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1.
J Mech Behav Biomed Mater ; 124: 104838, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34555621

RESUMO

To develop antimicrobial restorative materials for root caries, we assessed a 4-META/MMA-TBB resin (Bondfill SB Plus, Sun Medical) containing benzalkonium chloride (BAC) or cetylpyridinium chloride (CPC) at 1.25, 2.5, and 5.0 wt%. The same resin without antibacterial agent was used as control. The degree of conversion was measured by attenuated total reflectance-Fourier transform infrared spectroscopy. The 3-point flexural strength test was conducted according to ISO 4049. The antimicrobial effect against three oral bacteria (Streptococcus mutans, S. sobrinus, and Actinomyces naeslundii) was assessed using agar diffusion tests. The shear bond strength to root dentin was assessed after 24 h of storage in water with or without 10,000 thermal cycles. The shear bond strength data were statistically compared using a linear mixed-effects model (α = 0.05). The specimen with 5.0 wt% BAC showed a significantly higher degree of conversion than the control, but it also had significantly lower flexural strength and lower shear bond strength after thermal cycling than the other specimens. When BAC or CPC was added at ≥ 2.5 wt%, the resins inhibited the growth of the three investigated microbes. In conclusion, both BAC and CPC showed significant antimicrobial effects when added at 5.0 wt% to the 4-META/MMA-TBB resin. Up to 2.5 wt%, neither antimicrobial agent affected the degree of conversion, flexural strength, or shear bond strength of the resin.


Assuntos
Colagem Dentária , Cárie Radicular , Actinomyces , Antibacterianos , Compostos de Benzalcônio/farmacologia , Compostos de Boro , Cetilpiridínio/farmacologia , Humanos , Teste de Materiais , Metacrilatos , Metilmetacrilatos , Cimentos de Resina , Resistência à Tração
2.
Dent Mater J ; 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193728

RESUMO

There is limited research on the influence of different sintering temperatures on the properties of highly translucent zirconia ceramics. This study demonstrated the influence of different sintering temperatures on the translucency, crystallographic structure, biaxial flexural strength, microstructure, and low-temperature degradation (LTD) of three highly translucent zirconia grades, i.e., 3 mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP), 4 mol% yttria-partially-stabilized zirconia (4Y-PSZ), and 5 mol% yttria-PSZ (5Y-PSZ). The specimens were characterized using colorimetry, X-ray diffraction, scanning electron microscopy, Weibull analysis, and LTD tests (134°C; 20 h). The increase in the sintering temperature did not affect the translucency of 3Y-TZP, whereas it increased the translucencies of 4Y-PSZ and 5Y-PSZ. All the zirconia grades exhibited grain enlargement and unchanged biaxial flexural strengths with the increase in the sintering temperature. The degradation of 3Y-TZP and 4Y-PSZ at a sintering temperature of 1,600°C was faster than that at other sintering temperatures.

3.
Materials (Basel) ; 14(13)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34279264

RESUMO

We aimed to assess the crystallography, microstructure and flexural strength of zirconia-based ceramics made by stereolithography (SLA). Two additively manufactured 3 mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP: LithaCon 3Y 230, Lithoz; 3D Mix zirconia, 3DCeram Sinto) and one alumina-toughened zirconia (ATZ: 3D Mix ATZ, 3DCeram Sinto) were compared to subtractively manufactured 3Y-TZP (control: LAVA Plus, 3M Oral Care). Crystallographic analysis was conducted by X-ray diffraction. Top surfaces and cross-sections of the subsurface microstructure were characterized using scanning electron microscopy (SEM). Biaxial flexural strength was statistically compared using Weibull analysis. The additively and subtractively manufactured zirconia grades revealed a similar phase composition. The residual porosity of the SLA 3Y-TZPs and ATZ was comparable to that of subtractively manufactured 3Y-TZP. Weibull analysis revealed that the additively manufactured LithaCon 3Y 230 (Lithoz) had a significantly lower biaxial flexural strength than 3D Mix ATZ (3D Ceram Sinto). The biaxial flexural strength of the subtractively manufactured LAVA Plus (3M Oral Care) was in between those of the additively manufactured 3Y-TZPs, with the additively manufactured ATZ significantly outperforming the subtractively manufactured 3Y-TZP. Additively manufactured 3Y-TZP showed comparable crystallography, microstructure and flexural strength as the subtractively manufactured zirconia, thus potentially being a good option for dental implants.

