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ABSTRACT: MicroRNAs (miRNAs) are small RNA molecules of 21-25 nucleotides that regulate cell behavior through inhibition of translation from mRNA to protein, promotion of mRNA degradation and control of gene transcription. In this study, we investigated the miRNA expression signatures of cell cultures undergoing osteoblastic and osteocytic differentiation from mesenchymal stem cells (MSC) using mouse MSC line KUSA-A1 and human MSCs. Ninety types of miRNA were quantified during osteoblastic/osteocytic differentiation in KUSA-A1 cells utilizing miRNA PCR arrays. Coincidently with mRNA induction of the osteoblastic and osteocytic markers, the expression levels of several dozen miRNAs including miR-30 family, let-7 family, miR-21, miR-16, miR-155, miR-322 and Snord85 were changed during the differentiation process. These miRNAs were predicted to recognize osteogenic differentiation-, stemness-, epinegetics-, and cell cycle-related mRNAs, and were thus designated OstemiR. Among those OstemiR, the miR-30 family was classified into miR-30b/c and miR-30a/d/e groups on the basis of expression patterns during osteogenesis as well as mature miRNA structures. In silico prediction and subsequent qRT-PCR in stable miR-30d transfectants clarified that context-dependent targeting of miR-30d on known regulators of bone formation including osteopontin/spp1, lifr, ccn2/ctgf, ccn1/cyr61, runx2, sox9 as well as novel key factors including lin28a, hnrnpa3, hspa5/grp78, eed and pcgf5. In addition, knockdown of human OstemiR miR-541 increased Osteopontin/SPP1 expression and calcification in hMSC osteoblastic differentiation, indicating that miR-541 is a negative regulator of osteoblastic differentiation. These observations indicate stage-specific roles of OstemiR especially miR-541 and the miR-30 family on novel targets in osteogenesis.
PLoS ONE 01/2013; 8(3):e58796. · 4.09 Impact Factor
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Yoshizo Matsuka,
Ryu Nakajima,
Haruna Miki,
Aya Kimura,
Manabu Kanyama,
Hajime Minakuchi,
Shigehiko Shinkawa,
Hiroya Takiuchi,
Kumiko Nawachi,
Kenji Maekawa,
Hikaru Arakawa,
Takuo Fujisawa,
Wataru Sonoyama,
Atsushi Mine,
Emilio Satoshi Hara,
Takeshi Kikutani, Takuo Kuboki
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ABSTRACT: This educational trial was an eight-day problem-based learning (PBL) course for fourth-year predoctoral students at Okayama University's dental school who interviewed elderly residents living in a nursing home. The purpose of this PBL course was to introduce geriatric dentistry to the students by allowing them, independently, to discover the clinical problems of elderly patients as well as the solutions. The sixty-five students were divided into nine small groups and received patient information (age, gender, degree of care needed, medical history, food type, medications, and oral condition) in datasheets before visiting the nursing home. Each group of students directly interviewed one patient and the caregivers and identified the patient's medical, psychological, and social problems. After the interview, the students participated in a PBL tutorial to delineate a management approach for the patient's problems. To measure the efficacy of this program, the students completed a questionnaire before and after the course regarding their level of understanding of and attitudes toward geriatric dentistry, clinical research, and self-study. The results showed that student's perceptions of their knowledge about and attitudes toward oral health care for the elderly significantly increased after the PBL course, which suggests that such tutorials should be an option for dental curricula.
Journal of dental education 12/2012; 76(12):1580-8. · 0.91 Impact Factor
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ABSTRACT: OBJECTIVES: A dental adhesive without small and hydrophilic monomers such as 2-hydroxyethyl methacrylate (HEMA) and triethylene glycol dimethacrylate (TEGDMA) would be beneficial in order to avoid contact allergies. However, these monomers are important to increase infiltration and polymerization of the adhesive. Therefore, the purpose of this study was to evaluate the bonding effectiveness and bond durability of a more hydrophobic and biocompatible adhesive as compared to a conventional three-step etch-and-rinse adhesive. METHODS: Sixteen non-carious human third molars were used to determine the micro-tensile bond strength testing (μTBS) and interfacial ultrastructure by transmission electron microscopy (TEM) of the more hydrophobic cmf adhesive system (Saremco) adhesive as compared to the control OptiBond FL (Kerr). RESULTS: The more hydrophobic and biocompatible three-step etch-and-rinse adhesive was able to produce a reasonable short-time bonding effectiveness. In the long term, the collagen fibrils in the hybrid layer were not effectively protected and were prone to hydrolytic degradation. As a result, long-term bonding effectiveness of this novel adhesive was very low. CONCLUSIONS: Application of a more hydrophobic adhesive without altering the application procedure considerably results in a reduced durability of the created bond CLINICAL RELEVANCE: Omitting small and hydrophilic components from the adhesive formulation may impair the durability of your composite restoration.
