Autoinducer-2 produced by oral microbial flora and alveolar bone loss in periodontitis.

OBJECTIVE: The aim of this study was to investigate the association between autoinducer-2 (AI-2) of oral microbial flora and the alveolar bone destruction in periodontitis to determine if AI-2 may have the potential that monitor periodontitis and predict bone loss. BACKGROUND: Plaque biofilm was the initiating factor of periodontitis and the essential factor of periodontal tissue destruction. The formation of biofilms depended on the complex regulation of the quorum sensing (QS) system, in which bacteria could sense changes in surrounding bacterial density by secreting the autoinducer (AI) to regulate the corresponding physiological function. Most oral bacteria also communicated with each other to form biofilms administrating the QS system, which implied that the QS system of periodontal pathogens was related to periodontitis, but the specific relationship was unknown. METHOD: We collected the gingival crevicular fluid (GCF) samples and measured the concentration of AI-2 in samples using the Vibrio harveyi BB180 bioluminescent-reporter system. To explore the interaction between AI-2 and bone metabolism, we utilized AI-2 purified from Fusobacterium nucleatum to investigate the impact of F. nucleatum AI-2 on osteoclast differentiation. Moreover, we constructed murine periodontitis models and multi-species biofilm models to study the association between AI-2 and periodontal disease progression. RESULTS: The AI-2 concentration in GCF samples increased along with periodontal disease progression (p < .0001). F. nucleatum AI-2 promoted osteoclast differentiation in a dose-dependent manner. In the periodontitis mice model, the CEJ-ABC distance in the F. nucleatum AI-2 treatment group was higher than that in the simple ligation group (p < .01), and the maxilla of the mice in the group exhibited significantly lower BMD and BV/TV values (p < .05). CONCLUSIONS: We demonstrated that the AI-2 concentration varied with the alveolar bone destruction in periodontitis, and it may have the potential for screening periodontitis. F. nucleatum AI-2 promoted osteoclast differentiation in a dose-dependent manner and aggravated bone loss.

Efficacy of scaling and root planing with and without adjunct Nd:YAG laser therapy on glucose control and periodontal microecological imbalance in periodontitis patients with type 2 diabetes mellitus: a randomized controlled trial.

OBJECTIVE: The study aims to determine the effects of Nd:YAG laser-assisted with subgingival scaling and root planing (SRP) treatment on glucose control and the dynamic changes of subgingival microbiome in periodontitis with type 2 diabetes mellitus (T2DM). MATERIALS AND METHODS: Twenty-two patients were split into Nd:YAG group (n = 11) and SRP group (n = 11). Patients in the Nd:YAG group received SRP and auxiliary Nd:YAG laser treatment; patients in the SRP group received SRP treatment only. Periodontal tissue inflammation and glycemic control were assessed and analyzed during the treatment period and the changes of subgingival microbiome were analyzed by full-length 16S rRNA sequencing. RESULTS: After 3 months of treatment, PD and CAL values improved significantly in the Nd:YAG group compared to the SRP group. BOP in both groups improved significantly after treatment. FPG levels in the Nd:YAG group were significantly reduced after treatment. Porphyromonas and Porphyromonadaceae were enriched in the Nd:YAG group at baseline, and Fusobacteriota, Fusobacteriia, Fusobacteriales, Leptotrichiaceae, and Leptotrichia were enriched after treatment. CONCLUSION: Nd:YAG laser-assisted SRP therapy has additional benefits in improving periodontal tissue inflammation and blood glucose control in periodontitis patients with T2DM compared with SRP therapy alone and there was a trend towards a decrease in disease-associated taxa and an increase in health-associated taxa following auxiliary Nd:YAG laser treatment. CLINICAL RELEVANCE: The effects of Nd:YAG laser-assisted SRP treatment on inflammation, glucose control, and subgingival microbiome in periodontitis patients with T2DM were elucidated, and new ideas for the treatment of T2DM periodontitis were provided.