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1.
Evaluation of oral wetness using an improved moisture-checking device for the diagnosis of dry mouth
Yosuke Fukushima Tetsuya Yoda Ryuichiro Araki Takayoshi Sakai Shuji Toya Kayoko Ito Saori Funayama Yuichiro Enoki Tsuyoshi Sato 《Oral Science International》2017,14(2):33-36
Purpose
In 2013, we reported the results of a third-generation oral moisture-checking device in a multicentre clinical study involving patients with dry mouth and healthy volunteers. Subsequently, several improvements have been made to the third-generation device, and a fourth-generation device is now commercially available. This study aimed to confirm the usefulness of this improved fourth-generation device in the diagnosis of dry mouth and to assess the physiological wetness of lingual mucosa by using this device.Materials and Method
This multicentre study comprised subjects with dry mouth (dry mouth group) and those without dry mouth (healthy group).Results
In this study, the degree of moisture was considerably different between the two groups. Receiver operating characteristic analysis revealed an area under the curve value of 0.831. Sensitivity and specificity values were close to 80% in cases where the degree of moisture ≥29.6 was defined as normal, ≤27.9 was defined as dry mouth, and 28.0–29.5 was defined as borderline dry mouth.Conclusions
These results suggest that the improved fourth-generation moisture-checking device can be used for the diagnosis of oral dryness. 相似文献2.
Akinari Inui Ryohei Itou Toshirou Oyama Yoshihiro Tamura Kosei Kubota Wataru Kobayashi 《Oral Science International》2017,14(2):37-39
Aims
To compare the clinical characteristics of sialolithiasis between pediatric and adult patients.Settings and Design
Subject characteristics, clinical manifestations, salivary calculi characteristics, and treatment modalities and outcomes from medical records were retrospectively compared between pediatric and adult patients with sialolithiasis visiting the Department of Oral and Maxillofacial Surgery, Hirosaki University Hospital, between 2005 and 2014.Subjects
We included 5 pediatric (all boys) and 45 adult (20 men; 25 women) patients.Results
Most patients had submandibular swelling. The calculi were located on the right in 100.0% of pediatric patients and 57.8% of adult patients. Moreover, 20.0% of pediatric patients and 35.6% of adult patients exhibited sialoliths in the glands. Calculi were <5 mm in size in 100.0% of pediatric patients and 33.3% of adult patients. Pediatric sialolithiasis treatment included intraoral retrieval under local anesthesia in 4 cases (80.0%) and spontaneous expulsion from the duct in 1 case (20.0%). Adult sialolithiasis treatment included gland resection under general anesthesia in 8 cases (17.8%), intraoral retrieval under general anesthesia in 6 cases (13.3%), intraoral retrieval under local anesthesia in 19 cases (42.2%), spontaneous expulsion in 6 cases (13.3%), and follow-up only in 6 cases (13.3%).Conclusions
A large number of relatively small and distal sialoliths in pediatric patients was removed using intraoral retrieval under local anesthesia. This difference in the choice of treatment between pediatric and adult sialolithiasis may be attributed to the size and palpability of the calculi. 相似文献3.
Noriko Hiraishi Takahiro Maruno Naoya Tochio Ryohei Sono Masayuki Otsuki Tsutomu Takatsuka Junji Tagami Yuji Kobayashi 《Dental materials》2017,33(1):33-42
Objective
Dentin collagen can be modified by some plant-derived flavonoids to improve properties of dentin organic matrix. Hesperidin (HPN), a hesperetin-7-O-rutinoside flavonoid, has a potential of dentin modification for being based on evidence that a treatment with HPN may resist collagenase degradation and arrest demineralization of human dentin. In this study, biophysical and molecular-level information on the interaction of HPN and collagen was investigated.Methods
HPN is extracted from citrus fruits. Sample collagenous solution was prepared using atelocollagen (ATCL) as a triple-helical peptide model. We have performed circular dichroism spectroscopic analysis, sedimentation velocity measurement by ultracentrifuge and saturation transfer difference measurement (STD) by NMR on HPN-collagen in solution state.Results
The circular dichroism and sedimentation velocity measurement showed the evidence for the molecular interaction between ATCL and HPN, while HPN did not induce any conformational change of ATCL. The STD-NMR study further confirmed this interaction and suggested that HPN interacted with ATCL through its aromatic part, not through its disaccharide moiety.Significance
These findings indicated that HPN is weakly bound to ATCL not causing structural modification of collagen. This interaction may contribute to the preservation of collagen by protecting from collagenase degradation. 相似文献4.