Clinical Oral Investigations 12/2012; · 2.36 Impact Factor
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Emilio Satoshi Hara,
Mitsuaki Ono,
Satoshi Kubota,
Wataru Sonoyama,
Yasutaka Oida,
Takako Hattori,
Takashi Nishida,
Takayuki Furumatsu,
Toshifumi Ozaki,
Masaharu Takigawa, Takuo Kuboki
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ABSTRACT: A significant number of natural compounds have been shown to regulate the behavior of the cells, in collaboration with cellular proteins. CCN2/connective tissue growth factor (CTGF) has been reported to have essential roles in cartilage development, chondrocyte proliferation and differentiation as well as regulation of the extracellular matrix metabolism. Previous studies demonstrated the capability of CCN2 to regenerate surgical defects in articular cartilage of rat knee. Also, transgenic mice over-expressing cartilage-specific CCN2 were shown to be more resistant to aging-related cartilage degradation. We hypothesized that small molecules that induce CCN2 in chondrocytes could be novel candidates to increase the resistance to aging-related cartilage degradation, or even to correct cartilage degenerative changes incurred in OA. Therefore, this study screened a compound library and identified the β-carboline alkaloid harmine as a novel inducer of CCN2 in human chondrocytic HCS-2/8 cells and osteoarthritic articular chondrocytes. Harmine increased the expression of the cartilage markers aggrecan and type II collagen, as well as that of the master regulator of chondrogenesis, Sox-9. Moreover, harmine notably induced chondrogenesis of prechondrocytic ATDC5 cells in micromass cultures. The chondroprotective effect of harmine was investigated under inflammatory condition by stimulation with TNFα, and harmine was shown to ameliorate TNFα-induced decrease in expression of CCN2 and cartilage markers. These findings uncover novel chondrogenic effects of harmine and indicate harmine as a potential drug for prevention and/or repair of cartilage degradation.
Biochimie 10/2012; · 3.02 Impact Factor
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ABSTRACT: PURPOSE: Current clinical procedures to control or regenerate bone loss due to peri-implantitis are not predictable neither accomplish complete resolution. Therefore, early detection of the onset and the active periods of bone loss are crucial for prevention of extensive peri-implant bone resorption. This study aimed to determine a possible association between the presence of collagenases (MMP-1, MMP-8 and MMP-13) in peri-implant sulcular fluid (PISF) and active periods of bone loss by annually adjusted vertical bone loss (AVBL) measurements. METHODS: Intended sample consisted of 76 consecutive patients who received oral implant treatment at the Fixed Prosthodontic Clinic of Okayama University Hospital from 1990 to 2000. Twelve subjects were lost to follow-up or refused to participate. Consequently, the actual sample consisted of 64 patients who were followed-up for at least one year. Those patients with AVBL>0.6mm were included in the severe peri-implantitis group, and randomly selected, age-, gender- and implantation site-matched healthy patients (AVBL<0.3mm) comprised the control group. PISF samples were collected from both groups and further analyzed by western blot for detection of collagenases. RESULTS: Four patients presented severe peri-implantitis. MMP-8 was the only collagenase detected in peri-implant sites with ongoing bone loss. PISF samples from control group showed no positive reactions to any collagenase. CONCLUSION: This study showed MMP-8 as a possible marker for progressive bone loss in peri-implantitis.
