フッ化ジアミンシリケートの象牙質知覚過敏症治療剤への応用―抜去歯を用いた象牙細管封鎖能の検討―

Diamine silver fluoride (Saforide^[ !R]) is used clinically to prevent the progress of dental caries and desensitize hypersensitive teeth. Unfortunately, diamine silver fluoride stains teeth black due to silver precipitation; therefore, it is mainly applied to deciduous teeth. To overcome this drawback, ammonium hexafluorosilicate(SiF:(NH_4)_2SiF_6)was prepared. Silica was employed instead of silver because it does not change the color of teeth, and is well known to induce apatite formation from simulated body fluids. The purpose of this study was to evaluate the occluding ability and duration of dentin tubule occlusion after SiF treatment in a simulated oral environment. The occluding ability of SiF was evaluated using human dentin disks. The surface of dentin disks was observed with a scanning electron microscope (SEM)immediately after SiF treatment and 7 days after immersion in synthetic saliva. SEM observation showed that open dentin tubules were occluded completely with silica-calcium phosphate precipitate immediately after SiF treatment. In addition, newly formed crystals covered the dentin surface 7 days after immersion in synthetic saliva. EDXA analysis showed that the precipitate formed in the dentin tubules after SiF treatment contains silica, calcium and phosphorous indicating silica-calcium phosphate complex. The Ca/P molar ratio of the precipitate formed with SiF treatment was 2.02, and the value gradually decreased after immersion in synthetic saliva. In contrast, the Ca/P molar ratio of newly formed crystals at the dentin surface showed a relatively constant value(Ca/P=1.16-1.28)throughout the experimental period. It seems that calcium-deficient apatite may be precipitated at the dentin surface due to the Ca/P ratio being significantly lower than that of intertubular dentin. SiF treatment induced calcium phosphate precipitation from synthetic saliva; therefore, it has a continuous effect on dentin tubule occlusion under a simulated oral environment.

フッ化ジアンミン銀(サホライド^[○!R])は,齲蝕進行抑制剤および象牙質知覚過敏症治療剤として臨床で使用されている.しかしながら,フッ化ジアンミン銀は塗布後に銀の沈着による歯の黒変が起こる.したがって,フッ化ジアンミン銀は主に乳歯に使用されている.この欠点を改良するために,フッ化ジアミンシリケートを調製した.銀の代わりにシリカを導入した理由は,シリカは歯質の変色を起こさないこと,そして擬似体液からアパタイトの生成を誘導するからである.本研究の目的はヒト口腔内を模倣した環境下において,フッ化ジアミンシリケート処理後の象牙細管封鎖効果と持続性を評価することである.フッ化ジアミンシリケートの象牙細管封鎖効果は,ヒト抜去歯を用いて評価を行った.フッ化ジアミンシリケート処理直後および人工唾液浸漬7日後の象牙質プレートの表面を,走査電子顕微鏡(SEM)にて観察を行った.SEM観察の結果,開口象牙細管はフッ化ジアミンシリケート処理直後にはシリカ-リン酸カルシウム結晶により完全に封鎖されていた.さらに,人工唾液浸漬7日後には象牙質表面は新たに生成した結晶により覆われていた.EDXA分析によると,フッ化ジアミンシリケート処理直後に象牙細管内に析出した結晶はシリカ,カルシウム,リンを含有しており,シリカ-リン酸カルシウム結晶であることが明らかとなった.その結晶のカルシウムとリンのモル比はフッ化ジアミンシリケート処理直後には2.02であったが,人工唾液浸漬後には徐々に減少した.一方,象牙質表面に新たに生成した結晶は実験期間を通して,ほぼ一定の値(Ca/P=1.16∼1.28)であった.周囲の管間象牙質と比べて有意に低い値であることから,おそらくカルシウム欠損アパタイトが析出していると推察された.フッ化ジアミンシリケート処理は人工唾液中からリン酸カルシウムの析出を誘導し,したがって,ヒト口腔内を模倣した環境下において,持続的な象牙細管封鎖能を有することが明らかとなった.

The Japanese Journal of Conservative Dentistry


Soluble products from Eikenella corrodens induce cell proliferation and expression of interleukin-8 and adhesion molecules in endothelial cells via mitogen-activated protein kinase pathways

The periodontal vasculature is profoundly affected during the progression of periodontitis, and several specific bacteria are believed to be involved in this inflammatory disease. Eikenella corrodens is one of the common bacteria detected in periodontitis diseased lesions; however, the function of this organism in periodontitis is not well understood. In this study, we investigated the E. corrodens-induced endothelial cell alteration and inflammation process that leads to leukocyte infiltration in inflamed regions. Soluble products from E. corrodens (EcSP) induced the gene expression and protein production of vascular endothelial growth factor in oral epithelial cells and human umbilical vein endothelial cells (HUVEC). Direct stimulation by EcSP also activated endothelial cell proliferation. Moreover, EcSP induced ERK1/2 (p44/42) and p38 mitogen-activated protein kinase (MAPK) phosphorylation within 10-30 min in HUVEC, as demonstrated by Western blot analysis and up-regulated intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin and interleukin-8 (IL-8) production demonstrated by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. The specific p38 MAPK inhibitor SB203580 reduced the expression of ICAM-1, VCAM-1 and IL-8, whereas the blockade of p44/42 by MAPK kinase (MEK1) inhibitor, PD98059, inhibited only IL-8 expression. Our results indicate that E. corrodens can trigger a cascade of events that induce inflammatory responses in periodontal tissue via the MAPK cascade and may promote chronic periodontitis without bacteria-cell contact.


Proinflammatory effects of tumour necrosis factor-like weak inducer of apoptosis (TWEAK) on human gingival fibroblasts.