4.
J Dent Sci ; 16(2): 628-635, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33854712

RESUMO

Background/purpose: High translucent zirconia has been used as a new monolithic zirconia prosthesis, which has the potential to make anterior resin-bonded fixed dental prostheses (RBFDPs) without veneering porcelain. However, it is unclear whether the RBFDPs retainer can be thinned as much as conventional zirconia RBFDPs. The aim of this study was to assess the usability of high translucent zirconia RBFDPs with a thin retainer thickness by evaluating differences in retainer thickness on the surface strain. Materials and methods: A model with a missing upper lateral incisor was used. The abutment teeth were upper central incisor and canine. Three types of RBFDPs were fabricated as follows: metal RBFDPs with a retainer thickness of 0.8 mm (0.8M), and high translucent zirconia RBFDPs with a retainer thicknesses of 0.8 and 0.5 mm (0.8Z, 0.5Z) (n = 10). The fitness of the margins was evaluated by the silicone replica technique. The surface strain of each retainer under static loading was measured and statistically analyzed using a t-test with Bonferroni correction. Results: The marginal fitness of all RBFDPs was under 76.1 µm, which was clinically acceptable. Each strain of the 0.8Z and 0.5Z groups was significantly lower than that of the 0.8M (p < 0.05). There was no difference in strain of the zirconia RBFDPs even if the retainer thickness was changed. Conclusion: Our results suggest that the high translucent zirconia RBFDPs can be manufactured with a retainer thickness of 0.5 mm, which reduces the amount of tooth preparation compared to the metal RBFDPs.

5.
Dent Mater J ; 40(4): 877-884, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33678732

RESUMO

The influence of sulfinate agents applied as a dentin pretreatment or a mixture with multi-mode one-step self-etch adhesives (1-SEAs) on the degree of conversion (DC) and micro-tensile bond strength (µTBS) of light-cured 1-SEAs was investigated. 1-SEAs Clearfil Universal Bond Quick (UBQ) or Scotchbond Universal Adhesive (SBU) were applied to dentin in etch&rinse or self-etch mode using various application strategies: 1) no pretreatment, 2) pretreatment with 90 wt% ethanol, 3) pretreatment with a sulfinate agent Clearfil DC Activator (UDC) or Scotchbond Universal DCA (SDC), or 4) a mixture of UBQ+UDC or SBU+SDC. µTBS was measured after 24 h. Additionally, DC was measured using attenuated total reflectance Fourier-transform infrared spectroscopy. Pretreatment with sulfinate agents resulted in the highest µTBS and DC, significantly improving them especially in etch&rinse mode. The mixture of sulfinate agents with 1-SEAs was less effective. Pretreatment with ethanol significantly improved µTBS in etch&rinse mode but compromised µTBS in self-etch mode.


Assuntos
Colagem Dentária , Adesivos , Resinas Compostas , Cimentos Dentários , Dentina , Adesivos Dentinários , Teste de Materiais , Cimentos de Resina , Resistência à Tração
6.
Dent Mater J ; 40(3): 674-682, 2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-33518691