Journal of prosthodontic research. 10/2012;
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ABSTRACT: CCN family proteins 2 and 3 (CCN2 and CCN3) belong to the CCN family of proteins, all having a high level of structural similarity. It is widely known that CCN2 is a profibrotic molecule that mediates the development of fibrotic disorders in many different tissues and organs. In contrast, CCN3 has been recently suggested to act as an anti-fibrotic factor in several tissues. This CCN3 action was shown earlier to be exerted by the repression of the CCN2 gene expression in kidney tissue, whereas different findings were obtained for liver cells. Thus, the molecular action of CCN3 yielding its anti-fibrotic effect is still controversial. Here, using a general model of fibrosis, we evaluated the effect of CCN3 overexpression on the gene expression of all of the CCN family members, as well as on that of fibrotic marker genes. As a result, repression of CCN2 gene expression was modest, while type I collagen and α-smooth muscle actin gene expression was prominently repressed. Interestingly, not only CCN2, but also CCN4 gene expression showed a decrease upon CCN3 overexpression. These findings indicate that fibrotic gene induction is under the control of a complex molecular network conducted by CCN family members functioning together.
Journal of Cell Communication and Signaling 10/2012;
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ABSTRACT: The purpose of this study was to evaluate if a low-shrinking composite can improve the bonding effectiveness of adhesives in highly constrained conditions. A low-shrinking composite ('els-extra low shrinkage', Saremco) was bonded in standardized occlusal Class-I cavities using a three-step ('cmf', Saremco) and a two-step etch-and-rinse adhesive ('XP Bond', Dentsply). Both adhesives were also combined with a conventional composite ('Z100', 3M ESPE). Half of the restored cavities were exposed to 20,000 thermo-cycles. 3-way ANOVA revealed a significant effect for the factors 'adhesive' and 'composite' (both p<0.0001), but not for 'thermo-cycling' (p=0.994). Significantly higher bond strengths were recorded for the low-shrinking composite than for the control composite, using either of the adhesives. The low-shrinking composite in combination with the three-step etch-and-rinse adhesive performed best in the high C-factor Class-I cavity. The two-step etch-and-rinse adhesive suffered strongly from polymerization-shrinkage stress, which could be partially restored by using the low-shrinking composite.
Dental Materials Journal 05/2012; 31(3):418-26. · 1.14 Impact Factor
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ABSTRACT: Self-etch adhesives are well adopted in general practice, obviously primarily thanks to their ease of use and fast application time. Nevertheless, phosphoric acid is still often recommended to beforehand etch enamel following a so-called 'selective' enamel-etch technique, this in particular when most cavity margins end in enamel. The purpose of this study was to test if a new one-step adhesive can be applied in a multi-mode manner, this following different, either 'full' or 'selective', self-etch and etch-and-rinse approaches. Specific research hypotheses tested were that prior phosphoric-acid etching did not affect the bonding effectiveness of the one-step adhesive to enamel and dentine, and that the bonding effectiveness to dentine was also not affected when the adhesive was applied either following a 'dry-bonding' or 'wet-bonding' etch-and-rinse technique.
The micro-tensile bond strength (μTBS) of the one-step self-etch adhesive G-Bond Plus (GC, Tokyo, Japan; 1-SEA) was measured when it was bonded to bur-cut enamel following either a 'self-etch' or an 'etch-and-rinse' adhesive protocol, and to bur-cut dentine when applied following either a 'self-etch', a 'dry-bonding' or a 'wet-bonding' etch-and-rinse adhesive protocol. Bond-strength testing was corroborated by ultra-structural analysis of the interfacial interaction at enamel and dentine using transmission electron microscopy (TEM).
Prior phosphoric-acid etching significantly increased the bonding effectiveness of the 1-SEA to enamel. A clearly enhanced micro-retentive surface was revealed by TEM. To dentine, no statistically significant difference in bonding effectiveness was recorded when the 1-SEA was either applied following a self-etch or both etch-and-rinse approaches. The 'dry-bonding' etch-and-rinse protocol was significantly more effective than its 'wet-bonding' version. TEM however revealed indications of low-quality hybridisation following both etch-and-rinse approaches, in particular in the form of a porous and poorly resin-infiltrated collagen mesh.
While phosphoric-acid etching definitely improved bonding of the one-step self-etch adhesive to enamel, one should be more careful with additional phosphoric-acid etching of dentine. Although the bond strength was not reduced, the resultant adhesive interface appeared ultra-structurally more vulnerable to biodegradation.
