infected subjects (83%) were colonised by a single species of organism. A. actinomycetemcomitans presence was over-represented in the youngest age group but under-represented in the older age groups. Conversely, P. gingivalis and P. intermedia presence was under-represented in the youngest age group but over-represented in the older age groups. Differing trends in the distribution of these bacteria were observed between subjects depending upon the site of the infection or whether a single or mixed infection was present; however, these differences did not reach significance. Bacterial presence was strongly associated with pocket depth for both A. actinomycetemcomitans and P. gingivalis. For A. actinomycetemcomitans, the odds of a site containing this bacterium decrease with deeper pockets. In contrast, for P. gingivalis the odds of a site being positive are almost six times greater for pockets >3 mm than for pockets < or =3 mm. These odds increase further to 15.3 for pockets deeper than 5 mm. The odds of a site being P. intermedia positive were marginally greater (1.16) for pockets deeper than 3 mm. CONCLUSIONS: This cross-sectional study in a volunteer Australian population, demonstrated recognised periodontal pathogens occur as part of the flora of the subgingival plaque. Prospective longitudinal studies are needed to examine the positive relationship between pocket depth and pathogen presence with periodontal disease initiation and/or progression.     

Microbial ecology of Actinobacillus actinomycetemcomitans, Eikenella corrodens and Capnocytophaga spp. in adult periodontitis

Information on intraoral distribution of putative periodontal pathogens might be essential for controlling different forms of periodontal disease. Colonization may be either promoted or impeded by other bacteria competing in the subgingival ecosystem. In recent investigations microbial associations between dental organisms have been determined in a multitude of subgingival plaque samples within multiple patients and described by odds ratios, in most circumstances without taking into account the correlated structure of the observations within a single individual. The present investigation had 3 major objectives: (i) to describe the intraoral distribution of some facultatively anaerobic, Gram-negative rods, i.e. Actinobacillus actinomycetemcomitans, Eikenella corrodens-like organisms and Capnocytophaga spp., in a multitude of subgingival and extracrevicular samples of 10 adult subjects with A. actinomycetemcomitans-associated periodontitis; (ii) to analyse possible inconsistencies of microbial associations between these periodontal organisms; and (iii) to determine factors increasing the likelihood of isolating these bacteria in a given subgingival site by employing Generalized Estimation Equation (GEE) methods. Clinical examinations were carried out at 6 sites of every tooth present. In each subject, 13 extracrevicular (2 cheek mucosa, 3 tongue, 4 gingival, 2 tonsillar samples, 1 palatinal, 1 saliva sample) and between 22 and 44 subgingival samples from deepest sites of every tooth present (n=296) were selectively cultivated for A. actinomycetemcomitans, E. corrodens and Capnocytophaga spp. In extracrevicular material, A. actinomycetemcomitans, Capnocytophaga spp. and E. corrodens were isolated in 9, 10 and 6 patients, and from 65, 82 and 15% samples, respectively. The organisms were recovered from 51, 62 and 27% subgingival plaque samples, respectively. Heterogeneity tests did not reveal significant inconsistencies of microbial associations between bacteria in subgingival plaque. Mantel-Haenszel's odds ratios ranged between 2.0 for A. actinomycetemcomitans and Capnocytophaga spp. and 18.7 for Capnocytophaga spp. and E. corrodens. An exchangeable working dependence structure was employed in the GEE approach. The odds of isolating A. actinomycetemcomitans was increased by factor 3.7 in 4–6 mm deep pockets, and 9.5 in ≥ 7 mm deep pockets. The odds of presence of E. corrodens was increased by factor 10.8 in the case of presence of Capnocytophaga spp. and 2.1 in the case of presence of A. actinomycetemcomitans. Capnocytophaga spp. were associated with bleeding on probing and molar sites. Presence of E. corrodens was associated with clinical attachment loss but not periodontal probing depth. Results of the present study indicated an association of A. actinomycetemcoinitans with periodontal pathology. Whereas this organism and Capizocytopliagae were widely distributed in extracrevicular ecosystems of the mouth, E. corrodens only occasionally appeared in saliva or on mucous membranes of the oral cavity. In general, GEE methods seem to allow to determine factors associated with the presence of periodontal organisms in a multivariate approach and considering the correlated structure of the data.     