RESUMO

The purpose of this study was to evaluate the influence of resin-coating using one-bottle adhesives on the bond strength of resin cements in single-visit and multiple-visit treatments. Three one-bottle adhesives were used for resin-coating and/or pre-treatment adhesives prior to cementation, in conjunction with resin cements from the same manufacturers: Clearfil Universal Bond Quick with Panavia V5 (UBQ/Pv5), Scotchbond Universal Adhesive with RelyX Ultimate (SBU/RxU), and Optibond All-in-one with NX3 Nexus (OP/NX3). Bovine dentin surfaces were left uncoated or resin-coated. After 1-h water storage (single-visit) or 1-week water storage with a non-eugenol temporary cement (multiple-visit), a CAD/CAM resin block was cemented to uncoated or resin-coated dentin surfaces. Microtensile bond strengths (µTBSs) were measured and statistically analyzed (α=0.05). Application of resin-coating improved µTBSs. The multiple-visit group exhibited lower values of µTBS than the single-visit group. Selection of the materials affected µTBSs. Resin-coating and single-visit treatment are desirable for CAD/CAM resin composite restorations.


Assuntos
Colagem Dentária , Cimentos de Resina , Animais , Bovinos , Cimentos Dentários , Dentina , Adesivos Dentinários , Teste de Materiais , Resistência à Tração
7.
J Prosthodont Res ; 65(1): 39-45, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32938857

RESUMO

PURPOSE: To assess the degree of conversion (DC) of dual-curing composite cements when cured through ceramic-veneered zirconia disks. METHODS: Portions of mixed cement, either G-CEM LinkForce (GC), Panavia V5 (Kuraray Noritake) or ResiCEM (Shofu), were placed on the ATR crystal of a Fourier Transform Infrared Spectroscope (FTIR; iS50, Thermo Scientific) and squeezed to a 100-µm film thickness using a microscopy cover glass. DC (%) of the composite cements applied in self-curing mode was measured in the dark at 37°C. Following the dual-curing mode, the cements were light-cured directly (positive control) or through a ceramic-veneered zirconia disk (0.5-mm thick zirconia with a 1.0-mm thick veneering ceramic) for 40 sec using two light-curing units (G-Light Prima 2, GC; PenCure, Morita). Per experimental group, 5 tests were conducted to measure DC in self-cure and dual-cure mode (n=5). FTIR spectra of the composite cement films were acquired to determine DC every min up to 30 min. DC of the composite cements was statistically compared using two-way repeated-measures ANOVA (α=0.05). RESULTS: For all cements investigated, the self-curing mode resulted in significantly lower DC at 10, 20 and 30 min than the light-curing mode. When the composite cements were light-cured through the zirconia disk, DC at 30 min dropped significantly for ResiCem (Shofu), while not for Panavia V5 (Kuraray Noritake) and G-CEM LinkForce (GC). CONCLUSIONS: Self-curing slows down polymerization but does not reach for all composite cements the highest (light-cured) DC. Ceramic-veneered zirconia-based restorations may affect DC of some composite cements.


Assuntos
Luzes de Cura Dentária , Cura Luminosa de Adesivos Dentários , Cerâmica , Teste de Materiais , Cimentos de Resina
8.
Dent Mater J ; 40(1): 44-51, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32848103

RESUMO

This study aimed to assess the influence of different light curing units (LCUs) on the polymerization of various flowable resin composites. Three LCUs (Optilux 501, Elipar™ DeepCure-L LED and Bluephase®20i) and eight flowable resin composites: MI FIL Flow, Estelite Flow Quick, Estelite Universal Flow (medium), Estelite Universal Flow (super low), Beautifil Flow Plus, Clearfil Majesty ES Flow, Filtek Supreme Ultra flowable and TetricEvo Flow were tested. For Vickers microhardness (VHN) test and degree of conversion (DC), specimens were prepared and polymerized for 20 s. VHN test was performed at top surfaces (3 indentations) and DC for each specimen was measured using Fourier transform infrared (FT-IR) spectroscopy after 24 h dry storage in dark at 37˚C. The data were analyzed with 2-way ANOVA and t-test with Bonferroni correction. DC and hardness values showed a relationship between materials and LCUs. The curing efficacy of LCU type may depend on the material composition.