Journal of dentistry 02/2012; 40(6):475-84. · 2.00 Impact Factor
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ABSTRACT: Resin coating materials have been used for composite resin or provisional restoration in order to prevent plaque accumulation on their surfaces. However, it is not clear whether the coating materials influence attachment of periodontal bacteria. Therefore, we investigated the effect of resin coating materials on the attachment of Porphyromonas gingivalis (Pg). The polymerized auto cure resin plates were coated with two resin coating materials. To estimate the Pg attachment, each plate was immersed in brain heart infusion medium containing Pg. The quantity of bacteria attached on each plate was evaluated by crystal violet quantification. Morphological change of Pg was recorded using scanning electron microscopy. Both coating groups presented significantly lower Pg attachment compared to the control. The Pg shapes on the plates with resin coating materials were similar to the non-treated control plates. The resin coating materials clearly prevent Pg attachment on the polymerized auto cure resin plate.
Dental Materials Journal 02/2012; 31(1):86-91. · 1.14 Impact Factor
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ABSTRACT: PURPOSE: Small, self-contained electromyographic (EMG) detector/analyzer (D/A) devices have become available for the detection of jaw muscle activity events above threshold. These devices claim to be less intrusive to the subjects sleep so it is less prone to induce disturbed sleep. The objective of this study was to evaluate for night-to-night variability and examine for a systematic alteration on the first night in EMG levels. METHODS: Ten asymptomatic healthy volunteers (mean age, 26.8 ± 3.78) were recorded for six sequential nights in their home environment using EMG D/A system. The device yields a nightly EMG level above threshold score on a 0-4 level. Because the data are categorical and nonparametric, the data of the ten subjects across six nights were submitted to a Friedman repeated measures ANOVA. The significant level was set as alpha equal to 0.05. RESULTS: The median and mode values of the subjects were tabulated and analyzed and we did not find a significant difference in EMG D/A level across the six nights (p = 0.287, Kendall's coefficient of concordance = 0.124, Friedman two-way repeated measures ANOVA). The data did show clear and substantial night-to-night variability. CONCLUSION: Substantial night-to-night variability in masseter EMG activity levels was clearly observed in our subjects. There was no evidence of a suppressed or elevated first-night effect-like variability on masseter muscle EMG level seen in these subjects using a small portable self-contained EMG detector/analyzer. These data suggest that recordings should be at least 5-6-nights duration to establish a reasonable measure of an individual's average nightly masseter EMG level.
Sleep And Breathing 01/2012; · 1.84 Impact Factor
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Isao Hirata,
Yasuhiro Yoshida,
Noriyuki Nagaoka,
Kyou Hiasa,
Yasuhiko Abe,
Kenji Maekawa, Takuo Kuboki,
Yasumasa Akagawa,
Kazuomi Suzuki,
Bart Van Meerbeek,
Phillip B Messersmith,
Masayuki Okazaki
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ABSTRACT: Due to the high corrosion resistance and strength to density ratio titanium is widely used in industry, and also in a gamut of medical applications. Here we report for the first time on our development of a titanium passivation layer sensor that makes use of surface plasmon resonance (SPR). The deposited titanium metal layer on the sensor was passivated in air, similarly to titanium medical devices. Our "Ti-SPR sensor" enables analysis of biomolecule interactions with the passivated surface of titanium in real time. As a proof of concept, corrosion of a titanium passivation layer exposed to acid was monitored in real time. The Ti-SPR sensor can also accurately measure the time-dependence of protein adsorption onto the titanium passivation layer at sub-nanogram per square millimeter accuracy. Besides such SPR analyses, SPR imaging (SPRI) enables real time assessment of chemical surface processes that occur simultaneously at "multiple independent spots" on the Ti-SPR sensor, such as acid corrosion or adhesion of cells. Our Ti-SPR sensor will therefore be very useful to study titanium corrosion phenomena and biomolecular titanium-surface interactions with application in a broad range of industrial and biomedical fields.
Acta biomaterialia 12/2011; 8(3):1260-6. · 3.98 Impact Factor
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ABSTRACT: A great challenge regarding the ease-of-use of composites involves the development of 'self-adhesive' composites that no longer require a separate adhesive to bond to tooth enamel/dentin.
To characterize the interfacial ultra-structure of an experimental self-adhesive filling material bonded to enamel and dentin using transmission electron microscopy (TEM).
The experimental self-adhesive material was bonded to bur-cut human enamel and dentin, and to fractured (smear-free) dentin, strictly according to the manufacturers' instructions. The specimens were stored for 1 day in distilled water (37 °C) prior to further common specimen processing for TEM.
