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OBJECTIVES: To evaluate the mechanical and antimicrobial properties of boron-containing coating on translucent zirconia (5Y-PSZ). METHODS: 5Y-PSZ discs (Control) were coated with a glaze (Glaze), silver- (AgCoat), or boron-containing (BCoat) glasses. The coatings' antimicrobial potential was characterized using S. mutans biofilms after 48 h via viable colony-forming units (CFU), metabolic activity (CV) assays, and quantification of extracellular polysaccharide matrix (EPS). Biofilm architectures were imaged under scanning electron and confocal laser scanning microscopies (SEM and CLSM). The cytocompatibility was determined at 24 h via WST-1 and LIVE&DEAD assays using periodontal ligament stem cells (PDLSCs). The coatings' effects on properties were characterized by Vickers hardness, biaxial bending tests, and fractography analysis. Statistical analyses were performed via one-way ANOVA, Tukey's tests, Weibull analysis, and Pearson's correlation analysis. RESULTS: BCoat significantly decreased biofilm formation, having the lowest CFU and metabolic activity compared with the other groups. BCoat and AgCoat presented the lowest EPS, followed by Glaze and Control. SEM and CLSM images revealed that the biofilms on BCoat were thin and sparse, with lower biovolume. In contrast, the other groups yielded robust biofilms with higher biovolume. The cytocompatibility was similar in all groups. BCoat, AgCoat, and Glaze also presented similar hardness and were significantly lower than Control. BCoat had the highest flexural strength, characteristic strength and Weibull parameters (σF: 625 MPa; σ0: 620 MPa; m = 11.5), followed by AgCoat (σF: 464 MPa; σ0: 478 MPa; m = 5.3). SIGNIFICANCE: BCoat is a cytocompatible coating with promising antimicrobial properties that can improve the mechanical properties and reliability of 5Y-PSZ.
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Antiinfecciosos , Cerámica , Ensayo de Materiales , Boro/farmacología , Reproducibilidad de los Resultados , Circonio/farmacología , Propiedades de SuperficieRESUMEN
This study evaluated the physicochemical and biological properties of novel reparative materials composed of pure tricalcium silicate (Ca3 SiO5 ), Ca3 SiO5 doped with fluoride ions (Ca3 SiO5 -F) and their association with ZrO2 (Ca3 SiO5 + ZrO2 , Ca3 SiO5 -F + ZrO2 ), in comparison with Biodentine (BIO). Setting time radiopacity, pH, solubility, and dimensional change were evaluated based on ISO 6876 Standard. Volumetric change and flow/filling were assessed by microcomputed tomography (micro-CT). Biological properties were evaluated by the MTT assay 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), Neutral Red (NR), cell migration, alkaline phosphatase activity (ALP), and Alizarin Red Staining (ARS) assays. Statistical analysis was performed by ANOVA, Tukey, or Bonferroni tests (α = .05). Ca3 SiO5 -F + ZrO2 had higher radiopacity, shorter setting time, and lower solubility and volumetric loss than BIO (p < .05). Ca3 SiO5 -F + ZrO2 had flow and filling capacity similar to BIO (p > .05). All the cements evaluated had an alkaline pH. Ca3 SiO5 -F + ZrO2 demonstrated cell viability similar to negative control (p > .05), increase in ALP activity in 7 days, mineralized nodule production in 21 days and repair capacity according to cell migration. In conclusion, Ca3 SiO5 -F + ZrO2 had adequate setting time, radiopacity, solubility, and dimensional change. This material presented low volumetric change besides flow and filling capacity in micro-CT assessment. In addition, Ca3 SiO5 -F + ZrO2 was biocompatible and bioactive, suggesting its use as reparative material.
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Fluoruros , Materiales de Obturación del Conducto Radicular , Resinas Acrílicas , Compuestos de Calcio/química , Combinación de Medicamentos , Fluoruros/farmacología , Ensayo de Materiales , Óxidos/química , Materiales de Obturación del Conducto Radicular/química , Silicatos/química , Silicatos/farmacología , Microtomografía por Rayos X , Circonio/química , Circonio/farmacologíaRESUMEN
The requirement to achieve natural looking restorations is one of the most challenging aspects in dentistry. Although zirconia has provided new opportunities for achieving superior aesthetics and physicochemical outcomes, very little has been achieved for its cellular and molecular performance, especially considering angiogenesis and osteogenesis. As angiogenesis is a secondary event and concomitant to osteogenesis, an indirect effect of dental implant on endothelial cells could be the release of active molecules such as those already reported affecting osteoblasts. To better address this issue, we challenged human endothelial cells (HUVECs) with zirconia-conditioned medium up to 72 h to allow analysis specific gene expression and protein pattern of mediators of epigenetic machinery in full. Our data shows involvement of zirconia in triggering intracellular signaling through MAPK-ERK activation, leading the signal to activate histone deacetylase HDAC6 likely with concomitant well-modulated DNA methylation profile by DNMTs and TETs. These signaling pathways seem to culminate in cytoskeleton rearrangement of endothelial cells, an important prerequisite to cell migration expected in angiogenesis. Collectively, this study demonstrates for the first time epigenetic-related molecular mechanism involved in endothelial cells responding to zirconia, revealing a repertoire of signaling molecules capable of executing the reprogramming process of gene expression, which are necessary to drive cell proliferation, migration, and consequently angiogenesis. This set of data can further studies using gene editing approaches to better elucidate functional roles.