Tumour necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK), a member of the TNF family, is a multi-functional cytokine that regulates cellular proliferation, angiogenesis, inflammation and apoptosis. In this study, we investigated TWEAK expression in periodontally diseased tissues and the effect of TWEAK on human gingival fibroblasts (HGF). Reverse transcription-polymerase chain reaction (RT-PCR) analysis and immunohistochemistry revealed that TWEAK and the TWEAK receptor, fibroblast growth factor-inducible 14 (Fn14), mRNA and protein were expressed in periodontally diseased tissues. HGF expressed Fn14 and produced interleukin (IL)-8 and vascular endothelial growth factor (VEGF) production upon TWEAK stimulation in a dose-dependent manner. The IL-8 and VEGF production induced by TWEAK was augmented synergistically by simultaneous stimulation with transforming growth factor (TGF)-beta1 or IL-1beta. IL-1beta and TGF-beta1 enhanced Fn14 expression in a dose-dependent manner. Moreover, TWEAK induced intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) expression on HGF in a dose-dependent manner. The ICAM-1 expression induced by TWEAK was augmented by TGF-beta1. On the other hand, the TWEAK-induced VCAM-1 expression was inhibited by TGF-beta1. Phosphatidylinositol 3-kinase (PI3K) and nuclear factor-kappaB (NF-kappaB) inhibitor inhibit both ICAM-1 and VCAM-1 expression induced by TWEAK. However, mitogen-activated protein kinase (MEK) and c-Jun NH2-terminal kinase (JNK) inhibitor enhanced only VCAM-1 expression on HGF. These results suggest that TWEAK may be involved in the pathophysiology of periodontal disease. Moreover, in combination with IL-1beta or TGF-beta1, TWEAK may be related to the exacerbation of periodontal disease to induce proinflammatory cytokines and adherent molecules by HGF.


Cytokines differentially regulate ICAM-1 and VCAM-1 expression on human gingival fibroblasts.

The expression of intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) on human gingival fibroblasts (HGF) may be important for migration and retention of inflammatory cells in periodontally diseased tissue. This study aimed to assess which cytokines regulate ICAM-1 and VCAM-1 expression on HGF. Tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma enhanced both ICAM-1 and VCAM-1 expression on HGF. Interleukin (IL)-1beta mainly up-regulated ICAM-1 expression. On the other hand, IL-4 and IL-13 enhanced only VCAM-1 expression on HGF. IL-10 did not modulate both ICAM-1 and VCAM-1 expression. Transforming growth factor (TGF)-beta1 enhanced ICAM-1 expression. However, TGF-beta1 inhibited the VCAM-1 expression induced by TNF-alpha or IL-4. Both ICAM-1 and VCAM-1 expression by HGF was inhibited by nuclear factor-kappaB (NF-kappaB) activation inhibitor (MG-132). Mitogen-activated protein kinases (MAPK) inhibitors did not influence ICAM-1 expression induced by TNF-alpha. Interestingly, VCAM-1 expression was enhanced by MEK inhibitor (PD98059) and c-Jun NH2-terminal kinase (JNK) inhibitor (SP600125). These results mean that the balance of cytokines in periodontally diseased tissue may be essential for control of ICAM-1 and VCAM-1 expression on HGF, and the balance of ICAM-1 and VCAM-1 expression might be important for regulation of leucocytes infiltration and retention in periodontally diseased tissue.


Effect of ammonium hexafluorosilicate on dentin tubule occlusion for the treatment of dentin hypersensitivity

To evaluate the occluding ability of ammonium hexafluorosilicate (SiF). Dentin disks prepared from human extracted teeth were grouped as follows to prepare different situations of dentin hypersensitivity: (1) those sonicated for 20 minutes; (2) those treated with 0.5 mol/L EDTA for 2 minutes; (3) those treated with 6% citric acid for 2 minutes; (4) those treated with 50% citric acid for 2 minutes. Then, SiF or diamine silver fluoride (AgF) was applied to the dentin disks and the dentin tubule occlusion was observed with scanning electron microscopy (SEM). The percent of open tubules before and after SiF or AgF treatment were measured by NIH image using SEM photographs. Also, the dentin permeability was measured. SEM micrographs demonstrated that the dentin tubules were completely occluded by the precipitate after SiF treatment. Also, the dentin permeability was reduced to 10.3%. In contrast, most of the dentin tubules remained open after AgF treatment. EDXA analysis showed that the precipitate in the dentin tubules that forms after SiF treatment contains Si, Ca and P, indicating a silica-calcium phosphate complex.


Effects of plaque control on the patency of dentinal tubules-an in vivo study in beagle dogs

The aim of this in vivo study was to evaluate the effects of plaque control on the patency of dentinal tubules using vital teeth of beagle dogs. Class V cavities were prepared on the cervical areas of the mandibular and maxillary molars in each dog with a diamond point. To simulate the state of dentinal hypersensitivity, the teeth were etched with 50% citric acid for 2 minutes to obtain patent dentinal tubules. Plaque control was achieved by brushing the left-side teeth every day, whereas no plaque control was performed for the right-side teeth. A dentin biopsy was performed after 1, 2, and 3 weeks using the cylindrical diamond point to obtain dentin specimens. In the plaque control group, some of the dentinal tubules were occluded with precipitate (Ca/P=1.49), and the diameter of the dentinal tubules decreased from 2.42+/-0.33 microm (mean+/-SD) to 1.11+/-0.51 microm after 7 days, although most of the dentinal tubules remained open. In contrast, no precipitate was observed in the dentinal tubules of the non-plaque control group. Also, the diameter of the dentinal tubules increased from 2.42+/-0.33 to 2.9+/-0.49 microm, due to the demineralization of the peritubular and intertubular dentin. Plaque control plays a key role in reducing the patency of dentinal tubules and, therefore, might promote the natural repair of dentinal hypersensitivity.


Comparison of the occluding ability of dentinal tubules with different morphology between calcium phosphate precipitation method and potassium oxalate treatment

The aim of this study was to evaluate the occluding ability of calcium phosphate precipitation (CPP) method and potassium oxalate treatment when each method was applied to dentin disks with different surface morphology. Occluding ability was observed by scanning electron microscopy. Irrespective of the diameter of the dentinal tubules, the CPP method showed a consistent occluding ability for dentinal tubules at the dentin surface, and that the depths of the precipitate formed in the dentinal tubules by CPP method were not significantly different. In contrast, the occluding ability of potassium oxalate treatment was reduced with increasing diameter of the dentinal tubules. However, the reduction of the occluding ability of potassium oxalate treatment was more markedly affected by the demineralization of dentin surface. Since the CPP method showed a consistent occluding ability irrespective of the diameter of the dentinal tubules, it is suggested that the CPP method would be a useful means for treating dentin hypersensitivity.