Microbiological and clinical effects of surgical treatment of localized juvenile periodontitis

Since Actinobacillus actinomycetemcomitans appears to be a key etiologic agent in localized juvenile periodontitis, this study determined the effectiveness of different treatment modalities in suppressing A. actinomycetemcomitans in localized juvenile periodontitis lesions. A total of 25 deep periodontal lesions from 7 patients with localized juvenile periodontitis were included in the study. The test periodontal lesions either received scaling and root planing alone, scaling and root planing together with soft tissue curettage, or modified Widman flap surgery. Subgingival A. actinomycetemcomitans were enumerated using selective culturing. Clinical measurements included changes in probing periodontal attachment level, probing periodontal pocket depth, gingival index, plaque index, and digital subtraction of standardized serial radiographs. The microbiological and clinical effects of treatment were monitored over a period of 16 weeks. All periodontal lesions studied demonstrated high numbers of A. actinomycetemcomitans prior to treatment. Scaling and root planing alone did not markedly change the subgingival A. actinomycetemcomitans counts, nor any of the clinical parameters studied. In contrast, soft tissue curettage as well as modified Widman flap surgery suppressed A. actinomycetemcomitans to undetectable levels immediately after therapy in more than 80% of the lesions studied. A total of 5 periodontal lesions exhibited gain of probing periodontal attachment after subgingival curettage or Widman flap treatment; 3 of these sites revealed no detectable A. actinomycetemcomitans, and the remaining 2 sites harbored only low levels of A. actinomycetemcomitans. 5 periodontal lesions which lost probing attachment after treatment all demonstrated high numbers of subgingival A. actinomycetemcomitans. Changes in alveolar bone, assessed by digital subtraction of serial radiographs, correlated with changes in probing periodontal attachment level, confirming the clinical results. The present study revealed a close relationship between post-treatment A. actinomycetemcomitans levels and the clinical response to treatment, which supports the concept that A. actinomycetemcomitans is an important organism in the etiology of localized juvenile periodontitis. This study also showed that a substantial suppression of subgingival A. actinomycetemcomitans cannot be achieved by periodontal scaling and root planing alone, but can be accomplished by surgical removal of periodontal tissues.(ABSTRACT TRUNCATED AT 400 WORDS)     

Association between betel quid chewing, periodontal status and periodontal pathogens

The present investigation examined whether an association exists between betel quid chewing and signs of periodontal disease and determined the prevalence of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis by polymerase chain reaction. The periodontal status of 34 betel quid chewers and 32 non-betel quid chewers were compared. A significantly higher prevalence of bleeding on probing was found in betel quid chewers than non-chewers among the subjects with higher plaque level, greater gingival inflammation, deeper probing depth or greater attachment loss. Also, the results suggested that betel quid chewers may harbor higher levels of infection with A. actinomycetemcomitans and P. gingivalis than non-betel quid chewers. The association persists after adjusting for severity of the clinical parameters. In conclusion, betel quid chewing was associated with a higher prevalence of bleeding on probing where higher clinical levels of disease existed, and with a likelihood of subgingival infection with A. actinomycetemcomitans and P. gingivalis.     

Natural distribution of oral Actinobacillus actinomycetemcomitans in young men with minimal periodontal disease

A total of 1005 subgingival and extracrevicular samples from 201 male recruits, 18–25 yr old, were selectively cultivated for Actinobacillus actinomycetemcomitans. The organism was isolated in 55 subjects (27%); 9.5% of pooled subgingival plaque samples from first molars, 14% cheek mucosa, 20% dorsum of tongue and 20% saliva samples were culture-positive. In order to divide the study population into distinct clinical categories, cluster analysis was performed, based on previous caries experience, probing pocket depth categories, bleeding scores, visible plaque and calculus. Two clusters (n=86 and n=92, respectively) were identified with no or minimal periodontal disease (mean±standard deviation % of periodontal probing depth 1–2 mm 78.7±10.4% and 57.4±12.6%, respectively; virtually no periodontal probing/depth in excess of 4 mm) and a relatively low DMF-S (22±13). A third cluster (n=22) had, in contrast, a high DMF-S (47.7±173) and a relatively high % of periodontal pockets of ≥5 mm (5.9 ±5.2%). Prevalence of A. actinomycetemcomitans in this cluster was 41%, while the organism was found in 23% and 27% in the minimally diseased populations (p<0.15). Whereas no heterogeneity of associations between subgingival and extracrevicular occurrence of the organism could be ascertained in different clusters, the organism was significantly more often identified in extracrevicular material, especially dorsum of tongue samples, compared with subgingival plaque (McNemar's X²=12.45, p<0.001). Multiple linear regression analysis revealed the number of A. actino-mycetemcomitans positive samples as well as the % of sites bleeding on probing being positively associated with the % of sites with a probing pocket depth of ≥5 mm (R2=0.345, p≤0.0001). The present large-scale investigation points to the wide distribution of this putative periodontopathogen in young individuals with minimal periodontal disease.     

