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Notes: The present investigation was carried out in order to assess the development of periodontal disease in germfree rats infected with microorganisms associated with human gingivitis, periodontitis and periodontosis lesions. One hundred and forty gnotobiotic rats of the Spraque-Dawley strain were weaned 21 days after birth and then randomly divided into five groups (four experimental groups and one control) consisting of 28 animals each. After weaning the animals of the experimental groups were infected with one of the following strains; strain I (Actinomyces naeslundii), strain 1073 (Eikenella corrodens), strain 381 (Bacteroides asaccharolyticus), strain 4 (Capnocytophage sputigena). Animals were sacrificed to provide specimens for examination 14, 28, 56 and 84 days after infection. Germ-free controls were sacrificed at the same time intervals.The degree of alveolar bone loss was assessed on defleshed and dried jaws. Microscopic assessments regarding loss of connective tissue attachment, degree of bone resorption, and degree of impaction of hair and bedding material were determined in histological sections. In addition, a morphometric analysis of the gingival tissues was carried out using a standardized morphometric test procedure.The results showed that germfree rats monoinfected with different bacteria associated with human periodontal diseases may suffer severe breakdown of the periodontal tissues. The degree of breakdown tended to increase with increasing experimental time. However, periodontal tissue destruction was obviously related to the impaction of hair and bedding material. In fact, only in areas with severe impaction of foreign material could gross destruction of the supporting apparatus be recognized.

Notes: Fifteen gram-negative, saccharolytic rods isolated from advanced periodonlal pockeis were compared to type and reference strains of Arlinohacillus actinomycetemcomitans, Haemaphilus aphrophilus, and reference strains of Haemophilus paraphrophilus. Phenotypic features of organisms were used in cluster analysis and multidimensional scaling. Deoxyribonucleic acid (DNA) was extracted from all strains and moles percent guanine plus cytosine content determined. DNA/DNA homology experiments were performed between reference strains of each species and oral isolates. Five strains from periodontosis lesions, two strains from Papillon-Lefevre periodontal lesions, and four strains from periodontitis pockeis of adults were similar to A. actinomycetemcomitans by cluster analyses and by DNA/DNA homologies. Except for a single H. paraphrophilus isolate, the H. aphrophilus and H, paraphrophilus isolates could not be distinguished as two distinct species as there was overlap in biochemical characteristics and DNA/DNA homology. Two strains isolated from periodontosis lesions, two strains from adult periodontilis sites, and three oral reference strains were very similar to each other and to the H. aphrtiphilus type strain using phenotypic features. Hydrogen peroxide decomposition was not found to be a consistent feature of A. actinomycetemcumitans strains isolated from periodontal pockets.

Notes: The relationship between T cell proliferative responses to oral microorganisms and periodontal disease status was studied utilizing a standardized T cell/monocyte mixture previously shown to generate maximal proliferative responses in vitro. T cells from periodontally healthy and diseased subjects were found to respond equally well to all oral microorganisms tested. When subjects were grouped according to their T cell response profile by cluster analysis, a generalized high responder and generalized low responder group was defined. Low responders were found to have significantly more redness and bleeding on probing than high responders. No differences were found between the two groups with respect to suppuration, plaque, attachment level, pocket depth, or bone loss. Patients not falling into the high or low responder groups had intermediate proliferative responses and moderate amounts of inflammation. These findings indicate that T cell proliferative responses to oral microorganisms may identify subgroups of individuals with unique clinical features.

Notes: Three adult subjects were selected with moderate to advanced progressing periodontal destruction and generalized gingival inflammation. Progressive disease sites showed radiographic evidence of crestal alveolar bone loss within the previous three months. Darkfield and cultural microbiological samples were taken from both shallow and deep levels within progressing periodontal pockets and inactive control sites in the same individual.The microbiota at shallow and deep subgingival sites within most pockets was similar. W. recta and gram positive rod Type A, however, were elevated in proportions in deep pocket zones. The darkfield and cultural techniques provided different estimates of proportions of organisms in the same sample zone. The darkfield technique was more sensitive for detection of large and curved motile rods, but cultural techniques provided higher counts of fusiform-shaped species.Using cluster analysis and multiple linear regression, sites associated with recent bone loss were characterized by higher proportions of B. gingivalis, “fusiform”Bacteroides, and small spirochetes, than inactive sites. Inactive pockets contained similar species to progressive disease sites, but in lower proportions. F. nucleatum was isolated in similar proportions from pockets with evidence of recent disease and inactive sites.

