RESUMEN
The aim of this study was to characterize the mechanical properties of a bioactive-modified polyetheretherketone (PEEK) manufacturing approach for dental implants and to compare the in vitro biological behavior with titanium alloy (Ti6Al4V) as the reference. PEEK, PEEK with 5% hydroxyapatite (HA), PEEK with 5% beta-tricalcium phosphate (ßTCP), and Ti6Al4V discs were produced using hot pressing technology to create a functionally graded material (FGM). Surface roughness values (Ra, Rz), water contact angle, shear bond strength, and Vickers hardness tests were performed. Human osteoblasts and gingival fibroblasts bioactivity was evaluated by a resazurin-based method, alkaline phosphatase activity (ALP), and confocal laser scanning microscopy (CLSM) images of fluorescent-stained fibroblasts. Morphology and cellular adhesion were confirmed using field emission gun-scanning electron microscopy (FEG-SEM). Group comparisons were tested using analysis of variance (Tukey post hoc test), α = .05. All groups presented similar roughness values (P > .05). Ti6Al4V group was found to have the highest contact angle (P < .05). Shear bond strength and Vickers hardness of different PEEK materials were similar (P > .05); however, the mean values in the Ti6Al4V group were significantly higher when compared with those of the other groups (P < .05). Cell viability and proliferation of osteoblast and fibroblast cells were higher in the PEEK group (P < .05). PEEK-ßTCP showed the highest significant ALP activity over time (P < .05 at 14 days of culture). An enhanced bone and soft-tissue cell behavior on pure PEEK was obtained to the gold standard (Ti6Al4V) with equivalent roughness. The results substantiate the potential role of chemical composition rather than physical properties of materials in biological responses. The addition of 5% HA or ßTCP by FGM did not enhance PEEK mechanical properties or periodontal cell behavior.
Asunto(s)
Implantes Dentales , Benzofenonas , Humanos , Cetonas , Polietilenglicoles , Polímeros , Propiedades de Superficie , TitanioRESUMEN
Cutlery and flatware designs are an everchanging phenomenon of the manufacturing industry. Worldwide hospitality businesses demand perpetual evolution in terms of aesthetics, designs, patterns, colours, and materials due to customers' demands, modernisation, and fierce competition. To thrive in this competitive market, modern fabrication techniques must be flexible, adoptive, fast, and cost effective. For decades, static designs and trademark patterns were achieved through moulds, limiting production to a single cutlery type per mould. However, with the advent of laser engraving and design systems, the whole business of cutlery production has been revolutionised. This study explores the possibility of creating diverse designs for stainless steel 304 flatware sets without changing the entire production process. The research analyses three key laser process parameters, power, scanning speed, and number of passes, and their impacts on the resulting geometry, depth of cut, surface roughness, and material removed. These parameters are comprehensively studied and analysed for steel and zirconia ceramic. The study details the effects of power, scanning speed, number of passages, and fluence on engraved geometry. Fluence (power*number of passages/scanning speed) positively influences outputs and presents a positive trend. Medium power settings and higher scanning speeds with the maximum number of passages produce high-quality, low-roughness optimised cavities with the ideal geometric accuracy for both materials.
RESUMEN
As the aging population increases worldwide, the incidence of musculoskeletal diseases and the need for orthopedic implants also arise. One of the most desirable goals in orthopedic reconstructive therapies is de novo bone formation. Yet, reproducible, long-lasting, and cost-effective strategies for implants that strongly induce osteogenesis are still in need. Nanoengineered titanium substrates (and their alloys) are among the most used materials in orthopedic implants. Although having high biocompatibility, titanium alloys hold a low bioactivity profile. The osteogenic capacity and osseointegration of Ti-based implantable systems are limited, as they critically depend on the body-substrate interactions defined by blood proteins adsorbed into implant surfaces that ultimately lead to the recruitment, proliferation, and differentiation of mesenchymal stem cells (MSCs) to comply bone formation and regeneration. In this work, a hybrid Ti6Al4V system combining micro- and nanoscale modifications induced by hydrothermal treatment followed by functionalization with a bioactive compound (fibronectin derived from human plasma) is proposed, aiming for bioactivity improvement. An evaluation of the biological activity and cellular responses in vitro with respect to bone regeneration indicated that the integration of morphological and chemical modifications into Ti6Al4V surfaces induces the osteogenic differentiation of MSCs to improve bone regeneration by an enhancement of mineral matrix formation that accelerates the osseointegration process. Overall, this hybrid system has numerous competitive advantages over more complex treatments, including reproducibility, low production cost, and potential for improved long-term maintenance of the implant.
