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Notes: Abstract The effect of improved metabolic control on the clinical periodontal condition and the subgingival microflora of diseased and healthy periodontal pockets in 6 ambulatory insulin-dependent diabetes mellitus (IDDM) patients was prospectively studied. Duplicate measurements with a time-interval of 3 days were made every 4 moths for assessment of the metabolic status, the clinical periodontal condition and the subgingival microflora. During the study, patients maintained personal oral hygiene measures as they usually did before the study. Neither supplementary dental prophylaxis nor oral hygiene measures were applied during the investigation. Long-term metabolic control (HbA1c) improved significantly with intensive conventional insulin treatment. Gingival redness decreased significantly whereas gingival swelling showed a not significant trend to decrease. It is suggested that microvascular changes associated with improved metabolic control in diabetes mellitus may mediate the observed change in gingival redness. No effect could be demonstrated for probing pocket depth, probing attachment level, bleeding on probing and the plaque index. Statistical analysis of the effect of improved metabolic control on the subgingival microflora revealed that only the % of streptococci increased significantly in diseased periodontal pockets. In general, no significant changes were found in either healthy or diseased pockets with regard to the bacterial flora associated with periodontal disease. The results of the present study indicate that improved metabolic control in IDDM patients may have no potential impetus for an improved clinical periodontal condition nor on the subgingival bacterial flora. It is concluded that the periodontal condition in IDDM patients may only ameliorate when local oral hygiene measures are applied.

Notes: Abstract. The present study primarily aimed at investigating the oral microbiota in smokers and non-smokers with established gingivitis and monitoring its composition during experimental gingivitis. Secondly, it aimed at examining whether the composition of the microbiota is associated with different levels of gingival inflammation during this experimental gingivitis trial. For this purpose, 25 non-dental university students with gingivitis were recruited. 11 subjects were smokers and 14 were non-smokers. After achieving gingival health, they entered a 14-day experimental gingivitis trial. Plaque and bleeding were assessed before entering into the study (intake), at day 0. day 5 and at day 14 of the experiment. Microbiological samples from mucosal sites and dental plaque (taken at intake, day 0, and day 14) were analysed for the presence of Actinomyces species. Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Campylobacter rectus, Fusobacterium nucleatum, Peptostreptococcus micros. Porphyromonas gingivalis, Prevotella intermedia and Streptococcus species. At day 14 of the experimental period, the level of plaque formation was not different between smokers and nonsmokers, but bleeding scores were lower in smokers than in non-smokers (15% and 30%) respectively, p= 0.01). The change from natural gingivitis to a state of gingival health and a subsequent change from gingival health to experimentally induced gingivitis was accompanied by quantitative alterations in the cultivable microbiota in both groups. Changes were most prominent in the transition from gingival health to experimental gingivitis and were found in dental plaque for Actinomyces species, C. rectus, F. nucleatum, and P. intermedia. Within the group of non-smokers, a distinction was made between subjects with a‘weak’or 'strong’inflammatory response. No relationship with a single bacterial species could be established which would likely explain the differences in levels of inflammation. It is concluded that differences in response to experimental gingivitis are not caused by major differences in the composition of the oral microbiota.

Notes: Abstract The purpose of this study was to assess whether an intensive oral hygiene regimen practised during pregnancy results in a clinically healthy gingival state, and to assess whether experimentally-induced gingivitis differs in severity during pregnancy as compared to post-partum. In addition, levels of black-pigmented Gram negative anaerobes at subgingival and oral mucosal sites and plasma concentrations of free estrogens and prosterone were determined. These parameters were studied during a 14-day episode of experimental gingivitis induced in the 25th week of pregnancy, and again 6 months post-partum. The subjects were selected on shallow pockets ≤4 mm and interproximal loss of attachment not exceeding 2 mm. As a result of controlled oral hygiene, the gingival condition improved both during pregnancy and post-partum. At day 0 during pregnancy, however, gingival swelling, redness, and bleeding on probing were found to be higher than post-partum. Free plasma levels of estrogens and progesterone were found to be normal throughout the study. It was hypothesized that the increase in severity of gingival symptoms during pregnancy reflect microvascular physiologic effects of increased levels of these hormones. During pregnancy, more swelling, redness and bleeding on probing developed during experimental gingivitis than post-partum, whereas the amount of plaque was similar in both phases. This suggests that as a result of dental plaque accumulation, gingival inflammation develops superimposed on pregnancy-associated physiologic alterations. Microbiological evaluation showed that the mean proportions of Prevotella intermedia in subgingival plaque increased during experimental gingivitis performed during pregnancy, whereas no increase of this microorganism was found post-partum.

