Dental Materials Journal
Online ISSN : 1881-1361
Print ISSN : 0287-4547
ISSN-L : 0287-4547
早期公開論文
早期公開論文の26件中1~26を表示しています
  • Qiuying GAO, Yuli SHANG, Weiwei ZHOU, Shu DENG, Cheng PENG
    原稿種別: research-article
    論文ID: 2021-323
    発行日: 2022年
    [早期公開] 公開日: 2022/08/05
    ジャーナル フリー 早期公開

    The purpose of this study was to analyze the therapeutic effects of marine collagen peptides (MCPs) from tilapia skin on oral mucosal ulcers in a rat model. CCK-8 and wound healing assays were performed in vitro to evaluate proliferation and migration of L929 cells after treatment with MCPs. The effects of MCPs on the healing of oral mucosal ulcers in a rat model were macroscopically and microscopically analyzed in vivo. Results showed that MCPs promoted proliferation and migration of L929 cells. Moreover, 75%MCPs enhanced the ulcer healing process, suppressed inflammatory response and up-regulated the expression levels of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF). MCPs are potentially used as a new therapeutic strategy for oral mucosal ulceration.

  • Ana Cláudia DALMOLIN, Luisa Fernanda Alegria ACEVEDO, Letícia Antonel ...
    原稿種別: research-article
    論文ID: 2022-017
    発行日: 2022年
    [早期公開] 公開日: 2022/08/05
    ジャーナル フリー 早期公開

    Bioactive glasses have been recommended for the occlusion of dentinal tubules in treating cervical dentin hypersensitivity. This study evaluates an in vivo model of dentin exposure, and tests the efficacy of bioglass treatments. Thirty male Wistar rats received gingival recession surgery on the upper left first molar. The treatments were applied over the surface of the exposed dentin every 4 days for 28 days. The groups were as follows: Naive; Gingival recession; Cavity varnish; Biosilicate®; Strontium bioglass; and Potassium bioglass. Changes in the dentin-pulp complex, and the presence of substance P, were evaluated through hematoxylin-eosin and immunohistochemical staining. The groups had similar results. Teeth with exposed dentinal tubules in rats showed a typical pattern in the dentin-pulp complex and immunotracing for substance P. The materials did not cause pulp damage. The effects of gingival recession and open dentinal tubules on pulp tissue require further clarification.

  • Wei ZHOU, Zi-Xuan LIAO, Ji-Hua CHEN, Bi-Ying QIU, Yang ZHANG, Ling ZHA ...
    原稿種別: research-article
    論文ID: 2022-044
    発行日: 2022年
    [早期公開] 公開日: 2022/08/05
    ジャーナル フリー 早期公開

    This study aimed to comprehensively evaluate the effect of dual-cured resin luting agents with different initiator systems on the color stability of glass ceramic restorations by simulating various clinical glass ceramic restorations. Three commonly used shades from each of the two dual-cured resin luting agents with an amine-initiation system or without it were studied. The individual specimens had different translucency and thickness and were artificially aged using a xenon light aging machine. The color was measured before and after aging using a digital spectrophotometer with the difference calculated and analyzed statistically. As results, the amine-free dual-cured resin luting agents were more color stable than those using amine-initiation systems for both uncovered and bonding groups. The translucency and thickness of the ceramic, and shade and type of the resin luting agent significantly affected the color stability of glass ceramic restorations.

  • Taro IWASAKI, Shunsuke NAGATA, Takahiro ISHIKAWA, Yasuhiro TANIMOTO
    原稿種別: research-article
    論文ID: 2022-051
    発行日: 2022年
    [早期公開] 公開日: 2022/08/05
    ジャーナル フリー 早期公開

    The objective of this study is to investigate the mechanical properties, such as the dynamic hardness and indentation elastic modulus, of commercially available aesthetic orthodontic brackets, such as ceramic and plastic brackets, by the dynamic micro-indentation method. Five ceramic brackets, which were made of alumina (both monocrystalline and polycrystalline forms) or zirconia, and two plastic brackets, which were made of glass fiber-reinforced polycarbonate or polyamide, were tested. There were significant differences in the mechanical properties of the monocrystalline and polycrystalline alumina brackets. The mechanical properties of the glass fiber-reinforced plastic bracket were significantly superior to these of the non-glass-fiber-reinforced plastic bracket. The differences in the crystal structures of the ceramic brackets surface affected the dynamic hardness and indentation elastic modulus. Furthermore, the short glass fibers contained in the plastic bracket might contribute to the improvement of the mechanical properties.