Saad B. Qasim Shariq Najeeb Robin M. Delaine-Smith Andrew Rawlinson Ihtesham Ur Rehman 《Dental materials》2017,33(1):71-83
Objective
The regeneration of periodontal tissues lost as a consequence of destructive periodontal disease remains a challenge for clinicians. Guided tissue regeneration (GTR) has emerged as the most widely practiced regenerative procedure. Aim of this study was to electrospin chitosan (CH) membranes with a low or high degree of fiber orientation and examines their suitability for use as a surface layer in GTR membranes, which can ease integration with the periodontal tissue by controlling the direction of cell growth.Methods
A solution of CH-doped with polyethylene oxide (PEO) (ratio 95:5) was prepared for electrospinning. Characterization was performed for biophysiochemical and mechanical properties by means of scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, swelling ratio, tensile testing and monitoring degradation using pH analysis, weight profile, ultraviolet–visible (UV–vis) spectroscopy and FTIR analysis. Obtained fibers were also assessed for viability and matrix deposition using human osteosarcoma (MG63) and human embryonic stem cell-derived mesenchymal progenitor (hES-MP) cells.Results
Random and aligned CH fibers were obtained. FTIR analysis showed neat CH spectral profile before and after electrospinning. Electropsun mats were conducive to cellular attachment and viability increased with time. The fibers supported matrix deposition by hES-MPs. Histological sections showed cellular infiltration as well.Significance
The surface layer would act as seal to prevent junctional epithelium from falling into the defect site and hence maintain space for bone regeneration. 相似文献5.
Pietro Ausiello Stefano Ciaramella Franklin Garcia-Godoy Antonio Gloria Antonio Lanzotti Saverio Maietta Massimo Martorelli 《Dental materials》2017,33(1):e39-e47
Objective
To study the influence of the different class II mesio-occlusal-distal (MOD) cavity shape on the stress and strain distributions in adhesive indirect restorations, using numerical finite element analysis (FEA). To investigate the relationship between restored teeth failure and stiffness of food, three values of Young’s modulus were used for the food.Methods
A 3D model of a sound lower molar and three class II MOD cavities with different shape were created. Slide-type contact elements were used between tooth surface and food. An adhesive resin-based cement, modeled with fixed-type contact elements, and a single restorative filling materials were considered. To simulate polymerization shrinkage effect, which is basically restricted to the thin composite cement layer, shell elements were employed and the thermal expansion approach was used. A vertical occlusal load of 600 N was applied, while assigning fixed zero-displacements on the cutting surfaces below the crevices. All the materials were assumed to be isotropic and elastic. A static linear analysis was carried out.Results
In the lingual cusp, the displacements increased as the values of the stiffness food increased. In the restored teeth, the stress near the restoration-tooth interface was strongly dependent on the MOD cavity shape. The stress peaks were mainly located along the enamel–dentin interface at the lingual side; wedge-shaped MOD cavity with a low angle, in combination with the lowest food stiffness provided the best results.Significance
A more complex load application on the occlusal surfaces was introduced. Food stiffness slightly affected the stress distribution of the restored and sound teeth. Teeth with adhesive class II MOD indirect resin composite restorations were potentially more susceptible to damage if the class II MOD cavity-margin-angle was higher than 95°. Restored teeth with a higher cavity-margin-angle led to considerable stress concentration in the lingual cusp along the enamel–dentin interface. These models were more susceptible to fracture in the lingual cusps when compared to the buccal ones. 相似文献6.