Notes: Samples of bacterial plaque were removed from the mesial surfaces of the upper canine, and upper and lower first molars from 20 young adult subjects with gingivitis but without attachment loss. Absolute counts and proportions of 23 categories of microorganisms were enumerated by darkfield microscopy and on selective and elective media. The differences in means of absolute counts of each microbial group on the tooth surfaces were compared by one- and two-way analysis of variance using untransformed, log and square root transformed values. Data were compared with zero values or with zero values replaced with a minimum threshold of detection values of 105 for microscopic counts and 103 for cultural counts. The untransformed and transformed data with and without minimum thresholds replacing zero were tested for conformity to a normal distribution. Differences in counts of each microbial group on the different tooth surfaces were sought by the nonparametric Kruskal-Wallis one-way analysis of variance and the Friedman two-way analysis of variance. Differences in percentages of each microbial group were also sought using the same analyses on untransformed and arc sine transformed percentages.None of the untransformed absolute counts conformed to a normal distribution. Log transformation, particularly with minimum threshold values replacing zero, was more successful in fitting the data to a normal distribution than square root transformation. However, few groups conformed to a normal distribution after either transformation. Percentages with or without arc sine transformation in most instances were not normally distributed. Substitution of minimum thresholds for zero values did not markedly alter significance testing, but did help to decrease confidence intervals of the means, particularly of log transformed counts. Significant differences revealed by the nonparametric analyses of absolute counts were most similar to one- and two-way ANOVA of log transformed absolute counts. The use of nonparametric analyses for microbial counts is recommended because of the variability of the count data and the difficulties in interpreting zero values and in transforming the data to a normal distribution.

Notes: Conventional biochemical characterization and an ELISA technique were compared for their ability to identify reference cultures and fresh isolates from suppurating and non-suppurating periodontal pockets, as well as healthy gingival sulci in the same individual. Antisera to Bacteroides gingivalis strain 381, Bacteroides intermedius strains 581 and VP1 8944, and Bacteroides melaninogenicus ss. melaninogenicus strain 287 were prepared by immunizing rabbits. The antisera were conjugated with peroxidase and appropriate dilutions were chosen to minimize cross-reactions in the ELISA technique. Conventional characterization of the isolates included cellular and colonial morphology, biochemical characterization, and gas liquid chromatography of acid end products. The antisera appeared to be specific for each black-pigmented species, since cross-reactions were not observed to reference strains of heterologous species. There was a 94% agreement between the ELISA and conventional identifications of over 300 fresh isolates from periodontal sites.The predominant black-pigmented Bacteroides species isolated from suppurating sites was Bacteroides intermedius using either identification technique. The median value of proportions of this species was significantly increased in the suppurating periodontal pockets (16.5%) when compared to non-suppurating deep periodontal pockets (3%) and healthy gingival sulci (0%). Significant differences in proportions were not observed for the other species of black-pigmented Bacteroides.

Notes: Abstract The present investigation describes the effect of periodontal therapy in a group of patients who, following active treatment, were monitored over a 5-year period. One aim of the study was to analyze the role played by the patients’ self-performed plaque control in preventing recurrent periodontitis. In addition, probing depth and attachment level alterations were studied separately for sites with initial probing depths of 〈inlineGraphic alt="geqslant R: gt-or-equal, slanted" extraInfo="nonStandardEntity" href="urn:x-wiley:03036979:JCPE448:ges" location="ges.gif"/〉4 mm which were treated initially by either surgical or non-surgical procedures.Following active treatment (surgical/non-surgical), the patients were maintained on a plaque control regimen for 6 months, which included professional tooth cleaning once every 2 weeks. During the subsequent 18 months, the interval between the recall appointments was extended to 12 weeks and included prophylaxis as well as oral hygiene instruction. Following the 24-month examination, the interval between the recall appointments was further extended, now to 4–6 months. In addition, the maintenance program was restricted to oral hygiene instruction and professional, supragingival tooth cleaning, but further subgingival instrumentation was avoided. Clinical examinations including assessments of the oral hygiene, the gingival conditions, the probing depths and the attachment levels were performed at Baseline and after 24 and 60 months after completion of active therapy. Assessments of plaque and gingivitis were repeated annually.The results of the examinations showed that the patients’ standard of self-maintained oral hygiene had a decisive influence on the long-term effect of treatment. Patients who during the 5 years of monitoring consistently had a high frequency of plaque-free tooth surfaces showed little evidence of recurrent periodontal disease, while patients who had a low frequency of plaque-free tooth surfaces had a high frequency of sites showing additional loss of attachment. The present findings demonstrated that sites with an initial pocket depth exceeding 3 mm responded equally well to non-surgical and surgical treatments. This statement is based on probing depth and attachment level data from sites which were free of plaque at the 6-, 12-, 24-, 36-, 48- and 60-month reexaminations. It is suggested that the critical determinant in periodontal therapy is not the technique (surgical or non-surgical) that is used for the elimination of the subgingival infection, but the quality of the debridement of the root surface.