  • Jared MASON, Timothy KIRKPATRICK, Howard W. ROBERTS
    原稿種別: research-article
    論文ID: 2022-058
    発行日: 2022年
    [早期公開] 公開日: 2022/08/05
    ジャーナル フリー 早期公開

    This study evaluated the dislodgement push-out resistance of five bioceramic materials. One hundred single-rooted teeth with one canal had the apical 3 mm and crown resected to create a 14 mm standardized length. The canals were instrumented to an apical size 80 with a 3 mm root-end preparation made with ultrasonic diamonds. The prepared roots were randomly divided into 5 root-end restorative groups (n=20). ProRoot MTA, Biodentine, EndoSequence Root Repair Material, EndoSequence Fast Set Putty, and EndoSequence BC Sealer with each material placed following manufacturer’s instructions and stored at 100% humidity for 2 weeks. An apical-to-coronal static testing load with the identified dislodgement force converted into MPa with mean results analyzed with Kruskal-Wallis and Dunn’s post hoc tests (α=0.05). ProRoot MTA and Biodentine displayed similar push-out stress resistance and exhibited significantly greater stress resistance than the similar Endosequence materials. However, all materials failed cohesively and were not dislodged from the root canal surface.

  • Rahmi ANGGRAENI, Ika Dewi ANA, Dewi AGUSTINA, Ronny MARTIEN
    原稿種別: research-article
    論文ID: 2021-254
    発行日: 2022年
    [早期公開] 公開日: 2022/07/20
    ジャーナル フリー 早期公開

    Buccal mucosae are considered as a site for vaccine delivery since they are relatively abundant with antigen-presenting dendritic cells, mainly Langerhans cells. In this study, we formulated carbonated hydroxy apatite (CHA) with ovalbumin (OVA) (denoted as CHA-OVA), incorporated it into bilayer buccal membrane to form hydrogel films containing CHA-OVA complex for vaccination via buccal mucosae. Ethylcellulose blend with polyethylene glycol 400 were used as impermeable backing layer. Physical properties of all tested buccal membranes were found suitable for mucosal application. In vitro and ex vivo release study showed there was no burst release of OVA found from all tested formula. From the in vivo examination, rabbit buccal mucosae vaccinated by mucoadhesive membranes containing CHA-OVA complex demonstrated mucosal specific antibody induction, represented the potential of CHA as a candidate of needle-free vaccine adjuvant. Future research is awaiting to investigate proper CHA crystallinity in complex with protein against targeted diseases.

  • Hyun-Jin OH, Chang-Ha LEE, In-Bog LEE
    原稿種別: research-article
    論文ID: 2022-009
    発行日: 2022年
    [早期公開] 公開日: 2022/07/20
    ジャーナル フリー 早期公開

    This study investigated transmittance changes during photo-polymerization of composites in real-time. The transmittance changes of one conventional micro-hybrid, three conventional nano-hybrid, and four bulk-fill composites were measured before, during, and after photo-polymerization, and the maximum rate of transmittance change was compared with that of polymerization shrinkage. A significant difference in transmittance of composite between before and after photo-polymerization was observed. The transmittance of composites except for one bulk-fill composite increased during photo-polymerization. There was a correlation between the maximum rate of transmittance change and the maximum rate of polymerization shrinkage. The transmittance analysis of composites gives very important information to know for the final aesthetic restoration and allows to evaluate polymerization kinetics.

  • Soyeon KIM, Joo Won LEE, Jae-Heon KIM, Van Mai TRUONG, Young-Seok PARK
    原稿種別: research-article
    論文ID: 2022-022
    発行日: 2022年
    [早期公開] 公開日: 2022/07/20
    ジャーナル フリー 早期公開

    The microbial leakage at the implant–abutment interface (IAI) is one cause of peri-implant infection that puts long-term implant stability at risk. The present study compared two types of Morse taper implants in terms of sealing performance at the implanthealing abutment interface. Three implant systems, one of which exhibited a partial face-contact design (TSO) and the other two a line-contact design (TSM and BLT), were analyzed in vitro using two quantitative implant leakage measuring techniques: air-injection pressure measurement test and microbial examination. An in-house-developed device was used to determine implant leakage by recording the initial drop in pressure while injecting air through the implant. The microbial examination measured the absorbances of culture mediums in which the inoculated implants were contained. Significant difference was found between the partial face- and line-contact groups (p<0.001). Both tests revealed that partial face-contact implants are more prone to leakage than line-contact implants.