Increase of CCL20 expression by human gingival fibroblasts upon stimulation with cytokines and bacterial endotoxin

We have demonstrated recently that CCL20 was expressed in periodontal diseased tissues and abundant CCR6 positive T cells infiltrated in periodontally diseased tissue. However, it is uncertain which cells can elicit CCL20 production. In the present study, we examined the properties of CCL20 production by human gingival fibroblasts (HGF) culture. Here, we report that interleukin-1 beta (IL-1beta), tumour necrosis factor-alpha (TNF-alpha) and Escherichia coli lipopolysaccharide (LPS) can significantly induce the production of CCL20 by HGF. We found that TNF-alpha and E. coli LPS enhanced the production of CCL20 by HGF treated with IL-1beta. In contrast, interferon-gamma (IFN-gamma) dramatically diminished CCL20 production induced by IL-1beta. Moreover, we demonstrated that nuclear factor-kappaB (NF-kappaB), p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinases (ERK) play an important role in mediating the production of CCL20 induced by IL-1beta and TNF-alpha. On the other hand, we found that not only NF-kappaB, p38 MAPK and ERK but also c-Jun NH2-terminal kinase (JNK) are involved in CCL20 production induced by E. coli LPS. Finally, we found that HGF express CCR6, CCL20 receptor, and CCL20 induced vascular endothelial growth factor (VEGF) by HGF. Taken together, these findings that HGF will be a source of CCL20 in periodontal tissue, and the CCL20 production will be controlled by proinflammatory cytokine and bacterial LPS in periodontally diseased tissue. Thus, CCL20 by HGF might be involved in inflammatory cells infiltration, and promote the progression of periodontal disease.


CXCL12 and CXCR4 expression by human gingival fibroblasts in periodontal disease

CXCL12 is a CXC chemokine that is related to lymphocyte infiltration and angiogenesis in inflammatory sites such as arthritis. However, the expression and roles of CXCL12 in periodontal disease are uncertain. The aim of this study was to assess the expression of CXCL12 and its receptor, CXCR4, in periodontal tissue and to investigate the properties of CXCL12 and CXCR4 expression by human gingival fibroblasts (HGF). RT-PCR analysis revealed that CXCL12 and CXCR4 mRNA were expressed in both normal gingival tissues and periodontal diseased tissues. Immunohistochemistry disclosed that CXCL12 was expressed and CXCR4 positive cells were found in both normal and periodontal diseased gingival tissues. Our in vitro experiments elucidated that HGF constitutively produced CXCL12, and the levels were enhanced by stimulation with tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), transforming growth factor-beta (TGF-beta), regulated upon activation normal T cell expressed and secreted (RANTES) and macrophage inflammatory protein 3(alpha) (MIP-3(alpha)). On the other hand, heat killed Porphyromonas gingivalis (P. gingivalis) and P. gingivalis LPS reduced the CXCL12 production by HGF. Flow cytometry analysis clarified that CXCR4 was highly expressed on HGF, and CXCR4 expression was abrogated by TNF-alpha, IFN-gamma and P. gingivalis LPS. Moreover, CXCL12 induced vascular endothelial growth factor (VEGF) production by HGF. Our results demonstrated that CXCL12 might be related to CXCR4+ cells infiltration and angiogenesis both in normal periodontal tissues and periodontal diseased tissue. P. gingivalis, a known periodontal pathogen, inhibits the production of CXCL12 and the expression of CXCR4 by HGF. This fact means that P. gingivalis may inhibit CXCR4+ cells infiltration and neovascularization in periodontal tissue and escape from the immune response.


Ammonium hexafluorosilicate increase acid resistance of bovine enamel and dentine

Although diamine silver fluoride (AgF: (NH3)2AgF) stains teeth black, it is known as a very effective agent to prevent the dental caries progress. In order to find another fluoride that has a similar anticariogenic effect without changing tooth color, we prepared ammonium hexafluorosilicate (SiF: (NH4)2SiF6), in which the silver of AgF is replaced with silicon. In this study, the anticariogenic effect of SiF was evaluated using bovine teeth. Fluoride solutions, SiF, AgF, acidulated phosphate fluoride (APF), and sodium fluoride (NaF), were applied to bovine enamel and dentine blocks, and the depth of demineralization was measured after exposure to a demineralizing solution for 24 h. Also, fluoride was applied to a simulated dentine caries specimen to evaluate the caries progress-preventing ability. For the dentine specimens, mineral loss (Delta Z) was also measured with microradiography. We found that SiF treated enamel showed better acid resistance than specimens treated with NaF or APF. AgF treated enamel also showed similar acid resistance, but was stained black. SiF and AgF treated caries-affected dentine showed reduced demineralization when exposed to a demineralization solution for 24 h. Mineral loss (Delta Z) was reduced to 85% and 75%, respectively. Although the acid resistance of the SiF treated teeth was inferior to that of the AgF treated teeth, we consider that SiF has good potential as anticariogenic agent, since it increased acid resistance without changing tooth color.

Journal of Materials Science. Materials in Medicine


Effects of pre- or post- application with calcium chloride on occluding ability of potassium oxalate for the treatment of dentin hypersensitivity

To evaluate whether calcium ion supply using 1-6 mol/L CaCl2 solution could enhance the occluding ability of dentin tubules with 30% potassium oxalate treatment. Calcium chloride solution (1-6 mol/L) was applied to dentin disks before or after application of 30% potassium oxalate solution. Occluding ability after potassium oxalate treatment was evaluated with scanning electron microscopic (SEM) observation and measurement of dentin permeability. In addition, the composition of the precipitate formed when mixing potassium oxalate and calcium chloride was analyzed with a powder x-ray diffractometer (XRD). SEM observations revealed that the dentin tubules were occluded homogeneously and completely with the precipitate when calcium chloride solution was applied before or after potassium oxalate treatment. However, the depth of the precipitate in dentin tubules from the dentin surface became shallower when pre-treated with calcium chloride before potassium oxalate. Although dentin permeability was greatly reduced in both groups, no significant difference could be observed between samples with and without calcium chloride application.


