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Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers embedded with borate glasses of 45B5 composition doped with Co2+, Cu2+, and Zn2 +(46.1 B2O326.9-X CaO24.4 Na2O2.6 P2O5, X CoO/CuO/ZnO mol % (X = 0-5)) were produced by electrospinning for wound healing applications. Prior to their addition, the glasses exhibited two broad halos typical of a vitreous borate network, which were mainly composed of ring-type metaborate structural units. The particle distribution in the PHBV nanofibers embedded with 45B5 borate bioactive glasses is present in isolated and agglomerated states, being partially coated by a polymeric layer-except for the cobalt-doped glass, which resulted in a successful encapsulation with 100% embedding efficiency. The incorporation of the glasses reduced the PHBV crystallinity degree and its decomposition temperature, as well as its mechanical properties, including Young's modulus, tensile strength, and elongation at break. The neat PHBV fibers and those containing the cobalt-doped glasses demonstrated great cytocompatibility with human keratinocytes (HaCat), as suggested by the high cell viability after 7 days of exposure. Further studies are needed to fully understand the wound healing potential of these fibers, but our results significantly contribute to the area.
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Bandagens , Boratos , Cobalto , Cobre , Poliésteres , Zinco , Humanos , Cobre/química , Cobalto/química , Poliésteres/química , Boratos/química , Zinco/química , Vidro/química , Teste de Materiais , Cicatrização , Nanofibras/química , Linhagem Celular , Poli-HidroxibutiratosRESUMO
This study aimed to evaluate the effect of autoclave sterilization on the integrity and instruments' fracture number after multiple uses and cyclic fatigue of the original WaveOne Gold (Dentsply Sirona Endodontics) compared to four replica-like instruments (TF4-Gold, Roll-Wave-Gold, W-File, and Micro-Gold). The instruments were analyzed by scanning electron microscope (SEM) before being used in root canal instrumentation (baseline). One hundred and fifty human molars, freshly extracted for orthodontic reasons or periodontal disease and with severe curvature (between 30° and 60°), were used. Fifty teeth were instrumented with 10 instruments from each group and were evaluated for integrity. After sterilization in an autoclave, the instruments were analyzed by SEM. This procedure was repeated twice more, totaling three rounds of instrumentation, sterilization, and SEM analysis. Ten unused instruments from each group were evaluated for resistance to cyclic fatigue in a static test using a motor and a device simulating a canal with a 60° curvature angle. The instruments were driven by the motor until separation, visually verified, and the time measured in seconds. Data were analyzed by Chi-square, one-way ANOVA, and Tukey analysis, considering a significance level of 5%. It was found that there was no statistically significant difference between the groups tested in the effect of sterilization on the number of uses. The SEM analysis showed distortions in the instruments after the 3rd use. There was a statistically significant difference in the cyclic fatigue test between the results of WaveOne Gold, TF4 Gold, and Roll Wave Gold compared to W File and Micro Gold (P < 0.0001) and a statistically significant difference between the W File and Micro Gold groups (P < 0.0001). In conclusion, this study affirmed that WaveOne Gold, TF4-Gold, and Roll-Wave-Gold instruments exhibit comparable cyclic fatigue resistance. Besides, all examined instruments can be reliably employed for up to two cases.
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The purpose of this study was to evaluate the fatigue survival of 5Y-PSZ zirconia infiltrated with an experimental glass and bonded onto dentin analogues. Disc-shaped specimens of a 5Y-PSZ (Katana UTML Kuraray Noritake) were cemented onto dentin analogs (NEMA G10) and divided into four groups (n = 15): Zctrl Group (control, without infiltration); Zglz Group (Glaze, compression surface); Zinf-comp Group (Experimental Glass, compression surface); Zinf-tens Group (Experimental Glass, tension surface). Surface treatments were varied. Cyclic fatigue loading, oblique transillumination, stereomicroscope examination, and scanning electron microscopy were performed. Fatigue data were analyzed (failure load and number of cycles) using survival analysis (Kaplan-Meier and Log-Rank Mantel-Cox). There was no statistically significant difference in fatigue survival between the Zglz, Zctrl, and Zinf-comp groups. The Zinf-tens group presented a significantly higher failure load when compared to the other groups and exhibited a different failure mode. The experimental glass effectively infiltrated the zirconia, enhancing structural reliability, altering the failure mode, and improving load-bearing capacity over more cycles, particularly in the group where the glass was infiltrated into the tensile surface of the zirconia. Glass infiltration into 5Y-PSZ zirconia significantly enhanced structural reliability and the ability to withstand loads over an increased number of cycles. This approach has the potential to increase the durability of zirconia restorations, reducing the need for replacements and save time and resources, promoting efficiency in clinical practice.