  • Fang GUO, Shuo HUANG, Ning LIU, Min HU, Changquan SHI, Dichen LI, Chan ...
    原稿種別: research-article
    論文ID: 2022-063
    発行日: 2022年
    [早期公開] 公開日: 2022/07/20
    ジャーナル フリー 早期公開

    Compared with CAD/CAM, fused deposition modeling (FDM) 3D printing technology is simple and safe to operate and has a low cost and high material utilization rate; thus, it is widely used. The present investigation aimed to evaluate the mechanical properties and fit of polyetheretherketone (PEEK) removable partial dentures (RPDs) constructed by FDM. We analyzed mechanical properties of PEEK samples prepared by FDM, milling, or injection molding. RPDs were designed and finite element analysis models was constructed to evaluate maximum stress and strain in the RPDs, cortical bone and mucosa. Geomagic Qualify software was used to analyze gaps between the model and the tissue surface of the framework. The results showed that the compressive strength of the 3D-printed PRDs was greater than that of the injection-molded samples. Finite element analysis demonstrated that the maximum stress on the PRDs was less than the yield strength of the material. Overall, the mechanical properties and fit of the PEEK RPD fabricated by FDM technology essentially fulfilled clinical requirements.

  • Abdulrahman ALSHABIB, Carlos A. JURADO, Akimasa TSUJIMOTO
    原稿種別: review-article
    論文ID: 2022-080
    発行日: 2022年
    [早期公開] 公開日: 2022/07/20
    ジャーナル フリー 早期公開

    One technique for placing of resin-based composite for large posterior cavities is the use of short fiber-reinforced resin-based composite (SFRC) to replace dentin in a biomimetic approach. As endurance under mastication cycles is a significant consideration in the clinical success of resin-based composite posterior restorations, the use of SFRC as a base material may prevent restorative fracture due to the fibers’ effectiveness in stopping cracks. This review article specifies the characteristics of SFRC and describes the major underlying mechanisms of short fiber reinforcement for resin-based composite. Insights are further taken from laboratory studies used to define the short fiber-related properties of resin-based composite and the performance of currently available materials, focusing on aspects that are relevant to the reinforcement of resin-based composite. Finally, future standpoints on the development of SFRCs with nano fibers and different resin monomers, and their role in digital dentistry, are discussed.

  • Jae-Heon KIM, Soyeon KIM, Van Mai TRUONG, Joo Won LEE, Young-Seok PARK
    原稿種別: research-article
    論文ID: 2021-303
    発行日: 2022年
    [早期公開] 公開日: 2022/07/06
    ジャーナル フリー 早期公開

    The relative dentin abrasivity-profilometry equivalent values were compared using non-contact profilometry with three subtypes of regular toothpaste and two subtypes of whitening toothpaste containing sodium bicarbonate and 35% hydrogen peroxide. Bovine dentin specimens were assigned to six groups: regular toothpaste (R): R1 (BAMBOO SALT GUM OINTMENT); R2 (MEDIAN TARTAR ORIGINAL); R3 (PERIOE Alpha), Reference slurry: RS (calcium pyrophosphate), whitening toothpaste (W): W1 (NET. WT); W2 (Vussen 28 WHITENING). Relative dentin abrasion–profilometry equivalent (RDA-PE) was determined by brushing 10,000 times (n=8). The pH of the toothpaste was measured (n=5) and the abrasive constituents of the toothpaste was analyzed by FE-SEM and EDS. The RDA-PE values ranged from 26 to166, and the pH level ranges were 4.928–9.153. The RDA-PE value of the whitening toothpaste containing hydrogen peroxide was not high compared with that of the regular toothpaste. The RDA-PE values of whitening toothpaste could vary depending on the mechanism and ingredients of the whitening agents.