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Epigénesis Genética , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Transducción de Señal , Circonio/farmacología , Medios de Cultivo/química , Metilación de ADN/efectos de los fármacos , Metilación de ADN/genética , Epigénesis Genética/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Histona Desacetilasas/metabolismo , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana/enzimología , Humanos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
Biosilicate is a bioactive glass-ceramic used in medical and dental applications. This study evaluated novel reparative materials composed of pure tricalcium silicate (TCS), 30% zirconium oxide (ZrO2 ) and 10 or 20% biosilicate, in comparison with Biodentine. Setting time was evaluated based on ISO 6876 standard, radiopacity by radiographic analysis, solubility by mass loss, and pH by using a pH meter. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and NR assays. Alkaline phosphatase (ALP) activity and alizarin red were used to evaluate cell bioactivity. Antimicrobial activity was assessed on Enterococcus faecalis by the direct contact test. The data were submitted to analysis of variance (ANOVA)/Tukey; Bonferroni and Kruskal-Wallis, and Dunn tests (α = 0.05). The association of Biosilicate with TCS + ZrO2 had appropriate setting time, radiopacity, and solubility, alkaline pH, and antimicrobial activity. TCS and Biodentine showed higher ALP activity in 14 days than the control (serum-free medium). All cements produced mineralized nodules. In conclusion, Biosilicate + TCS ZrO2 decreased the setting time and increased the radiopacity in comparison to TCS. Biosilicate + TCS ZrO2 presented lower solubility and higher radiopacity than Biodentine. In addition, these experimental cements promoted antimicrobial activity and mineralization nodules formation, suggesting their potential for clinical use.
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Compuestos de Calcio/química , Vidrio/química , Silicatos/química , Circonio/química , Fosfatasa Alcalina , Antraquinonas , Materiales Biocompatibles , Cementos para Huesos , Neoplasias Óseas/patología , Compuestos de Calcio/farmacología , Compuestos de Calcio/toxicidad , Línea Celular Tumoral , Cementos Dentales , Enterococcus faecalis/efectos de los fármacos , Humanos , Concentración de Iones de Hidrógeno , Ensayo de Materiales , Osteosarcoma/patología , Cemento de Silicato , Silicatos/farmacología , Silicatos/toxicidad , Solubilidad , Circonio/farmacología , Circonio/toxicidadRESUMEN
Photobiomodulation (PBM) therapy is used to stimulate cell proliferation and metabolism, as well as reduce inflammatory cytokine synthesis, which plays a main role in the long-term stability of implants. This study assessed the response of gingival fibroblasts cultured on titanium (Ti) and zirconia (ZrO2), submitted to PBM and exposed to lipopolysaccharide (LPS). Cells seeded on Ti and ZrO2 were irradiated (InGaAsP; 780 nm, 25 mW) 3 times, using 0.5, 1.5, and 3.0 J/cm2 doses, and exposed to Escherichia coli LPS (1 µg/mL). After 24 h, cell viability (alamarBlue, n = 8), interleukin 6 (IL-6) and 8 (IL-8) synthesis (ELISA, n = 6), and IL-6 and vascular endothelial growth factor (VEGF) gene expression (qPCR, n = 5) were assessed and statistically analyzed (one-way ANOVA, α = 0.05). Cell morphology was evaluated by fluorescence microscopy. Increased cell viability occurred in all groups cultured on Ti compared with that of the control, except for cells exposed to LPS. Fibroblasts cultured on ZrO2 and LPS-exposed exhibited reduced viability. PBM at 3.0 J/cm2 and 1.5 J/cm2 downregulated the IL-6 synthesis by fibroblasts seeded on Ti and ZrO2, as well as IL-8 synthesis by cells seeded on ZrO2. Fibroblasts seeded on both surfaces and LPS-exposed showed increased IL-6 gene expression; however, this activity was downregulated when fibroblasts were irradiated at 3.0 J/cm2. Enhanced VEGF gene expression by cells seeded on Ti and laser-irradiated (3.0 J/cm2). Distinct patterns of cytoskeleton occurred in laser-irradiated cells exposed to LPS. Specific parameters of PBM can biomodulate the inflammatory response of fibroblasts seeded on Ti or ZrO2 and exposed to LPS.