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Dentina , Vidro , Teste de Materiais , Zircônio , Zircônio/química , Vidro/química , Dentina/química , Humanos , Microscopia Eletrônica de Varredura , Propriedades de SuperfícieRESUMO
In recent years, there has been a notable surge of interest in hybrid materials within the biomedical field, particularly for applications in bone repair and regeneration. Ceramic-polymeric hybrid scaffolds have shown promising outcomes. This study aimed to synthesize bioactive glass (BG-58S) for integration into a bioresorbable polymeric matrix based on PDLLA, aiming to create a bioactive scaffold featuring stable pH levels. The synthesis involved a thermally induced phase separation process followed by lyophilization to ensure an appropriate porous structure. BG-58S characterization revealed vitreous, bioactive, and mesoporous structural properties. The scaffolds were analyzed for morphology, interconnectivity, chemical groups, porosity and pore size distribution, zeta potential, pH, in vitro degradation, as well as cell viability tests, total protein content and mineralization nodule production. The PDLLA scaffold displayed a homogeneous morphology with interconnected macropores, while the hybrid scaffold exhibited a heterogeneous morphology with smaller diameter pores due to BG-58S filling. The hybrid scaffold also demonstrated a pH buffering effect on the polymer surface. In addition to structural characteristics, degradation tests indicated that by incorporating BG-58S modified the acidic degradation of the polymer, allowing for increased total protein production and the formation of mineralization nodules, indicating a positive influence on cell culture.
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Regeneração Óssea , Cerâmica , Vidro , Poliésteres , Alicerces Teciduais , Cerâmica/química , Alicerces Teciduais/química , Regeneração Óssea/efeitos dos fármacos , Vidro/química , Porosidade , Poliésteres/química , Materiais Biocompatíveis/química , Concentração de Íons de Hidrogênio , Humanos , Sobrevivência Celular/efeitos dos fármacos , Teste de MateriaisRESUMO
The present study aimed to characterize the microstructure of a temporary 3D printing polymer-based composite material (Resilab Temp), evaluating its optical properties and mechanical behavior according to different post-curing times. For the analysis of the surface microstructure and establishment of the best printing pattern, samples in bar format following ISO 4049 (25 × 10 × 3 mm) were designed in CAD software (Rhinoceros 6.0), printed on a W3D printer (Wilcos), and light-cured in Anycubic Photon for different lengths of time (no post-curing, 16 min, 32 min, and 60 min). For the structural characterization, analyses were carried out using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The mechanical behavior of this polymer-based composite material was determined based on flexural strength tests and Knoop microhardness. Color and translucency analysis were performed using a spectrophotometer (VITA Easy Shade Advanced 4.0), which was then evaluated in CIELab, using gray, black, and white backgrounds. All analyses were performed immediately after making the samples and repeated after thermal aging over two thousand cycles (5-55 °C). The results obtained were statistically analyzed with a significance level of 5%. FT-IR analysis showed about a 46% degree of conversion on the surface and 37% in the center of the resin sample. The flexural strength was higher for the groups polymerized for 32 min and 1 h, while the Knoop microhardness did not show a statistical difference between the groups. Color and translucency analysis also did not show statistical differences between groups. According to all of the analyses carried out in this study, for the evaluated material, a post-polymerization time of 1 h should be suggested to improve the mechanical performance of 3D-printed devices.