  • Narongrit LARPBUNPHOL, Theerapat CHANAMUANGKON, Niyom THAMRONGANANSKUL
    原稿種別: research-article
    論文ID: 2022-005
    発行日: 2022年
    [早期公開] 公開日: 2022/07/06
    ジャーナル フリー 早期公開

    The important factors contributing to the effectiveness of fluoride varnish are the amount of fluoride ion release and the retention time of the varnish on the tooth surface. Commercial fluoride varnishes are susceptible to mechanical removal; therefore, patients are informed to avoid eating or performing oral hygiene for at least 12–24 h, which results in patient inconvenience. However, cyanoacrylate-based fluoride varnish would not have these disadvantages. This study compared the daily fluoride ion release, abrasion resistance to brushing, and toxicity to human gingival fibroblasts (hGFs) between a newly-developed cyanoacrylate-based fluoride varnish and conventional fluoride varnish (Duraphat varnish). The results demonstrated that the cyanoacrylate varnish had a significantly higher fluoride release for 9 days after application, higher abrasion resistance to brushing, and slightly less toxicity to hGFs compared with Duraphat varnish. This novel cyanoacrylate varnish could be an alternative fluoride varnish for preventing dental caries.

  • Carlos A. JURADO, Francisco PINEDO, Daniel Alberto CORTES TREVINO, Quo ...
    原稿種別: research-article
    論文ID: 2022-018
    発行日: 2022年
    [早期公開] 公開日: 2022/07/06
    ジャーナル フリー 早期公開

    This study uses fracture tests and fractographical analysis to compare computer-aided design and computer-aided manufacturing (CAD/CAM) lithium disilicate molar crowns with the previous occlusal thickness recommendation of 1.5-mm, the new recommendation of 1.0-mm, and a less invasive thickness of 0.8-mm. After fatigue application, fracture tests and fractographic analysis were conducted. The fracture resistance of CAD/CAM lithium disilicate molar crowns was different depending on the occlusal thickness of the restoration, and decreased with lower the thickness. However, the fracture resistance of crowns of all three thicknesses exceeded the reported maximum bite force in the first molar region after the fatigue process, and can be considered acceptable for use in the clinic.

  • Hiro MATSUMOTO, Takatsugu YAMAMOTO, Tohru HAYAKAWA
    原稿種別: research-article
    論文ID: 2022-021
    発行日: 2022年
    [早期公開] 公開日: 2022/07/06
    ジャーナル フリー 早期公開

    The present study examined color changes in the tooth-colored restorative materials, zirconia (3Y-TZP), resin composite, and porcelain. The colors (CIELab) of these materials were measured using a spectrophotometer. Specimens were immersed in black tea or curry for 1 and 7 days, after which colors were re-assessed. Color differences (∆E*ab) before and after immersion were calculated. Specimens after the 7-day immersion were ultrasonically cleaned, and colors were measured again to assess the color recovery rate. The surface free energy, roughness, and water sorption/solubility of each material were also evaluated. Specimens were observed under a scanning electron microscope. The ∆E*ab of 3Y-TZP was the smallest with both immersions. Resin composite had the smallest recovery rate. The surface free energy and roughness of 3Y-TZP were smaller than those of porcelain. 3Y-TZP and porcelain showed almost no sorption during the 7-day period. The present results revealed that 3Y-TZP exhibited the strongest resistance to discoloration.

  • Hiroaki KAKINUMA, Kuniyuki IZUMITA, nobuhiro YODA, Hiroshi EGUSA, Keii ...
    原稿種別: research-article
    論文ID: 2022-074
    発行日: 2022年
    [早期公開] 公開日: 2022/07/06
    ジャーナル フリー 早期公開

    This study aimed to compare the dimensional accuracies of three-dimensional (3D)-printed and milled resin-composite crowns, and to determine acceptable abutment-tooth shapes for printing. Four first-molar abutment models were prepared: the master model form and three models with sharp occluso-axial line angles. Crowns were designed on each abutment using computer-aided design software. The drill-offset value was set at 0.0 or 0.5 mm to evaluate the effect on the dimensional accuracy of milling. A digital light processing-based 3D printer was used to fabricate 3D-printed crowns. Milled crowns were fabricated by wet-milling. The trueness was evaluated by superimposing the design data. Regardless of the abutment form, 3D-printed crowns showed higher accuracy with fewer marginal discrepancies than milled crowns. Milled crowns showed significant dimensional deviations, especially at cusps. Moreover, offset correction resulted in grooves on the internal surface of milled crowns with negative deviations, which were especially evident in crowns for the sharp models.