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Escherichia coli/metabolismo , Fibroblastos/efectos de la radiación , Encía/citología , Lipopolisacáridos/farmacología , Terapia por Luz de Baja Intensidad , Titanio/farmacología , Circonio/farmacología , Proliferación Celular , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Células Cultivadas , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Interleucina-6/biosíntesis , Adulto JovenRESUMEN
OBJECTIVES: To evaluate the radiopacity of Biodentine (BD) and BD associated with 15% calcium tungstate (BDCaWO4) or zirconium oxide (BDZrO2), by using conventional and digital radiography systems, and their physicochemical and biological properties. MATERIALS AND METHODS: Radiopacity was evaluated by taking radiographs of cement specimens (n=8) using occlusal film, photostimulable phosphor plates or digital sensors. Solubility, setting time, pH, cytocompatibility and osteogenic potential were also evaluated. Data were analyzed using one-way ANOVA and Tukey post-test or two-way ANOVA and Bonferroni post-test (α=0.05). RESULTS: BD radiopacity was lower than 3 mm Al, while BD ZrO2 and BD CaWO4 radiopacity was higher than 3 mm Al in all radiography systems. The cements showed low solubility, except for BDCaWO4. All cements showed alkaline pH and setting time lower than 34 minutes. MTT and NR assays revealed that cements had greater or similar cytocompatibility in comparison with control. The ALP activity in all groups was similar or greater than the control. All cements induced greater production of mineralized nodules than control. CONCLUSIONS: Addition of 15% ZrO2 or CaWO4 was sufficient to increase the radiopacity of BD to values higher than 3 mm Al. BD associated with radiopacifiers showed suitable properties of setting time, pH and solubility, except for BDCaWO4, which showed the highest solubility. All cements had cytocompatibility and potential to induce mineralization in Saos-2 cells. The results showed that adding 15% ZrO2 increases the radiopacity of BD, allowing its radiography detection without altering its physicochemical and biological properties.
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Compuestos de Calcio/química , Radiografía Dental Digital/métodos , Silicatos/química , Compuestos de Tungsteno/química , Circonio/química , Fosfatasa Alcalina/análisis , Análisis de Varianza , Antraquinonas , Compuestos de Calcio/farmacología , Supervivencia Celular/efectos de los fármacos , Humanos , Concentración de Iones de Hidrógeno , Ensayo de Materiales , Osteoblastos/efectos de los fármacos , Valores de Referencia , Reproducibilidad de los Resultados , Silicatos/farmacología , Solubilidad , Factores de Tiempo , Compuestos de Tungsteno/farmacología , Circonio/farmacologíaRESUMEN
Abstract Objectives: To evaluate the radiopacity of Biodentine (BD) and BD associated with 15% calcium tungstate (BDCaWO4) or zirconium oxide (BDZrO2), by using conventional and digital radiography systems, and their physicochemical and biological properties. Materials and Methods: Radiopacity was evaluated by taking radiographs of cement specimens (n=8) using occlusal film, photostimulable phosphor plates or digital sensors. Solubility, setting time, pH, cytocompatibility and osteogenic potential were also evaluated. Data were analyzed using one-way ANOVA and Tukey post-test or two-way ANOVA and Bonferroni post-test (α=0.05). Results: BD radiopacity was lower than 3 mm Al, while BD ZrO2 and BD CaWO4 radiopacity was higher than 3 mm Al in all radiography systems. The cements showed low solubility, except for BDCaWO4. All cements showed alkaline pH and setting time lower than 34 minutes. MTT and NR assays revealed that cements had greater or similar cytocompatibility in comparison with control. The ALP activity in all groups was similar or greater than the control. All cements induced greater production of mineralized nodules than control. Conclusions: Addition of 15% ZrO2 or CaWO4 was sufficient to increase the radiopacity of BD to values higher than 3 mm Al. BD associated with radiopacifiers showed suitable properties of setting time, pH and solubility, except for BDCaWO4, which showed the highest solubility. All cements had cytocompatibility and potential to induce mineralization in Saos-2 cells. The results showed that adding 15% ZrO2 increases the radiopacity of BD, allowing its radiography detection without altering its physicochemical and biological properties.
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Humanos , Circonio/química , Compuestos de Tungsteno/química , Silicatos/química , Compuestos de Calcio/química , Radiografía Dental Digital/métodos , Osteoblastos/efectos de los fármacos , Valores de Referencia , Solubilidad , Factores de Tiempo , Circonio/farmacología , Ensayo de Materiales , Supervivencia Celular/efectos de los fármacos , Reproducibilidad de los Resultados , Análisis de Varianza , Antraquinonas , Compuestos de Tungsteno/farmacología , Silicatos/farmacología , Compuestos de Calcio/farmacología , Fosfatasa Alcalina/análisis , Concentración de Iones de HidrógenoRESUMEN
The modification of biomaterials approved by the Food and Drug Administration could be an alternative to reduce the period of use in humans. Porous bioceramics are widely used as support structures for bone formation and repair. This composite has essential characteristics for an implant, including good mechanical properties, high chemical stability, biocompatibility and adequate aesthetic appearance. Here, three-dimensional porous scaffolds of Al2 O3 containing 5% by volume of ZrO2 were produced by the replica method. These scaffolds had their surfaces chemically treated with phosphoric acid and were coated with calcium phosphate using the biomimetic method simulated body fluid (SBF, 5×) for 14 days. The scaffolds, before and after biomimetic coating, were characterized mechanically, morphologically and structurally by axial compression tests, scanning electron microscopy, microtomography, apparent porosity, X-ray diffractometry, near-infrared spectroscopy, inductively coupled plasma optical emission spectroscopy, energy dispersive X-ray spectroscopy and reactivity. The in vitro cell viability and formation of mineralization nodules were used to identify the potential for bone regeneration. The produced scaffols after immersion in SBF were able to induce the nodules formation. These characteristics are advantaged by the formation of different phases of calcium phosphates on the material surface in a reduced incubation period. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2615-2624, 2018.