Notes: Abstract The objectives of the present study were to establish in a long-term investigation the safety as well as the clinical and microbiological efficacy of scaling and rootplaning combined with local application of 2% minocycline hydro-chloride-gel versus placebo-gel in patients with moderate to severe chronic adult periodontitis. This was an 18 months, randomized, double-blind, parallel, comparative study, in which 20 healthy patients with moderate to severe chronic periodontitis participated. At baseline, all patients received professional oral hygiene instruction and supra-and subgingival scaling and root planing. The minocycline-gel was applied subgingivally baseline, 2 weeks. 1, 3, 6, 9 and 12 months. Microbiological evaluation was carried out using DMDx to identify the following bacteria: Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans. Campylobacter rectus. Fusobacterium nucleatum and Treponema denticola. In addition standard microbiological techniques were used for the detection of P. gingivalis, P intermedia, P. micros, A. actinomycetemcomitans. C. rectus, F. nucleatum, C. albicans and Enterobacteriaceae. Results showed a statistically significant improvement for all clinical parameters irrespective of the treatment modality. No differences were observed between test and control with regard to probing depth and attachment level. The DMDx data showed a significant reduction in both the numbers and the prevalence over the 15 months period, but no significant difference between groups. Culture data showed that at baseline two–third were positive for P. gingivalis and P intermedia. Analysis over the 18 month period showed no significant difference between the two treatment modalities. C albicans and Enterobacteriaceae were detected only in small proportions at each time interval in a limited number of patients. No adverse reactions were observed during the trial period. The present patient group responded favourably to scaling and rootplaning, but did not benefit from an effect of local of minocycline. Subgingival debridement in combination with oral hygiene instruction by itself has been shown to be effective. It remains to be studied whether local application of minocycline can be effective as an adjunct to mechanical therapy in sites that respond poorly to conventional treatment.

Notes: Abstract On the basis of glycosylated hemoglobin (HbAIC)values, 22 type I (insulin-dependent) diabetic adults were grouped into patients with near normal (HbAt1c≤7.7%) and Poor (HbAtc≥9.9%) metabolic control. A total of 44 subgingival sites were examined for Actinobacillus actinomycetemcomitans, black-pigmented Bacteroides species and Capnocytophaga species. No significant difference could be demonstrated between patients in the 2 test groups with regard to periodontal condition. Neither age of diabetic patients nor duration of diabetes mellitus influenced the periodontal parameters. In both test groups, pocket depth of 4 mm or more (≥4 mm) was found to be significantly associated with increased swelling, bleeding after probing and amount of marginal plaque. Proportionally high %s of cultivable A. actinomycetemcomitans (mean 4.3%; range 2.8–5.8%), Bacteroides gingival (33.2% and 34.6%) and Bacteroides intermedius (mean 4.2%; range 0.001–13.5%) were isolated from diseased periodontal pockets. In diabetic patients with poor metabolic control, B. intermedius was isolated from diseased periodontal pockets with a mean % of 7.2%, range 0.3–12.5%. Independent of the degree of metabolic control, low %s of Capnocytophaga species were isolated from diseased and healthy periodontal pockets, mean 0.9% (range 0.003–3.9%) and mean 1.4% (range 0.04–4.9%), respectively. It was concluded from this study that metabolic control seems to have no direct effect on the periodontium. Furthermore, the role of Capnocytophaga species in the pathogenesis of infectious periodontal disease in type I diabetic patients seems to be overestimated. However, A. actinomycetemcomitans and blackpigmented Bacteroides species may be important pathogens in periodontal disease in type I diabetic patients, as they are known to be in non–diabetic periodontal patients.