  • Reiya HORINOUCHI, Kae HARADA, Mamoru MURAKAMI, Yusuke YAMASHITA, Yuji ...
    原稿種別: research-article
    論文ID: 2022-007
    発行日: 2022年
    [早期公開] 公開日: 2022/06/28
    ジャーナル フリー 早期公開

    The need for denture adhesives is increasing worldwide, but few denture-care products target denture adhesive users. Foam denture cleaners have been recently marketed to assist brush denture cleaning, but there is a lack of objective evaluation. In this study, we compared the detergency of denture adhesives using six commercial foam-denture cleaners. For removing the adhesives, most of the tested cleaners were effective in immersion experiments, and three cleaners were more effective in the denture cleaning experiment compared to control water. However, only one could effectively remove the slime that is derived from the adhesive and detergency of artificial dirt. The surface roughnesses of the denture base and the relining material revealed that prolonged immersion in some cleaners could be affected. The results suggest that different commercial foam denture cleaners have different detergency levels, and that some cleaners may affect the properties of denture materials upon long-term use.

  • Mi-Ah KIM, Prasanna NEELAKANTAN, Kyung-San MIN
    原稿種別: research-article
    論文ID: 2022-012
    発行日: 2022年
    [早期公開] 公開日: 2022/06/28
    ジャーナル フリー 早期公開

    This study aimed to investigate the effect of N-2-methyl-pyrrolidone (NMP) on the removal of Enterococcus faecalis biofilm. Colony-forming unit (CFU) counting, crystal violet staining, and extracellular DNA (eDNA) measurements were performed to analyze removal of the biofilms formed in a bovine root canal. A confocal laser scanning microscope (CLSM) assay was used to measure the volume of the biofilms. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to investigate the biofilm-associated genes. The morphologic feature of the biofilms was observed under a scanning electron microscope (SEM). NMP decreased CFU numbers, eDNA levels, and biofilm biomass significantly compared to control. qRT-PCR showed that NMP increased the expression of some virulence-associated genes, but downregulated genes related to colonization and persistency. SEM showed that the numerous dentinal tubules were exposed as a result of removal of the biofilm. Collectively, NMP has the potential to be used as a vehicle for endodontic intracanal medicaments.

  • Eun Hyun PARK, Sang-Hoon RHEE, Hae Won CHOI, Won-Jun SHON
    原稿種別: research-article
    論文ID: 2022-036
    発行日: 2022年
    [早期公開] 公開日: 2022/06/28
    ジャーナル フリー 早期公開

    This study aimed to investigate in vitro biologic properties of mineral trioxide aggregate (MTA) mixed with 3% PVA (MTA-3% PVA) and in vivo dental pulp responses to direct capping in comparison with MTA mixed with distilled water (MTA-DW). Cell proliferation and osteogenic differentiation in culture of human dental pulp cells (hDPCs), and pH changes were evaluated. Pulps in 24 mandibular premolars of four 9-month-old beagle dogs were mechanically exposed and direct pulp capping was performed. Histological specimens were scored according to the degree of mineralization. MTA-3% PVA showed similar cell proliferation and similar or superior osteogenic differentiation of hDPCs compared with MTA-DW. All specimens were associated with calcified bridge formation and there were no significant differences in mineralization scores between the groups (p>0.05). The results suggested that MTA-3% PVA exhibited favorable biocompatibility and osteogenic differentiation in vitro compared with MTA-DW. Furthermore, both groups demonstrated similar results when used as pulp-capping agents in vivo.

  • Nooruldeen Ali SAEED, Antonin TICHY, Yasushi SHIMADA
    原稿種別: research-article
    論文ID: 2021-310
    発行日: 2022年
    [早期公開] 公開日: 2022/06/09
    ジャーナル フリー 早期公開

    This study investigated how the double application of adhesives and dentin moisture level influence the microtensile bond strength (µTBS) of universal adhesives containing different hydrophilic monomers to bur-cut dentin. Four universal adhesives (Scotchbond Universal, Clearfil Universal Bond Quick, Prime&Bond Universal, BeautiBond Universal) were applied to wet and dry bur-cut dentin either in one or two layers. The µTBS test was performed after 25,000 thermal cycles, and scanning electron microscopy was used for the analysis of failure mode and interfacial ultrastructure. Double application significantly improved µTBS on wet dentin (p<0.001), but the effect was not significant on dry dentin (p>0.050). Double application also enhanced the formation of resin tags and limited voids within the adhesive layer of BeautiBond Universal. Dentin moisture had a significant effect on µTBS only if the adhesives were applied in a single layer (p=0.007). Except for Prime&Bond Universal, the tested universal adhesives performed better on dry dentin.

