Publications (28) View all
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Article: Gingival vascular functions are altered in type 2 diabetes mellitus model and/or periodontitis model.
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ABSTRACT: The association of vascular reactivity between diabetes and periodontal disease has not been clarified. Gingival blood flow was measured by laser Doppler flowmetry for 31 weeks in Wistar rats, Wistar rats orally challenged with Porphyromonas gingivalis (Wistar rats + Porphyromonas gingivalis), Goto-Kakizaki rats, and Goto-Kakizaki rats orally challenged with Porphyromonas gingivalis (Goto-Kakizaki rats + Porphyromonas gingivalis). Effects of alveolar bone resorption on periodontal tissue was enhanced in Wistar rats + Porphyromonas gingivalis, and Goto-Kakizaki rats, with this effect being significantly enhanced by Goto-Kakizaki rats + Porphyromonas gingivalis. Using the L-band electron spin resonance technique, we succeeded in measuring oxidative stress as decay rate constant (K(1) and K(2)) of 3-carbamoyl-2,2,5,5-tetramethylpyrrolidin-1-yloxy in the oral and maxillofacial region of the animal models. The decay rate constant (K(1)) of 3-carbamoyl-2,2,5,5-tetramethylpyrrolidin-1-yloxy was significantly greater in the oral and maxillofacial region of Goto-Kakizaki rats + Porphyromonas gingivalis compared to Wistar rats, Wistar rats + Porphyromonas gingivalis and Goto-Kakizaki rats groups. Gingival reactive hyperemia was attenuated by periodontal disease, and this effect was also remarkable in the diabetes mellitus model. Taken together, we found that vascular endothelial function was decreased in diabetes mellitus and/or periodontal disease animal models due to increasing oxidative stress in the gingival circulation.Journal of Clinical Biochemistry and Nutrition 09/2012; 51(2):108-13. · 1.98 Impact Factor -
Article: Dental resin curing blue light induced oxidative stress with reactive oxygen species production.
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ABSTRACT: Dental resin curing blue light has been used in the treatment of tooth bleaching and to restore teeth with resin-based composite fillings. However, there has been little consideration of its effect on oral tissues such as dental pulp and oral mucosa. The aim of this study was to investigate whether dental resin curing blue light irradiation affects the dental pulp, especially the blood vessels that are known as the first target of reactive oxygen species (ROS), which play an important role in vascular reactivity. We found that blue light irradiation increased the level of lipid peroxidation in isolated rat aorta blood vessels by measuring malondialdehyde. Furthermore, cell proliferative activity was decreased in a time-dependent manner and apoptosis of human aorta vascular smooth muscle cells (VSMCs) was induced. These results indicated that (ROS) such as hydrogen peroxide and hydroxyl radicals were generated in VSMCs by irradiation with blue light, and they induced cytotoxicity associated with oxidative stress, which increased lipid peroxidation and apoptosis. In addition, N-acetyl-l-cysteine, which is a typical intracellular antioxidant, protected VSMCs against cytotoxicity associated with oxidative stress. These findings suggested that antioxidants may be used to prevent oxidative stress in dental pulp by repeated and/or multiple treatments with blue light irradiation in future dental treatments.Journal of photochemistry and photobiology. B, Biology 05/2012; 114:73-8. · 1.87 Impact Factor -
Article: ESR investigation of ROS generated by H2O2 bleaching with TiO2 coated HAp.
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ABSTRACT: It is well known that clinical bleaching can be achieved with a solution of 30% hydrogen peroxide (H2O2) or H2O2/titanium dioxide (TiO2) combination. This study examined the hypothesis that TiO2 coated with hydroxyapatite (HAp-TiO2) can generate reactive oxygen species (ROS). ROS are generated via photocatalysis using electron spin resonance (ESR). The bleaching properties of HAp-TiO2 in the presence of H2O2 can be measured using hematoporphyrin litmus paper and extracted teeth. We demonstrate that superoxides (O2(•-)) and hydroxyl radicals (HO(•)) can be generated through excitation of anatase TiO2, rutile TiO2, anatase HAp-TiO2, and rutile HAp-TiO2 in the presence of H2O2. The combination of R HAp-TiO2 with H2O2 produced the highest level of HO(•) generation and the most marked bleaching effects of all the samples. The superior bleaching effects exhibited by R HAp-TiO2 with H2O2 suggest that this combination may lead to novel methods for the clinical application of bleaching treatments.Dental Materials Journal 05/2012; 31(3):458-64. · 1.14 Impact Factor -
Article: Assessments of salivary antioxidant activity using electron spin resonance spectroscopy.
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ABSTRACT: In recent years, the function of saliva has been focused on evaluation of general status. The relationship between salivary antioxidant activity and periodontal disease progression is unclear. The aim of this study is to assess the relationship between periodontal disease and salivary antioxidant activity towards various reactive oxygen species (ROS) using electron spin resonance (ESR) technique. We demonstrated that whole saliva derived rats or human subjects scavenged ROS such as superoxide (O(2)(·-)) and hydroxyl radical (HO(·)) using ESR spectroscopy with spin trapping agent. In addition, we assessed the relationship between antioxidants activity towards ROS and periodontal index with superoxide dismutase (SOD) activity in human subject saliva. Antioxidant activity towards O(2)(·-) was increased by Porphyromonas gingivalis (P. gingivalis) infection in rat, although antioxidant activity towards HO(·) was not changed. In human, a strong correlation (r = 0.88, p < 0.01) recognized between salivary antioxidant activity towards O(2)(·-) and probing pocket depth (PPD). In addition, the intensity of salivary antioxidant activity depended on SOD activity level. SOD activity was also correlated with PPD. Rat salivary antioxidant activity towards O(2)(·-) was up-regulated by the inflammatory response caused by P. gingivalis infection. Similar response was recognized in human saliva with periodontal index. Additionally, a linear correlation between antioxidant activity towards O(2)(·-) and SOD activity was verified by ESR technique. Therefore, evaluation of the salivary antioxidant activity towards O(2)(·-) might be an effective parameter for the objective assessment of periodontal disease progression.Archives of oral biology 01/2012; 57(6):654-62. · 1.65 Impact Factor -
Article: Soft-food diet induces oxidative stress in the rat brain.
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ABSTRACT: Decreased dopamine (DA) release in the hippocampus may be caused by dysfunctional mastication, although the mechanisms involved remain unclear. The present study examined the effects of soft- and hard-food diets on oxidative stress in the brain, and the relationship between these effects and hippocampal DA levels. The present study showed that DA release in the hippocampus was decreased in rats fed a soft-food diet. Electron spin resonance studies using the nitroxyl spin probe 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl directly demonstrated a high level of oxidative stress in the rat brain due to soft-food diet feeding. In addition, we confirmed that DA directly react with reactive oxygen species such as hydroxyl radical and superoxide. These observations suggest that soft-food diet feeding enhances oxidative stress, which leads to oxidation and a decrease in the release of DA in the hippocampus of rats.Neuroscience Letters 12/2011; 508(1):42-6. · 2.11 Impact Factor