Expression of fractalkine (CX3CL1) and its receptor, CX3CR1, in periodontal diseased tissue

The regulatory role of chemokines and chemokine receptors on specific leucocyte recruitment into periodontal diseased tissue is poorly characterized. We observed that leucocytes infiltrating inflamed gingival tissue expressed marked levels of CX3CR1. In periodontal diseased tissue, the expression of fractalkine and CX3CR1 mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) and further, fractalkine was distributed mainly on endothelial cells, as shown by immunohistochemistry. Moreover, we can detect CX3CR1-expressing cells infiltrated in periodontal diseased tissue by immunohistochemical staining. Furthermore, fractalkine production by human umbilical vein endothelial cells (HUVEC) was up-regulated by pathogen-associated molecular patterns (PAMPs), including Porphyromonas gingivalis lipopolysaccharide (LPS). Thus, these findings suggested that CX3CR1 and the corresponding chemokine, fractalkine may have an important regulatory role on specific leucocyte migration into inflamed periodontal tissue.


Expression of macrophage inflammatory protein 3alpha in human inflamed dental pulp tissue

Severe pulpitis resulting from dental caries is characterized by marked inflammatory infiltrate such as lymphocytes. Little is known about the recruitment of these cells into the dental pulp lesions of carious teeth. Macrophage inflammatory protein-3alpha (MIP-3alpha), a CC chemokine attracts CC chemokine receptor 6 (CCR6)-expressing T cells. We examined the distribution of MIP-3alpha-positive and/or CCR6-positive cells in human inflamed and normal dental pulp by immunohistochemistry. MIP-3alpha was observed in all inflamed pulp sections, and was mostly distributed in macrophages that had accumulated in the area adjacent to carious lesions. Furthermore, CCR6 expression was also observed in the infiltrating lymphocytes. In contrast, MIP-3alpha and CCR6 were rarely detected in normal pulp. These findings suggest that MIP-3alpha plays a role in the advancement of pulpal inflammation via the recruitment of CCR6-expressing lymphocytes.


An immunohistological study of the localization of bacteria invading root pulpal walls of teeth with periapical lesions

We immunohistologically examined the prevalence and localization of bacteria invading dentinal tubules of the roots of teeth with infected canals. Forty extracted teeth with apical lesions were selected and divided into two groups: a group of untreated teeth and a group of canal-enlarged teeth. The bacteria in the specimens were detected by Brown-Brenn stain and the labeled-streptavidin-biotin method with specific antisera for 16-bacteria. Seventy percent of the examined teeth showed bacteria invading the dentinal tubules of the roots. Fusobacterium nucleatum, Eubacterium alactolyticum, E. nodatum, Lactobacillus casei, and Peptostreptococcus micros were abundant. Even in the canal-enlarged group, invasion of bacteria was observed in 65% of teeth. This study revealed the actual condition of bacteria in infected root dentin and suggested that the canal-enlargement procedure could not completely remove all the bacteria in the infected dentinal tubules of the root.


N-acetyl-D-galactosamine specific lectin of Eikenella corrodens induces intercellular adhesion molecule-1 (ICAM-1) production by human oral epithelial cells

During the acute inflammatory response in periodontitis, gingival epithelial cells are considered to play important roles in the recruitment of inflammatory cells to the site of infection through the secretion of chemokines. However, little is known about the expression of molecules that are involved in the interaction between the epithelium and neutrophils following bacterial attachment. Earlier work reported that periodontopathogenic Eikenella corrodens strain 1,073 up-regulated the expression and secretion of chemokines such as interleukin-8 (IL-8) from KB cells (a human oral epithelial cell line derived from a human oral epidermoid carcinoma). To elucidate the mechanism of the transmigration of neutrophils through the epithelium, the present study investigated the expression of adhesion molecules on KB cells in response to E. corrodens attachment. Adhesion molecule gene expression was assessed by RT-PCR and adhesion proteins expressed on KB cell surfaces were determined by cell-based ELISA and FACS. In RT-PCR, ICAM-1 mRNA levels were significantly increased within 1 h in response to exposure to E. corrodens and continued to increase over the 12-h period of study. In ELISA, increased surface ICAM-1 expression was paralleled by increased ICAM-1 mRNA levels. Furthermore, the increases in ICAM-1 expression on epithelial cells infected with E. corrodens were observed to be due to the N-acetyl-D-galactosamine (GalNAc) specific bacterial lectin-like substance of E. corrodens (EcLS), which was one of the adhesins of E. corrodens. This is the first study to report that a bacterial lectin-like substance increased the expression of ICAM-1 on gingival epithelial cells.


Calcium phosphate precipitation method for the treatment of dentin hypersensitivity

To evaluate the feasibility of the calcium phosphate precipitation (CPP) method as a treatment for dentin hypersensitivity using vital teeth of beagle dogs. Also, gingival tissue response to two types of CPP methods was examined histologically. Dentin tubules of the dogs' vital teeth were exposed by shallow cavity preparation followed by etching with 50% citric acid to simulate the condition of hypersensitive dentin. After CPP treatment was applied to the vital tooth, the dentin surface and longitudinal sections were observed by SEM to evaluate the occluding ability of the CPP method. The precipitate was also analyzed by energy-dispersive X-ray microanalysis to obtain compositional information. The gingival tissue before and after CPP method was examined histologically with light microscopy. Dentin tubules were occluded homogeneously and completely with an apatitic mineral after application of the CPP treatment in vital teeth. However, the depth of the precipitate in dentin tubules from the dentin surface was approximately half that seen in extracted teeth. No histological change was observed in gingival tissues when NaHCO3 was used as a post-treatment solution of the CPP method, whereas another CPP method using NaOH solution resulted in atrophy and degeneration of the epithelium of gingival tissue.