Notes: Abstract Today, 10 black-pigmented Bacteroides (BPB) species are recognized. The majority of these species can be isolated from the oral cavity. BPB species are involved in anaerobic infections of oral and non-oral sites. In the oral cavity. BPB species are associated with gingivitis, periodontitis, endodontal infections and odontogenic abscesses. Cultural studies suggest a specific role of the various BPB species in the different types of infection. Bacteroides gingivalis is closely correlated with destructive periodontitis in adults as well as in juveniles. Bacteroides intermedius seems to be less specific since it is found in gingivitis, periodontitis, endodontal infections and odontogenic abscesses. The recently described Bacteroides endodontalis is closely associated with endodontal infections and odontogenic abscesses of endodontal origin. There are indications that these periodontopathic BPB species are only present in the oral cavity of subjects suffering from periodontal breakdown, being absent on the mucosal surfaces of subjects without periodontal breakdown. BPB species associated with healthy oral conditions are Bacteroides melaninogenicus, Bacteroides denticola and Bacteroides loescheii. There are indications that these BPB species are part of the normal indigenous oral microflora. Many studies in the past have documented the pathogenic potential and virulence of BPB species. This virulence can be explained by the large numbers of virulence factors demonstrated in this group of microorganisms. Among others, the proteolytic activity seems to be one of the most important features. Several artificial substrates as well as numerous biological proteins are degraded. These include anti-inflammatory proteins such as alpha-2-macroglobulin, alpha-1-antitrypsin, C3 and C5 complement factors and immunoglobulins. B. gingivalis is by far the most proteolytic species, followed by B. endodontalis. Like other bacteria, the lipopolysaccharide of B. gingivalis has shown to be active in bone resorption in vitro and is capable in stimulating interleukin-1 production in human peripheral monocytes. Based on the well documented association with periodontal disease and the possession of relevant virulence factors. BPB species must be considered as important micro-organisms in the etiology of oral infections. B. gingivalis seems to be the most pathogenic and virulent species.

Notes: Abstract. In a previous study, an edentulous subject showed the presence of P. gingivalis. only in saliva. The present case report is a longitudinal follow-up on this proband (female, 63 years) and her spouse with periodontitis (67 years). Samples were taken from the proband and the spouse for microbiological analysis at several occasions during a 3-year period and a 1 -year period respectively. In the edentulous proband, P. gingivalis was present in saliva only, at ail times. In the spouse, P. gingivalis was present in the periodontal pocket and on the mucous membranes, but the saliva was culture-negative for this species at both sampling times. The restriction enzyme analysis (REA) patterns of isolates (n=7) of P. gingivalis from the proband recovered over 3 years showed no differences. This indicated that the same clonal type of P. gingivalis persisted for 3 years in the proband. The P. gingivatis isolates (n=13) from the spouse showed no differences when REA patterns were compared. Comparison of REA patterns from the proband and the spouse also showed no differences. Thus the same clonal type of P. gingivalis can persist over several years in an edentulous subject and at least for 1 year in a subject with periodontal disease.

