Journal of Osaka Dental University
Online ISSN : 2189-6488
Print ISSN : 0475-2058
ISSN-L : 0475-2058
Volume 38 , Issue 1
Showing 1-10 articles out of 10 articles from the selected issue
  • Kazuyo Yamamoto, Koichiro Suzuki, Sayaka Suwa, Hidehiko Miyaji, Kazuhi ...
    Type: Article
    2004 Volume 38 Issue 1 Pages 1-5
    Published: 2004
    Released: December 08, 2016
    JOURNALS FREE ACCESS
    Self-etching primers that treat both enamel and dentin have recently been developed. We evaluated the in vitro bond strength of two self-etching primer adhesive systems that bond to enamel and dentin : UniFil Bond/UniFil F (GC Inc., Tokyo, Japan) and Fluorobond/Beautifil (Shofu Inc., Kyoto, Japan). The facial surfaces of bovine incisors were ground with wet SiC paper up to 600 grit to prepare flat bonding surfaces on either enamel or dentin. The adhesive systems were applied according to the manufacturer's instructions, with an additional 15 seconds of phosphoric acid etching on the enamel. The tensile bond strengths were determined at a cross head speed of 0.3 mm/min after immersion in water at 37℃ for one day, and thermocycling between 5℃ and 55℃ in water 5,000 times. The bond strength to dentin was satisfactory for both systems. However, although the bond strength to enamel was not durable, it was improved with phosphoric acid etching. These results suggest that enamel etching with phosphoric acid is recommended when using these self-etching primer adhesive systems. (J Osaka Dent Univ 2004 ; 38 : 1-5.)
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  • Yasuo Nishikawa, Kazuhiro Tanaka, Kenji Uchihashi, Yuichi Shoju, Hiros ...
    Type: Article
    2004 Volume 38 Issue 1 Pages 7-15
    Published: 2004
    Released: December 08, 2016
    JOURNALS FREE ACCESS
    It is thought that information from deep-pain sensations in the lingual muscle projects to the brainstem through the hypoglossal nerve. We investigated the distribution of nociceptive neurons responding to electrical stimulation of the hypoglossal afferent nerve supplying the lingual muscle in the caudal medulla oblongata and the thalamus of a cat anesthetized with urethane and chloralose, using glass capillary microelectrodes filled with 2% pontamine sky blue in 0.5 M sodium acetate. The extracellular activity of single neurons was obtained from the subnucleus reticularis ventralis (SRV) in the caudal medulla oblongata, and the nucleus centralis lateralis (CL) in the thalamus. The SRV and CL neurons excited by chemical and noxious mechanical stimulation of the lingual muscle, regularly responded to electrical and mechanical stimulation of other parts of the maxillofacial areas in addition to the lingual muscle. This suggests that sensory information from the lingual muscle is transmitted to the central nervous system through the hypoglossal nerve, and clarifies that this sensory information includes lingual muscle pain. In the caudal area of the medulla oblongata, sensory information from the lingual muscle primarily projects to the SRV, while some ascends to the CL. Therefore, sensory information from the lingual muscle, in particular, deep-pain sensation from the lingual muscle, is sent directly to the CL via the SRV or indirectly through the brainstem reticular formation. (J Osaka Dent Univ 2004 ; 38 : 7-15.)
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  • Kazuyo Yamamoto, Masanori Omae, Kazushi Yoshikawa, Masayuki Kawamoto, ...
    Type: Article
    2004 Volume 38 Issue 1 Pages 17-22
    Published: 2004
    Released: December 08, 2016
    JOURNALS FREE ACCESS
    We compared the bond strength of composite resin to ground dentin and to Er : YAG laser irradiated dentin using three types of dentin adhesive systems : Single Bond, which is an acid etch/wet bonding agent, Clearfil Megabond, which is a self-etching/bonding agent, and Reactmerbond, which is an all in one self-etching bonding agent. Tensile bond strength was measured with and without thermocycling (TC). The mean and standard deviation of the tensile bond strength in MPa with and without thermocycling were : for the Ground Group was 14.1 (2.8)/13.2 (2.9) for Single Bond, 28.5 (4.6)/22.7 (4.2) for Megabond, and 9.5 (2.3)/8.1 (2.3) for Reactmerbond. For the Laser Irradiation Group it was 6.6 (1.4)/6.4 (2.6) for Single Bond, 5.2 (1.8)/4.8 (2.3) for Megabond, and 5.6 (1.0)/5.5 (1.5) for Reactmerbond. The tensile bond strengths for the laser treatment groups were significantly less than for the ground groups. We concluded that Er : YAG laser irradiated dentin is unsuitable for adhesion of composite resin. (J Osaka Dent Univ 2004 ; 38 : 17-22.)