Tritala K. Vaidyanathan Jayalakshmi Vaidyanathan Pambadikandathil Philipose Lizymol Saraswathy Ariya Kalliyana Venketeswaran Krishnan 《Dental materials》2017,33(1):1-11
Objective
The goal of the study was to characterize the efficiency of polymerization of Type 1 and Type 2 initiators for visible light cure of a BisGMA-TEGDMA monomer mixture.Methods
Raman spectroscopy was used to follow conversion during polymerization of a BisGMA-TEGDMA mixture using a Type I photoinitiator diphenyl(2,4,6 dimethylbenzoyl)phosphine oxide (TPO) and a Type II photoinitiator camphorquinone (CQ) and an amine, both initiators at 0.5 wt.%. Different light exposure times and storage times after light curing were used as variables.Results
There was a significant difference between the relative exposure times of TPO and CQ/amine (5 s for TPO vs. 20 s for CQ/Amine) for attaining maximum % conversion (78% in TPO vs. 65% in CQ/Amine). There was also a significant difference in the effect of storage time (no effect in TPO vs. increased % conversion with CQ/Amine). These effects are attributed to differences in the rate controlling steps of free radical generation in Type 1/Type 2 initiators, and the potential for radiative and non-radiative energy losses in CQ/Amine in its excited state.Conclusions
The results confirm that photo-polymerization of BisGMA is much more efficient with TPO than with CQ/amine. Both exposure and storage times were important variables in CQ/amine, but not in TPO.Significance
TPO photolysis generates significantly more free radicals with potentially very little radiative and non-radiative energy loss in comparison with CQ/amine. The resulting improved monomer conversion is of major importance in resisting chemical and mechanical degradation and preventing toxicological adverse effects. 相似文献7.
Han Xie Melissa Chua Intekhab Islam Ricardo Bentini Tong Cao José Carlos Viana-Gomes Antônio Hélio Castro Neto Vinicius Rosa 《Dental materials》2017,33(1):e13-e21
Objective
The objective was to investigate the potential of graphene (Gp) to induce odontogenic and osteogenic differentiation in dental pulp stem cells (DPSC).Methods
Gp was produced by chemical vapor deposition. DPSC were seeded on Gp or glass (Gl). Cells were maintained in culture medium for 28 days. Every two days, culture medium from Gp was used to treat cells on Gl and vice versa. Mineralization and differentiation of DPSC on all substrates were evaluated after 14 and 28 days by alizarin red S staining, qPCR, immunofluorescence and FACS. Statistics were performed with two-way ANOVA and multiple comparisons were performed using Tukey's post hoc test at a pre-set significance level of 5%.Results
After 14 and 28 days, Gp induced higher levels of mineralization as compared to Gl. Odontoblastic genes (MSX-1, PAX and DMP) were down-regulated and osteogenic genes and proteins (RUNX2, COL and OCN) were significantly upregulated on Gp comparing to Gl (p < 0.05 for all cases). Medium from Gp induced downregulation of odontoblastic genes and increased bone-related gene and protein on Gl.Significance
Graphene induced osteogenic and not odontoblastic differentiation of DPSC without the use of chemical inducers for osteogenesis. Graphene has the potential to be used as a substrate for craniofacial bone tissue engineering research. 相似文献8.
H. Schweikl M. Godula C. Petzel C. Bolay K.A. Hiller W. Buchalla 《Dental materials》2017,33(1):110-118
Objective
Resin monomers such as 2-hydroxyethyl methacrylate (HEMA) induce apoptosis because of the excess formation of reactive oxygen species (ROS). The portion of ROS including superoxide anions, hydrogen peroxide or hydroxyl radicals in monomer-induced apoptosis is unknown. Here, the effectiveness of superoxide anions or hydroxyl radicals was analyzed using tempol or sodium formate as radical scavengers.Methods
RAW264.7 mouse macrophages were exposed to HEMA (0–6–8 mM) in the presence of tempol (0–0.05–0.5–5.0 mM) or sodium formate (0–1–5–10 mM). The formation of ROS using DCFH2-DA or dihydrorhodamine 123 (DHR123) as fluorescent dyes and the induction of apoptosis was determined by flow cytometry after 1 h or 24 h exposure periods. Expression of enzymes related to ROS metabolism was detected by Western blotting.Results
DCF fluorescence significantly increased after short exposure (1 h) while DHR123 fluorescence was enhanced after a long exposure period (24 h) in cells treated with HEMA. Although no influence was detected on the formation of ROS, tempol or sodium formate protected cells from HEMA-induced apoptosis. The number of cells in late apoptosis or necrosis induced with 6 or 8 mM HEMA was reduced in the presence of tempol or low concentrations of sodium formate. HEMA-induced expression of catalase, indicating oxidative stress, decreased in the presence of tempol.Significance
Superoxide anions and hydroxyl radicals contribute to HEMA-induced apoptosis. The current findings support the development of strategies based on the pharmacological inhibition of enzymes producing superoxide anions finally converted to hydroxyl radicals to compensate for potential adverse tissue reactions associated with dental composites. 相似文献9.