The experimental self-adhesive filling material revealed a typical micro-hybrid filler distribution. At bur-cut enamel, a tight interface was formed, mostly exhibiting only tiny micro-tags without distinct surface demineralization. At bur-cut dentin, the experimental self-adhesive filling material interacted superficially, with the surface structure being more irregular because of the bur preparation. No clear resin tags were formed due to the obstruction of dentin tubules with smear plugs. At fractured dentin, the formation of a relatively thin hybrid layer of maximum a few hundreds of nanometer was disclosed without clear surface demineralization. Distinct resin tags were formed due to the absence of smear plugs. Silver-nitrate infiltration showed a pattern of spot-like appearance of nano-leakage. Ag deposition was observed more along the dentin-adhesive interface of bur-cut dentin, as compared to that of fractured dentin.
The obtained tight interface at both enamel and dentin demonstrates the self-adhesive capacity of the experimental self-adhesive filling material.
Dental materials: official publication of the Academy of Dental Materials 05/2011; 27(8):818-24. · 2.88 Impact Factor
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ABSTRACT: This study evaluated the test-retest reliability for determining the temporomandibular joint (TMJ) disk position, diagnosed using magnetic resonance imaging (MRI). These assessments were done as a base-line measurement for a prospective cohort study, which examines the risk factors for precipitation and progression of temporomandibular disorders. Fifteen subjects (mean age, 24.2 ± 0.94 years; male/female = 8/7) were recruited from the students of Okayama University Dental School. Sagittal MR TMJ images were taken with a 1.5-T MR scanner (Magneton Vision, Siemens) in close and maximal open positions twice at about 1-week (6-11 days) interval. The images were displayed using 200% magnification on a computer screen with a commercially available image software package (OSIRIS, UIN/HCUG). Three calibrated examiners diagnosed the disk positions using the standardized criteria. The disk position of each joint was classified as normal, anterior disk displacement with or without reduction, and others. The first and second disk position diagnoses were compared, and the test-retest reliability level was calculated using the kappa index. The second disk position diagnosis was consistent with the first in 27 out of 30 joints. The calculated kappa value representing the test-retest reliability level between the first and second disk position diagnosis was 0.812. These results indicated that the test-retest reliability of MRI-based diagnosis of TMJ disk positions at about 1-week interval was substantially high, even though they were not completely consistent.
Clinical Oral Investigations 10/2010; 16(1):101-8. · 2.36 Impact Factor
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ABSTRACT: The aim of this study was to investigate the intramuscular metabolic state in chronically painful muscles using positron-emission tomography/computerized tomography (PET/CT).
The study included 140 consecutive noncancer subjects who underwent PET/CT screening for a physical checkup (mean age 56.0 +/- 10.22 y). The demographic data and information on pain in the neck/shoulder region were obtained using a questionnaire. The subjects who had an awareness of pain in the neck/shoulder region for >6 months were regarded to be pain subjects (n = 39). The minimal and maximal standardized uptake values (SUV) of [(18)F]fluorodeoxyglucose ((18)F-FDG) of the trapezius muscle in each subject were automatically calculated.
The unpaired t test revealed that both the minimal and the maximal SUVs were significantly lower in the pain subjects than in the asymptomatic subjects. A multiple linear regression analysis also demonstrated a significant association between pain in the neck/shoulder region and the SUVs in the trapezius muscle.
Uptake of (18)F-FDG was lower in the chronically painful trapezius muscle.
Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics 07/2010; 110(1):54-61. · 1.50 Impact Factor
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ABSTRACT: CCN2/CTGF, previously known as Connective Tissue Growth Factor, is a crucial regulator of extra-cellular matrix (ECM), which
promotes ECM synthesis and stabilization. As their family name clearly implies, matrix metalloproteases (MMPs) are also localized
in the ECM, where they function as proteases, modulating cell signaling by cleaving proteins such as matrix proteins, growth
factors and growth factor receptors. Strong expression of CCN2/CTGF in chondrocytic cells occurs through transcription enhancer
dominant in chondrocytes (TRENDIC). Matrix metalloprotease-3 (MMP3) is a novel TRENDIC-binding transcription factor for CCN2/CTGF
expression. First, MMP3 cDNA was cloned as a TRENDIC-binding factor by Southwestern screening. The interaction between MMP3
and TRENDIC was confirmed by a gel shift assay and chromatin immunoprecipitation. The CCN2/CTGF promoter was activated by transfected MMP3, whereas a TRENDIC mutant for the promoter lost the response. In addition, the
knockdown of MMP3 suppressed CCN2/CTGF expression. Cytochemical and histochemical analyses demonstrated that MMP3 was detected
in the nuclei of chondrocytic cells in culture and also in the nuclei of normal and osteoarthritic chondrocytes in vivo. The
nuclear translocation of externally added recombinant MMP3 was observed in 30min after the addition, and six putative nuclear
localization signals were found in MMP3. These results indicated a novel trans-activation mechanism of CCN2/CTGF by the nuclear translocation of MMP3 through binding with TRENDIC in chondrocytes. Although
MMPs historically had been recognized as a protease for extra-cellular proteins, this study indicated that it also stimulates
ECM synthesis through CCN2/CTGF trans-activation. This novel regulatory role of the ECM may contribute to understanding the mechanism of not only the development,
but also the pathogenesis of arthritis fibrosis and periodontitis.