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  • Yukiko Hata, Fumihiko Suwa, Hisao Imai
    Type: Article
    2004 Volume 38 Issue 1 Pages 23-29
    Published: 2004
    Released: December 08, 2016
    JOURNALS FREE ACCESS
    It has been reported that more than 90% of diabetes mellitus (DM) patients in Japan suffer from the type II variety of the disease. Many studies have been conducted on the relationship between DM and periodontal disease. However, only a very few have focused on the morphological investigation of the epithelium in a type II diabetic rat model. When we investigated and compared morphological changes in the gingival epithelium of both normal and type II diabetic rats, we found that development of the epithelial ridge was poor in the type II animals. We concluded that this epithelium might be very weak to external stimuli. (J Osaka Dent Univ 2004; 38: 23-29.)
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  • Isao Tamura, Toshio Sakaki, Tetsunari Nishikawa, Yoshihito Tanaka, Sei ...
    Type: Article
    2004 Volume 38 Issue 1 Pages 31-36
    Published: 2004
    Released: December 08, 2016
    JOURNALS FREE ACCESS
    We investigated expression of early growth response (EGR)-1 and EGR-2 in human periodontal ligament fibroblasts (PLFs). After cultivating PLFs in Dulbecco's modified Eagle's medium (DME) for two days without 10% fetal calf serum (FCS), we incubated them in DME supplemented with FCS for 15, 30, 45, 60 and 120min. 5-bromo 2'-deoxyuridine incorporation showed a peak in the PLFs treated for 45 min. Expressions of EGR-1 protein and mRNA were seen beginning 15 min after treatment. EGR-1 protein gradually increased during this period. Anti-EGR-1 antibody strongly reacted with the nuclear region at 30 min. Maximum expression of EGR-2 protein was seen at 30 min, and it was localized in and around the nucleus. Expression of EGR-2 mRNA showed a peak at 15 min. These results demonstrate that EGR expression is more pronounced in FCS-stimulated PLFs, that it localizes in the cytoplasm of resting cells, and that the expression is translocated to the nuclei upon FCS stimulation. EGR plays a potentially important role in PLF growth. (J Osaka Dent Univ 2004 ; 38 : 31-36.)
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  • Mansjur Nasir, Masatoshi Ueda, Takayoshi Tsubai, Chizuko Ogata, Takeo ...
    Type: Article
    2004 Volume 38 Issue 1 Pages 37-40
    Published: 2004
    Released: December 08, 2016
    JOURNALS FREE ACCESS
    Observation of gingival color has been a popular area of dental research. However, it is difficult to analyze for other than the most basic conditions and colors. We introduce here a new alternative method that uses image analysis to measure gingival color. We examined 30 female students for this research. Digital images were acquired to compare the gingival color with a bite holder and a standard color scale. The images were input to a computer and the curves dialog box was used for color adjustment. It allows adjustment of the entire tonal range of an image. The system of digital capture and comparison of color images separates and analyzes three channels for the free and attached gingival surface images, and matches them with colorimetric scales. Analysis showed that the attached gingiva had a more vivid red and yellow compared with the free gingiva. We concluded that this system may be useful for demonstrating the diversity of gingival color as well as for analyzing gingival health. (J Osaka Dent Univ 2004; 38: 37-40.)
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  • Hideo Mukunoki, Kenji Uchihashi, Yasuo Nishikawa
    Type: Article
    2004 Volume 38 Issue 1 Pages 41-52
    Published: 2004
    Released: December 08, 2016
    JOURNALS FREE ACCESS
    We examined the influence of transforming growth factor (TGF)-β1 on the cells cell-cell interaction of submandibular gland cells, with particular emphasis on the regulation of junctional complex formation. Male Wistar rats weighing 250-280 g were used. Tight junctional permeability was detected cytochemically using microperoxidase as a tracer. The distribution of TGF-β1, TGF-β type II receptor and junctional proteins were observed immunocytochemically. The granular convoluted tubule (GCT) cells were intensely immunoreactive for TGF-β1. In contrast, both granule depletion and immunoreactive reduction were induced by isoprenaline stimulation. In unstimulated cells, TGF-β type II receptor immunoelectron staining was detected on both the apical and basolateral cellular membrane of the acinar cells. The cytochemical tracer test showed that isoprenaline stimulation increased tight junctional permeability in both acinar and duct cells. Treatment of the basolateral membrane with TGF-β1 led to enhancement of tight junctional permeability and breakdown of the junctional complex in both the tight and adherens junctions. However, breakdown in the tight junctional complex was not seen in the cells with isoproterenol stimulation of the gland. These results suggest that assembly of the intercellular junction in the rat submandibular gland acinar cells may be affected by TGF-β1 induced by paracrine action of GCT cells. (J Osaka Dent Univ 2004; 38: 41-52.)