Jinglong Liu Quan Shi Shuo Yang Qianxin Wang Juan Xu Bin Guo 《Journal of the American Dental Association (1939)》2017,148(10):743-749.e9
Background
The relationship between levels of salivary and serum interleukin (IL)-6 and oral lichen planus (OLP) is not understood fully. The authors conducted a systematic review and meta-analysis to compare levels of salivary and serum IL-6 among people with OLP and healthy control participants.Methods
The authors searched the literature for studies whose investigators had evaluated the relationships between IL-6 and OLP before treatment. The authors used meta-analysis to compare the standardized mean differences (SMD) of the levels of salivary and serum IL-6 between people who had OLP and people who did not have OLP and between patients with erosive OLP and patients with nonerosive OLP.Results
The results of separate meta-analyses, which included 5 studies each, indicated that the levels of salivary and serum IL-6 were significantly higher among patients with OLP than among healthy control participants (SMD, 2.35; 95% confidence interval [CI], 0.50 to 4.19; P = .01; and SMD, 2.03; 95% CI, 0.74 to 3.33; P = .002; respectively). The results of a meta-analysis of 4 studies indicated that the levels of IL-6 were not significantly different between patients with erosive OLP and patients with nonerosive OLP (SMD, 1.37; 95% CI, ?0.26 to 3.00; P = .10). There was significant heterogeneity among the studies (P < .00001).Conclusions
Through the results of this meta-analysis, the authors found significant differences in the levels of IL-6 in saliva and serum between patients with OLP and healthy control participants. The authors found no differences in the levels of serum IL-6 between patients with erosive OLP and patients with nonerosive OLP. These results should be considered with caution because there was a high degree of heterogeneity among studies.Practical Implications
Levels of IL-6 in saliva and serum may be potential biomarkers for OLP. However, additional research is needed to confirm findings of this meta-analysis. 相似文献10.
Takehiro Yaguchi 《Dental materials》2017,33(1):23-32
Objective
The 10-methacryloyloxydecyl dihydrogen phosphate (MDP) (EX adhesives)-based one-step self-etch adhesives have become widely utilized due to their simplified application procedures. The aim of this study was to determine the type of the molecular species of calcium salts of MDP (MDP-Ca salts) that form a layered structure and to understand the layering mechanism of MDP-Ca salts.Methods
The EX adhesives were prepared by varying the amounts of MDP (25.6, 49.9, 80.5 and 116.1 mg) added in 1 g of the EX adhesive. Enamel and dentin reactant residues were obtained after the reaction of each EX adhesive to enamel or dentin particles for 30 s. The chemical analyses of both reactant residues were then performed.Results
The molecular species of MDP-Ca salts that form a layered structure were determined as mono-calcium salt (MCS-MD) and di-calcium salts of the MDP dimer (DCS-MD). The dentin sample showed two types of characteristic XRD peaks assigned to the layer structure, since the dentin produced DCS-MD along with MCS-MD in contrast to the enamel sample. A mono-calcium salt of the MDP monomer (MCS-MM), a predominant molecular species, was not contributed to a layered-structure formation, since the intensities of characteristic XRD peaks are limited by the production of DCS-MD and MCS-MD.Significance
The self-assembled layering of MCS-MD and DCS-MD is associated by a hydrophobic bond between two 10-methylene groups in MCS-MD and DCS-MD. The MCS-MD may form a more tightly-packed layered structure than DCS-MD by the hydrogen bonded interaction between hydroxy groups bonded to each phosphorous atom. 相似文献11.
