Detection of putative periodontopathic bacteria in type 1 diabetic and healthy children: A comparative study.

Aim: The aim of this study was to compare and assess the risk of periodontitis due to the presence of four putative periodontopathic bacteria (Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Aggregatibacter actinomycetemcomitans) in type 1 diabetic and healthy children. Materials and Methods: Fifty type 1 diabetic and 50 healthy children in the age group of 7-14 years were recruited for the study. Subgingival plaque samples collected from permanent first molars were subjected to polymerase chain reaction assay to detect 16S rRNA gene of P. gingivalis, T. forsythia, T. denticola and A. actinomycetemcomitans. The data were analyzed using Fisher exact test. The P < 0.05 was considered statistically significant. Results: The prevalence of subgingival periodontal pathogens in diabetic and healthy children was 2% and 4% for P. gingivalis, 34% and 34% for T. denticola, 20% and 18% for A. actinomycetemcomitans and for T. forsythia, 4% and 34%, respectively. Significant statistical difference was not observed with regard to the prevalence of P. gingivalis, T. denticola, and A. actinomycetemcomitans among type 1 diabetic and healthy children (P = 1.00). Conversely, T. forsythia was less prevalent in diabetic children compared to healthy children. Conclusion: Statistical significance was not observed for the prevalence of periodontopathic bacteria in type 1 diabetic subjects. The results of the present study thus reveal the absence of risk of periodontitis by these bacterial species in type 1 diabetic subjects.

Relation between the interval of supportive periodontal therapy and the prevalence of the subgingival microflora / 대한치주과학회지

This study was performed to evaluate the relation between the interval of supportive periodontal therapy and the prevalence of the subgingival microflora. The subgingival plaques from 108 patients were used in the study. Control group were the patients with no periodontal treatment and test groups were assigned into 3 groups according to the period of recall check : group 1; 1-2 months, group 2; 3-4 months, group 3; 6months or more. The polymerase chain reaction (PCR) used for direct identification of periodontal pathogens (P. gingivalis, T. forsythensis, T. denticola) in subgingival plaque. The results of this study were as follows. 1. The prevalence of P. gingivalis, T. forsythensis, T. denticola in control group were 100%, 87%, 90%. 2. In clinical parameters such as plaque index, gingival index, bleeding on probing, control group was not significant different with group 1 but significant different with group 2, group 3. 3. In group 1, the majority of P. gingivalis had type II fimA. 4. When group 3 were compared with group 1, the prevalence of P. gingivalis increased. But the prevalence of P. gingivalis with type II fimA, which have the virulence factor, decreased. 5. We were unable to find the correlation between P. gingivalis with type IV fimA and periodontal disease. 6. The prevalence of T. forsythensis, T. denticola in test group were 85%, 93% or more. From the above results, we were able to find the relation between the interval of supportive periodontal therapy and the prevalence of the subgingival microflora and the need of the strict supportive periodontal therapy to prevent recurrence of periodontal disease, because there were high prevalence of periodontal pathogens.

The effect of Treponema denticola immunoinhibitory protein on cytokine expression in T cells / 대한치과보존학회지

Immunoinhibitory protein extracted from sonicated Treponema denticola have been shown to suppress cell cycle progression of human lymphocytes. To study in detail about the effect of this microorganism on the function of lymphocytes, we investigated the levels of Interleukin-2 (IL-2) and Interleukin-4 (IL-4) production by T lymphocytes before and after the addition of 12.5 microg/ml T. denticola sonicated extracts. In this study, levels of IL-2 and IL-4 produced from T cells pretreated with sonicated extracts were evaluated by using the quantitative sandwich enzyme immunoassay technique. In response to phytohemagglutinin (PHA) stimulation, T cell produced increased levels of IL-2 and IL-4. However, the expressions of both cytokines were significantly inhibited when PHA activated-T cells were pre-exposed to sonicated T. denticola extracts (p < 0.05). These findings suggest that the T. denticola sonicated extracts induced-immunosuppression in Th1 and Th2 cell functions could be a part of the pathogenic mechanism of the endodontic failure associated with this microorganism.