Assuntos
Luzes de Cura Dentária , Cura Luminosa de Adesivos Dentários , Resinas Compostas , Dureza , Teste de Materiais , Polimerização , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície
9.
J Prosthodont ; 30(7): 617-624, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33219705

RESUMO

PURPOSE: To investigate the risk of debonding of resin-bonded fixed dental prosthesis frameworks and the effects on the periodontal tissue in patients with reduced alveolar bone levels. MATERIALS AND METHODS: The abutment teeth were the upper central incisor and the canine. Resin-bonded fixed dental prosthesis framework fabricated using zirconia was set to models with five different alveolar bone levels. A 200-N load (the maximum clenching force of the anterior teeth) was applied to the center of the pontic to analyze the internal stress on the framework, adhesive cement, and periodontal tissue using finite element analysis. RESULTS: The mean maximum principal stress generated in the framework was 25.33 and 29.35 MPa in the models with the normal and the lowest alveolar bone level, respectively. Regarding shear stress on the adhesive cement, stress concentration was observed on the connector side in all models, and it increased on the cervical side of the central incisor as the alveolar bone level decreased. In addition, the mean maximum and minimum principal strains generated on the periodontal ligament of the central incisor and canine tended to increase as alveolar bone loss progressed. Furthermore, the mean maximum principal stress on the cortical bone was the greatest in the model with the most significant bone loss at 5.10 MPa. CONCLUSIONS: This study suggested that the risk of debonding and periodontal tissue damage might be higher when resin-bonded fixed dental prosthesis frameworks were used in patients with reduced alveolar bone levels compared to those in a healthy state.


Assuntos
Implantes Dentários , Análise do Estresse Dentário , Análise de Elementos Finitos , Humanos , Cimentos de Resina , Zircônio
10.
J Mech Behav Biomed Mater ; 115: 104268, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33338964

RESUMO

The objective of this study was to assess the influence of alumina sandblasting on the flexural strength of the latest generation of highly translucent yttria partially stabilized dental zirconia (Y-PSZ). Fully-sintered zirconia disk-shaped specimens (14.5-mm diameter; 1.2-mm thickness) of four Y-PSZ zirconia grades (KATANA HT, KATANA STML, KATANA UTML, all Kuraray Noritake; and Zpex Smile, Tosoh) were sandblasted at 0.2 MPa with 50-µm alumina (Al2O3) sand (Kulzer) or left as-sintered (control). For each zirconia grade, the yttria (Y2O3) content was determined using X-ray fluorescence (XRF). Surface roughness was assessed using 3D confocal laser microscopy. Micro-Raman spectroscopy (µ-Raman) and X-ray diffraction (XRD) were used to assess potentially induced residual stresses. Biaxial flexural strength (n = 20) was statistically compared by Weibull analysis. Focused ion beam - scanning electron microscopy (FIB/SEM) was used to observe the subsurface microstructure. Fracture surfaces after biaxial flexural strength testing were observed by SEM. KATANA UTML had the highest Y2O3 content (6 mol%), followed by KATANA STML and Zpex Smile (5 mol%), and KATANA HT (4 mol%). Al2O3-sandblasting significantly increased surface roughness of KATANA UTML and Zpex Smile. µRaman and XRD revealed the presence of residual compressive stress on all Al2O3-sandblasted surfaces. FIB/SEM revealed several sub-surface microcracks in the sandblasted specimens. Weibull analysis revealed that Al2O3-sandblasting increased the characteristic strength of KATANA HT, KATANA STML, whereas it decreased the strength of KATANA UTML. The strength enhancement after Al2O3-sandblasting of KATANA HT was the highest, followed by KATANA STML. For Zpex Smile, the influence was statistically insignificant. The impact of Al2O3-sandblasting on the Weibull modulus was controversial. The strength of zirconia after Al2O3-sandblasting is determined by the balance between microcrack formation (decreased strength) and surface compressive stress build-up (increased strength).