  • Pichamon TRIBUMRUNGSUK, Anak KHANTACHAWANA, Kamolapatr JANYAPRASERT
    原稿種別: research-article
    論文ID: 2021-295
    発行日: 2022年
    [早期公開] 公開日: 2022/05/27
    ジャーナル フリー 早期公開

    This study aims to compare the static friction of untreated and fine particle shot peening (FPSP) treated stainless steel and ceramic bracket slots. A total of 60 pieces of stainless steel and 60 pieces of ceramic brackets (Roth prescription, 0.022×0.028 in2) were divided into 3 groups: control (n=20), silica glass bead particle surface treatment (n=20) and stainless steel (SUS316L) particle surface treatment (n=20). Ten brackets of each group were combined with 0.019×0.025 in2 orthodontic stainless steel arch wires and were analyzed for static friction. The remaining 10 brackets of each group were tested for slot surface roughness and hardness. The result shows that stainless steel brackets treated with FPSP exhibited lower static friction, with smoother and harder surfaces than the control group (p<0.05). In contrast, treated ceramic brackets showed no difference from the control group in terms of static friction, roughness, and hardness (p>0.05).

  • Melissa Mei-Yi KHOR, Vinicius ROSA, Chien Joo SIM, Catherine Hsu Ling ...
    原稿種別: research-article
    論文ID: 2021-319
    発行日: 2022年
    [早期公開] 公開日: 2022/05/27
    ジャーナル フリー 早期公開

    Silver-modified atraumatic restorative technique (SMART) is an emerging restorative technique; however, the effect of silver diamine fluoride (SDF) application on the bond strength of glass ionomer cement (GIC) is unknown. This study aimed to determine if SDF application to sound and artificial caries-affected dentin (ACAD) immediately prior to GIC restoration affected microtensile bond strength (µTBS). Caries was induced on extracted molars using a pH-cycling protocol that was validated against natural caries (similar µTBS). Dentin surfaces were treated with 38% SDF, control groups with de-ionized water and immediately restored. Beam-shaped specimens were sectioned and subjected to tensile forces for µTBS determination. Two hundred and eighty-seven specimens from 40 teeth were tested. SDF application significantly (p<0.001) reduced µTBS in sound dentin (19.00±8.20 MPa vs. 14.60±6.68 MPa), while no difference was found in ACAD. No difference was found in failure mode among groups. For SMART, SDF application on sound dentin before immediate GIC restoration may decrease bond strength.

  • Motoya SHIOGAMA, Haruhisa NAKANO, Moeka SAWAMURA, Naoki YAMAGUCHI, Nao ...
    原稿種別: research-article
    論文ID: 2021-339
    発行日: 2022年
    [早期公開] 公開日: 2022/05/27
    ジャーナル フリー 早期公開

    Orthodontic aligners undergo deformation during installation, producing an unexpected component of elastic restoring force that causes unintended changes in the dentition. The aim of this study was to investigate the relationship between strain and elastic recovery of the aligner. We distinguished the contributions to aligner deformation due to molding and installation by measuring the thickness distribution of an aligner after molding using micro-CT and tracking changes in grid patterns drawn on the sheet used to fabricate the aligner. The aligner was installed on a device that simulated canine movement. Although canine strain was quite strong around the cusp, and in premolar, it was observed mainly in their centers. Furthermore, after molding, thickness distribution of the aligner was found. But, it is no clear relationship between the thickness distribution and the strain distribution. Our method of analysis can help improve aligner design and establish molding method to deliver optimal orthodontic treatment.