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This study aimed to develop gelatin methacryloyl (GelMA)-injectable hydrogels incorporated with 58S bioactive glass/BG-doped with strontium for vital pulp therapy applications. GelMA hydrogels containing 0% (control), 5%, 10%, and 20% BG (w/v) were prepared. Their morphological and chemical properties were evaluated by scanning electron microscopy/SEM, energy dispersive spectroscopy/EDS, and Fourier transform infrared spectroscopy/FTIR (n = 3). Their swelling capacity and degradation ratio were also measured (n = 4). Cell viability (n = 8), mineralized matrix formation, cell adhesion, and spreading (n = 6) on DPSCs were evaluated. Data were analyzed using ANOVA/post hoc tests (α = 5%). SEM and EDS characterization confirmed the incorporation of BG particles into the hydrogel matrix, showing GelMA's (C, O) and BG's (Si, Cl, Na, Sr) chemical elements. FTIR revealed the main chemical groups of GelMA and BG, as ~1000 cm-1 corresponds to Si-O and ~1440 cm-1 to C-H. All the formulations were degraded by day 12, with a lower degradation ratio observed for GelMA+BG20%. Increasing the concentration of BG resulted in a lower mass swelling ratio. Biologically, all the groups were compatible with cells (p > 0.6196), and cell adhesion increased over time, irrespective of BG concentration, indicating great biocompatibility. GelMA+BG5% demonstrated a higher deposition of mineral nodules over 21 days (p < 0.0001), evidencing the osteogenic potential of hydrogels. GelMA hydrogels incorporated with BG present great cytocompatibility, support cell adhesion, and have a clinically relevant degradation profile and suitable mineralization potential, supporting their therapeutic potential as promising biomaterials for pulp capping.
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Zirconia implants are gaining attention as a viable alternative to titanium implants due to their comparable osseointegration development, improved soft tissue adaptation, and enhanced aesthetics. An encouraging avenue for improving zirconia implant properties involves the potential application of bioactive coatings to their surfaces. These coatings have shown potential for inducing hydroxyapatite formation, crucial for bone proliferation, and improving implant mechanical properties. This study aimed to evaluate the effect of coating zirconia implants with two bioactive glasses, 45S5 and BioK, on osteogenesis in vitro and osseointegration in vivo. Zirconia samples and implants were prepared using Zpex zirconia powder and blocks, respectively. The samples were divided into three groups: polished zirconia (ZRC), zirconia coated with 45S5 bioglass (Z + 45S5), and zirconia coated with BioK glass (Z + BK). Coatings were applied using a brush and sintered at 1200°C. Chemical analysis of the coatings was carried out using x-ray diffraction and Fourier Transform Infrared Spectroscopy. Surface topography and roughness were characterized using scanning electron microscopy and a roughness meter. In vitro experiments used mesenchymal cells from Wistar rat femurs, and the coated zirconia implants were found to promote cell viability, protein synthesis, alkaline phosphatase activity, and mineralization, indicating enhanced osteogenesis. In vivo experiments with 18 rats showed positive results for bone formation and osseointegration through histological and histomorphometric analysis and a push-out test. The findings indicate that bioactive glass coatings have the potential to improve cell differentiation, bone formation, and osseointegration in zirconia implants.