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Óxido de Aluminio , Materiales Biomiméticos , Cerámica , Materiales Biocompatibles Revestidos , Ensayo de Materiales , Circonio , Óxido de Aluminio/química , Óxido de Aluminio/farmacología , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacología , Línea Celular Tumoral , Cerámica/química , Cerámica/farmacología , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Humanos , Porosidad , Circonio/química , Circonio/farmacologíaRESUMEN
For the long-term success of implants, it is necessary to achieve a direct contact between the implant and the subjacent bone. To avoid bacterial penetration that could adversely affect the initial wound healing as well as the long-term behavior of the implants, an early tissue barrier must form that is able to protect the biological peri-implant structures. Given the need of an effective tissue early barrier around dental implants, the present study evaluated, in vitro, the influence of physical and chemical characteristics of two implant abutment surfaces on gingival epithelial cells (OBA-9) adhesion. To this end, titanium (Ti) and zirconia (ZrO2 ) disk-shaped specimens were used mimicking the abutment components surfaces, while bovine enamel (BE) and glass cover slips (GCS) disks served as positive and negative controls, respectively. Roughness and surface free energy (SFE) of all materials were evaluated previously to cellular adhesion step. In sequence, the effect of each material on cells morphology and viability was analyzed after 1 and 24 hr. The results showed that roughness and SFE had no effect on the cell viability data or on their interaction (p = .559), independent of a post-contact analysis of 1 or 24 hr. However, cells attachment and spreading increased after 24 hr on Ti and ZrO2 than BE, corresponding to the highest SFE values. SFE appears to be an important property interfering on the quality of the soft tissue surrounding dental implants. These data can be considered a trigger point for developing new material surfaces.
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Adhesión Celular , Pilares Dentales , Implantes Dentales , Células Epiteliales/fisiología , Encía/citología , Animales , Bovinos , Supervivencia Celular/efectos de los fármacos , Materiales Dentales/química , Células Epiteliales/efectos de los fármacos , Humanos , Propiedades de Superficie/efectos de los fármacos , Titanio/química , Titanio/farmacología , Circonio/farmacologíaRESUMEN
AIM: To evaluate the influence of the addition of microparticulate (micro) and nanoparticulate (nano) zirconium oxide (ZrO2 ) and niobium pentoxide (Nb2 O5 ) to a calcium silicate-based cement (CS) on the subcutaneous healing process in rats compared with MTA Angelus™. METHODOLOGY: In each rat, two polyethylene tubes filled with the following materials: (i) MTA; (ii) CS + ZrO2 micro; (iii) CS + ZrO2 nano; (iv) CS + Nb2 O5 micro or (v) CS + Nb2 O5 nano were implanted subcutaneously; empty polyethylene tubes were used in the Control group. After 7, 15, 30 and 60 days, the specimens (n = 5 per group in each period) were fixed and embedded in paraffin. Masson's trichrome sections were used to obtain the volume density of the inflammatory cells (VvIC) and fibroblasts (VvFb). The sections were also stained with Picrosirius-red to calculate the birefringent collagen content. Fibroblast growth factor-1 (FGF-1) was detected by immunohistochemistry, and the number of immunolabelled cells was obtained. The data were subjected to two-way anova followed by Tukey's test (P ≤ 0.05). RESULTS: At all periods, the VvIC was significantly lower (P < 0.001) in all the CS and Control groups than in the MTA group. At all periods, the VvFb was reduced significantly (P = 0.023) in the MTA group in comparison with the other groups. In addition, the number of immunolabelled cells in the capsules of the CS groups was significantly higher (P < 0.001) than in the MTA group at all time-points. CONCLUSIONS: The experimental materials (CS + ZrO2 and CS + Nb2 O5 ) induced fibroblast proliferation and accelerated the regression of the inflammatory reaction. However, the addition of nanoparticulate radiopacifiers did not improve the biological properties of a calcium silicate-based cement when compared to microparticulate agents.
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Compuestos de Calcio/farmacología , Colágeno/efectos de los fármacos , Cementos Dentales/farmacología , Fibroblastos/efectos de los fármacos , Niobio/farmacología , Óxidos/farmacología , Silicatos/farmacología , Circonio/farmacología , Animales , Proliferación Celular/efectos de los fármacos , Técnicas para Inmunoenzimas , Implantes Experimentales , Masculino , Ensayo de Materiales , Tamaño de la Partícula , Politetrafluoroetileno , RatasRESUMEN
AIM: To compare the bioactivity of Biodentine (BIO, Septodont), MTA Plus (MTA P, Avalon) and calcium silicate experimental cement (CSC) with resin (CSCR) associated with zirconium (CSCR ZrO2 ) or niobium (CSCR Nb2 O5 ) oxide as radiopacifiers. METHODOLOGY: According to the relevance of osteoblastic cell response for mineralized tissue repair, human osteoblastic cells (Saos-2) were exposed to test materials and assessed for viability (MTT), cell proliferation, gene expression of alkaline phosphatase (ALP) osteogenic marker by real-time PCR (RT-qPCR), ALP activity assay and alizarin red staining (ARS) to detect mineralization nodule deposition in osteogenic medium. Unexposed cells acted as the control group (C). Statistical analysis was carried out using ANOVA and the Bonferroni post-test (P < 0.05). RESULTS: All tested cements showed dose-dependent responses in cell viability (MTT). Exposed cells revealed good viability (80-130% compared to the control group) in the highest dilutions of all types of cement. MTA P, BIO and CSCR ZrO2 significantly increased the velocity of cell proliferation after three days of cell exposure in the wound-healing assay (P < 0.05), which corroborated MTT data. On day 3, the ALP transcript level increased, especially to CSCR Nb2 O5 (P < 0.05). All cements exhibited suitable ALP enzyme activity, highlighting the 7-day period of cell exposure. ARS, CSCR Nb2 O5 , revealed a significant potential to induce mineralization in vitro. CONCLUSIONS: All materials had suitable biocompatibility and bioactivity. The MTA P, BIO and CSCR ZrO2 groups had the highest viability rates and velocity of proliferation whilst the CSCR Nb2 O5 group produced more mineralized nodules.