Renan Belli Michael Wendler Dominique de Ligny Maria Rita Cicconi Anselm Petschelt Herwig Peterlik Ulrich Lohbauer 《Dental materials》2017,33(1):84-98
Objective
A deeper understanding of the mechanical behavior of dental restorative materials requires an insight into the materials elastic constants and microstructure. Here we aim to use complementary methodologies to thoroughly characterize chairside CAD/CAM materials and discuss the benefits and limitations of different analytical strategies.Methods
Eight commercial CAM/CAM materials, ranging from polycrystalline zirconia (e.max ZirCAD, Ivoclar-Vivadent), reinforced glasses (Vitablocs Mark II, VITA; Empress CAD, Ivoclar-Vivadent) and glass-ceramics (e.max CAD, Ivoclar-Vivadent; Suprinity, VITA; Celtra Duo, Dentsply) to hybrid materials (Enamic, VITA; Lava Ultimate, 3M ESPE) have been selected. Elastic constants were evaluated using three methods: Resonant Ultrasound Spectroscopy (RUS), Resonant Beam Technique (RBT) and Ultrasonic Pulse-Echo (PE). The microstructures were characterized using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Raman Spectroscopy and X-ray Diffraction (XRD).Results
Young’s modulus (E), Shear modulus (G), Bulk modulus (B) and Poisson’s ratio (ν) were obtained for each material. E and ν reached values ranging from 10.9 (Lava Ultimate) to 201.4 (e.max ZirCAD) and 0.173 (Empress CAD) to 0.47 (Lava Ultimate), respectively. RUS showed to be the most complex and reliable method, while the PE method the easiest to perform but most unreliable. All dynamic methods have shown limitations in measuring the elastic constants of materials showing high damping behavior (hybrid materials). SEM images, Raman spectra and XRD patterns were made available for each material, showing to be complementary tools in the characterization of their crystal phases.Significance
Here different methodologies are compared for the measurement of elastic constants and microstructural characterization of CAD/CAM restorative materials. The elastic properties and crystal phases of eight materials are herein fully characterized. 相似文献12.
Norio Aoyama Jun-ichi Suzuki Hiroki Sato Asuka Yoshida Yuka Shiheido Yuichi Izumi 《Journal of oral biosciences / JAOB, Japanese Association for Oral Biology》2017,59(2):104-107
Objectives
The relationship between length of leisure time and periodontal condition is unknown. The aim of this cross-sectional study was to clarify the association between leisure time and periodontal states.Methods
This study was conducted on a cross-sectional sample of male (n=68) and female (n=30) Japanese healthy workers aged between 22 and 75 years. Periodontal states, including probing pocket depth, attachment level, bleeding on probing and serum antibody level for periodontal bacteria, and self-reported work conditions were assessed.Results
Subjects with long leisure times on a weekday showed increased probing pocket depth and attachment loss compared to subjects with shorter free times. The serum antibody level of a major periodontal pathogen, Porphyromonas gingivalis, was higher in the long leisure group than in the short time group.Conclusions
Subjects with long leisure time showed aggregated periodontal condition consistent with increased serum antibody against periodontal bacteria compared to subjects with short free time. 相似文献13.
Miao Ai Zhiyun Du Siqi Zhu Hongjuan Geng Xu Zhang Qing Cai Xiaoping Yang 《Dental materials》2017,33(1):12-22
Objective
The object is to find a functional one-dimensional nanofibrous filler for composite resin, which is able to provide both efficient reinforcement and high antibacterial activity.Methods
Hydroxyapatite (HA) nanowires were synthesized via hydrothermal technique using calcium oleate as the precursor. Polydopamine (PDA)–coated HA (HA–PDA) nanowires were prepared by soaking HA nanowires in dopamine (DA) aqueous solution. Silver nanoparticles (AgNPs)–laden HA (HA–PDA–Ag) nanowires were prepared via reduction reaction by adding silver nitrate and glucose into HA–PDA suspensions in DI water. The resulted HA–PDA–Ag nanowires were then mixed into Bis-GMA/TEGDMA (50/50, w/w) at 4–10 wt.%, thermal-cured, and submitted to characterizations including mechanical properties, interfacial adhesion between filler and resin matrix, distribution of HA nanowires and AgNPs, as well as silver ion release, cytotoxicity and antibacterial activity.Results
HA–PDA–Ag nanowires were readily obtained and the loading amounts of AgNPs could be controlled by adjusting the feeding doses of silver nitrate and HA–PDA nanowires. Benefiting from the PDA surface layer, HA–PDA–Ag nanowires could disperse well in composite resin and form good interfacial adhesion with the resin matrix. In comparison with neat resin, significant increases in flexural strength and modulus of cured composites were achieved at the addition amounts of HA–PDA–Ag nanowires being 6–8 wt.%. The distribution of AgNPs was homogeneous throughout the resin matrix in all designs, which endowed the composites with high antibacterial activity against streptococcus mutans. Continuous silver ion release from composites was detected, however, it was determined the composites would have insignificant cytotoxicity based on the proliferation of L929 fibroblasts in extracts of HA–PDA–Ag nanowires.Significance
The finding proved that HA–PDA–Ag nanowires could serve as functional nanofillers for composite resins, which should help much in developing materials for satisfactory long-term clinical restorations. 相似文献14.
