The purpose of this study was to evaluate the association between signs of trauma from occlusion, severity of periodontitis and radiographic record of bone support. The maxillary first molars of 300 individuals were independently evaluated by two examiners for signs of trauma from occlusion, pattern or occlusal contacts and severity of periodontitis. Each site was also evaluated radiographically by an independent third examiner. The results indicated that: teeth with either bidigital mobility, functional mobility, a widened periodontal ligament space or the presence of radiographically visible calculus had a deeper probing depth, more loss of clinical attachment and less radiographic osseous support than teeth without these findings, teeth with occlusal contacts in centric relation, working, nonworking or protrusive positions did not exhibit any greater severity of periodontitis than teeth without these contacts, teeth with both functional mobility and radiographically widened periodontal ligament space had deeper probing depth, more clinical attachment loss and less radiographic osseous support than teeth without these findings and given equal clinical attachment levels, teeth with evidence of functional mobility and a widened periodontal ligament space had less radiographic osseous support than teeth without these findings.

This investigation included a cross-sectional component (284, 20-40-year-old subjects/568 sites) and a longitudinal component (19 subjects with moderate to advanced periodontitis/76 sites). Subgingival plaque samples and clinical data were obtained from all upper second bicuspids and first molars in the longitudinal subjects and from both upper first molars in the cross-sectional subjects. The purpose was to: determine/confirm changes in proportions of selected subgingival microorganisms following root planning combined with conventional oral hygiene procedures in the longitudinal subjects, evaluate those changes in terms of an estimate of the naturally occurring distribution of subgingival microorganisms based on data obtained from the cross-sectional subjects and relate shifts in the subgingival microorganisms to changes in clinical measurements. Changes following treatment at sites with pre-instrumentation probing depths greater than or equal to 4.5 mm included cocci, 18.3 to 46.9%; spirochetes, 20.9 to 3.1%; total motile organisms, 28.5 to 5.9%; Fusobacterium spp., 10.2 to 2.2%; and dark-pigmented Bacteroides spp., 14.0 to 9.7%. Translating proportions of microorganisms in samples from subjects in the longitudinal treatment study to equivalent percentile ranks within the large cross-sectional data base demonstrated that at probing depths greater than or equal to 4.5 mm cocci moved from below the 50th percentile in our estimate of the naturally occurring distribution of subgingival microorganisms to above, and spirochetes, total motile organisms and Fusobacterium spp. moved from above the 50th percentile to below. The microbiological findings were consistent with statistically significant improvements in clinical measurements. Statistically significant changes also occurred in microorganisms at sites with initial probing depths less than 4.5 mm.

The periodontal status of maxillary first molars in 284 young adults demonstrating near-health to early disease was evaluated, and supragingival and subgingival plaque samples were collected. Plaque samples were processed anaerobically, enumerated microscopically for bacterial morphotypes, and cultivated on various media to enumerate the microflora. Although haemophili were ubiquitous (recovered in 98.5 and 96.2% of the supragingival and subgingival plaque samples, respectively), 50% of the respective samples had proportions of .1.5% and c0.33% total Haemophilus spp. based on total cultivable microflora. To study the distribution of Haemophilus spp., 377 colonies were identified from modified chocolate agar (selective for oral haemophili) from 14 supragingival and corresponding subgingival samples from 14 subjects. The most prevalent species, Haemophilus parainfluenzae, was found in significantly higher proportidns, based on total haemophili on modified chocolate agar, in supragingival and subgingival samples from teeth with shallower probing depths (.3.0 mm) versus deeper probing depths (.3.0 mm). Additional statistically significant findings included Haemophilus segnis in higher proportions in supragingival samples from deeper sites, Haemophilus aphrophilus in higher proportions in subgingival samples from deeper sites, and Haemophilus paraphrophilus in higher proportions in subgingival samples from shallower sites. Scatter diagrams illustrating the bivariate distributions of proportions of haemophili with proportions of dark-pigmented Bacteroides spp., spirochetes, and streptococci demonstrated that high proportions of haemophili were never recovered from sites with high proportions of Bacteroides spp. or spirochetes. All levels of haemophili, however, were recovered from sites with all levels of streptococci. Two potential systems for interpreting haemophili data were hypothesized for predicting periodontal probing depths. There was highly significant agreement between the two systems. Small but statistically significant correlations were found between the gingival index, probing depth, and attachment level, and proportions of total Haemophilus species in the respective samples.

