Naoto Yoshinuma

Salivary microbial levels in relation to periodontal status and caries development

BACKGROUND AND OBJECTIVE Although an inverse relationship between caries and periodontal disease has been suggested, some studies have reported a positive correlation between periodontal disease and the decayed, missing and filled teeth (DMF) index. The aim of the present study was to examine the relationship between caries and periodontal disease. MATERIAL AND METHODS We assessed the clinical parameters and salivary levels of Porphyromonas gingivalis and Streptococcus mutans using real-time polymerase chain reaction in 40 subjects with varying degrees of caries and periodontal disease. RESULTS The salivary levels of S. mutans were significantly higher in the periodontally healthy group than in the periodontitis group. The salivary levels of P. gingivalis were significantly higher in the caries-free group than in the periodontally healthy group with caries. The salivary levels of S. mutans were significantly increased after the initial periodontal treatment. CONCLUSIONS This study showed that an inverse relationship exists between periodontitis and caries in terms of the clinical and bacteriological findings.

Detection of Streptococcus anginosus from saliva by real-time polymerase chain reaction

Aims: The purpose of the present investigation was to assess the salivary levels of Streptococcus anginosus in periodontitis patients.

The effect of butyric acid on adhesion molecule expression by human gingival epithelial cells

BACKGROUND AND OBJECTIVE Short-chain fatty acids, such as butyric acid, are detected in periodontal pockets and are thought to be involved in the initiation and progression of periodontal disease. In the present study, we examined the effects of butyric acid on adhesion molecule expression by human gingival epithelial cells. MATERIAL AND METHODS The human gingival carcinoma cell line, Ca9-22, was cultured in media that contained different concentrations of butyric acid. RESULTS Cell numbers were significantly decreased in a dose-dependent manner by butyric acid at concentrations of > or = 0.2 mM. The expression of intercellular adhesion molecule-1 mRNA was significantly increased 6 h after stimulation. By contrast, the expression levels of integrins alpha 6 and beta 4 were decreased. Similar results were obtained by flow cytometry. CONCLUSION The results of the present study indicate that butyric acid alters the expression of adhesion molecules by Ca9-22 cells. The elucidation of the mechanism of action of butyric acid on the periodontium may help to clarify several aspects of the onset and progression of periodontal disease.

Nicotine-induced expression of low-density lipoprotein receptor in oral epithelial cells.

Background Nicotine use is one of the most important risk factors for the development of cardiovascular and periodontal diseases. Numerous reports have suggested the possible contribution of disturbed lipid metabolism for the development of both disease groups. Despite these observations, little is known about the relationship between tobacco smoking and the development of these diseases. Our previous microarray data revealed that nicotine induced low-density lipoprotein receptor (LDLR) expression in oral epithelial cells (OECs). The aim of the present study was to confirm nicotine-mediated LDLR induction and to elucidate the signaling mechanisms leading to the augmented expression of LDLR in OECs. Methods and Results LDLR and nicotinic acetylcholine receptor (nAChR) subunit expression was detected by real-time PCR. The production of LDLR was demonstrated by immunofluorescence staining. nAChR-mediated LDLR induction was examined by pre-incubation of the cells with its specific inhibitor, α-bungarotoxin (α-BTX). The functional importance of transcription factor specific protein 1 (Sp1) was examined by luciferase assay, mithramycin pre-incubation or by small interfering RNA (siRNA) transfection. The specific binding of Sp1 to R3 region of LDLR 5’-untranslated region was demonstrated with electrophoretic mobility shift assay (EMSA) and streptavidin-agarose precipitation assay followed by western blotting. The results confirmed that nicotine induced LDLR expression at the transcriptional level. Nicotine was sensed by nAChR and the signal was transduced by Sp1 which bound to the R3 region of LDLR gene. Augmented production of LDLR in the gingival epithelial cells was further demonstrated by immunofluorescence staining using the gingival tissues obtained from the smoking patients. Conclusions Taken together, the results suggested that nicotine might contribute to the development of both cardiovascular and periodontal diseases by inducing the LDLR in OECs thereby disturbing lipid metabolism.

Periodontal regeneration with 0.3% basic fibroblast growth factor (FGF-2) for a patient with aggressive periodontitis: a case report

This case report describes the clinical efficacy of treatment with basic fibroblast growth factor (FGF-2) for periodontal regeneration. A patient with aggressive periodontitis participated in a clinical trial involving administration of 0.3% FGF-2 in comparison with a placebo control. To evaluate the efficacy of FGF-2, standardized radiographs were taken before surgery and at 12, 24, and 36 weeks after FGF-2 treatment. The rate of increase in alveolar bone height was 86.9% at 36 weeks. The 6-year postoperative radiograph showed significant development of alveolar bone in comparison with the first visit. FGF-2 treatment may be effective for periodontal regeneration in cases of aggressive periodontitis. (J Oral Sci 58, 137-140, 2016).

The effect of B vitamin supplementation on wound healing in type 2 diabetic mice

The aim of this study was to test the effects of B-group vitamin supplements on wound healing in diabetic mice. The mice in the experimental group were treated daily with 1 g/L B6, 1.25 mg/L B12, and 62.5 mg/L folic acid in their drinking water. Full-thickness excision wounds were created with 6-mm skin biopsy punches. Each wound closure was digitally photographed. Beginning on day 3 after wounding, the wound area in the diabetic mice was statistically larger than that of normal mice (p<0.05 vs diabetic mice). The diabetic mice treated with B vitamins displayed accelerated wound closure on day 3 (wound area 42.8 ± 11.3%, p<0.05). On day 9 after wounding, the wound area in the diabetic mice was also statistically larger than that of normal mice (p<0.05 vs diabetic mice). The diabetic mice treated with B vitamins displayed accelerated wound closure on day 3 (wound area 13.2 ± 16.8%, p<0.05). In addition, the high glucose level in the diabetic animals decreased significantly in response to B vitamin treatment. In conclusion, the results of this study indicate that B vitamin supplementation may improve wound healing in diabetic mice.

Effects of Minocycline-HCl Paste on Human Dentin Surfaces.

歯周疾患に対して, スケーリング, ルートプレーニングに代表される機械的プラークコントロールが行われている。近年, 化学的プラークコントロールの効果が着目され, 臨床で多く行われている。化学的プラークコントロールのひとつとして, 抗生物質の局所投与剤である塩酸ミノサイクリンペーストが臨床で応用されている。細菌学的効果および臨床パラメーターの改善について多くの報告がなされているが薬剤が接するであろう歯根表面への影響を検討した報告は見あたらない。そこで, 歯根面に対する塩酸ミノサイクリンペーストの影響をin vitroで検討することを目的とした。ヒト抜去歯から象牙質試片を切り出し, 濃度の異なる塩酸ミノサイクリンペースト溶液に順次浸漬され, その表面性状の変化と細胞親和性を知る目的で試片上でヒト歯根膜細胞を培養し, 走査型電子顕微鏡で観察した。なお, コントロールは, リン酸緩衝液で処理を行った。コントロール群に比較して塩酸ミノサイクリン処理群の試片は, スメヤー層が除去され, 歯根膜細胞の付着が多く認められた。また, 細胞が付着した状態で塩酸ミノサイクリンペーストを用いたことを想定して付着細胞に対して培養液中50μg/ml濃度になるように塩酸ミノサイクリンペースト溶液を添加し24時間培養した。しかし, 細胞増殖に対する著明な効果は認められなかった。以上の結果から化学的プラークコントロールを併用することにより, 象牙質表面のスメヤー層が除去され, 細胞が付着しやすい環境を作ることが示唆された。