Jung-Hwan Lee Hae-Hyoung Lee Hae-Won Kim Je-Wook Yu Kyoung-Nam Kim Kwang-Mahn Kim 《Dental materials》2017,33(1):e1-e12
Objective
The study assessed the cytotoxicity and immunomodulatory/anti-inflammatory effect of extract from zinc oxide–eugenol (ZOE)-based dental materials during setting using immortalized human dental pulp stem cells (IHDPSCs) and mouse bone marrow monocytes (IMBMMs), and identified the responsible extract component.Methods
In accord with the ISO 10993-12, we extracted a mixture of ZOE cement and sealer after a specified time. The extract was analyzed by two types of mass spectrometry (ICP-MS and GC–MS). Cell viability was evaluated with extract and serial concentrations of ZnCl2, ZnSO4, and eugenol liquid by WST assay. The immunomodulatory/anti-inflammatory effect of a ZOE component was determined by RT-PCR to detect the downregulatory effect of inflammatory mRNA expression after lipopolysaccharide (LPS)-induced inflammation.Results
Zn2+ and eugenol (2–20 ppm) were detected in the ZOE cement and sealer extracts. During the early stage of setting, significant cytotoxicity was observed in IHDPSCs and IMBMMs (p < 0.05). The half maximal effective concentration of Zn2+ was 5–8 ppm, whereas that of eugenol could not be detected within 80 ppm. After extract treatment, the expression of inflammatory mRNA was significantly lower in inflamed IHDPSCs, but not inflamed IMBMMs, than in the LPS control (p < 0.05). However, eugenol, not Zn2+, at 5–20 ppm downregulated inflammatory mRNA expression in the inflamed IMBMMs with and without the exchange of LPS-pretreated medium.Significance
ZOE was highly cytotoxic, especially during setting, to both cells due to Zn2+ while the immunomodulatory/anti-inflammatory effect of ZOE was induced by eugenol. 相似文献15.
Erica Roitero Federico Lasserre Marc Anglada Frank Mücklich Emilio Jiménez-Piqué 《Dental materials》2017,33(1):e28-e38
Objective
The aim of this work is to generate micrometric linear patterns with different topography on dental grade zirconia by means of UV laser interference and to assess the quality of the produced surface, both in term of the geometry produced and of the surface damage induced in the material.Methods
The third harmonic of a Q-switched Nd:YAG laser (355 nm, pulse duration of 10 ns and repetition rate of 1 Hz) was employed to pattern the surface of 3Y-TZP with micrometric-spaced lines. The resulting topography was characterized with White Light Interferometry and Scanning electron microscopy: pattern depth (H), amplitude roughness parameters (Sa, filtered-Sa), Fourier spatial analysis and collateral damages were related to laser fluence and number of pulses employed.Results
With our experimental setup, line-patterning of zirconia surfaces can be achieved with periodicities comprised within 5 and 15 μm. Tuning laser parameters allows varying independently pattern depth, overall roughness and surface finish. Increasing both fluence and number of pulses allows producing deeper patterns (maximum achievable depth of 1 μm). However, increasing the number of pulses has a detrimental effect on the quality of the produced lines. Surface damage (intergranular cracking, open porosity and nano-droplets formation) can be generated, depending on laser parameters.Significance
This work provides a parametric analysis of surface patterning by laser interference on 3Y-TZP. Best conditions in terms of quality of the produced pattern and minimum material damage are obtained for low number of pulses with high laser fluence. With the employed method we can produce zirconia materials with controlled topography that are expected to enhance biological response and mechanical performance of dental components. 相似文献16.