Assuntos
Resistência à Flexão , Zircônio , Óxido de Alumínio , Cerâmica , Materiais Dentários , Teste de Materiais , Propriedades de Superfície , Ítrio
11.
Beilstein J Nanotechnol ; 11: 1685-1692, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33194517

RESUMO

Gene therapy has been explored as a future alternative for treating heart disease. Among several gene delivery systems aimed at penetrating specific target cells, we focused on safe and non-viral gene delivery materials with a high transfection efficiency. Although various techniques have been developed, the mechanisms underlying the cellular uptake of gene delivery materials have not yet been sufficiently studied in cardiomyocytes. The aim of this study was to determine how hydroxyapatite (HAp) nanoparticles contribute to the delivery of plasmid DNA (pDNA) into cardiomyocytes. We fabricated HAp nanoparticles using the water-in-oil (W/O) emulsion method and used these nanoparticles as the delivery vector for transfecting cardiomyocyte-derived HL-1 cells. HAp exhibited particles on the nanoscale and with a low cytotoxicity in HL-1 cells. The transfection assay performed with several endocytosis inhibitors suggested that the HAp/pDNA complexes were internalized by HL-1 cells through macropinocytosis. Furthermore, this HL-1 cell uptake was generated in response to HAp stimulation. Thus, HAp is a positive regulator of macropinocytosis in HL-1 cells and a good system for gene delivery in cardiomyocytes.

12.
Dent Mater J ; 39(6): 1057-1063, 2020 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-32684612

RESUMO

This study aims to elucidate the relationships between the flexural strength and surface topography of composite resin blocks, utilized for the CAD/CAM system, after milling in various step-over amounts. The rectangular specimens were milled from CAD/CAM blocks with step-over amount 0.01, 0.02, 0.05, 0.1, and 0.2 mm; further, a three-point bending test was conducted to reveal the flexural strength. The surface morphology after milling was assessed by a 3D laser microscope. The surface roughness significantly decreased by reducing the step-over amount. Although there was significant association between the surface roughness and flexural strength by the Pearson correlation, the 95% confidence intervals of the flexural strength were between the mirror-polished and sand-blasted groups. These results suggest that a precise step-over amount enables us to obtain a smooth surface. Furthermore, the flexural strength of the rough surface milled by a large step-over amount caused no damage to the composite resin for CAD/CAM crown.


Assuntos
Resinas Compostas , Resistência à Flexão , Cerâmica , Desenho Assistido por Computador , Teste de Materiais , Propriedades de Superfície
13.
J Funct Biomater ; 11(2)2020 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-32580288

RESUMO

Recently, silver (Ag) and copper (Cu) have been incorporated into a titanium (Ti) surface to realize their antibacterial property. This study investigated both the durability of the antibacterial effect and the surface change of the Ag- and Cu-incorporated porous titanium dioxide (TiO2) layer. Ag- and Cu-incorporated TiO2 layers were formed by micro-arc oxidation (MAO) treatment using the electrolyte with Ag and Cu ions. Ag- and Cu-incorporated specimens were incubated in saline during a period of 0-28 days. The changes in both the concentrations and chemical states of the Ag and Cu were characterized using X-ray photoelectron spectroscopy (XPS). The durability of the antibacterial effects against Escherichia coli (E. coli) were evaluated by the international organization for standardization (ISO) method. As a result, the Ag- and Cu-incorporated porous TiO2 layers were formed on a Ti surface by MAO. The chemical state of Ag changed from Ag2O to metallic Ag, whilst that of Cu did not change by incubation in saline for up to 28 days. Cu existed as a stable Cu2O compound in the TiO2 layer during the 28 days of incubation in saline. The concentrations of Ag and Cu were dramatically decreased by incubation for up to 7 days, and remained a slight amount until 28 days. The antibacterial effect of Ag-incorporated specimens diminished, and that of Cu was maintained even after incubation in saline. Our study suggests the importance of the time-transient effects of Ag and Cu on develop their antibacterial effects.