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Compuestos de Aluminio/farmacología , Materiales Biocompatibles/farmacología , Compuestos de Calcio/farmacología , Cementos Dentales/farmacología , Osteoblastos/efectos de los fármacos , Óxidos/farmacología , Materiales de Obturación del Conducto Radicular/farmacología , Silicatos/farmacología , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Combinación de Medicamentos , Humanos , Ensayo de Materiales , Niobio/farmacología , Circonio/farmacologíaRESUMEN
OBJECTIVE: Mineral Trioxide Aggregate (MTA) is a calcium silicate cement composed of Portland cement (PC) and bismuth oxide. Hydroxyapatite has been incorporated to enhance mechanical and biological properties of dental materials. This study evaluated physicochemical and mechanical properties and antibiofilm activity of MTA and PC associated with zirconium oxide (ZrO2) and hydroxyapatite nanoparticles (HAn). MATERIAL AND METHODS: White MTA (Angelus, Brazil); PC (70%)+ZrO2 (30%); PC (60%)+ZrO2 (30%)+HAn (10%); PC (50%)+ZrO2 (30%)+HAn (20%) were evaluated. The pH was assessed by a digital pH-meter and solubility by mass loss. Setting time was evaluated by using Gilmore needles. Compressive strength was analyzed by mechanical test. Samples were radiographed alongside an aluminum step wedge to evaluate radiopacity. For the antibiofilm evaluation, materials were placed in direct contact with E. faecalis biofilm induced on dentine blocks. The number of colony-forming units (CFU mL-1) in the remaining biolfilm was evaluated. The results were submitted to ANOVA and the Tukey test, with 5% significance. RESULTS: There was no difference in pH levels of PC+ZrO2, PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p>0.05) and these cements presented higher pH levels than MTA (p<0.05). The highest solubility was observed in PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p<0.05). MTA had the shortest initial setting time (p<0.05). All the materials showed radiopacity higher than 3 mmAl. PC+ZrO2 and MTA had the highest compressive strength (p<0.05). Materials did not completely neutralize the bacterial biofilm, but the association with HAn provided greater bacterial reduction than MTA and PC+ZrO2 (p<0.05) after the post-manipulation period of 2 days. CONCLUSIONS: The addition of HAn to PC associated with ZrO2 harmed the compressive strength and solubility. On the other hand, HAn did not change the pH and the initial setting time, but improved the radiopacity (HAn 10%), the final setting time and the E. faecalis antibiofilm activity of the cement.
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Compuestos de Aluminio/química , Biopelículas/efectos de los fármacos , Compuestos de Calcio/química , Durapatita/química , Enterococcus faecalis/efectos de los fármacos , Nanopartículas/química , Óxidos/química , Silicatos/química , Circonio/química , Compuestos de Aluminio/farmacología , Análisis de Varianza , Bismuto/química , Bismuto/farmacología , Compuestos de Calcio/farmacología , Recuento de Colonia Microbiana , Fuerza Compresiva , Cementos Dentales/química , Cementos Dentales/farmacología , Combinación de Medicamentos , Durapatita/farmacología , Enterococcus faecalis/crecimiento & desarrollo , Concentración de Iones de Hidrógeno , Ensayo de Materiales , Óxidos/farmacología , Silicatos/farmacología , Solubilidad , Factores de Tiempo , Circonio/farmacologíaRESUMEN
ABSTRACT Objective Mineral Trioxide Aggregate (MTA) is a calcium silicate cement composed of Portland cement (PC) and bismuth oxide. Hydroxyapatite has been incorporated to enhance mechanical and biological properties of dental materials. This study evaluated physicochemical and mechanical properties and antibiofilm activity of MTA and PC associated with zirconium oxide (ZrO2) and hydroxyapatite nanoparticles (HAn). Material and Methods White MTA (Angelus, Brazil); PC (70%)+ZrO2 (30%); PC (60%)+ZrO2 (30%)+HAn (10%); PC (50%)+ZrO2 (30%)+HAn (20%) were evaluated. The pH was assessed by a digital pH-meter and solubility by mass loss. Setting time was evaluated by using Gilmore needles. Compressive strength was analyzed by mechanical test. Samples were radiographed alongside an aluminum step wedge to evaluate radiopacity. For the antibiofilm evaluation, materials were placed in direct contact with E. faecalis biofilm induced on dentine blocks. The number of colony-forming units (CFU mL-1) in the remaining biolfilm was evaluated. The results were submitted to ANOVA and the Tukey test, with 5% significance. Results There was no difference in pH levels of PC+ZrO2, PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p>0.05) and these cements presented higher pH levels than MTA (p<0.05). The highest solubility was observed in PC+ZrO2+HAn (10%) and PC+ZrO2+HAn (20%) (p<0.05). MTA had the shortest initial setting time (p<0.05). All the materials showed radiopacity higher than 3 mmAl. PC+ZrO2 and MTA had the highest compressive strength (p<0.05). Materials did not completely neutralize the bacterial biofilm, but the association with HAn provided greater bacterial reduction than MTA and PC+ZrO2 (p<0.05) after the post-manipulation period of 2 days. Conclusions The addition of HAn to PC associated with ZrO2 harmed the compressive strength and solubility. On the other hand, HAn did not change the pH and the initial setting time, but improved the radiopacity (HAn 10%), the final setting time and the E. faecalis antibiofilm activity of the cement.