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  • Kayoko Hashimoto, Yasushi Sakuma, Junichiro Kotani
    Type: Article
    2004 Volume 38 Issue 1 Pages 53-59
    Published: 2004
    Released: December 08, 2016
    JOURNALS FREE ACCESS
    Although paclitaxel is an effective anticancer drug for treatment of gynecologic cancer, it is associated with peripheral neuropathy. Using a rat model of continuous administration of paclitaxel directly to the sciatic nerve (paclitaxel model), we investigated the mechanism of neuropathic pain by histologically examining the sciatic nerve. Male Sprague-Dawley rats were divided into six groups : the local administration group consisting of the paclitaxel group and the saline group ; the systemic administration group consisting of the 4 mg/kg paclitaxel group, the 8 mg/kg paclitaxel group, and the saline group ; and the control group. One, two, three and four weeks after surgery, sciatic nerve sections were prepared and observed under a light microscope. In addition, the number of myelinated nerve fibers per unit area was calculated, and the ratios of small-diameter to largediameter nerve fibers were compared.
    The local paclitaxel group showed features of segmental demyelination, such as a marked decrease in large-diameter myelinated nerve fibers, thinning and destruction of myelin sheaths, and atrophy of axons. These changes were caused by the direct action of paclitaxel on the nerve, indicating that the paclitaxel model is an animal model of segmental demyelination. (J Osaka Dent Univ 2004; 38: 53-59.)
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  • Masahiro Yamamoto
    Type: Article
    2004 Volume 38 Issue 1 Pages 61-71
    Published: 2004
    Released: December 08, 2016
    JOURNALS FREE ACCESS
    I analyzed the mechanical profile of movement of the human maxillary first molar when orthodontic forces were applied in various directions. A three-dimensional finite element model of the tooth and alveolar bone was developed to perform linear static finite element analysis. Force was applied to the crown of this model from the lingual, buccal, mesial, and distal, and the stress distributions in the alveolar bone were determined and compared.
    When force was applied from various directions, the maxillary first molar exhibited the following movement patterns. When force was applied to the lingual of the crown from the lingual direction, the tooth moved in a mesiobuccal direction. When it was applied to the buccal of the crown from the buccal direction, the tooth moved in a mesiolingual direction, with the magnitude of the mesial component being smaller than the lingual component. When force was applied to the mesial of the crown from the mesial direction, the tooth moved in a distobuccal direction. When force was applied to the distal of the crown from the distal direction, the tooth moved in a mesial direction. When force was applied to the lingual of the crown from the lingual direction, the stress on the alveolar bone on the compressed side was greater than when the force was applied to the buccal of the crown from the buccal direction. When force was applied to the mesial of the crown from the mesial direction, the stress on the alveolar bone on the compressed side was greater than when the force was applied to the distal of the crown from the distal directon.
    These results suggest that when orthodontic force is applied to the human maxillary first molar, the direction of loading and the direction of movement may vary as a result of the complex root morphology, and that pressure on the alveolar bone may also vary. (J Osaka Dent Univ 2004; 38: 61-71.)
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  • Seung-Goo Kang, Tatsuo Kawamoto
    Type: Article
    2004 Volume 38 Issue 1 Pages 73-81
    Published: 2004
    Released: December 08, 2016
    JOURNALS FREE ACCESS
    Persistent problems involving the tongue, especially the root of the tongue, are often encountered in clinical orthodontics. We devised a method of measurement referred to as the perpendicular line passing upward from the hyoid bone to the palatal plane (PHP), which locates the root of the tongue in the oral cavity. We investigated the influence of the location of the tongue root in the oral cavity on denture and skeletal patterns in 51 adult Japanese females. Our results revealed that the greater the PHP value, the greater was the incidence of open bite with accompanying tongue thrust, and the greater was the probability that the person would be classified as having Angle Class Ⅰ bimaxillary protrusion. Conversely, the more negative the PHP value, the greater was the incidence of deep bite. These results indicate that location of the tongue root is closely related to the status of the maxillary and mandbular anterior teeth, and has a strong correlation with overbite. We therefore think that evaluation of the location of the tongue root using PHP values can contribute to determination of the appropriate orthodontic treatment of problems that are related to the tongue.
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