KeywordsCCN2/CTGF-Nuclear MMP3-Transcription-Chondrocytes
04/2010: pages 255-264;
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ABSTRACT: The low-shrinking composite composed of combined siloxane-oxirane technology (Filtek Silorane, 3M ESPE, Seefeld, Germany) required the development of a specific adhesive (Silorane System Adhesive, 3M ESPE), in particular because of the high hydrophobicity of the silorane composite. The purpose of this study was to characterize the interfacial ultra-structure at enamel and dentin using transmission electron microscopy (TEM).
Non-demineralized/demineralized 70-90 nm sections were prepared following common TEM specimen processing procedures.
TEM revealed a typical twofold build-up of the adhesive resin, resulting in a total adhesive layer thickness of 10-20 microm. At bur-cut enamel, a tight interface without distinct dissolution of hydroxyapatite was observed. At bur-cut dentin, a relatively thin hybrid layer of maximum a few hundreds of nanometer was formed without clear surface demineralization. No clear resin tags were formed. At fractured dentin, the interaction appeared very superficial (100-200 nm). Distinct resin tags were formed due to the absence of smear plugs. Silver-nitrate infiltration showed a varying pattern of both spot- and cluster-like appearance of nano-leakage. Traces of Ag were typically detected along some part of the enamel-adhesive interface and/or between the two adhesive resin layers. Substantially more Ag-infiltration was observed along the dentin-adhesive interface of bur-cut dentin, as compared to that of fractured dentin.
The nano-interaction of Silorane System Adhesive should be attributed to its relatively high pH of 2.7. The obtained tight interface at both enamel and dentin indicates that the two-step self-etch adhesive effectively bridged the hydrophilic tooth substrate with the hydrophobic silorane composite.
Dental materials: official publication of the Academy of Dental Materials 03/2010; 26(6):524-32. · 2.88 Impact Factor
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ABSTRACT: The objective of this study was to investigate the association between TMJ pain/disk pathosis and the muscle tenderness pattern in the orofacial and neck/shoulder region.
One hundred seventy-one TMD patients were divided into 4 groups, including group 1: patients with painful unilateral TMJ disk displacement (DD); group 2: patients with painless unilateral TMJ DD; group 3: patients with painless bilateral TMJ DD; and group 4: patients with a bilateral normal TMJ disk position (n = 41). Each subject underwent muscle palpation and the side-by-side number of muscle tenderness points was combined as the number of muscle tenderness points on each side. Within each group, DD with and without reduction subjects were separated into subgroups and then were analyzed.
In group 1, the median muscle tenderness points on the side with painful TMJ DD without reduction was significantly higher than on the normal side (P = .019), whereas the palpation scores for painless DD patients showed no significant difference between the DD and normal sides.
These results indicated painful disk displacement to possibly be correlated with ipsilateral muscle tenderness.
Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics 01/2010; 109(1):86-90. · 1.50 Impact Factor
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ABSTRACT: To examine gene expression profile changes in the mouse masseter muscle tissue after repetitive electrical stimulation by using a DNA microarray technique.