The association between Actinobacillus actinomycetemcomitans and periodontal disease in juveniles has been well documented. The purpose of this investigation was to determine the prevalence and proportions of A. actinomycetemcomitans in supragingival and subgingival plaque samples from the maxillary first molars of a large number of young adults. The study population included 284 adults, aged 20^0, ranging in periodontal disease status from healthy to moderate periodontitis but with the majority exhibiting early periodontal disease. The clinical characteristics of probing depth, attachment level, plaque index, and gingival index were measured. Supragingival and subgingival plaque samples were evaluated microscopically for microbial forms. They were also cultured on supplemented blood agar and various selective agar media including selective media for A. actinomycetemcomitans. The prevalence o? A. actinomycetemcomitans in subgingival and supragingival plaque for individuals in the population was 13.0% (37/284) and 4.9% (14/284), respectively. Proportions of actinobacilli, based on total anaerobic counts, were found at or below 1% in 87% of 47 subgingival sites from 37 subjects. Supragingival and subgingival sites with actinobacilli were compared to sites without actinobacilli. Subgingival sites with A. actinomycetemcomitans had a significantly higher mean plaque index, with 79% of these sites having a plaque index greater than 1.0 compared to 30% of sites without actinobacilli. The mean gingival index, probing depth, and attachment level of sites with actinobacilli were also higher, but not significantly, than those without. Of the microbial forms enumerated, only spirochetes had a significantly higher mean proportion at subgingival sites when compared to sites without actinobacilli. Mean proportions of the cultivable microorganisms, Veillonella spp. and Streptococcus spp., were significantly lower at sites with A. actinomycetemcomitans. Differences in the mean proportions of certain microorganisms were compared between the 47 subgingival sites with actinobacilli divided into three groups by probing depth. Mean proportions of A. actinomycetemcomitans were significantly higher at intermediate probing depths between 3.0 and 5.0 mm compared to deeper sites with probing depths above 5.0 mm. On the other hand, dark-pigmented Bacteroides spp. mean proportions were significantly higher at deeper probing depths than at either intermediate or shallow, less than or equal to 3.0 mm, probing depths. There were no significant differences in the mean proportions of spirochetes between shallow, intermediate, or deeper probing depths of the 47 subgingival sites with actinobacilli.

This study was designed to examine human subgingival plaque for the presence of dark‐pigmented Bacteroides (DPB) species in a large adult population that had been following a rigorous oral hygiene and recall program for 2 years. Subjects received scaling and root planing and oral hygiene instructions at the time of entry and then a prophylaxis and/or oral hygiene instructions at frequent intervals. Clinical measurements were determined and microbial flora identified in subgingival plaque. The DPB species were found in 63% of the subjects and 47% of the total sites. The N‐acetyl‐B‐glucosaminidase‐positive DPB species (B. melaninogenicus, B. denticola or B. loescheii), B. intermedius, B. gingivalis and strains of unclassified pigmenting Bacteroides were found in 25, 50, 3 and 40% of the subjects, respectively, and at 15, 35, 2 and 25% of the sites, respectively. Plaque and bleeding indices, probing depth and mean proportions of motile rods and spirochetes were higher at sites with DPB as compared to sites without DPB species. Sites with B. intermedius had higher plaque and gingival indices and greater loss of probing attachment than sites with DPB other than B. intermedius. The prevalence of B. intermedius and other DPB species was high even though subjects were on a rigorous oral hygiene and recall program.