Intraoral distribution of Actinobacillus actinomycetemcomitans in young adults with minimal periodontal disease

The aim of the present study was to investigate the intraoral distribution of Actinobacillus actinomycetemcomitans in young adults with minor signs of periodontal disease but harboring the organisms in the oral cavity. 17 healthy volunteers, 20 to 27 years of age, participated. Samples from mucosal surfaces of the oro-pharyngeal cavity and saliva (n = 221) as well as subgingival plaque from every tooth (n =477) were selectively cultivated for A. actinomycetemcomitans. Species identity and presence of the leukotoxin encoding gene, ltxA, were checked by multiplex polymerase chain reaction. Moreover, the leukotoxin promoter region was analyzed. No isolate harbored a 530 bp deletion in the promoter region of the leukotoxin gene, signaling minimally toxic strains. 42.1 +/- 30.4% extracrevicular and 34.4 +/- 29.5% subgingival samples were culture-positive. In extracrevicular samples, the organism could easily be recovered from cheek mucosa (62%), saliva (59%) and the palatal tonsils (41%). Mean log-transformed numbers of A. actinomycetecomitans colony forming units (CFU/ml) in culture-positive material ranged between 1.8 from the hard palate and 2.3 from 10 microl saliva. The highest prevalence in subgingival plaque was observed at maxillary 3rd molars (55%) followed by maxillary lateral incisors (50%) and mandibular 3rd molars (41%). Mean log-transformed counts of CFU/ml ranged between 2.2 at maxillary 3rd molars and 3.4 at upper central incisors. When adjusted for jaw, site and tooth type, the odds of isolating higher numbers of the organism were increased with every mm probing depth by a factor of 1.35 (p <0.05). The odds ratio for bleeding on probing was 1.38. Thus, in this young adult population with minor periodontal disease, A. actinomyetemcomitans was mainly associated with some deviation from gingival health. Of concern might be a minority of subjects (29%) with an extremely wide distribution of the organism in the oral cavity.     

Periodic subgingival antimicrobial irrigation of periodontal pockets

The present investigation was undertaken to study the clinical effect of professionally performed periodic subgingival irrigation per se and as an adjunct to scaling and root planing. 10 patients suffering from moderate-severe periodontal disease participated in the study. Following an initial 3-month period of supervised supragingival plaque control, a total of 102 periodontal sites with probing pocket depth greater than or equal to 6 mm and "bleeding on probing" were selected and subjected to a Baseline examination comprising assessments of oral hygiene and gingival conditions, probing depths and probing attachment levels. The pockets in the various jaw quadrants were randomly assigned to one of the following treatment groups: (1) periodic subgingival irrigation with hydrogen peroxide, (2) periodic subgingival irrigation with chlorhexidine, (3) periodic subgingival irrigation with saline and (4) no subgingival treatment. During the first part of the study (baseline-32 weeks), no mechanical debridement of the subgingival area was performed. The irrigation treatment was carried out by the operator 3 times per week during weeks 1 + 2 and 5 + 6 of the trial. In the 2nd part of the trial (32-52 weeks), the sites were subjected to scaling and root planing combined with professional irrigation during weeks 32-38. The previously non-irrigated control sites were not subjected to adjunctive irrigation when mechanically debrided. During the entire study, the patients were recalled for professional tooth cleaning once every 4 weeks. Re-examinations were carried out at 4, 6, 32, 40 and 52 weeks. The results revealed that repeated professional irrigation of unscaled periodontal pockets with chlorhexidine or hydrogen peroxide resulted in a temporarily reduced frequency of bleeding sites, but not in any clinically significant changes in probing assessments. A similar improvement of bleeding scores was observed in the saline-irrigated control group. Scaling and root planing, in combination with an optimal supragingival plaque control, resulted in a marked resolution of the clinical symptoms of periodontal disease. Adjunctive irrigation with chlorhexidine or hydrogen peroxide did not improve the healing result above and beyond that obtained after mechanical debridement alone or in combination with saline irrigation. Hence, the study failed to demonstrate that professionally performed periodic subgingival irrigation with chlorhexidine or hydrogen peroxide, used alone or in combination with thorough mechanical debridement, has a significant therapeutic effect.     