Macrophage Inflammatory Protein 3α-CC chemokine receptor 6 interactions play an important role in CD4+ T-cell accumulation in periodontal diseased tissue.

The regulatory role of chemokines and chemokine receptors on specific lymphocyte recruitment into periodontal diseased tissue is poorly characterized. We observed that lymphocytes infiltrating inflamed gingival tissue expressed marked levels of CCR6. In periodontal diseased tissue, the expression of MIP-3alpha mRNA was detected by RT-PCR and further, MIP-3alpha was distributed in the basal layer of gingival epithelial cells, microvascular endothelial cells and the areas of inflammatory cells as shown by immunohistochemistry. Moreover, CCR6-expressing cells infiltrated into periodontal diseased tissue, and the proportion of CCR6-positive CD4+ T cells was significantly elevated in periodontal diseased tissue compared with peripheral blood in the same patients. Furthermore, gingival lymphocytes isolated from patients showed migration toward MIP-3alpha in an in vitro chemotaxis assay in which migration was abrogated by specific antibody to CCR6. Thus, these findings suggested that CCR6 and the corresponding chemokine, MIP-3alpha may have an important regulatory role in specific lymphocyte migration into inflamed periodontal tissue.


Soluble products from Eikenella corrodens stimulate oral epithelial cells to induce inflammatory mediators

In the inflammatory response elicited by bacterial colonization in periodontal pockets, pocket epithelial cells not only serve as a barrier to isolate the pocket microenvironment from external stimuli but also regulate the functions of neighboring cells including fibroblasts and inflammatory cells. To elucidate this mechanism, we characterized the effects of periodontopathic bacterium Eikenella corrodens 1073 components on the production of some inflammatory mediators in a human oral epithelial cell line (KB). In enzyme-linked immunosorbent assay (ELISA), the E. corrodens supernatant induced interleukin-6 (IL-6), IL-8 and prostaglandin E2 but not interferon-gamma (IFN-gamma) production by KB cells. After incubation with E. corrodens supernatant, KB cells showed a marked increase in the levels of IL-6, IL-8 and PG G/H synthase (cyclooxygenase)-2, but not IFN-gamma, gene expression by reverse-transcriptase polymerase chain reaction. All these E. corrodens products responsible for production of these inflammatory mediators resisted freezing and boiling and were present in a 10-kDa filtrate. These results imply that these soluble small-molecular-mass products from E. corrodens stimulate various inflammatory mediator productions by human oral epithelial cells and may play a role in the initiation of periodontal inflammation and subsequently perpetuate the inflammatory response during chronic infection.


An immunohistological study on cyclooxygenase-2 in human dental pulp.

Characteristics of cyclooxygenase-2 (COX-2) expressing cells in human dental pulp were immunohistologically studied. Extirpated pulpal tissues from extracted teeth were examined to elucidate the localization and distribution of COX-2. Pulpal tissues were examined by the labeled streptavidin biotin method using specific mouse monoclonal antibodies for COX-2. Cell types of the COX-2 expressing cells were also investigated by the double stain technique using both monoclonal antibodies for CD68/macrophage and anti-COX-2. COX-2 expressing cells could be found in all of the inflamed pulps, and these cells were mostly distributed close to the area of accumulation of inflammatory cells. COX-2 was mainly expressed in fibroblasts rather than macrophages. In contrast, COX-2 expressing cells were scarcely found in the normal pulps. These findings indicate that pulpal fibroblasts, as well as macrophages, may participate in the production of prostaglandin through COX-2 expression in pulpal inflammation, and might be involved in the pathogenesis of irreversible pulpitis.


Effects of plaque control on the patency and occlusion of dentine tubules in situ.

To elucidate the nature of dentine hypersensitivity, the effects of plaque control on the patency and occlusion of dentinal tubules were investigated systematically in situ using human dentine slabs embedded in partial dentures. The dentine slabs were divided into three groups. In group I, the dentine slabs were kept in an oral cavity without plaque control. In group II, plaque was removed mechanically by brushing. Plaque control was carried out chemically using chlorhexidine in group III. After being kept in the oral cavities for 1, 2 and 3 weeks, the slabs were removed from the partial denture, followed by SEM observation to determine the morphological changes of the dentinal tubules. When no attempt was made to remove plaque, the diameter of tubule orifices increased to 390% of the original values within 3 weeks. In contrast, dentinal tubules were found to be occluded, i.e. the tubule orifices became <20% of the original value within 1 week when plaque control efforts were made, using either method of plaque control. We conclude that plaque control plays one of the key roles in the patency versus occlusion of dentinal tubules, and thus in the aetiology and natural reparative process of dentine hypersensitivity.


In Vitro Resin Bonding to Artificial Carious Dentin


Comparison of conventional vs self-etching adhesive bonds to caries-affected dentin


Immunohistological Studies on Localization of Selected Bacteria in Infected Root Canal Systems

ヒト感染根管における侵入細菌の局在性に関する免疫組織学的研究

The Japanese Journal of Conservative Dentistry


Effect of antibiotics on CD15s-related antigen expressed on the Streptococcus anginosus group


Application of Sealed Restoration to Root Caries:Resin Adhesion to Root Carious Dentin

根面う蝕へのシールド·レストレーションの応用:根面う蝕象牙質へのレジン接着性


Adhesion of a new commercial self-etching/self-priming bonding resin to human caries-infected dentin


Evaluation of post-treatment solutions for clinical use with the calsium phosphate precipitation method