14.
Dent Mater J ; 39(4): 639-647, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32249235

RESUMO

This study investigated the efficacy of copper (Cu) as an antibacterial element incorporated on titanium (Ti) surface by electrochemical treatment. Cu was incorporated onto Ti surface by micro-arc oxidation (MAO). A small amount of Cu was incorporated into the oxide layer and was found to be in oxidized states. Cu-incorporated samples exhibited no-harmful effect on the proliferation of osteoblastlike cells. Moreover, the difference in antibacterial property between fresh and incubated samples was evaluated using gram-positive and gram-negative facultative anaerobic bacteria. The specific antibacterial property of Cu incorporated into the Ti surface were confirmed. The antibacterial property prolonged upon immersion in physiological saline for 28 days. In other words, MAO-treated Ti containing Cu in this study is expected to achieve long-term antibacterial property in practical usage.


Assuntos
Cobre , Titânio , Antibacterianos , Bactérias Anaeróbias , Staphylococcus aureus , Propriedades de Superfície
15.
J Biomed Mater Res A ; 108(3): 537-544, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31702862

RESUMO

Osteochondral defects of articular cartilage cannot regenerate spontaneously. For its surgical treatment, advancements in cartilage tissue engineering have particularly focused on subchondral bone lesions that tend to delay healing. Therefore, it is important to understand interactions between subchondral bone and chondrocytes. This study aimed to investigate the behavior of chondrogenic ATDC5 cells on oriented hydroxyapatite (HAp) films that mimic bone surfaces. HAp nanoparticles prepared herein were needle like and plate like. HAp films were formed through self-organization of the nanoparticles and had 2D structures regularly arrayed with the particles. Both films prominently comprised a-plane orientation surfaces but differed in the degree of hydrophilicity because of the patterns of particle self-assembly. ATDC5 cells cultured on the HAp film with plate-like particles could adhered in a shorter period but could not spread. The adhesive force of cells was weaker with the hydrophilic surface than with other surfaces, as determined using a trypsin-based cell detachment assay. In addition, ATDC5 cells displayed enhanced proliferation and chondrogenic differentiation. Our results suggest that the oriented HAp film formed using plate-like particles provided chondrogenic cells with a desired scaffold as that of subchondral bone to increase cell proliferation and differentiation.


Assuntos
Substitutos Ósseos/química , Condrócitos/citologia , Condrogênese , Durapatita/química , Tecidos Suporte/química , Animais , Adesão Celular , Diferenciação Celular , Linhagem Celular , Humanos , Camundongos , Engenharia Tecidual
17.
Materials (Basel) ; 13(1)2019 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-31877887

RESUMO

Titania (TiO2) has attracted much attention recently for reducing bacterial diseases by the generation of reactive oxygen species (ROS) under UV irradiation. However, demand for higher photocatalytic activity due to higher recombination of electron and hole remains. The aims of this study were to make titania with higher antibacterial property and show the mechanisms of the bactericidal effect. In this study, we hydrothermally synthesized TiO2 nanosheets (NS) with highly-oriented structures. Samples were divided into five groups, depending on the fluorine/titanium ratio in the raw material, namely NS1.0, NS1.2, NS1.5, NS1.8, and NS2.0. Facet ratio and nanosheet size increased with an increase of fluorine/titanium ratio. The photocatalytic activity of TiO2 nanosheet was assessed by the generation of ROS. Hydroxyl radicals and superoxides were generated efficiently by ultraviolet light irradiation on NS1.5 and NS1.0, respectively. Antibacterial activity against Streptococcus mutans was assessed in the presence and absence of UV irradiation; NS1.0 showed superior antibacterial properties compared to commercially available TiO2 nanoparticles, under both conditions, due to the oxidation of intracellular components and cell membrane. These results together suggested TiO2 nanosheet induced bacterial cell death by oxidation, and TiO2 facet engineering resulted in enhancement of both photocatalytic and antibacterial activities of TiO2.

