The objective of this study was to observe the morphological characteristics of self-etch adhesives bonding to non-carious cervical sclerotic dentin using Confocal Laser Scanning Microscope (CLSM). Thirty human premolars with buccal non-carious cervical sclerotic lesions were selected, and artificially prepared wedge-shaped lesion was made in lingual surface of this tooth. The dentin lesions were bonding with one-step self-etch adhesive (XENO III and G-Bond Plus) and two-step self-etch adhesive (Clearfil SE Bond) according to the manufacturer’s instruction, respectively. The bonding adhesive component was labeled with 0.1 wt.% Rhodamine B Isothiocyanate. The hybrid layer and resin tags of resin-dentin interface were observed using CLSM. Statistical analysis showed that there were significant differences between non-carious sclerotic dentin and normal dentin in the thickness of hybrid layer and length of resin tags (p < 0.05). The self-etch adhesives significantly affected the hybrid layer thickness and resin tags length between resin and normal dentin interface (p < 0.05), while for resin-sclerotic dentin interface, no significant difference was observed (p > 0.05). The sclerotic dentin presented thinner hybrid layer and shorter resin tags than the normal dentin. There were similar morphological characteristics of resin-sclerotic dentin interface using one-step and two-step self-etch adhesives.

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Statins, inhibitors of 3-hydroxy-2-methyl-glutaryl coenzyme A reductase, were recently reported to promote the differentiation of osteoblasts produced by the stimulation of bone morphogenetic protein-2 (BMP-2). The aim of this study was to investigate the osteogenic effect of a local administration of fluvastatin in senile osteoporosis model rats using a fluvastatin-gelatin complex. The gelatin-hydrogel was put into cylindrical titanium tubes 1.5 mm in diameter and 2.2 mm high. It was then crosslinked by ultraviolet irradiation, after which it was lyophilized. Subsequently, the carriers were placed in the fluvastatin solution (300 µM) for one day to bind the alkaline gelatin and acidic statin electrostatically (fluvastatin-gelatin complex; statin group). A control group consisted of the carriers immersed in sterilized water. Specimens of both the statin group and the control group were implanted into the femur of 15-week-old male senile osteoporosis model rats (SHRSP). Radiographic analysis, histologic examination, and immunohistochemical staining (BMP-2 and Runx2) were then performed. At 14 and 21 days, the bone volumes of the newly formed bone in the statin group was significantly higher compared to those of the control group (P<0.05). Histological observation showed that a high level of new bone formation was present in the statin group compared to that of the control group during all time periods. At 7 days, positive immune reactions with BMP-2 and Runx2 were seen in the statin group. The local administration of the fluvastatin-gelatin complex facilitated bone formation in senile osteoporosis model rats.

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Transparent DNA/chitosan complex film was prepared from DNA/chitosan complex powder via hydrothermal hot pressing. In this study, we investigated the binding of daunorubicin hydrochloride (DH), proteins adsorption (fibronectin and albumin), mineral deposition, and rat soft-tissue response to the DNA/chitosan complex film to determine whether this film has potential for use in membranes for bone tissue engineering. The binding ratio of DH to DNA/chitosan complex film was very close to the excision number of 3.7 for the binding of DH by native DNA. This indicated that DNA in the complex did not denature as a result of hot pressing. Apatite was formed on the surface of the film after immersion in simulated body fluid. However, quartz crystal microbalance analysis showed that protein absorption to the DNA/chitosan complex was very low. It was found that this film has an affinity for minerals rather than proteins. Although the film remained in an almost unchanged configuration at 21 days after subcutaneous implantation, the response of rat soft tissues to the film was mild. These results suggest that DNA/chitosan complex film has potential for use as a membrane in bone tissue engineering.

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Stainless steel is used for various medical devices. Titanium is also widely used because of its tight bonding to bone tissue, namely osseointegration. The aim of the present study was to investigate the efficacy of three-dimensional stainless steel and titanium porous structure scaffolds by in vitro and in vivo experiments. Stainless steel and titanium fiber materials were designed as non-degradable metallic three-dimensional scaffolds with a three-dimensional porous structure for bone reconstruction. In one in vitro experiment, stainless steel and titanium disks were immersed in simulated body fluid. After immersion, a greater amount of hydroxyapatite precipitation was observed on titanium disks than on stainless steel disks. The crystallographic structure of precipitated hydroxyapatite was confirmed by the measurement of X-ray diffraction patterns. In another in vitro study, the adsorption behavior of fibronectin to stainless steel and titanium was monitored by the quartz crystal microbalance (QCM) method, which demonstrated more fibronectin adsorption onto titanium than onto stainless steel. In an in vivo experiment, three-dimensional stainless steel or titanium fibers were implanted into the cortical bone of the tibia of rabbits. Histological and histomorphometrical evaluation revealed a significantly greater amount of bone formation inside the porous area of the titanium fibers after 4 weeks of implantation. The present study also revealed better osteoconductivity of titanium than stainless steel. It is presumed that this was due to the differences in the characteristics of passive film between titanium and stainless steel. Titanium fibers are expected to be useful as a non-resorbable three-dimensional scaffold in bone reconstruction.

