Toshiro Kodama

Guided tissue regeneration using a collagen barrier and bone swaging technique in noncontained infrabony defects.

This clinical study evaluated the effectiveness of guided tissue regeneration using a resorbable collagen membrane and bone swaging in noncontained infrabony defects by assessing changes in probing pocket depth, probing attachment level, and radiographic bone level after 6 months, 1 year, and 2 years. Postsurgical clinical and radiographic measurements were statistically significantly different from presurgical measurements. The rate of bone fill was positively associated with the baseline depth of the bone defect but not associated with the width. The noncontained infrabony defects treated with this combined regenerative method improved clinically and radiographically.

Relationship between non-alcoholic fatty liver disease and periodontal disease: a review and study protocol on the effect of periodontal treatment on non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease that is prevalent worldwide. Non-alcoholic steatohepatitis (NASH) is an advanced form of NAFLD and carries the risk of progression from hepatic inflammation and fibrosis to cirrhosis and hepatocellular carcinoma. Pathological mechanisms of NAFLD have been proposed, such as the two-hit hypothesis and the multiple parallel hit hypothesis. Periodontal disease is a chronic infectious disease of the tissues surrounding the teeth that result in tooth loss. Several reports have indicated that periodontal infection is related to NAFLD. NAFLD and periodontal disease are chronic inflammatory conditions that are known as ‘silent diseases’. Therefore, both conditions need to be detected early and treated under collaborative medical and dental care in order to prevent progression to NASH. For this purpose, further investigations in humans on the relationship between NAFLD and periodontal disease and on the effect of periodontal treatment on NAFLD are necessary. In this paper, studies on the relationship between NAFLD and periodontal disease are reviewed and a clinical study investigating the effect of periodontal treatment on NAFLD is introduced. Introduction Several studies in recent years have reported on the relationship between systemic disease and periodontal disease [1,2]. It has been reported that chronic periodontal disease is related to conditions, such as diabetes mellitus (DM), atherosclerosis and heart disease [3-6]. We have previously reported that infection with periodontal pathogens is associated with the progression of atherosclerosis [7]. Fatty liver disease, which is one of the causes of atherosclerosis [8,9], includes non-alcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD) [10]. NAFLD (in which fat accumulates in the liver without a history of drinking or immune system disease) has gained attention worldwide. NAFLD includes simple steatosis and nonalcoholic steatohepatitis (NASH), which is characterized by a chronic and progressive liver pathology [11]. The prevalence of NAFLD in the American general adult population is 10%-40% and that of NASH is approximately 2%-5% [12]. Recent animal and human investigations have indicated that NAFLD/NASH is related to periodontal disease [13,14]. As patients with liver or periodontal disease have few subjective and early symptoms, the diseases are often severe when they are discovered at medical institutions. [15,16]. Therefore, early detection and treatment under collaborative medical and dental care is important to prevent progression to NASH, which may then develop into cirrhosis or liver cancer. Further investigations in humans on the relationship between NAFLD and periodontal disease and on the effect of periodontal treatment on NAFLD are desired. This paper reviews studies on NAFLD and periodontal *Correspondence to: Dr. Chieko Kudo, DDS, PhD, Lecturer, Division of Periodontology, Department of Oral Function and Restoration, Graduate School of Dentistry, Kanagawa Dental University, 82 Inaoka-cho, Yokosuka, Kanagawa 238-8580, Japan, Tel: +81-46-822-8855; E-mail: kudo@kdu.ac.jp

Ultrastructural Changes of Single Cilia in the Junctional Epithelium Following Application of Protease.

付着上皮は外的要因に対して生体防御機構を示すことが知られているが, 炎症の初期段階における細胞応答に関して不明な点が多い。そこで従来より他の器官・組織でその存在が報告され, 感覚もしくは化学受容器と類推されている孤立線毛に着目し, 健康な付着上皮と炎症初期における付着上皮中の孤立線毛の動態を形態学的に観察し, 付着上皮の機能解明を試みた。ラットの上頸右側第1臼歯口蓋側歯肉溝に細菌性プロテアーゼを塗布し, 初期炎症を惹起させたものを実験群として用いた。対照群として, 上頸左側第1臼歯口蓋側歯肉溝に生理食塩水を塗布したものを用いた。実験期間は, 塗布1, 3, 5日間とし, それぞれ電子顕微鏡にて観察した。観察対照部位は付着上皮及び歯肉溝上皮とした。その結果, 付着上皮において対照群では孤立線毛の分布は全層にわたって認められたが, 実験群では漸次消失した。また歯肉溝上皮では対照群と実験群では差異は認められなかった。以上の結果より対照群と実験群では, 孤立線毛の分布に差異が認められた。これらのことから孤立線毛が感覚受容器もしくは化学受容器として初期炎症に何らかの関係を有していることが示唆された。

[The implantation of hydroxyapatite and tricalcium phosphate in periodontal osseous defects in dogs--histological study].

歯周外科治療に数多く使用されているHydroxyapatite顆粒 (HAP) と, Tricalcium phosphate顆粒 (TCP) を移植し, 歯周組織との経時的反応の差異を知る目的で実験を行なった。実験には雑種成犬18頭を用い, 下顎骨臼歯部に形成した3壁性人工的骨欠損に移植手術を施行後, 3日から3ヵ月の期間について組織学的観察および計測を行なった。今回は特に骨組織の反応を中心に, 類骨や根面側の形態に注目して行なった。その結果HAPは骨組織中の核となって残存する一方, TCPはマクロファージの貪食により吸収され, 骨組織と置換することがわかった。骨再生量やOsteoidについても, 術後2週, および3週といった期間では, その量や形成パターンに差異が認められた。また根面側の影響については対照群で差異が認められたが, 両移植群には認められなかった。以上の結果より両移植材料共に骨移植材として使用し得る材料であるが歯周領域に応用する際には, この相違を考慮し, 症例により選択的に使用することが望ましいと考えられた。

Imaging technologic study of periodontal disease 2. Effect of K.V. and density change on the Wiener spectrum.

画像上の骨変化に関する最大情報量を得る為の適切な撮影条件を決定する為に, ウィーナースペクトル法に直接影響を及ぼすであろうと考えられる管電圧及び, 濃度依存性について基礎実験を行った。実験は, 規格撮影された人体摘出下顎骨のX線写真を使用し, 管電圧及び, 写真濃度を変化させた時のウィーナースペクトルの変化につい、て検討を行った。結果として, ウィーナースペクトルは, 管電圧よりも写真濃度に影響を受けることがわかった。特にその影響は, 骨梁成分を示す空間周波数0～5LP/mmよりも, ノイズ成分を示す高周波領域5～25LP/mmにおいて大であった。