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Óxidos/química , Circonio/química , Enterococcus faecalis/efectos de los fármacos , Silicatos/química , Durapatita/química , Compuestos de Calcio/química , Compuestos de Aluminio/química , Biopelículas/efectos de los fármacos , Nanopartículas/química , Óxidos/farmacología , Solubilidad , Factores de Tiempo , Circonio/farmacología , Bismuto/farmacología , Bismuto/química , Ensayo de Materiales , Recuento de Colonia Microbiana , Análisis de Varianza , Enterococcus faecalis/crecimiento & desarrollo , Silicatos/farmacología , Durapatita/farmacología , Compuestos de Calcio/farmacología , Compuestos de Aluminio/farmacología , Fuerza Compresiva , Cementos Dentales/farmacología , Cementos Dentales/química , Combinación de Medicamentos , Concentración de Iones de HidrógenoRESUMEN
Veneer fracture is the most common complication in zirconia-based restorations. The aim of this study was to evaluate the mechanical behavior of a zirconia-based crown in a lower canine tooth supporting removable partial denture (RPD) prosthesis, varying the bond quality of the veneer/coping interface. Microtomography (µCT) data of an extracted left lower canine were used to build the finite element model (M) varying the core material (gold core - MAu; zirconia core - MZi) and the quality of the veneer/core interface (complete bonded - MZi; incomplete bonded - MZi-NL). The incomplete bonding condition was only applied for zirconia coping by using contact elements (Target/Contact) with 0.3 frictional coefficients. Stress fields were obtained using Ansys Workbench 10.0. The loading condition (L = 1 N) was vertically applied at the base of the RPD prosthesis metallic support towards the dental apex. Maximum principal (σmax) and von Mises equivalent (σvM) stresses were obtained. The σmax (MPa) for the bonded condition was similar between gold and zirconia cores (MAu, 0.42; MZi, 0.40). The incomplete bonded condition (MZi-NL) raised σmax in the veneer up to 800% (3.23 MPa) in contrast to the bonded condition. The peak of σvM increased up to 270% in the MZi-NL. The incomplete bond condition increasing the stress in the veneer/zirconia interface.
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Coronas , Dentadura Parcial Removible , Análisis de Elementos Finitos , Microtomografía por Rayos X , Circonio/farmacología , Animales , Análisis del Estrés Dental/métodos , Perros , Oro/química , Humanos , Ensayo de Materiales , Estrés MecánicoRESUMEN
Com a evolução do Biomateriais houve melhorias nas opções de tratamentos e atualmente são utilizados em substituição de partes do corpo que foram perdidas e promovem a recuperação de funções biológicas. Dentre eles existem as chamadas Biocerâmicas, que incluem alumina, zircônia e derivadas de fosfato de cálcio. A hidroxiapatita possui composição e estrutura minerais semelhantes à fase mineral óssea e apresenta como propriedades a biocompatibilidade, osteocondutividade e bioatividade. O trabalho avaliou a viabilidade celular em cerâmica de hidroxiapatita experimental de origem bovina em comparação com dois tipos de zircônia comerciais e liga de titânio comercialmente puro, para que futuramente possa ser utilizada como material base para implantes dentários. A avaliação in vitro foi realizada por meio de testes nos quais células pré-osteoblásticas cultivadas de linhagem murina MC3T3-E1 foram colocadas em contato indireto e direto com estes materiais. Para viabilidade celular (n=8) foram feitos testes de ensaio MTT e Cristal Violeta em duplicata e após 24, 48 e 72 horas os níveis de absorbâncias foram analisados por meio de espectrofotometria no leitor de Elisa. Para as analises por microscopia eletrônica de varredura (n=6) as células foram plaqueadas diretamente sobre as superfícies dos discos, fixadas em vapor de tetróxido de ósmio 2% após 24 e 48 horas, seguido da metalização após 48 horas da fixação das células para análise em Microscópio Eletrônico de Varredura. Os resultados para viabilidade indireta foram submetidos ao teste paramétrico ANOVA, seguido de teste de Tukey (p<0,05). Tanto no teste de MTT quanto no Cristal Violeta, de acordo com o grupo controle positivo, todos os grupos apresentaram resultados satisfatórios. A cerâmica de hidroxiapatita não apresentou diferença estatística significante, demonstrando não ser um material citotóxico. Pelas imagens geradas no MEV do teste de viabilidade direta, verificou-se que houve adesão...
