The role of Toll-like receptor 2 and 4 in gingival tissues of chronic periodontitis subjects with type 2 diabetes.

BACKGROUND AND OBJECTIVE: Diabetes is one important risk factor of chronic periodontitis. However, the roles of toll-like receptor (TLR) 2 and TLR4, which are implicated in the inflammatory process in both chronic periodontitis and diabetes, have not been studied. This study aimed to determine whether TLR2 and TLR4 might be involved in the relationship between chronic periodontitis and diabetes by examining TLR2 and TLR4 expression in gingival tissues from subjects with chronic periodontitis without diabetes (CP) and with diabetes (CP+DM) and from periodontally healthy subjects without diabetes (PH) and with diabetes (PH+DM). MATERIAL AND METHODS: Gingival tissues were collected from 23 CP subjects, 21 CP+DM subjects, 22 PH subjects and 20 PH+DM subjects. The expression of TLR2 and TLR4 in gingival tissues was determined using an immunohistochemical method. In gingival epithelium, staining patterns and intensity levels of TLR2 and TLR4 expression were studied. In connective tissues, the percentages of TLR2- and TLR4-positive cells were calculated. The intensity levels and the percentages of positive cells were statistically analyzed. RESULTS: Chronic periodontitis or diabetes showed no significant effect on TLR2 expression in the oral epithelium. However, diabetes increased the expression of TLR2 in sulcular epithelium and changed the pattern of TLR2 expression in gingival epithelium. Chronic periodontitis decreased the expression of TLR4 in gingival epithelium. In connective tissue under sulcular epithelium, CP+DM subjects showed statistically significant higher percentages of TLR2- and TLR4-positive cells compared with PH and PH+DM subjects. CONCLUSION: Our results suggest that hyperglycemia and chronic periodontitis had effects on TLR2 and TLR4 expression in gingival tissue. The differences in TLR2 and TLR4 expression could contribute to a greater inflammatory response, leading to periodontal disease initiation and progression.

Intra- and inter-examiner reproducibility in keratinized tissue width assessment with 3 methods for mucogingival junction determination.

BACKGROUND: Although the need for "adequate" amount of keratinized tissue (KT) for periodontal health is questionable, the mucogingival junction (MGJ) often serves as a measurement landmark in periodontal evaluations. Limited information is available on the reproducibility of KT width (KTW) assessment. The purpose of this study was to assess intra- and inter-examiner reproducibility in measuring KTW by using 3 different methods to identify MGJ location. METHODS: Fifteen patients provided 17 teeth which had undergone a gingival augmentation procedure (connective tissue graft; surgery group) and an equal number of contralateral, non-treated teeth (control group). At the midbuccal aspect of each tooth, KTW was assessed by 2 independent examiners after MGJ identification by the visual (VM), functional (FM), and visual with histochemical staining (HM) method. Data analysis was based on intra-class correlation coefficients (ICC) and 3-way analysis of variance (ANOVA) for differences between replicate measurements. RESULTS: KTW was significantly different between treated and control teeth. No significant differences in KTW were found in relation to method for MGJ determination and examiner. Intra- and inter-examiner reproducibility was high, regardless of treatment status or method for MGJ determination (ICC = 0.92 - 0.99). Standard deviations of the difference between replicate measurements ranged from 0.46 mm for VM to 0.21 mm for HM. CONCLUSIONS: Intra- and inter-examiner reproducibility has been shown to be substantially consistent when different methods for MGJ determination are used to measure the apico-coronal dimension of the gingiva. The level of reproducibility does not seem to be affected whether or not the mucogingival complex has been surgically altered by a gingival augmentation procedure.

Periodontal repair in dogs: effect of rhBMP-2 concentration on regeneration of alveolar bone and periodontal attachment.

The objective of this study was to evaluate the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) concentration on regeneration of alveolar bone and cementum, and on associated root resorption and ankylosis. Contralateral, critical size, supra-alveolar, periodontal defects were surgically produced and immediately implanted with rhBMP-2 in an absorbable collagen sponge (ACS) carrier in 8, young adult, male, beagle dogs. 6 animals received rhBMP-2/ACS (rhBMP-2 at 0.05, 0.10, or 0.20 mg/mL; total construct volume/defect approximately 4.0 mL) in contralateral defects following an incomplete block design. 2 animals received rhBMP-2/ACS (rhBMP-2 at 0 and 0.10 mg/mL) in contralateral defects (controls). The animals were euthanised at 8 weeks post-surgery and block sections of the defects were collected for histologic and histometric analysis. Supra-alveolar periodontal defects receiving rhBMP-2 at 0.05, 0.10, or 0.20 mg/ml exhibited extensive alveolar regeneration comprising 86%, 96%, and 88% of the defect height, respectively. Cementum regeneration encompassed 8%, 6%, and 8% of the defect height, respectively. Root resorption was observed for all rhBMP-2 concentrations. Ankylosis was observed in almost all teeth receiving rhBMP-2. Control defects without rhBMP-2 exhibited limited, if any, evidence of alveolar bone and cementum regeneration, root resorption, or ankylosis. Within the selected rhBMP-2 concentration and observation interval, there appear to be no meaningful differences in regeneration of alveolar bone and cementum. There also appear to be no significant differences in the incidence and extent of root resorption and ankylosis, though there may be a positive correlation with rhBMP-2 concentration.