18.
Biomed Mater Eng ; 30(4): 375-386, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31476142

RESUMO

BACKGROUND: The scaffold for head and neck reconstruction needs mechanical strength to maintain specific forms. Hydroxyapatite (HA) enhances the mechanical strength of hydrogel and is routinely used for cartilage regeneration. However, there is a demand for hydroxyapatite that controls chondrogenic cell behavior. OBJECTIVE: Our aim was to regulate HA morphology through a hydrothermal process using organic acid and enhance chondrocyte proliferation and differentiation using shaped-regulated HA. METHODS: HA was synthesized from dodecanedioic acid (DD:HA) and oleic acid (OA:HA) by a hydrothermal method and then coated onto glass plates. Surface properties of the samples were compared by various techniques. Surface roughness and contact angles were calculated. Proliferation and differentiation of chondrogenic cells were measured by MTT assays and Alcian Blue staining, respectively, after various incubation periods. RESULTS: The morphological structures of DD:HA and OA:HA were different; however, the crystallinity and chemical structures were similar. Surface roughness and hydrophilic behavior were higher on DD:HA. DD:HA enhanced chondrogenic cell proliferation over time. The differentiation of ATDC5 cells was also increased on the DD:HA surface compared with those in other groups. CONCLUSIONS: DD:HA enhanced cell viability to a greater extent than OA:HA did, indicating its excellent potential as an inorganic material compatible with chondrocyte regeneration.


Assuntos
Materiais Biocompatíveis/química , Condrócitos/citologia , Condrogênese , Ácidos Dicarboxílicos/química , Durapatita/química , Animais , Materiais Biocompatíveis/síntese química , Diferenciação Celular , Linhagem Celular , Proliferação de Células , Ácidos Dicarboxílicos/síntese química , Durapatita/síntese química , Camundongos , Propriedades de Superfície , Tecidos Suporte/química
19.
J Oral Sci ; 61(3): 459-467, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31378752

RESUMO

This experiment assessed the effect of elapsed time between air abrasion and bonding on tensile bond strength (TBS) between computer-aided design/computer-aided manufacturing (CAD/CAM) composite resin blocks and luting agents. Specimens were divided into eight groups classified by block type (Estelite Block or HC Block), elapsed time after air abrasion (none [D0] or 1 week [D7]), luting agent type (Estecem [ESC] or Rely X Ultimate [RLU]), and polymerization condition (chemical cured [CC] or light cured [LC]). In the CC+ESC group, TBS was significantly higher at D0 than at D7. There was also a significant difference between blocks in all groups except the LC+ESC group. Scanning electron microscopy and atomic force microscopy were used to observe the surfaces of blocks after air abrasion and indicated that blocks absorbed water in air with elapsed time, which affected TBS between CAD/CAM composite resin blocks and luting agents.


Assuntos
Colagem Dentária , Cimentos Dentários , Resinas Compostas , Desenho Assistido por Computador , Análise do Estresse Dentário , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina , Propriedades de Superfície , Resistência à Tração
20.
Dent Mater J ; 38(3): 464-470, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30971651

RESUMO

In the present study, the influence of the SiO2 content of polyetheretherketone (PEEK) on the bonding between PEEK and resin cement, and the corresponding mechanical properties, were evaluated. Three experimental PEEK samples with varying amounts of SiO2, and PEEK containing 20 wt% of TiO2 (DK), were investigated. The tensile bond strength (TBS) was evaluated before and after 10,000 thermal cycles, upon polishing, sandblasting, and conditioning of the specimens with BONDMER lightless containing a silane coupling agent, and bonded with ESTECEM II. The crystallinity, flexural modulus, and flexural strength were determined after 10,000 thermal cycles. TBS values were analyzed by two-way ANOVA and a t-test with Bonferroni correction (α<0.05), while the crystallinity, flexural modulus, and flexural strength were analyzed with one-way ANOVA followed by a t-test with Bonferroni correction (α<0.05). The TBS improved with increasing SiO2 content in PEEK; moreover, DK and the sample with 40 wt% SiO2 exhibited the highest flexural strength.


Assuntos
Colagem Dentária , Cimentos de Resina , Resinas Compostas , Resistência à Flexão , Cetonas , Teste de Materiais , Polietilenoglicóis , Dióxido de Silício , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração
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