We have proposed a calcium phosphate precipitation (CPP) method that occludes dentine tubules with apatitic minerals for the treatment of dentine hypersensitivity. The current CPP method uses 1 mol/l NaOH as the post-treatment solution. However, its high pH is not desirable for clinical use. The aim of this study was to evaluate several solutions, especially buffer solutions, as post-treatment solutions for the CPP method. The CPP solution was mixed with several post-treatment solutions at various mixing ratios in test tubes. The precipitates were collected, and freeze-dried in a vacuum. Their weights were measured to evaluate the feasibility of buffer solution for the post-treatment solutions. Among the solutions, we selected one buffer solution and have done further evaluation using human dentine disks. The degree of occlusion of dentine tubules was evaluated by scanning electron microscopic observation and measurement of dentine permeability. Also, the composition of the precipitate was analyzed using energy-dispersive X-ray microanalysis and powder X-ray diffraction. Among the solutions, 1 mol/l NaHCO3 gave sufficient amounts of precipitate at a relatively mild pH, and thus was considered to be a good candidate for a post-treatment solution. Scanning electron microscopic observation showed that dentine tubules were occluded with the precipitate to a depth of approximately 10 microns from the surface when the CPP treatment was done twice, and dentine permeability was reduced to 98.8%. The precipitate was dicalcium phosphate dihydrate (DCPD; CaHPO4-2H2O) when the post-treatment solution was free of NaF. In contrast, the precipitate was an apatitic mineral with CaF2 as a by-product when the post-treatment solution contained NaF. We concluded that 1 mol/l NaHCO3 containing 0.3 mol/l NaF would be suitable as the post-treatment solution for the CPP method as it has a relatively mild pH and occludes dentinal tubules well.


エナメル質形成不全症の1症例

エナメル質形成不全症の1症例

The Japanese Journal of Pediatric Dentistry


Resin Infiltration into Artificial Carious Dentin

人工う蝕象牙質へのレジン浸透性


Relationships between activity of daily living, and oral cavity care and the number of oral cavity microorganisms in patients with cerebrovascular diseases

We examined the relationships among the activity of daily living (ADL), oral cavity care, and the number of oral cavity microorganisms in 40 patients with cerebrovascular diseases (CVD). The CVD patients were classified into 4 groups, I, II, III and IV based on their ADL and the method used for oral cavity care. The ADL was highest in group I and lowest in group III. Only the patients of only group III could not eat by themselves and were receiving naso-esophageal feeding. Oral cavity care was performed by the patients themselves in groups I and IV, but was performed by caregivers in groups II and III. The group IV patients had no teeth, but could eat by themselves using full dentures. The numbers of microorganisms in the pharyngeal swabs from the 4 groups were measured and expressed as colony-forming units (cfu). The numbers of both Staphylococci spp. and Candida spp. were significantly higher in group III than in the other groups. Moreover, Pseudomonas aeruginosa was isolated only from patients of group III (in about 66%). The oral cavity care by caregivers was almost the same in groups II and III, but the numbers of oral cavity microorganisms were significantly higher in group III than in group II. These results indicated that microorganisms grow more easily in the oral cavities of CVD patients with low ADL compared with CVD patients with higher ADL, and that eating is thought to be important for the prevention of an increase of microorganisms in the oral cavity.

The Journal of Medical Investigation : JMI


Interleukin-6 (IL-6) and IL-8 are induced in human oral epithelial cells in response to exposure to periodontopathic Eikenella corrodens


Resin Adhesion to Carious Infected Dentin-Effects of Self-Etching Bonding Systems

う蝕感染象牙質へのレジン接着性:セルフェッチングボンディングシステムの効果


Resin Infiltration of Caries-infected Dentin

う蝕感染象牙質のレジン浸透性


Regional bond strengths of self-etching/self-priming adhesive systems

The purpose of this study was to measure the regional tensile bond strengths (TBS) at various portions of human tooth enamel and dentin, and to observe the resin-dentin interfaces of two commercially available self-etching/self-priming adhesive systems by scanning electron microscopy (SEM). Twelve extracted human cuspid teeth were used to measure TBS and four additional teeth were used for scanning electron microscopy (SEM). Outer enamel and dentin were removed from the labial tooth surfaces to form a long cavity preparation into middle dentin extending from the mid-crown to the apex of the root within the same tooth. Either Clearfil Liner Bond 2 (LB 2, Kuraray) or Fluoro Bond (FB, Shofu) was bonded to the surfaces, and covered with resin-composite. The resin-bonded teeth were serially sliced at right angles to the long axis of the tooth, and the bonded surfaces were trimmed to give a bonded cross-sectional surface area of 1 mm2 for TBS tests. LB 2 and FB showed significantly higher TBS in coronal, cervical and middle root dentin than that in enamel and apical root dentin. SEM showed that the thickness of the hybrid layer of both systems was about 1.0 microm in coronal, cervical and middle root dentin, and less than 0.5 microm in apical root dentin. These results suggested that the self-etching/self-priming systems produce good adhesion in coronal, cervical and middle root dentin by creating thin hybrid and transitional layers, but bonding to enamel and apical root dentin should be improved.


Fosfomycin reduces CD15s-related antigen expression of Streptococcus pyogenes

We have previously shown the immunological mimicry of human sialyl-Lewis(x) (CD15s) by a surface antigen of Streptococcus pyogenes. This mimicking surface antigen may act as a ligand to the selectin family and may induce antibody production against CD15s on host cells, suggesting a possible role in the pathogenesis of S. pyogenes. In this study, the effects of antibiotics on the CD15s-related antigen expression of S. pyogenes were examined at a concentration below the MIC (sub-MIC). The amounts of CD15s on the surfaces of S. pyogenes cells and on the surfaces of S. pyogenes biofilms were determined by a whole-cell enzyme-linked immunosorbent assay and by laser scanning fluorescence microscopy, respectively, by using an anti-CD15s monoclonal antibody. At the sub-MICs, fosfomycin (1R,2S-1,2-epoxypropyl phosphonic acid), its enantiomer (1S,2R-1,2-epoxypropyl phosphonic acid), and benzylpenicillin significantly inhibited the CD15s expression of all strains studied. The effects of fosfomycin and its enantiomer on biofilms were also observed by scanning electron microscopy. Incubation of S. pyogenes with the sub-MIC of fosfomycin or its enantiomer, which has no antibacterial activity, reduced the amount of CD15s on the biofilm surface and made it smooth. These results suggest that fosfomycin or its enantiomer might be useful for preventing S. pyogenes adherence to human CD15s receptors and the resulting immunological pathogenicity.