Notes: Abstract The aim of the present study was to investigate the prevalence of periodontopathic microorganisms and periodontal destruction in the spouses and children of adult periodontitis patients. For this study, 24 families were selected on the basis of one parent with severe periodontal breakdown and the presence of Actinobacillus actinomycetemcomitans and/or Porphyromonas gingivalis and/or more than 30%Prevotella intermedia subgingivally. The clinical examination of both parents and children included pocket depth and clinical attachment loss (CAL) measurements. Samples for bacterial examination were obtained from the mucous membranes, the saliva and pockets. Pocket selection was based on the most advanced periodontitis situation found in a subject. The samples were cultured for the detection of A. actinomycetemcomitans, P. gingivalis and P. intermedia. By phase-contrast microscopy, the % of spirochetes and motile microorganisms was assessed. The number of children within each family varied between 1 and 3. In total 49 children were investigated with a range in age of 3 months to 15 years. Results showed that under the age of 5 years, none of the children had CAL. whereas in the age group of 5–15 years, 26.5% had 1–5 sites in the primary and/or permanent dentition with 1–3 mm CAL. 3 of the spouses had no interproximal CAL. 16 of the 24 spouses had a light to moderate form of periodontitis, with at least one site with 1 to 4 mm CAL and 5 spouses had severe periodontal breakdown with sites showing at least 8 mm CAL. Spirochetes, motile microorganisms and P. intermedia were frequently present in all family members. 18 out of the 24 probands were positive for P. gingivalis. This organism was found once only in a 5-year-old boy and in 11 of the spouses. A. actinomycetemcomitans was detected in 13 probands; 5 children and 5 of the spouses were also positive for this bacterium. If a child harboured one of the periodontopathogens, at least 1 of the parents was also positive for that bacterium. This phenomenon may be due to transmission of microorganisms between family members. Comparison of the clinical data reported in the present study with similar clinical parameters from epidemiological studies of the Dutch population suggest that the spouses and children of adult periodontitis patients might be at relatively high risk of developing periodontal breakdown.

Notes: Abstract We investigated direct and immune-cell-mediated effects of Bacteroides gingivalis on bone metabolism in vitro. Fetal mouse long-bone rudiments were cultured under aerobic conditions in the presence of (a) intact bacteria, (b) low molecular weight (MW 〈 1000) metabolic products of the bacteria, or (c) conditioned media of mouse spleen cells activated by whole bacteria. A suspension of intact bacteria, added directly to the bone culture, had no effect on bone resorption or bone formation. Low molecular weight (MW 〈 1000) excretion products of the bacteria inhibited bone resorption and transiently reduced mineralization of the diaphysis, while the growth in length of the bones was not affected. However, conditioned media of bacteria-activated spleen cells strongly enhanced bone resorption and increased osteoclast numbers in the bone culture, while inhibiting mineral formation in the diaphysis. This led to a strongly negative mineral balance. These data do not support a direct effect of either bacteria or bacterial products on bone tissue as a likely explanation for bone loss in periodontal disease. Rather, they favour the concept that the loss of bone in this disease is an indirect effect of the host response, resulting from the contact of immune cells with the bacteria. This implies that bacterial invasion of the connective tissue of the gingiva may not be a prerequisite for alveolar bone loss.

Notes: Aim: The occurrence of Prevotella intermedia (Pi) and Prevotella nigrescens (Pn) in relation to natural gingivitis, gingival health and 14-day experimental gingivitis was investigated in 25 non-dental students.〈section xml:id="abs1-2"〉〈title type="main"〉Materials and Methods:Samples were taken from the dorsum of the tongue, the tonsils (or tonsillar area), and the supra- and subgingival plaque.Results: The microbiological results show that 73% of the samples were positive for the bacterial species presumed to be Pi and/or Pn. In natural gingivitis, gingival health and in experimental gingivitis 25, 23 and 25 subjects were found to be positive for Pi and/or Pn, respectively. The results of the 889 isolates that were succesfully purified and differentiated, show that almost all subjects were colonized with Pn whereas approximately half of the study population harboured Pi. These 2 species were isolated from both dental plaque and mucosal sites and were found to colonize the oral cavity simultaneously.Conclusion: In natural gingivitis, at the start and after 14 days of experimental gingivitis, Pn was the predominant micro-organism.