17.
Lena Rothmund Franz-Xaver Reichl Reinhard Hickel Panorea Styllou Marianthi Styllou Kai Kehe Yang Yang Christof Högg 《Dental materials》2017,33(1):54-62
Objective
An increment layering technique in a thickness of 2 mm or less has been the standard to sufficiently convert (co)monomers. Bulk fill resin composites were developed to accelerate the restoration process by enabling up to 4 mm thick increments to be cured in a single step. The aim of the present study is to investigate the effect of layer thickness on the elution of components from bulk fill composites.Methods
The composites ELS Bulk fill, SDR Bulk fill and Venus Bulkfill were polymerized according to the instruction of the manufacturers. For each composite three groups with four samples each (n = 4) were prepared: (1) samples with a layer thickness of 2 mm; (2) samples with a layer thickness of 4 mm and (3) samples with a layer thickness of 6 mm. The samples were eluted in methanol and water for 24 h and 7 d. The eluates were analyzed by gas chromatography/mass spectrometry (GC/MS).Results
A total of 11 different elutable substances have been identified from the investigated composites. Following methacrylates showed an increase of elution at a higher layer thickness: TEGDMA (SDR Bulk fill, Venus Bulk fill), EGDMA (Venus Bulk fill). There was no significant difference in the elution of HEMA regarding the layer thickness. The highest concentration of TEGDMA was 146 μg/mL for SDR Bulk fill at a layer thickness of 6 mm after 7 d in water. The highest HEMA concentration measured at 108 μg/mL was detected in the methanol eluate of Venus Bulk fill after 7 d with a layer thickness of 6 mm.Significance
A layer thickness of 4 mm or more can lead to an increased elution of some bulk fill components, compared to the elution at a layer thickness of 2 mm. 相似文献18.
Midori Nakamura Yuko Nakamichi Toshihide Mizoguchi Masanori Koide Teruhito Yamashita Toshiaki Ara Hiroshi Nakamura Josef M. Penninger Yuriko Furuya Hisataka Yasuda Nobuyuki Udagawa 《Journal of oral biosciences / JAOB, Japanese Association for Oral Biology》2017,59(3):146-151
Objective
A RANKL-binding peptide, WP9QY (W9), is known to inhibit mouse osteoclastogenesis by stimulating the production of autocrine factors such as bone morphogenetic proteins (BMPs) to induce osteoblast differentiation. In the present study, we investigated whether osteoblastic differentiation is mediated by RANKL signaling.Methods
The effect of W9 on the differentiation of osteoclasts and osteoblasts was examined in mouse bone-marrow cultures, and in a mouse co-culture system consisting of primary osteoblasts derived from RANKL-deficient or wild-type (WT) newborn mouse calvariae, with WT-derived bone marrow mononuclear cells.Results
The addition of the W9 peptide to the WT mouse bone-marrow culture simultaneously inhibited RANKL-induced tartrate-resistant acid phosphatase (TRAP)-positive osteoclast differentiation, and stimulated alkaline phosphatase (ALP)-positive osteoblastic calcified nodule formation. RANKL-deficient osteoblasts exhibited weak ALP activity compared to WT osteoblasts. W9 treatment strongly inhibited TRAP-positive osteoclast formation, and stimulated ALP-positive osteoblast differentiation in co-cultures of WT-derived osteoblasts and bone-marrow cells, in the presence of bone-resorbing factors. In contrast, W9 exerted only a weak effect on ALP-positive osteoblast differentiation in co-cultures with RANKL-deficient osteoblasts, even in the presence of the W9 peptide, parathyroid hormone, and/or BMP-2.Conclusions
The W9 peptide inhibited RANKL-mediated osteoclast formation in osteoblasts. It also directly stimulated osteoblast differentiation, both via RANKL signaling-mediated autocrine factors, and alternative mechanisms. 相似文献19.
20.
Ji won Kim Joo-Cheol Park 《Journal of oral biosciences / JAOB, Japanese Association for Oral Biology》2017,59(4):211-217