With the evolution biomaterials there were improvements in treatment options, and are currently used in replacement body parts that were lost and promote the recovery of biological functions. Among them are the bioceramic which include alumina, zirconia and calcium phosphate derivative. Hydroxyapatite has mineral composition and structure similar to bone mineral phase and can be used as a biomaterial having biocompatibility, osteoconductivity and bioactivity. The study evaluated the cell viability in experimental hydroxyapatite ceramic bovine compared the two types of commercial zirconia and titanium alloy commercially pure, so that in future it can be used as base material for dental implants. In vitro evaluation was carried by means of tests in which the pre-osteoblastic cells MC3T3-E1 murine lineage cultured were placed in indirect and direct contact with these materials. For cell viability (n=8) were carried MTT assay and Crystal Violet tests in duplicate and after 24, 48 and 72 hours the absorbance levels were analyzed by spectrophotometry Elisa reader. For analysis by Scanning Electron Microscope variable pressure (n = 6) cells were plated directly on the discs surfaces, fixed in osmium tetroxide steam 2% after 24 and 48 hours, followed by metallization after 48 of cells fixation. The results for the cell viability were submitted to parametric test ANOVA, followed by Tukey test (p<0.05). Both in the MTT assay as Crystal Violet all groups exhibited satisfactory results absent cytotoxicity. By means of the SEM images produced, it was found that there was adhesion and proliferation of cells on the materials surfaces in the two periods. Therefore, it can be stated that the hydroxyapatite ceramic was presented as a biocompatible material.
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Animales , Durapatita/farmacología , Materiales Biocompatibles/farmacología , Osteoblastos , Titanio/farmacología , Circonio/farmacología , Células Cultivadas , Colorimetría/métodos , Ensayo de Inmunoadsorción Enzimática , Violeta de Genciana , Microscopía Electrónica de Rastreo , Muridae , Reproducibilidad de los Resultados , Supervivencia Celular , Factores de TiempoRESUMEN
So far, the antibacterial activity of some organic and inorganic compounds has been studied. Barium zirconate titanate [Ba(Zr xTi1-x)O3] (x = 0.05) nanoparticle is an example of inorganic materials. In vitro studies have provided evidence for the antibacterial activity of this nanoparticle. In the current study, the nano-powder was synthesized by sol-gel method. X-ray diffraction showed that the powder was single-phase and had a perovskite structure at the calcination temperature of 1000 ºC. Antibacterial activity of the desired nanoparticle was assessed on two gram-positive (Staphylococcus aureus PTCC1431 and Micrococcus luteus PTCC1625) and two gram-negative (Escherichia coli HP101BA 7601c and clinically isolated Klebsiella pneumoniae) bacteria according to Radial Diffusion Assay (RDA). The results showed that the antibacterial activity of BZT nano-powder on both gram-positive and gram-negative bacteria was acceptable. The minimum inhibitory concentration of this nano-powder was determined. The results showed that MIC values for E. coli, K. pneumoniae, M. luteus and S. aureus were about 2.3 µg/mL, 7.3 µg/mL, 3 µg/mL and 12 µg/mL, respectively. Minimum bactericidal concentration (MBC) was also evaluated and showed that the growth of E. coli, K. pneumoniae, M. luteus and S. aureus could be decreased at 2.3, 14, 3 and 18 µg/mL of BZT. Average log reduction in viable bacteria count in time-kill assay ranged between 6 Log10 cfu/mL to zero after 24 h of incubation with BZT nanoparticle.
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Antibacterianos/farmacología , Compuestos de Bario/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Nanopartículas/química , Titanio/farmacología , Circonio/farmacología , Compuestos de Bario/química , Compuestos de Bario/síntesis química , Pruebas de Sensibilidad Microbiana , Difracción de Rayos XRESUMEN
So far, the antibacterial activity of some organic and inorganic compounds has been studied. Barium zirconate titanate [Ba(Zr xTi1-x)O3] (x = 0.05) nanoparticle is an example of inorganic materials. In vitro studies have provided evidence for the antibacterial activity of this nanoparticle. In the current study, the nano-powder was synthesized by sol-gel method. X-ray diffraction showed that the powder was single-phase and had a perovskite structure at the calcination temperature of 1000 ºC. Antibacterial activity of the desired nanoparticle was assessed on two gram-positive (Staphylococcus aureus PTCC1431 and Micrococcus luteus PTCC1625) and two gram-negative (Escherichia coli HP101BA 7601c and clinically isolated Klebsiella pneumoniae) bacteria according to Radial Diffusion Assay (RDA). The results showed that the antibacterial activity of BZT nano-powder on both gram-positive and gram-negative bacteria was acceptable. The minimum inhibitory concentration of this nano-powder was determined. The results showed that MIC values for E. coli, K. pneumoniae, M. luteus and S. aureus were about 2.3 µg/mL, 7.3 µg/mL, 3 µg/mL and 12 µg/mL, respectively. Minimum bactericidal concentration (MBC) was also evaluated and showed that the growth of E. coli, K. pneumoniae, M. luteus and S. aureus could be decreased at 2.3, 14, 3 and 18 µg/mL of BZT. Average log reduction in viable bacteria count in time-kill assay ranged between 6 Log10 cfu/mL to zero after 24 h of incubation with BZT nanoparticle.