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Cerâmica , Implantes Dentários , Próteses e Implantes , Zircônio , Ratos , Animais , Ratos Wistar , Osseointegração , Propriedades de Superfície , Titânio/farmacologia , Titânio/química , Materiais Revestidos Biocompatíveis/farmacologia , Materiais Revestidos Biocompatíveis/química , Microscopia Eletrônica de VarreduraRESUMO
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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Anti-Infecciosos , Cerâmica , Teste de Materiais , Boro/farmacologia , Reprodutibilidade dos Testes , Zircônio/farmacologia , Propriedades de SuperfícieRESUMO
The development of bioactive membranes with bone repair properties is great interest in the field of tissue engineering. In this study, we aimed to fabricate and characterize a composite membrane composed of sol-gel synthesized bioceramics and electrospun polycaprolactone (PCL) fibers for bone tissue regeneration applications. The bioceramics were prepared using the sol-gel method with nitrate (N) and chloride (CL) as precursors. PCL and bioceramic solutions were electrospun to obtain ultrafine fiber mats. Raman spectroscopy, x-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to characterize the materials. The results showed that both chlorinated and non-chlorinated bioceramics contained NBOs (non-bridge bonds) and crystallized the α-wollastonite phase, with the chlorinated version doing so at lower temperatures. In vitro tests were performed to evaluate cytotoxicity, cell adhesion, and mineralized matrix formation on the membranes. The composite membranes showed improved cell viability and promoted mineralization nodules formation. This study presents a promising approach for the development of bioactive membranes for bone tissue engineering, with potential applications in bone regeneration therapies.
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Poliésteres , Engenharia Tecidual , Poliésteres/química , Engenharia Tecidual/métodos , Espectroscopia de Infravermelho com Transformada de Fourier , Osso e Ossos , Alicerces Teciduais/química , Materiais Biocompatíveis/químicaRESUMO
This paper explores the application of cross-linked cellulose beads as a sustainable and cost-effective support for the ZnO/SnO2/carbon xerogel hybrid photocatalyst. The application of the developed photocatalytic beads, named CB-Cat, was directed at a simultaneous adsorption/photocatalysis process, which was carried out under simulated sunlight. The characterization of the CB-Cat indicated a good dispersion of the photocatalyst of choice throughout the cellulose matrix, confirming its incorporation into the cellulose beads. Furthermore, it is possible to observe the presence of the photocatalyst on the surface of the CB-Cat, confirming its availability for the photonic activation process. The results showed that the simultaneous adsorption/photocatalysis process was optimal for enhancing the efficiency of methylene blue (MB) removal, especially when compared to the isolated adsorption process. Additionally, the regeneration of the CB-Cat between cycles was favorable toward the maintenance of the MB removal efficiency, as the process carried out without regeneration displayed significant efficiency drops between cycles. Finally, the mechanism evaluation evidenced that hydroxyl and superoxide radicals were the main responsible for the MB photocatalytic degradation during illumination with simulated sunlight.
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Poluentes Químicos da Água , Óxido de Zinco , Carbono , Adsorção , Celulose , Luz Solar , Azul de MetilenoRESUMO
The aim of this study was to evaluate the effect of two finishing techniques, glazing or polishing, in comparison with the as-cut condition, on the biaxial-flexural-strength (BFS) of a zirconia-reinforced lithium silicate ceramic (ZLS). Cylinders were milled from CAD/CAM blocks and sliced to obtain disc-shaped specimens (ISO6872:2015). Polished and glazed specimens were processed following the manufacturer's instructions. Thirty-three specimens were obtained for each condition and microstructural and BFS/fractographic characterizations were performed. BFS and roughness data were analyzed using Weibull statistics and ANOVA one-way with Tukey post-hoc test, respectively. While a rougher surface was observed for as-cut specimens, smoother surfaces were observed for polished and glazed ZLS at microscopical evaluation and confirmed through surface-roughness evaluation. X-ray spectra depicted a glass phase for all groups and characteristic metasilicate, lithium disilicate, and lithium phosphate peaks for the as-cut and polished specimens. Glazed specimens showed higher characteristic strength than polished and as-cut specimens, which did not differ significantly. While higher Weibull-modulus was observed for the polished than for the as-cut specimens, no statistically significant differences were noted between glazed and polished, and between glazed and as-cut specimens. ZLS presents higher strength when glazed, and polishing increases the structural reliability of the material relative to the as-cut condition. Both finishing techniques reduced surface roughness similarly.