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The purpose of this study was to evaluate the DDM as a carrier of recombinant human BMP-2 (rhBMP-2). In the study 1, the rhBMP-2 was fixed to inorganic bovine bones, tricalcium phosphate (TCP), DDM powder, and DDM chip. Over a period of 36 days, the amount of rhBMP-2 released was analyzed. In the study 2, the expression of protein markers by rhBMP-2 combined with DDM was evaluated in mice at 1, 2 and 4 weeks. In the control group (n=20 mice), 20 μg grafts of TCP+rhBMP-2 (concentration=0.05 mg/ml) were applied, while in the experimental group (n=20 mice), 20 μg grafts of DDM powder+rhBMP-2 (concentration=0.05 mg/ml) were applied. In the study 1, the slow release of rhBMP-2 was exhibited by all four graft types throughout the 36-day, a statistically significant large amount of rhBMP-2 was released from the DDM powder compared to the other materials (p<0.05). In the study 2, the expression of osteonectin was found to be limited to adjacent areas of TCP in the control group, however, it was observed in the DDM in the experimental group. The experimental group exhibited significant mature bone formation in the 4th week, but not in the 1st week of the experiment. Within limited research in this study DDM powder appears to have great potential as an effective scaffold for rhBMP-2. In the DDM powder+rhBMP-2, new bone formation was evidently shown and the amount of released rhBMP-2 was the highest. It was proposed that DDM powder might be an effective carrier of rhBMP-2.

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Far infrared ray (FIR) energy radiated by the natural ceramics (Rhyolite) cooled FIR ceramics activates water molecules and blood circulation to stimulate skin and other tissues. The aim of our study is to make clear whether the FIR ceramics radiating FIR energy affect or not on the new bone formation in vivo and in vitro. Methods: MC3T3-E1 cells were cultured in FIR CO₂ incubator. The cell proliferation and the gene expression were analyzed by using WST-8 assay kit, RT-PCR and micro array analysis. The enzyme activities were analyzed by using the api^RZYM kit. Furthermore, titanium and natural FIR ceramics compounds were implanted under the periosteium of rat skull bone by injection method. Four weeks later, the samples were examined by the light microscope and micro CT analyses. Results: Proliferation of MC3T3-E1 cell was and DNA concentrations were inhibited by FIR energy radiation. TheALP activities were accelerated and the area of calcification nodules increased on 4 weeks. The RT-PCR data showed that the gene Runx2, Osterix, BSP, OCN, Col1a1 and OPN expression of MC3T3-E1 osteoblast like cells was activated. Bone mineral density (BMD mg/cm²) of implanted sites of T50-F50, T25-F75 and F100 groups was significantly enhanced after 4 weeks compared with control groups. This data shows FIR energy radiation by the natural FIR ceramics promoted bone-forming activity of osteoblasts. Significance: This study suggested that new bioactive ceramics such us natural FIR ceramics was useful for some clinically applications to repair bone defects for example of dental implant surgery.

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Mouse subcutaneous tissue reaction to an embedded calcium hydroxide-based root canal filling material was analyzed histopathologically. After the material was placed within the mouse dorsal subcutaneous tissues, we performed examinations using histopathological, histochemical and immunohistochemical techniques. Two weeks after embedment, the proliferation of granulation tissue had already begun to surround the calcification. Most of the cells observed were macrophages. Likewise, multinucleated giant cells increased significantly. The multinucleated giant cells were observed as two types. In one, the centers of the giant cells were vacuoles, while in the others there were deeply stained calcifications with hematoxylin. Twelve weeks after embedment of the materials, further growth of multinucleated giants cells were sighted. Histochemically, von Kossa-stain-positive granules were observed within the macrophages and multinucleated giant cells as black fine granules. According to the TRAP stained specimens, the multinucleated giant cells especially reacted strongly at 4 weeks. However, the reaction became very weak at 12 weeks. CD68 immunohistochemical staining showed positive reactions in the cytoplasm of the proliferating macrophages and multinucleated giant cells. These results suggest that multinucleated giant cells are present in the surrounding tissues due to implantation of the calcium hydroxide-based root canal filling material, and that the presence of ACP in the cells is due to ingested calcium during active phagocytosis, which would disappear later on.

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The purpose of this study was to evaluate the validity and reliability of orthodontic measurements made on digital models created with Hirox digital microscope (HDM). The data sources were plaster dental models from the archives of School of Dental Sciences, Universiti Sains Malaysia. A total of 11 dental models with 396 variables were measured using the plaster dental casts, and Hirox digital models were created. The study inclusion and exclusion criteria were followed. Two investigators (A and B) carried out the measurements of the selected dental casts using a digital caliper (DC) and the HDM. Dental plaster models were scanned using the HDM for the fabrication of the Hirox digital models. The tooth size and arch width were measured by DC and HDM. The validity of the digital measurements for examiners A and B the ICC coefficients were statistically significant (p<0.001), and the values of coefficient were in the range of strong correlation. The ICC coefficient values for inter-examiner A and B were all in the range of strong correlation for both tooth size and arch width variables in which the reliability coefficient values were comparable between digital measurements using HDM and measurements using DC. All ICC coefficient values were statistically significant (p<0.001). The results show that linear measurements of dental casts using a digital microscope are valid and reliable.