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Antibacterianos/farmacología , Compuestos de Bario/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Nanopartículas/química , Titanio/farmacología , Circonio/farmacología , Compuestos de Bario/química , Compuestos de Bario/síntesis química , Pruebas de Sensibilidad Microbiana , Difracción de Rayos XRESUMEN
The aim of the present study was to evaluate the antibiofilm activity against Enterococcus faecalis, compressive strength. and radiopacity of Portland cement (PC) added to zirconium oxide (ZrO2), as radiopacifier, with or without nanoparticulated zinc oxide (ZnO). The following experimental materials were evaluated: PC, PC + ZrO2, PC + ZrO2 + ZnO (5%), and PC + ZrO2 + ZnO (10%). Antibiofilm activity was analyzed by using direct contact test (DCT) on Enterococcus faecalis biofilm, for 5 h or 15 h. The analysis was conducted by using the number of colony-forming units (CFU/mL). The compressive strength was performed in a mechanical testing machine. For the radiopacity tests, the specimens were radiographed together with an aluminium stepwedge. The results were submitted to ANOVA and Tukey tests, with level of significance at 5%. The results showed that all materials presented similar antibiofilm activity (P > 0.05). The addition of nanoparticulated ZnO decreased the compressive strength of PC. All materials presented higher radiopacity than pure PC. It can be concluded that the addition of ZrO2 and ZnO does not interfere with the antibiofilm activity and provides radiopacity to Portland cement. However, the presence of ZnO (5% or 10%) significantly decreased the compressive strength of the materials.
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Biopelículas/efectos de los fármacos , Compuestos de Calcio/farmacología , Enterococcus faecalis/efectos de los fármacos , Materiales de Obturación del Conducto Radicular/farmacología , Silicatos/farmacología , Óxido de Zinc/farmacología , Circonio/farmacología , Animales , Biopelículas/crecimiento & desarrollo , Compuestos de Calcio/química , Bovinos , Fuerza Compresiva/efectos de los fármacos , Medios de Contraste/química , Cementos Dentales/química , Cementos Dentales/farmacología , Enterococcus faecalis/fisiología , Técnicas In Vitro , Incisivo/cirugía , Ensayo de Materiales , Nanopartículas/química , Materiales de Obturación del Conducto Radicular/química , Silicatos/química , Óxido de Zinc/química , Circonio/químicaRESUMEN
The physicochemical and biological properties of calcium silicate-based cement (CS) associated to microparticulated (micro) or nanoparticulated (nano) zirconium oxide (ZrO2 ) were compared with CS and bismuth oxide (BO) with CS. The pH, release of calcium ions, radiopacity, setting time, and compression strength of the materials were evaluated. The tissue reaction promoted by these materials in the subcutaneous was also investigated by morphological, immunohistochemical, and quantitative analyses. For this purpose, polyethylene tubes filled with materials were implanted into rat subcutaneous. After 7, 15, 30, and 60 days, the tubes surrounded by capsules were fixed and embedded in paraffin. In the H&E-stained sections, the number of inflammatory cells (ICs) in the capsule was obtained. Moreover, detection of interleukin-6 (IL-6) by immunohistochemistry and number of IL-6 immunolabeled cells were carried out. von Kossa method was also performed. The differences among the groups were subjected to Tukey test (p ≤ 0.05). The solutions containing the materials presented an alkaline pH and released calcium ions. The addition of radiopacifiers increased setting time and radiopacity of CS. A higher compressive strength in the CS + ZrO2 (micro and nano) was found compared with CS + BO. The number of IC and IL-6 positive cells in the materials with ZrO2 was significantly reduced in comparison with CS + BO. von Kossa-positive structures were observed adjacent to implanted materials. The ZrO2 associated to the CS provides satisfactory physicochemical properties and better biological response than BO. Thus, ZrO2 may be a good alternative for use as radiopacifying agent in substitution to BO.
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Cementos para Huesos , Compuestos de Calcio , Ensayo de Materiales , Nanopartículas/química , Silicatos , Circonio , Animales , Cementos para Huesos/química , Cementos para Huesos/farmacología , Compuestos de Calcio/química , Compuestos de Calcio/farmacología , Inflamación/inducido químicamente , Inflamación/metabolismo , Inflamación/patología , Interleucina-6/metabolismo , Ratas , Ratas Sprague-Dawley , Silicatos/química , Silicatos/farmacología , Circonio/química , Circonio/farmacologíaRESUMEN
New titanium alloys have been developed with the aim of utilizing materials with better properties for application as biomaterials, and Ti-Zr system alloys are among the more promising of these. In this paper, the influence of zirconium concentrations on the structure, microstructure, and selected mechanical properties of Ti-Zr alloys is analyzed. After melting and swaging, the samples were characterized through chemical analysis, density measurements, X-ray diffraction, optical microscopy, Vickers microhardness, and elasticity modulus. In-vitro cytotoxicity tests were performed on cultured osteogenic cells. The results showed the formation essentially of the α' phase (with hcp structure) and microhardness values greater than cp-Ti. The elasticity modulus of the alloys was sensitive to the zirconium concentrations while remaining within the range of values of conventional titanium alloys. The alloys presented no cytotoxic effects on osteoblastic cells in the studied conditions.