X-ray Microanalysis of Resin-dentin Adhesive Interfaces

X線微小分析法による象牙質接着界面の解析

The Japanese Journal of Conservative Dentistry


An immunohistochemical study on the localization of Porphyromonas gingivalis, Campylobacter rectus and Actinomyces viscosus in human periodontal pockets


Microbial Properties of Titanium and Its Alloys for Oral Bacterium S. mutans

チタンおよびチタン合金の口腔内バクテリア S.mutans に対する細菌学的性質


Cloning, sequencing and expression of an Eikenella corrodens gene encoding a component protein of the lectin-like adhesin complex


Molecular analysis of the gene encoding a protein component of the Eikenella corrodens adhesin complex that is close to the carbohydrate recognition domain


A clinical study of direct pulp capping applied to carious-exposed pulps


A Histological Analysis of T and B Cells in Periodontal Tissue Destruction

We immunohistologically examined the cell densities and distribution of T and B cells in periodontitis and analyzed their relationship in terms of periodontal tissue destruction. Specimens were labeled with monoclonal antibodies for T cells (CD3) and B cells (CD20) and developed using the double staining technique. CD3^+ cells appeared in low density infiltrates and increased gradually with the number of total infiltrates; in contrast, CD20^+ cells did not appear in small infiltrates but increased rapidly with the number of infiltrates. The number of fibroblastic cells negatively correlated with that of the total infiltrates and CD20^+ cells, but it did not correlate with the number of CD3^+ cells. These findings suggest that the T cells infiltrated into the inflamed sites at the onset and increased gradually with the development of inflammation and that B cells infiltrated later than T cells and their number increased rapidly with inflammation.


A Study on Human Subgingival Plaque-Qualitative Analysis of Periodontal Disease associated Bacteria in Plaque-free Zones by a Scanning Immunoelectron Microscopy Method-

ヒト歯肉縁下プラークの研究 ープラークフリーゾーンにおける歯周病関連細菌の走査免疫電顕法による検索ー

Journal of the Japanese Association of Periodontology


Immunoglobulins in periapical exudates of infected root canals: correlations with the clinical findings of the involved teeth


Quantitative analysis of immunoglobulins and inflammatory factors in human pulpal blood from exposed pulps


A Study on Human Subgingival Plaque-Participation of Bacterial Biofilms in the Colonization of Plaque Bacteria-

ヒト歯肉縁下プラークの研究 -プラーク細菌の定着·増殖における細菌バイオフィルムの関与についてー


Interleukin-1 alpha and interleukin-1 beta periapical exudates of infected root canals: correlations with the clinical findings of the involved teeth


A quantitative comparison of selected bacteria in human carious dentine by microscopic counts.


Mitogenic stimulation of murine B lymphocytes by the N-acetyl-D-galactosamine specific bacterial lectin-like substance from Eikenella corrodens


A Study on Human Subgingival Plaque -Localization of Periodontopathic Bacteria in Human Periodontal Pockets-

ヒト歯肉縁下プラークの研究 -ヒト歯周ポケットにおける歯周病原性細菌の局在性-


A Study on Human Subgingival Plaque Immunohistochemical Observation of Tooth Attached Subgingival Plaque

ヒト歯肉縁下プラークの研究 歯根付着性プラークの免疫組織学的検索


Diagnosis of Pulpitis Using Pulpal Blood --- Establishment of the Method for Collection of Pulpal Blood

歯髄血液を用いた客観的歯髄診断法の開発に関する研究 --- 微量歯髄血液の採取法について

The Japanese Journal of Conservative Dentistry


Immunohistological Studies on the Localization of Selected Bacteria in Human Carious Dentin Located in Root Surfaces

歯根部の象牙質齲蝕病巣における侵入細菌の局在性に関する免疫組織学的研究


Immunohistological Studies on the Localization of Selected Bacteria in Human Carious Dentin Located in Fissures and Smooth Surface Coronal Surfaces

小窩裂溝部および平滑面部の象牙質齲蝕病巣における侵入細菌の局在性に関する免疫組織学的研究


Purification and partial amino acid sequence of suppressive lymphokine from a CD8+ CD57+ human T hybridoma


Quantitative analysis of immunocompetent cells in human periapical lesions: correlations with clinical findings of the involved teeth


Treatment of Dentin Hypersensitivity-Effect of a Light-curing Resin Liner on Tubule Occlusion-

象牙質知覚過敏症の治療法ー光重合型レジンライナーによる象牙細管封鎖効果ー


Evaluation of Periodontopathogenicity of Subgingival Plaque Bacteria by Inflammatory Mediators in Gingival Crevicular Fluid

歯肉溝浸出液中の炎症反応のメディエーターによる歯周病原性細菌の探索


Clinical Findings in Relation to theSuccess Rate of Direct Pulp Capping

直接覆髄における術前および術中所見と術後成績の関係について


Clinical Evaluation of Pathogenecity of Infected Root Canals --- The Prognosis for Endodontic Treatment of Overfilling Cases

根管治療の予後を左右する因子について --- 特に過剰根管充填の場合


Immunohistological Study of Immunocompetent Cells on Periapical Granulomata and Periapical Cysts --- T Cell Subpopulation and Ig Bearing Cells

歯根肉芽腫と歯根嚢胞における免疫担当細胞の検索 --- T細胞サブセットと免疫グロブリン保有細胞との関係


Human Interleukin-1α,Interleukin-1β and Immunoglobulins in Periapical Exudates of Infected Root Canals:Relationship to Clinical Findings

感染根管における根管浸出液中のインターロイキンー1(IL-1α/β)および免疫グロブリンと臨床所見との関連性


The Function of Gingival Lymphocytes on the Establishment of Human Periodontitis


Suppressor factor secreted by T hybridoma established from peripheral blood lymphocytes of a bone marrow transplantation patient. I. Establishment of human T-cell hybridoma and partial characterization of suppressor factor

A stable human T-cell hybridoma was established by cell fusion between activated human peripheral blood lymphocytes from an allogeneic bone marrow transplantation patient and the JD1-17 cell line, a subclone of the human T leukemia Jurkat cell line. This hybrid clone 1-8, which bore the surface phenotype of suppressor cells (CD8+HNK1+), spontaneously secreted a factor which, at high dilutions, suppressed the responses of T and B cells induced by mitogens and alloantigens. This suppressor factor was found to be heat-resistant (56 degrees C, 30 min), stable at alkaline but not acid pH, unaffected by 2-mercaptoethanol, and sensitive to trypsin. Preparative isoelectric focusing revealed an isoelectric point of 5.35. The suppressor activity was selectively absorbed by blast T cells. By gel filtration on Sephacryl S-200 and HPLC, the suppressor activity was found in two peaks corresponding to 40-45 kDa (monomer) and 90-95 kDa (dimer).