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Cerâmica , Lítio , Reprodutibilidade dos Testes , Teste de Materiais , Propriedades de Superfície , Cerâmica/química , Porcelana Dentária/química , Zircônio/química , Silicatos , Desenho Assistido por ComputadorRESUMO
OBJECTIVE: This study evaluated the effect of an experimental borosilicate glass on the mechanical and optical behavior of 5Y-PSZ zirconia and comparing it to commercial glaze and as-sintered. METHODS: Disc-shaped specimens of a 5Y-PSZ (Zpex Smile) were prepared and sintered (1550 °C, 2 h). The zirconia discs were randomly divided according to the surface treatment: as-sintered (C), commercial glaze (G), and experimental borosilicate glass (SL). Glaze and experimental glass powders were mixed with building liquids and applied to zirconia with a brush. G specimens were fired at 950 °C and SL at 1200 °C. An extended dwell time of 20 min was applied to both groups. Biaxial flexural strength, roughness (Ra and Rz), translucency (TP00), color alteration (ΔE00), Vickers hardness, fracture toughness, residual stresses, and x-ray diffraction analyses were conducted. Statistical analyses were performed with Weibull statistics, Kruskal-Wallis, or ANOVA tests (α = 5%). RESULTS: SL yielded the highest flexural strength (799.35 MPa), followed by G (662.34 MPa), and C (485.38 MPa). The fracture origin of SL specimens was in the bulk zirconia, while G and C showed fractures starting at the surface. As-sintered reached the highest fracture toughness and hardness. Glaze and borosilicate glass provided surface compressive stresses. Borosilicate glass application led to phase transformation (tâm). SL and G showed the lowest roughness. TP00 and ΔE00 were similar among groups. SIGNIFICANCE: Borosilicate glass improved strength without harming the optical properties of third-generation zirconia. Toughness and roughness provided by the experimental glass were similar to those from commercial glaze.
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Cerâmica , Resistência à Flexão , Teste de Materiais , Propriedades de Superfície , Zircônio , Materiais DentáriosRESUMO
This study aimed to develop a recycling process for the remnants of milled 3Y-TZP and enhance their properties using glass infiltration. 3Y-TZP powder was gathered from the vacuum system of CAD-CAM milling equipment, calcined and sieved (x < 75 µm). One hundred twenty discs were fabricated and pre-sintered at 1000 °C/h. These specimens were then divided into four groups, categorized by glass infiltration (non-infiltrated [Zr] or glass-infiltrated [Zr-G]) and sintering temperature (1450 °C [Zr-1450] or 1550 °C [Zr-1550]/2h). After sintering, the specimens were characterized by X-Ray Diffraction (XRD), relative density measurement, and scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS). The biaxial flexural strength test was performed according to the ISO 6872 and followed by fractographic analysis. Subsequent results were analyzed using Weibull statistics. Relative density values of the sintered specimens from Zr-1450 and Zr-1550 groups were 86.7 ± 1.5% and 92.2 ± 1.7%, respectively. Particle size distribution revealed particles within the range of 0.1-100 µm. XRD analysis highlighted the presence of the ZrO2-tetragonal in both the Zr-1450 and Zr-1550 groups. Glass infiltration, however, led to the formation of the ZrO2-monoclinic of 9.84% (Zr-1450-G) and 18.34% (Zr-1550-G). SEM micrographs demonstrated similar microstructural characteristics for Zr-1450 and Zr-1550, whereas the glass-infiltrated groups exhibited comparable infiltration patterns. The highest characteristic strength was observed in the glass-infiltrated groups. Fractographic analyses suggested that fracture origins were related to defects on the tensile side, which propagated to the compression side of the samples. Both the sintering temperature and glass infiltration significantly influenced the mechanical properties of the 3Y-TZP recycled.