Changes of periodontal status in patients with Down syndrome during a 7-year period

The development of periodontal disease in Down syndrome adolescents (n = 34) was studied clinically and on intraoral radiographs during a 7-yr period. The occurrence of gingival inflammation (GBI), pathological periodontal pockets (>4 mm), sub- and supragingival calculus, alveolar bone height, alveolar bone loss, and the occurrence of the periodontal pathogens Actinobacillus actinomycetemcomitans, Capnocytophaga, and Porphyromonas gingivalis in subgingival plaque were determined. Of the subjects, 41% had one or more pathological periodontal pockets at baseline compared to 65% at follow-up. At the baseline examination, 35% of the individuals exhibited alveolar bone loss compared to 74% at the follow-up. The median value of sites with alveolar bone loss increased from 0 to 1, the new lesions mainly being located in the incisor region. The estimated annual reduction of alveolar bone height in each subject was 0.04 mm on average. The occurrence of the periodontal pathogens A. actinomycetemcomitans, Capnocytophaga, and P. gingivalis in subgingival plaque did not differ between baseline and follow-up. The results of the present study indicate that the frequency of periodontitis, mainly located on the lower incisors, markedly increased during a 7-yr period in Down syndrome individuals, although the severity and progression was limited compared to what has previously been described.     

Subgingival temperature and microbiota in initial periodontitis

Abstract. The association between subgingival temperature, other clinical characteristics, and the subgingival microbiota was examined in adult subjects with initial periodontitis and differing levels of gingival inflammation, 43 subjects were measured at 6 sites per tooth for pocket depth, attachment level, presence of plaque, gingival redness, bleeding on probing and subgingival temperature at 3-month intervals for 1 year. Subgingival plaque was sampled from 15 initial active periodontitis sites (10 subjects), 121 gingivitis, sites (20 subjects) and 202 healthy sites (13 subjects), and included the 5 hottest and 5 coldest sites in each subject. Plaque samples were analyzed for 13 subgingival species using whole-genomic DNA probes. The major influences on the subgingival microbiota were the clinical status of sites, pocket depth, and the presence of supragingival plaque. No significant association between species and site temperature was observed. Initial active sites were associated with Bacteroides forsythus and Campylobacter rectus. and had a higher mean subgingival temperature and deeper mean pocket depth than inactive sites, A weak association between pocket depth and site temperature was noted. The major influence on subgingival temperature of sites was the anterior to posterior anatomical temperature gradient in the mandible and maxilla.     

The effect of supragingival plaque control on the progression of advanced periodontal disease

Abstract. The aim of the present trial was to study the effect of meticulous supragingival plaque control on (i) the subgingival microbiota, and (ii) the rate of progression of attachment loss in subjects with advanced periodontal disease. An intra-individual group of sites exposed to non-surgical periodontal therapy served as controls. 12 patients with advanced periodontal disease were subjected to a baseline examination (BL) including assessments of oral hygiene status, gingival condition (BoP), probing depth, clinical attachment level and subgingival microbiota from pooled samples from each quadrant. The assessments were repeated after 12, 24 and 36 months. Following BL, a split mouth study was initiated. The patients received oral hygiene instruction, supragingival scaling and case presentation. 2 quadrants in each patient were identified as “test” and the remaining 2 as “control” quadrants. Subgingival therapy was performed in all bleeding sites in the control quadrants. Oral hygiene instructions and plaque control exercises were repeated once every 2 weeks during the initial 3 months of the study. Thereafter the plaque control program was repeated once every 3 months for the duration of the 3 years. Sites demonstrating loss of clinical attachment ≥2 mm in the test quadrants were treated subgingivally. The results showed that in both test and control quadrants repeated oral hygiene instructions and supragingival plaque removal procedures resulted in low plaque scores throughout the study. The gingival bleeding scores and the frequency of periodontal pockets ≥4 mm was, however, significantly higher in the test quadrants than in the control quadrants. At the end of the 3 year study, the control quadrants showed significantly more reduced (≥2 mm) pockets than the test quadrants, 265 versus 96. The number of sites in the test quadrants showing probing attachment loss ≥2 mm was more than 4× greater than in the control quadrants (59 versus 13). The microbiological findings indicate a more pronounced reduction only for P. gingivalis in the control quadrants. None of the other 4 marker bacteria consistently reflected or predicted the clinical parameters. The present study shows that only supragingival plaque control fails to prevent further periodontal tissue destruction in subjects with advanced periodontal disease.     