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The bactericidal potency of ozone was examined for exploring the potential of dental application of ozone gel. Treatment with10 ppm ozone gel with quenching after 3 h and treatment with 100-ppm ozone gel with immediate quenching showed antimicrobial effects in eight aerobic strains, namely, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candidaalbicans, Methicillin-resistant S. aureus(MRSA), S. epidermidis, Klebsiella pneumoniae, and Streptococcus mutans. For five of these strains (E. coli, P. aeruginosa, C. albicans, K. pneumoniae, and S. mutans), the number of colony forming units (CFUs) were below the detection limit after treatment with 10 ppm ozone gel with quenching after 3 h. For Bacillus subtilis, an antimicrobial effect was observed after 3 h of treatment with 100 ppm of ozone gel. In the case of anaerobic bacteria, bactericidal effect was observed for five strains, namely, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, and Eikenella corrodens, by using ozone gel and ozone cream. Of these, the number of CFUs for three strains (P. gingivalis, P. intermedia, and F. nucleatum) was below the detection limit. These results suggest that the ozone gel can be clinically useful in oral surgery for implant treatment because of its instantaneous antimicrobial effects, and that it can be used against a variety of bacterial strains.

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Dens invaginatus (DI) is one of the rare developmental tooth anomaly, and generally resulting from invagination of the inner enamel epithelium into the dental papilla before calcification. However, it remains unclear whether the invaginated enamel mineralizaion is lower than outer enamel, the association with the resistance to invaginated enamel caries and the inflammatory lesions mediated their invagination. Because of the difficulties of treating and the tendency of their inflammatory lesions mediated their malformed structures, teeth extracted from the patients with DI, were collected in our hospital and analyzed by three-dimensional micro-focusing computed tomography (µCT) to clarify the differences of the invaginated enamel in mineral density (MD), and to find their pathogenesis of tooth anomaly and associated inflammatory lesions by histological analysis. The teeth were fixed with 10% formaldehyde and analyzed by µCT, decalcified specimens were performed to histological (HE) and immunohistochemistry for cytokeratin AE1/AE3. All invaginated teeth enamel showed extremely lower MD than did the outer enamel. Interestingly there were no carious lesions in the invaginated enamel. HE showed thin reduced enamel epithelium on the surface of invaginated enamel and cytokeratin AE1/AE3 markedly showed positive their cellular matrix. The persistent reduced enamel epithelium of the invaginated enamel indicates delayed or inhibited maturation after tooth eruption. This failure of maturation results in lower MD but resistance to enamel caries. However, the structural abnormalities of DI teeth may allow bacteria to enter the interior of the tooth through the invagination, causing pulpitis or apical periodontitis. (243 words)

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The study aims to understand the role of the Th1/Th2 polarization in the pathogenesis of AA. PBMNCs from patients with CAA and the healthy controls with PMA were studied, ionomycin and intracellular protein transport inhibitor BFA in vitro were detected the surface markers CD3, CD4, CD8 and HLA-DR as well as the intracellular productions of IFN-γ and IL-4 with direct immunofluorescent method. We found that both CD3/CD4 and CD4/CD8 were decreased in the CAA, while CD3/CD8 and CD8/HLA-DR were increased. These results implied that IFN-γ was increased as activity of cytokine. Furthermore, the proportion of Th1 cells in PBMNCs was significantly higher in patients with CAA, while the proportion of Th2 cells had no significant difference, indicating that Th1 cells play a dominant role in patients with CAA. Correlation analysis confirmed that Th1 cells was positively correlated with CD3⁺CD8⁺ cells, but negatively correlated with the relative value of reticulocytes and ANC, further suggesting that Th1 cells play an important role in the pathogenesis of CAA. The ratio of Th1 cells was correlated with blood reticulocyte and neutrophils and minus number, and the Th1/Th2 ratio biases indicated that the imbalance between Th1 and Th2 cells plays a crucial role in the pathogenesis of CAA. Artificial restoration of the balance between Th1 and Th2 cells may be a new strategy for the treatment of chronic aplastic anemia.

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Among patients who visited our hospital with a chief complaint of disorders involving the oromandibular region, with suspected carotid artery calcification based on panoramic radiography, and who underwent computed tomography for a detailed examination of these disorders, there were four patients in whom a definitive diagnosis of carotid artery calcification was made. We herein provide an overview of these cases, along with a brief review of the relevant literature. When imaging findings suggestive of carotid artery calcification are obtained on panoramic radiographs, dentists can request detailed examinations and treatment at specialized medical institutions in the early stage by providing patients with information about the risks of atherosclerotic diseases. Early detection and treatment may reduce the severity or risks of complications and damage caused by atherosclerotic diseases, as well as possibly contributing to improved quality of life. In this study, we evaluated carotid artery calcification visible on panoramic radiographs. However, it seems that further detailed analysis is needed to examine the association between carotid artery calcification and a past history of risk factors for arteriosclerosis.

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