Clinical Evaluation of Pathogenecity of Infected Root Canals --- The Relation of Clinical Findings to the Success Rate of Endodontic Therapy

感染根管の病原因子の臨床的評価について --- 歯内治療の予後との関連性


Subgingival Plaque Bacteria and Inflammatory Mediators in Gingival Crevicular Fluid in Periodontally Diseased Sites and Healthy Sites

歯周病変部と健常部における歯肉縁下プラーク細菌と歯肉溝浸出液中の炎症反応のメディエーター


Possible role of T cells in the establishment of IgG plasma cell-rich periodontal lesion--Augmentation of IgG synthesis in the polyclonal B cell activation response by autoreactive T cells


Development of the Computerized System for the Recording and Totaling of the Training Items based on the Clinical Training Common Curriculum for Junior-Residents at National University Dental Hospitals

国立大学歯学部附属病院卒後臨床研修共通カリキュラムに基づいた研修項目の集計ならびに評価システムの開発

The Journal of Japanese Association for Dental Education

日本歯科医学教育学会雑誌


Immunological Studies on Spontaneous Colon Carcinoma of Wistar-Furth Rats:Demonstration of the Tumor Antigen and Syngeneic Anti-tumor Antibodies

Wistar-Furth 系ラット自然発生大腸癌の免疫学的研究:腫瘍抗原の解析と抗腫瘍抗体の検索

The Journal of Osaka University Dental Society


自然発生大腸癌宿主Wistar-Furth 系ラット血清に認められた抗腫瘍抗体

自然発生大腸癌宿主Wistar-Furth 系ラット血清に認められた抗腫瘍抗体

Journal of Clinical and Experimental Medicine


電子灸の施灸後の免疫機能への影響(1)

電子灸の施灸後の免疫機能への影響(1)


Conception of Infected Root Canal Treatment

It is a well-established fact that bacterial infection of the dental pulp ultimately results in the formation of apical periodontitis. And apical periodontitis may develop periapical leisons consisting granulomas and cysts. In this article, we show the pathologic condition of infected root canal systems and periapical lesions immunohistologically. We also describe the possible causes of refractory apical periodontitis that conventional root canal therapy could not work effectively. Finally,we explain our newly developing treatment for refractory apical periodontitis named electro-magnetic apical treatment, and illustrate clinical efficacy of this treatment.


Effects of ammonium hexafluorosilicate concentration on crystallinity of hydroxyapatite powder and enamel


水溶性MPCポリマーの口腔細菌付着抑制効果

水溶性MPCポリマーの口腔細菌付着抑制効果

口腔細菌によるbiofilm，すなわちdental plaqueの形成にはいくつかのkey stepがあり，dental plaque形成の抑制のためにはそれらのkey stepに効果的に働く方法を選択する必要が有る．我々は，超親水性表面を得ることができる2-methacryloloxethyl phosphorylcholine(MPC)co-polymerを用いてプラスチック表面をコートした界面は微生物の付着抑制に関与することを報告してきた．本実験では5%水溶性MPCポリマーで処理したHydroxyapatite(HY)プレートと培養歯肉上皮細胞(RT-7)へのStreptococcus mutansの付着状況を顕微鏡下にて観察した．その結果，5%水溶性MPCポリマー処理でHYプレート及び培養歯肉上皮細胞上へのS.mutansの付着は抑制されることが示された．以上よりHYプレートや培養歯肉上皮細胞に吸着した水溶性MPCポリマーは，プラスチックへのコーティングと同様にS.mutansの付着抑制効果を発揮することが示唆された．


歯周病患者に対する禁煙指導について --- ニコチネルの応用

歯周病患者に対する禁煙指導について --- ニコチネルの応用


Evaluation of optimal time of mouth care on the basis of oral cavity bacterial number, and of subjective sense

口腔内細菌数と自覚感による口腔ケアの至適時間の検討

The sbjects were classified 3 groups. Oral care was effectively carried out at 10o'clok in the morning group, 15o'clok in the midday group and 19o'clok in the night group. The number of Streptococci spp. and Staphlococci spp. in the samples was quantitatively measured. These results showed that effect of mouth care is not influenced by the time when it is done, as far as it is effectively done once in a day, and suggested that in the subjects who can not perform oral care by themselves, and can not receive oral care service several times in a day. It is important to perform effective mouth care which remove completely dental plaque, once in a day, by caregivers.

Bulletin of School of Medical Sciences, the University of Tokushima

徳島大学医療技術短期大学部紀要


臼歯部の動揺を伴う歯周病患者への対応 --- 特にメインテナンスにおける歯科衛生士の役割


更年期障害を有する歯周病患者の一症例

更年期障害を有する歯周病患者の一症例


口腔がん患者における歯周治療および管理の重要性

口腔がん患者における歯周治療および管理の重要性


喫煙習慣を持つ歯周病患者への対応

喫煙習慣を持つ歯周病患者への対応


含嗽の咽頭ぬぐい液細菌数に対する影響

含嗽の咽頭ぬぐい液細菌数に対する影響

徳島大学医療技術短期大学部紀要


歯科衛生士の立場から見た若年性歯周炎

歯科衛生士の立場から見た若年性歯周炎


Biological Roles of Extracellular DNA in Bacterial Infection

Asean Plus and Tokushima Joint International Conference, Program and Proceeding Book


High prevalence of Pseudomonas aeruginosa from oropharyngeal biofilm in patients with cerebrovascular infarction and dysphagia.