Comparison of immediate vs. delayed guided tissue regeneration in Infrabony defect of second molars after adjacent third molar extraction: a retrospective study.

BACKGROUND: The distal aspect of the second molar (d-M2) often exhibits infrabony defects due to the adjacent third molar. Although the defects can be treated by guided tissue regeneration (GTR) after removing the third molar, the optimal timing remains uncertain following third molar removal in clinical decision-making. This study aimed to compare delayed and immediate GTR treatments to assist in clinical decision-making. METHODS: D-M2 infrabony defects with a minimum 1-year follow-up were collected and divided into three groups: Immediate GTR group, which underwent third molar extraction and received GTR simultaneously; Delayed GTR group, which underwent delayed GTR at least 3 months after third molar extraction; and Control group, which underwent only scaling and root planing during third molar extraction. The clinical and radiographic parameters related to the infrabony defect before GTR and post-surgery were evaluated using the Kruskal-Wallis test or one-way ANOVA, followed by post-hoc Dunn's test or the Bonferroni test for pairwise comparisons. RESULTS: A total of 109 d-M2 infrabony defects were assessed. No significant differences were found between the two GTR groups, although both of them showed significant reductions in infrabony defect depth: the immediate GTR group (2.77 ± 1.97 mm vs. 0.68 ± 1.03 mm, p < 0.001) and the delayed GTR group (2.98 ± 1.08 mm vs. 0.68 ± 1.03 mm, p < 0.001) compared to the control group. CONCLUSION: GTR can effectively improve d-M2 infrabony defects when the third molar is removed, whether simultaneously or delayed. Patients may experience less discomfort with immediate GTR treatment as it requires only one surgery.

[Expression and correlation of IL-35 in gingival crevicular fluid and serum with chronic periodontitis].

PURPOSE: To investigate the concentration of IL-35 in serum and gingival crevicular fluid (GCF) and the correlation between IL-35 and periodontal clinical parameters, and explore the possible role of IL-35 in chronic periodontitis (CP). METHODS: Twenty patients with moderate or severe chronic periodontitis were selected as experimental group and 20 healthy people were included as control group. The patients' baseline information, probing depth (PD) and clinical attachment level (CAL) were recorded. Their serum and GCF were collected and then the concentration of IL-35 in GCF and serum were detected by ELISA. SPSS19.0 software package was used for statistical analysis. RESULTS: The concentration of IL-35 in GCF and serum of chronic periodontitis were significantly higher than the control group (P<0.001). There was significant negative correlation between IL-35 and clinical parameters. CONCLUSIONS: Chronic periodontitis may increase the concentration of IL-35 in serum and GCF; IL-35 level is negatively correlated with periodontitis.

[Characteristics of the immune status in aged mice with experimental periodontitis].

PURPOSE: To establish mice model with periodontitis by oral infection with Porphyromonas gingivalis, simulating human periodontal disease. The immune status of youth and aged mice were compared, and the cytokines expression of regulatory T cells and Th17 cells in this model were analyzed. METHODS: Entity microscope was used to evaluate the extent of periodontal bone resorption. H-E staining was used to observe infiltration of inflammatory cells in periodontal lesions. TRAP staining was used to observe osteoclastes in alveolar bone. The expression levels of TGF-ß1, IL-10, IL-17A and RANKL mRNA in periodontal tissues were detected by real-time quantitative PCR. SPSS 17.0 software package was used for statistical analysis. RESULTS: At 4-week after infection, the distance of cemento-enamel junction to the alveolar crest was significantly increased in the periodontal disease group compared with the normal control group (P<0.01); In the aged mice, the cemento-enamel junction to the alveolar crest distance significantly increased compared with youth mice (P<0.01). Periodontal tissues had inflammatory cell infiltration, and deep periodontal pockets. Moreover, the expression levels of TGF-ß1 and IL-10 mRNA were significantly decreased (P<0.01) and the expression levels of IL-17A, RANKL mRNA qsignificantly increased (P<0.01). CONCLUSIONS: The expression of inflammation mediator is abnormal in aged mice with more serious periodontal lesions than youth mice. It is suggested that the inflammatory status of periodontitis not only has a relationship with the decreased expression of inhibitory cytokines, but also relates to aging.

[Comparison of the IL-27 level in gingival crevicular fluid of cross-quadrant and the upper and lower half-mouth subgingival scaling].

PURPOSE: To investigate the changes of IL-27 in gingival crevicular fluid (GCF) before and after treatment with different methods for chronic periodontitis. METHODS: Sixty patients with moderate or severe chronic periodontitis were selected as study group to divide into group A (cross-quadrant) and group B (upper and lower half-mouth) randomly. Another 30 healthy people were selected as group C. Gingival crevicular fluid of group A and B were collected at baseline and each week during treatment. At the same time, the clinical parameters including PD, AL, BI and PLI were recorded. And the levels of IL-27 in GCF were measured by ELISA. SPSS 17.0 software package was used for statistical analysis. RESULTS: The levels of IL-27 in GCF 2 and 3 weeks after treatment were higher in study group compared with those at baseline, while PD, AL, BI and PLI showed significant reduction. The changes except PLI in group A was more obvious than group B, which had a significant difference. After three-week treatment, IL-27 in group A had no remarkable difference compared with group C. There were significantly negative correlation between PD, AL, BI, PLI and IL-27. CONCLUSIONS: IL-27 in GCF can be considered as a potential target for prevention and treatment of chronic periodontitis. Compared with the upper and lower half-mouth subgingival scaling, cross-quadrant has more pronounced short-term effect.