  • Suparaksa YAMOCKUL, Niyom THAMRONGANANSKUL
    原稿種別: research-article
    論文ID: 2021-301
    発行日: 2022年
    [早期公開] 公開日: 2022/05/19
    ジャーナル フリー 早期公開

    The aim of this study was to develop a polishing paste containing ceria to polish lithium disilicate. The samples were prepared, polished with sandpaper using a polishing-machine, the surface roughness (Ra) was measured using a profilometer and randomly divided into 7 groups (n=10). The control group was polished with diamond paste (D). The 6 remaining groups were polished with alumina-ceria paste with different ratios of deionized water:alumina:ceria by weight: 1:0.5:0.5 (AC0.5), 1:0.5:1 (AC1), 1:0.5:1.5 (AC1.5), 1:0.5:2 (AC2), 1:0.5:2.5 (AC2.5) and 1:0.5:3 (AC3). The specimens were polished for 30 s and their Ra values were determined. The surface roughness measurement was repeated after an additional 30 s of polishing until 120 s of polishing had been performed. The Ra values decreased as the ratio of ceria increased. The surface morphology of the samples analyzed using scanning electron microscopy corresponded with their Ra values.

  • Zhengfan SUN, Xiaoxiao YOU, Jie XU, Long CHEN, Sihui LI, Zhenghao ZHAN ...
    原稿種別: research-article
    論文ID: 2021-305
    発行日: 2022年
    [早期公開] 公開日: 2022/05/19
    ジャーナル フリー 早期公開

    The study evaluated the effect of sodium hypochlorite (NaOCl) treatment on fluorotic enamel bonding of four adhesive systems. They were Single Bond 2 (SB2), Prime&Bond NT (PBN), Clearfil SE Bond (CSB), and Single Bond Universal (SBU). One hundred eighteen extracted moderate fluorotic molars were divided into eight groups according to NaOCl pretreatment and four adhesive systems. The microshear bond strength (μSBS), etching pattern, and penetration depth (PD) were observed. The statistical method was two-way ANOVA and least significant difference (LSD) test (α=0.05). The application of NaOCl significantly increased the μSBS of PBN and SBU (p<0.05). The enamel-etching pattern of CSB and SBU was deeper under SEM. A noticeable increase of PD was in SB2 and SBU after the application of NaOCl (p<0.05). Pretreatment of 5.25% NaOCl for the 60 s can increase μSBS of PBN and SBU, PD of SB2 and SBU, and improve enamel-etching pattern of CSB and SBU to fluorotic enamel.

  • Idris M. MEHDAWI, Ranna KITAGAWA, Haruaki KITAGAWA, Satoshi YAMAGUCHI, ...
    原稿種別: research-article
    論文ID: 2022-004
    発行日: 2022年
    [早期公開] 公開日: 2022/05/19
    ジャーナル フリー 早期公開

    The aim of this study was to evaluate the maximum amount of chlorhexidine (CHX) that could be incorporated to self-adhesive resin cements to add antibacterial effect without affecting the physical properties. The CHX was incorporated into a commercial self-adhesive resin cement at mass fractions of 0.5–15 wt%, and the CHX-release profile, antibacterial effect, flexural and bond strengths of experimental cements were evaluated. Increasing the CHX content from 5 to 15 wt% resulted in a higher released concentration of CHX. In agar diffusion tests, experimental cements containing 5, 10, and 15 wt% CHX produced inhibition zones against oral bacteria. In flexural strength and shear bond strength to dentin, no significant reduction was observed with the incorporation of 5 wt% CHX. This in vitro study suggests that the addition of 5 wt% CHX yielded an antibacterial self-adhesive cement and had no adverse effect on the flexural and shear bond strengths.

  • Masao KUROSAKA, Yu KATAOKA, Takashi MIYAZAKI
    原稿種別: research-article
    論文ID: 2021-231
    発行日: 2022年
    [早期公開] 公開日: 2022/04/29
    ジャーナル フリー 早期公開

    The fixation of titanium implants in bone tissue is affected by the presence of a passive titanium oxide (TiO2) layer. Specifically, oxidation products in the amorphous TiO2 matrix enhance the mechanical properties of mineralized tissues. In addition, in vitro mineralization mediated by primary osteoblasts on amorphous TiO2 generates stiff tissues in a process that resembles pathological mechanisms connected with tumors and proceeds through hydrogen peroxide-inducible clone-5 (Hic-5) expression. However, the relationship between surface-based peroxidation and stiff mineralized tissue formation remains unclear. In this study, titanium samples were processed using wire electrical discharge machining to generate oxidation products in amorphous TiO2. The gene expression profiles of primary osteoblasts cultured on these specimens were characterized. Increased expression of Hic-5 was correlated with the presence of peroxidation products. The crystallization of amorphous TiO2 in these samples reduced the expression of both Hic-5 and lysyl oxidase, an enzyme that promotes matrix cross-linking.

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