Nine male ICR mice aged 10 weeks were used. Each anesthetized mouse was secured on a platform in a supine position and the masseter muscle tissues on both sides were exposed. Bipolar electrodes were set on the right masseteric fascia to electrically stimulate the masseter muscle (8 V, 10 Hz, 20 ms) for 30 min. After cessation of stimulation bilateral masseter muscle tissues were sampled at 0 h (n=3), 1h (n=3), 2h (n=3). Total RNA was isolated from the homogenized muscle tissues and purified mRNA samples (50 microg) were processed and hybridized with microarray slides. Probe arrays were then scanned and analyzed to calculate the signal density. Gene expression profiles were compared at each time point between the right (stimulation side) and left (control side) masseter. When the gene expression levels were different more than 2-fold, the difference was regarded as positive.
Of the 6400 genes assessed, 1733 genes were up-regulated and 515 genes were down-regulated in the stimulation side at least once during the experimental time course. These up- or down-regulated genes were associated with autoimmune/inflammatory disease (28/114), cardiovascular disease (17/61), neuroscience (12/50), apoptosis (27/93), diabetes/obesity (9/28), signal transduction (66/250) and others. 28 genes were up-regulated and 25 genes were down-regulated at all time points.
Dramatic gene expression changes were induced by the repetitive electrical muscle stimulation in mouse masseter.
Journal of prosthodontic research. 10/2009; 54(1):36-41.
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ABSTRACT: Among contemporary adhesives, self-etch adhesives have been adopted by general practitioners for routine adhesive restorative purposes, mainly because of their ease of use. However, many versions that differ for their clinical application procedure, pH, number of components, etc., are currently available on the market. The purpose of this study was to determine the bonding effectiveness of two new self-etch adhesives (Adper Easy Bond and Adper ScotchBond SE, 3M ESPE) to enamel and dentin using a micro-tensile bond strength (microTBS) protocol and to characterise the interfacial ultra-structure at enamel and dentin using transmission electron microscopy (TEM).
The adhesives were applied onto coronal human enamel and dentin surfaces and built up with the micro-hybrid resin composite Z100 (3M ESPE). The 'gold-standard' two-step self-etch adhesive Clearfil SE Bond (Kuraray) served as control. Specimens were sectioned to sticks and trimmed at the interface to a cylindrical hour-glass shape ('trimmed' micro-specimens). Non-demineralized and demineralized TEM sections through the adhesive-dentin/enamel interface were prepared by ultra-microtomy.
The microTBS of the two self-etch adhesives to enamel was statistically significantly lower than that of the control. To dentin, the microTBS of Adper Easy Bond was significantly lower than that of Adper ScotchBond SE and the control. TEM showed a tight interface to enamel for all three self-etch adhesives. A relatively thick, completely demineralized and acid-resistant hybrid layer was formed at dentin by Adper ScotchBond SE, whereas the interaction of Adper Easy Bond was much shallower, and comparable to that of so-called 'ultra-mild' self-etch adhesives. Some degree of spot- and cluster-like nano-leakage was observed for both adhesives, but did not differ in extent and form from that observed for the control.
Although the new two self-etch adhesives revealed a tight interaction at both enamel and dentin, their bond strength to both tooth tissues was generally lower than that of the control adhesive. Nevertheless, their bonding effectiveness appears in line with other simplified self-etch adhesives.
Journal of dentistry 08/2009; 37(11):872-83. · 2.00 Impact Factor
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Yosuke Okamoto,
Wataru Sonoyama,
Mitsuaki Ono,
Kentaro Akiyama,
Takuo Fujisawa,
Masamitsu Oshima,
Yohei Tsuchimoto,
Yoshizo Matsuka,
Tatsuji Yasuda,
Songtao Shi, Takuo Kuboki
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ABSTRACT: Statin, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, is known to promote bone formation. However, it is not clear whether statin affects the differentiation of pulp cells. This study used a cell proliferation assay, cell cycle analysis, quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and in vivo transplantation to examine the effects of simvastatin on human dental pulp stem cells (DPSCs) in vitro and in vivo. Simvastatin at 1 mumol/L was able to significantly suppress the proliferation of DPSCs without inducing apoptosis. Quantitative RT-PCR revealed both osteocalcin and dentin sialophosphoprotein to be significantly up-regulated when DPSCs were cultured with simvastatin in comparison to bone morphogenetic protein-2 treatment. The in vivo transplantation data showed that simvastatin treatment promoted mineralized tissue formation. Taken together, these results suggest that statin might be an ideal active ingredient to accelerate the differentiation of DPSCs.
Journal of endodontics 04/2009; 35(3):367-72. · 2.95 Impact Factor