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Resistência à Flexão , Zircônio , Temperatura , Teste de Materiais , Zircônio/química , Ítrio/química , Propriedades de Superfície , Materiais Dentários , Cerâmica/químicaRESUMO
This study aimed to evaluate the effect of the number of uses and autoclave sterilization on the cyclic fatigue resistance of four replica-like instruments RC Blue; Only One File Blue; Recip One Blue; and Micro Blue compared to the original system Reciproc Blue (VDW, Munich, Germany). The instruments were analyzed by scanning electron microscope (SEM) before being used in root canal instrumentation (baseline). Fifty molars were instrumented by ten instruments (n=10). After sterilization in an autoclave, the instruments were analyzed by SEM. This procedure was repeated twice more using different molars, totaling 3 rounds of instrumentation, sterilization and SEM analysis. Then, ten different instruments from each brand were tested for cyclic fatigue resistance. Number of uses data were analyzed using Chi-squared analysis, and cyclic fatigue data were analyzed by one-way Anova followed by Tukey's test as the data had normal distribution. The fracture times for all systems had no significant difference, but Micro Blue had significantly lower values than the other systems (p < 0.05). The SEM analysis showed distortions in the instruments after the 3rd use. Therefore, all tested instruments except of Micro Blue have similar resistance to cyclic fatigue, and all are reliable for use in up to 2-cases.
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Preparo de Canal Radicular , Esterilização , Falha de Equipamento , Estresse Mecânico , Teste de Materiais , Desenho de Equipamento , TitânioRESUMO
To assess the influence of dentifrices with different abrasiveness levels on the properties of dental reconstructive materials. Forty-eight cylinders were obtained from four polymeric materials, being two CAD/CAM acrylic resins (Ivotion-Dent and Ivotion-Base), one injected acrylic resin (IvoBase-Hydrid) and one light-cured resin composite (Empress Direct). Specimens were allocated to four subgroups for toothbrushing simulation according to the dentifrice relative dentin abrasivity (RDA) and silica content: (i) RDA 0 = 0%; (ii) RDA 50 = 3%; (iii) RDA 100 = 10%; and (iv) RDA 120 = 25%. Specimens were then subjected to toothbrushing. Surface analyses [surface roughness Ra (SR) and scanning electron microscopy (SEM)] along with hardness and optical properties [translucency parameter (TP) and contrast ratio (CR)] were evaluated before and after toothbrushing. Statistical analyses were performed using ANOVA and Tukey test. A significant increase in SR was observed after toothbrushing with higher RDA toothpastes for Ivotion-Dent (100 and 120) and IvoBase-Hybrid (120). Ivotion-Base and Empress Direct presented no significant differences in SR when analyzed as a function of timepoint and RDA levels. Hardness was not influenced by toothbrushing with different RDA dentifrices, except for Empress Direct with RDA 0 toothpaste, where a decrease in the hardness was observed. TP of Ivotion-Dent and Empress Direct significantly decreased after toothbrushing with higher RDA dentifrices and CR of Ivotion-Dent, Empress Direct and IvoBase-Hybrid significantly increased with higher RDA dentifrices. The levels of dentifrice abrasiveness affected differently the SR, hardness and optical properties of polymeric reconstructive materials after toothbrushing.
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The objective of this study was to investigate the osteogenic and antimicrobial effect of bioactive glass S53P4 incorporated into ß-tricalcium phosphate (ß-TCP) scaffolds in vitro and the bone neoformation in vivo. ß-TCP and ß-TCP/S53P4 scaffolds were prepared by the gel casting method. Samples were morphologically and physically characterized through X-ray diffraction (XRD) and scanning electron microscope (SEM). In vitro tests were performed using MG63 cells. American Type Culture Collection reference strains were used to determine the scaffold's antimicrobial potential. Defects were created in the tibia of New Zealand rabbits and filled with experimental scaffolds. The incorporation of S53P4 bioglass promotes significant changes in the crystalline phases formed and in the morphology of the surface of the scaffolds. The ß-TCP/S53P4 scaffolds did not demonstrate an in vitro cytotoxic effect, presented similar alkaline phosphatase activity, and induced a significantly higher protein amount when compared to ß-TCP. The expression of Itg ß1 in the ß-TCP scaffold was higher than in the ß-TCP/S53P4, and there was higher expression of Col-1 in the ß-TCP/S53P4 group. Higher bone formation and antimicrobial activity were observed in the ß-TCP/S53P4 group. The results confirm the osteogenic capacity of ß-TCP ceramics and suggest that, after bioactive glass S53P4 incorporation, it can prevent microbial infections, demonstrating to be an excellent biomaterial for application in bone tissue engineering.
