Yasushi Miyazawa

Lipoproteins of Actinomyces viscosus induce inflammatory responses through TLR2 in human gingival epithelial cells and macrophages.

Actinomyces viscosus has been suggested to be associated with periodontal disease. However, the pathogenicity of this bacterium is not known. In this study, we examined inflammation-inducing activity by A. viscosus. Whole cells and a lipophilic fraction of A. viscosus ATCC19246 induced production of interleukin-8 and tumor necrosis factor alpha from both human oral epithelial cells and human monocytoid cells. This cytokine production was blocked by lipoprotein lipase treatment of the lipophilic fraction. In addition, anti-Toll-like receptor 2 antibody blocked the cytokine production. These results suggest that lipoprotein of A. viscosus triggers inflammatory responses in periodontitis by activation of Toll-like receptor 2.

Periodontal soft tissue management with a high pulse rate Er:YAG laser

Abstract The purpose of this study was to evaluate the effectiveness and safety of periodontal minor soft tissue surgery with the Er/YAG laser at a high pulse rate of 30 Hz and the subsequent clinical wound healing. Sixty-one patients were subjected to gingivectomy, removal of gingival melanin pigmentation, or frenectomy using the Er/YAG laser. Clinical parameters were evaluated before, immediately after, at 1 week and 4 weeks after surgery. The Er/YAG laser was capable of cutting or ablating gingival soft tissue easily and effectively with less or no bleeding as well as less pain. The healing process was uneventful without any complications or side effects. The results of this study suggest that the Er/YAG laser at 30 Hz could be used safely and effectively for minor periodontal soft tissue management without causing major thermal damage as well as the delay of wound healing.

Statin decreases IL-1 and LPS-induced inflammatory cytokines production in oral epithelial cells

Periodontitis is a choronic inflammatory disease associated with degradation of periodontal tissues. This disease is considered to result of production of proinflammatory cytokines and tissue degradative enzymes which are initiated and advanced by lipopolysaccharide (LPS) of oral bacteria.

Removal effects of subgingival calculus on root surface after Er:YAG laser irradiation at a high pulse rate

Abstract This aim of this study was to evaluate the clinical effectiveness of Er:YAG laser at a high pulse rate (ER-D1: HOYA continuum, Japan) for scaling of subgingival calculus and root planning. Sixty-one patients with calculus deposition were treated with the Er:YAG laser (panel setting 30–108 mJ/pulse, 30 Hz) using contact tips and the results were then subjected to clinical analysis. Clinical assessments of calculus index, pain, redness, swelling, discomfort, roughness of root surface, efficiency of scaling, PlI, PD, BOP and mobility were made prior to and at 1, 4 weeks and 3 months after treatment. Fifteen of the sixty-one patients were treated during the flap operation. The Er:YAG laser high-pulse-rate irradiation was capable of ablating the calculus on the root surface precisely and effectively. The roughness of root surface after debridement was evaluated to be adequately plane for 41 cases and still rough for 20 cases. BOP and PD were significantly improved throughout the 3-month examination of this study. No negative side effects or influences were observed on the healing of periodontal tissue following Er:YAG laser irradiation during this clinical study. In conclusion, the Er:YAG laser high-pulse-rate irradiation would be a safe and effective, alternative method for root surface treatment in both nonsurgical and surgical periodontal therapy.

Introduction of a method of promoting periodontal disease awareness.

In periodontal diseases, due to lack of subjective symptoms, disease awareness and professional consultations are often dismissed even by subjects with already established periodontal lesions. The purpose of this study was to gain data concerning the relationship between bleeding induced by interdental stimulating and some of the clinical indices used in routine periodontal examinations in order to consider if wooden interdental cleaners, which are available to patients themselves, could be used as a means of arousing disease awareness. Furthermore, the buccolingual insertion of interdental cleaners was confirmed together with reconsiderations on its role as a means of proximal plaque control. 180 interdental sites of 30 new out-patients suspected of gingivitis or periodontitis consisted the material. As comparative indices to interdental stimulating, Bleeding on Probing (BOP), Probing Depth (PD), Gingival Index (GI) and Gingival Crevicular Fluid (GCF) measurement were selected. The interdental cleaning efficiency was reconsidered by assessment of interproximal plaque removal. As a result, bleeding was induced both by interdental stimulating and probing in 106 of the 180 experimental sites and was the majority. In relation to PD, concerning pockets less than 1.5 mm, bleeding was not induced by interdental stimulating. 58.8% of 3 mm pockets and all of the pockets deeper than 5 mm bled on interdental stimulating. Concerning the relationship with the GI, no site evaluated GI. 0 bled on interdental stimulating. 12.9% of sites evaluates GI. 1, 73.3% of sites evaluated GI. 2, and all of the sites evaluated GI. 3 bled on interdental stimulating. 39.0% of sites with GCF measurement of 0-21, 51.9% of sites with GCF measurement of 21-40 and 96.8% of sites with GCF measurement of over 81 showed bleeding on interdental stimulating.(ABSTRACT TRUNCATED AT 250 WORDS)