Supragingival and subgingival microbiota of adult patients with Down’s syndrome. Changes after periodontal treatment

In this longitudinal study, five adult Down’s syndrome patients with periodontitis were placed on a frequent recall visit schedule (every 6 weeks) after treatment, in order to investigate: 1) the microbiological status, both supragingivally and subgingivally, and the changes that occurred after treatment and 2) the effect of frequent professional supragingival plaque control on the subgingival microbiota and clinical variables in these patients. The clinical variables recorded were probing pocket depth, probing attachment level, bleeding on probing and presence of plaque (full mouth, six surfaces per tooth). Microbiological examination was performed separately for supragingival and subgingival samples from the same site for 14 species, using whole genomic DNA probes and the “checkerboard” DNA‐DNA hybridization technique. The findings indicate that, although a reduction of periodontal indices was noticed, plaque levels remained high (60%) even at the end of the experimental period. Periodontal pathogens including Porphyromonas gingivalis, Bacteroides forsythus and Actinobacillus actinomycetemcomitans were frequently detected both supragingivally and subgingivally (>30%). The presence of a species supragingivally and the presence at the same time points subgingivally were correlated. This finding suggested that supragingival plaque acts as a reservoir for reinfection of treated sites. A reduction of the percentages of detection of these species was noticed 1 month after an oral hygiene period as well as at 3 and 6 months after treatment. Inadequate oral hygiene as performed by these patients probably affected supragingival, and consequently subgingival, plaque composition.     

Prevalence of suspected periodontal pathogens identified using ELISA in adolescents of differing ethnic origins

Abstract The aim of this study was to determine the prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in a group of adolescents and investigate the association of these organisms with various clinical parameters. A total of 527, 11-13-year-old children, of whom 333 (63%) were white Caucasian, 187 (35%) Indo-Pakistani and 7 (1%) Afro-Caribbean, participated in the study. Subgingival plaque samples, collected from the mesio-buccal of both upper first permanent molars using sterile paper points, were stored in phosphate buffered saline with 0.01% thiomersal and analysed for the presence of A. actinomycetemcomitans, P. gingivalis and P. intermedia using ELISA. The mesio-buccal sites of both upper 1st permanent molars were also examined and the presence/absence of supragingival plaque, subgingival calculus, bleeding on probing and pocket depths greater than 3 mm were recorded. The % of white Caucasian children in whom the monoclonal antibody identified at least 1 site with A. actinomycetemcomitans, P. gingivalis and P. intermedia were 4%, 3% and 2%, respectively, and for Indo-Pakistanis were 3%, 17% and 2%. The difference for P. gingivalis was statistically significant (p < 0.001). The associations between the clinical parameters and the 3 organisms were considered separately for both upper first molar sites. The prevalence of P. gingivalis was higher for sites with subgingival calculus, pockets >3 mm and bleeding on probing (p < 0.001).     

Recolonization of a subgingival microbiota following scaling in deep pockets

The present investigation was carried out to study some aspects of the recolonization of a subgingival microbiota following subgingival instrumentation in sites with deep pockets. 16 patients were recruited for the study. From each patient 4 inflamed gingival sites with deep pockets were selected. These sites were examined for plaque, overt gingivitis, bleeding on probing and probing depth. Samples of the subgingival microbiota were obtained and examined in the darkfield microscope and in a Neubauer chamber. Following the Baseline examination the teeth of all 4 jaw quadrants were carefully scaled and planed. Subgingival instrumentation was carried out under local anesthesia and required between 2-4 appointments. The patients were subsequently divided into 2 groups (Groups A and B) consisting of 9 and 7 subjects, respectively. During the first 16 weeks of maintenance the patients of Group A were not supervised regarding their self-performed plaque control measures and they accumulated supragingival plaque. The patients of Group B, however, were during these 16 weeks recalled once every 2 weeks for professional tooth cleaning. In addition they rinsed twice daily with a 0.2% solution of chlorhexidine digluconate. Reexaminations including assessments of the same parameters as those studied at Baseline were performed after 2, 4, 8, 12 and 16 weeks. After the 16-week examination the patients of Group A received a new sequence of subgingival scaling and root planing. During the subsequent 16 weeks the patients of Group A were also recalled for professional tooth cleaning. They were reexamined 18, 20, 24, 28 and 32 weeks after the Baseline examination. Subgingival scaling followed by carefully supervised oral hygiene measures resulted in a marked improvement of periodontal conditions. This improvement was accompanied by a pronounced and sustained reduction in the motile segments of the subgingival microbiota. In the presence of supragingival plaque (Group A), however, a subgingival microbiota containing large numbers of spirochetes and motile rods was soon (4-8 weeks) reestablished. A small number of sites with deep pockets (greater than or equal to 8 mm) was not substantially reduced in depth following subgingival instrumentation. In these sites which were kept free from supragingival deposits a subgingival microbiota with a large proportion of motile bacteria soon recurred.     