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PURPOSE: The aim of this study was to evaluate staining layer behavior applied to high-translucency zirconia (YZHT), feldspathic ceramics (FD), and zirconia-reinforced lithium silicate (ZLS) surfaces against different antagonists. METHODS AND MATERIALS: Monolithic ceramic discs (n = 120) (ø 12 mm; thickness, 1.2 mm; ISO 6872) were obtained, 30 from YZHT and FD, and 60 from ZLS CAD/CAM blocks (staining layer applied before or after the crystallization procedure). The specimens were divided into 12 subgroups (n = 10) according to the antagonists: steatite, polymer-infiltrated ceramic, or zirconia. Mechanical cycling (1.5 × 104 cycles; 15 N; horizontal displacement, 6 mm; 1.7 Hz) and flexural strength tests (1 mm/min-1000 kg cell) were performed. The differences between final and initial roughnesses (Ra, Rz, and Rsm), the mass loss, and the flexural strength data were individually analyzed by two-way ANOVA and Tukey's test (α = 0.05). RESULTS: The roughnesses of all ceramics did not present a statistically significant difference before wear simulation: Ra (p = 0.3348), Rz (p = 0.5590), and Rsm (p = 0.5330). After the wear simulation, the Ra parameter was not affected by an interaction between ceramic and antagonist (p = 0.595). The Rz and Rsm parameters were affected only by the antagonist pistons (both, p = 0.000). The ceramics used in this study showed statistically significant differences in mass loss after the wear test (p < 0.0001). The additional firing (2 steps) of the ZLS2 led to a higher lost mass quantity. CONCLUSION: All ceramics presented similar initial roughnesses and similar roughnesses after the wear simulation. The zirconia antagonist showed better performance against ceramics with high crystalline content. CLINICAL SIGNIFICANCE: It is clear that restorative materials must be carefully selected by dental practitioners according to indications, properties, and antagonists. The steatite antagonist, that is, an enamel analog, showed better performance against vitreous ceramics, while the zirconia antagonist showed better performance against ceramics with high crystalline content. Wear affects the surface roughnesses of the ceramics. Additional firing for the staining of the zirconia-reinforced lithium silicate ceramic led to a greater loss of mass.
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Porcelana Dentária , Lítio , Humanos , Porcelana Dentária/química , Odontólogos , Teste de Materiais , Papel Profissional , Cerâmica/química , Zircônio/química , Silicatos , Propriedades de Superfície , Desenho Assistido por ComputadorRESUMO
The use of identical prosthetic components for all implant diameters could reduce the production costs by companies and the complexity of component selection for the clinician and his team. However, it would imply in reduction of thickness of the cervical walls of tapered internal connection implants, which could compromise the reliability of narrow and extra-narrow implants. Therefore, this study aims to evaluate the probability of survival and failure modes of extra-narrow implant systems with the same internal diameter as standard-diameter implants using the same prosthetic components. It was used eigth different implant system configurations, including narrow (Ø 3.3 mm) (N) extra-narrow (Ø 2.9 mm) (EN) and extra-narrow-scalloped (Ø 2.9 mm) (ENS) implants, both with cementable abutments (Ce) or titanium bases (Tib) and one-piece implants (Ø 2.5 mm and Ø 3.0 mm) (OP) (Medens, Itu, SP, Brazil), comprising the following groups: OP 3.0; OP 2.5; N Ce; N Tib; EN Ce, EN Tib, ENS-Ce and ENS-Tib. The implants were embedded using polymethylmethacrylate acrylic resin in a 15 mm matrix. Standardized maxillary central incisor crowns were virtually designed and milled to fit on the different studied abutments and cemented using a dual self-adhesive resin cement. The specimens were submitted to SSALT (Step Stress Accelerated Life Testing) at 15 Hz in water until failure or suspension of the test, until a maximum load of 500 N. Fractographic analysis of the failed specimens were realized in scanning electron microscopy. All implant systems demonstrated high probability of survival (90-100%) for missions at 50 and 100 N and values of characteristic strength superior to 139 N. Failure modes were restricted to the abutment in all the implant configurations tested. Therefore, the use extra-narrow implants with standardized prosthetic components for different implant diameters is a viable option for the replacement of anterior teeth.
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Coroas , Incisivo , Reprodutibilidade dos Testes , Teste de Materiais , Titânio , Análise do Estresse Dentário , Falha de Restauração Dentária , ZircônioRESUMO
The demands for dental materials continue to grow, driven by the desire to reach a better performance than currently achieved by the available materials. In the dental restorative ceramic field, the structures evolved from the metal-ceramic systems to highly translucent multilayered zirconia, aiming not only for tailored mechanical properties but also for the aesthetics to mimic natural teeth. Ceramics are widely used in prosthetic dentistry due to their attractive clinical properties, including high strength, biocompatibility, chemical stability, and a good combination of optical properties. Metal-ceramics type has always been the golden standard of dental reconstruction. However, this system lacks aesthetic aspects. For this reason, efforts are made to develop materials that met both the mechanical features necessary for the safe performance of the restoration as well as the aesthetic aspects, aiming for a beautiful smile. In this field, glass and high-strength core ceramics have been highly investigated for applications in dental restoration due to their excellent combination of mechanical properties and translucency. However, since these are recent materials when compared with the metal-ceramic system, many studies are still required to guarantee the quality and longevity of these systems. Therefore, a background on available dental materials properties is a starting point to provoke a discussion on the development of potential alternatives to rehabilitate lost hard and soft tissue structures with ceramic-based tooth and implant-supported reconstructions. This review aims to bring the most recent materials research of the two major categories of ceramic restorations: ceramic-metal system and all-ceramic restorations. The practical aspects are herein presented regarding the evolution and development of materials, technologies applications, strength, color, and aesthetics. A trend was observed to use high-strength core ceramics type due to their ability to be manufactured by CAD/CAM technology. In addition, the impacts of COVID-19 on the market of dental restorative ceramics are presented.
Assuntos
COVID-19 , Materiais Dentários , Humanos , Materiais Dentários/química , Cerâmica/química , Desenho Assistido por Computador , Porcelana Dentária , Zircônio/química , Teste de Materiais , Propriedades de SuperfícieRESUMO
PURPOSE: To evaluate the effect of plasma-enhanced chemical vapor deposition (PECVD) with silicon hydride (SiH4) at different times on HT-zirconia surface characteristics and bonding of composite cement before and after thermocycling. MATERIALS AND METHODS: Blocks of HT zirconia were obtained, polished, sintered and divided into five groups, according to PECVD time (n = 31): Zr-30 (30 s), Zr-60 (60 s), Zr-120 (120 s) and Zr-300 (300 s). The control group (Zr-0) did not receive PECVD. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS) in conjunction with field-emission scanning electron microscopy (FE-SEM), x-ray photoelectron spectroscopy (XPS), goniometry, and profilometry tests were used for chemical and topographic characterization. Monobond N silane (Ivoclar Vivadent) was applied to the surface, and a cylinder of composite cement (Variolink N) was made (3 x 3 mm). Half of the specimens of each group were stored for 24 h or subjected to thermocycling (6 x 103 cycles). A shear bond strength (SBS) test was performed. Results were subjected to one-way ANOVA and Tukey's tests (α = 0.05). RESULTS: For experimental groups, XPS showed that formation of Si-O bonds contributed to increased surface free energy (SFE). FE-SEM and EDS showed that the longer the deposition time, the greater the amount of silicon on the surface. Zr-60 and Zr-300 presented higher and lower surface roughnesses, respectively. The silicon penetrated the microstructure, causing higher stress concentrations. The bond strength to composite cement was improved after all PECVD deposition times. CONCLUSION: The PECVD technique with SiH4, associated with chemical treatment with primer based on silane methacrylate, is a solely chemical surface treatment capable of maintaining bonding between composite cement and HT zirconia.