Analysis of the activity to induce toll-like receptor (TLR)2- and TLR4-mediated stimulation of supragingival plaque

BACKGROUND: The deleterious effects of the accumulation of supragingival plaque are well known, but the role of the proinflammatory property of supragingival plaque in periodontal diseases has not been completely elucidated. The aim of this study was to determine the relevance of Toll-like receptor (TLR)2- and TLR4-stimulating activity of supragingival plaque to periodontal parameters. METHODS: We isolated 144 supragingival plaque samples and analyzed TLR2- and TLR4-stimulating activity using genetically engineered Chinese hamster ovary reporter cells that express a reporter molecule upon activation of nuclear factor-kappa B through TLR2 or TLR4. The numbers of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), and Streptococcus mutans cells in each plaque sample were determined by real-time polymerase chain reaction. RESULTS: The activity to induce TLR4-mediated stimulation, but not TLR2-mediated stimulation, was positively associated with the plaque score and bleeding on probing score of the teeth from which the plaque samples were taken. The activity to induce TLR2-mediated stimulation, but not TLR4-mediated stimulation, was negatively associated with probing depth and clinical attachment level. The ratio of TLR4-/TLR2-mediated stimulation was positively associated with all of those parameters. The number of P. gingivalis cells in each plaque sample was associated with the plaque score and clinical attachment level, but no strong association was observed between the ratio of examined bacteria in each plaque sample and the activity to induce TLR2- or TLR4-mediated stimulation, except for a weak correlation between the ratio of A. actinomycetemcomitans cells and the activity to induce TLR4-mediated stimulation. CONCLUSION: The TLR2- and TLR4-stimulating activity of supragingival plaque is associated with clinical parameters for gingivitis and periodontitis.     

The detection of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia using an ELISA in an adolescent population with early periodontitis

Abstract The aim of the study was to compare the occurrence and levels of A. actinomycetemcomitans. P. gingivalis, and P. intermedia in the subgingival plaque from sites with and without early periodontitis in adolescents using an ELISA. 47, 15- to 16-year-old adolescents (39 Indo-Pakistani. 8 white Caucasian) were examined for clinical attachment level, probing depth, supragingival plaque, subgingival calculus and bleeding on probing on the mesio-buccal and disto-buccal aspects of the 1st molars and the incisors. Based on the clinical data, 2 sites per subject were selected for subgingival plaque sampling 3 weeks later: in 32 subjects with loss of attachment mm, a diseased site (D) and a healthy comparison control site (C) were sampled: in 15 subjects in whom loss of attachment had not yet developed. 1 of the upper molar sites was selected, called the at-risk site (R), together with a C site. The presence and levels of A. actinomycetemcomitans, P. gingivalis, and P. intermedia were determined using an ELISA. The loss of attachment subgroup had significantly more pockets 4 mm, subgingival calculus and bleeding on probing (p<0.05). Significantly more of the D than C sites had P. gingivalis both at detectable and at measurable levels (p<0.05). In subjects who had no loss in clinical attachment levels, fewer sampled sites harboured any of the suspected peridontopathogens investigated, and no significant differences were found between the R or C sites (p>0.05). Although there was a significantly higher prevalence and extent of loss of attachment 1 mm in the Indo-Pakistani subjects compared with the Caucasians (p<0.05), no differences could be identified in the distribution of the bacteria. It is concluded that monitoring of the subgingival plaque may be useful in studies of early periodontitis in adolescents, and the role of P. gingivalis needs to be elucidated in prospective longitudinal investigations.