RESUMEN
Osseointegration is defined by a stable and functional union between bone and a surface of a material. This phenomenon is influenced by the geometric and surface characteristics of the part where the bone cells will attach. A wide variety of studies proves that ceramic materials are strong competitors against conventional metals in the scope of bone tissue engineering. Ceramic scaffolds, porous structures that allow bone ingrowth, have been studied to enhance the osseointegration phenomenon. Geometric and dimensional parameters of the scaffold have influence in its performance as mechanical and structural supporter of bone growth. However, these parameters are conditioned by the manufacturing process by which these scaffolds are obtained. Several studies focusing on the production process of ceramic scaffolds have been developed, using 3D printing, stereolithography, selective laser sintering, green machining, robocasting, and others. The main purpose of this work is to evaluate and compare the different manufacturing processes by which ceramic scaffolds can be produced. This comparison addresses scaffold parameters like pore size, pore shape, porosity percentage, roughness, and so forth. Additionally, the different materials used in different manufacturing processes are also mentioned and discussed given its influence on a successful osseointegration while simultaneously displaying adequate mechanical properties. After making a screening on the available ceramic scaffolds manufacturing processes, several examples are presented, proving the potential of each of these manufacturing process for a given scaffold geometry.
Asunto(s)
Materiales Biocompatibles , Sustitutos de Huesos , Huesos/patología , Cerámica , Oseointegración/efectos de los fármacos , Andamios del Tejido/química , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/uso terapéutico , Sustitutos de Huesos/química , Sustitutos de Huesos/uso terapéutico , Cerámica/química , Cerámica/uso terapéutico , Humanos , Ensayo de Materiales , Porosidad , Impresión Tridimensional , Ingeniería de TejidosRESUMEN
Adding a biological apatite layer to the implant surface enhances bone healing around the implant. Objective This study aimed to characterize the mechanical properties and test human gingival fibroblasts behavior in contact with Zirconia and Titanium bioactive-modified implant materials. Methodology 6 groups were considered: Titanium (Ti6Al4V), Ti6Al4V with 5% HA and 5% ßTCP, Zirconia (YTZP), YTZP with 5% HA and 5% ßTCP. For each group, we produced discs using a novel fabrication method for functionally graded materials, under adequate conditions for etching and grit-blasting to achieve equivalent surface microroughness among the samples. Surface roughness (Ra, Rz), water contact angle, shear bond strength, and Vickers hardness were performed. Human gingival fibroblasts immortalized by hTERT gene from the fourth passage, were seeded on discs for 14 days. Cell viability and proliferation were assessed using a resazurin-based method, and cellular adhesion and morphology using field emission gun scanning electron microscopy (FEG-SEM). After 3 days of culture, images of fluorescent nucleic acid stain were collected by confocal laser scanning microscopy (CLSM). Results Results were presented as mean ± standard deviation (SD). We compared groups using one-way ANOVA with Tukey's post-hoc test, and significance level was set at p<0.05. After 14 days of culture, cell viability and proliferation were significantly higher in YTZP group than in other groups (p<0.05). Samples of YTZP-ßTCP presented significantly higher wettability (p<0.05); yet, we observed no improvement in cell behavior on this group. Fibroblast spreading and surface density were more evident on YTZP specimens. Adding calcium-phosphate bioactive did not alter the tested mechanical properties; however, Ti6Al4V material shear bond strength was statistically higher than other groups (p<0.05). Conclusion Adding bioactive materials did not improve soft-tissue cell behavior. When compared to other zirconia and titanium groups, pure zirconia surface improved adhesion, viability and proliferation of fibroblasts. Cell behavior seems to depend on surface chemical composition rather than on surface roughness.
Asunto(s)
Implantes Dentales , Fibroblastos , Titanio , Circonio , Humanos , Microscopía Electrónica de Rastreo , Propiedades de SuperficieRESUMEN
This study intends to develop a novel zirconia scaffold design with a significantly lower Young's Modulus than zirconia bulk material (210â¯GPa) aiming to match this elastic property with that of the host bone, for application as endosseous implants. This scaffold with a complex interconnected structure can allow bone ingrowth, vascularization and provide a good initial stability. This novel thin-walled zirconia scaffold was manufactured by green machining and afterwards furnace sintered. The obtained YM of this zirconia scaffold was found significantly lower than zirconia bulk material due a less stiff geometry with small (walls and floors) dimensions. Insertion replication tests were performed for evaluating the fixation at the initial moment of implantation, being experimentally verified a high static initial coefficient of friction. The capillarity of these scaffolds was also assessed, revealing a very high rising speed of water inside these structures. This study proved that this novel ceramic scaffold design can be fabricated for several dimensions for obtaining desired elastic properties. The proposed fabrication strategy allows the fabrication of thin-walled structures unachievable by conventional machining.
Asunto(s)
Sustitutos de Huesos/química , Huesos/química , Ingeniería de Tejidos/instrumentación , Andamios del Tejido/química , Circonio/química , Cerámica/química , Fuerza Compresiva , Durapatita/química , Módulo de Elasticidad , Humanos , Ensayo de Materiales , Trasplante de Neoplasias , Presión , Estrés Mecánico , Temperatura , Ingeniería de Tejidos/métodosRESUMEN
PURPOSE: The aim of this study was to characterize and compare the behavior of human osteoblasts and human gingival fibroblasts in contact with polyetheretherketone (PEEK), zirconia, and titanium implant surface materials. MATERIALS AND METHODS: PEEK, yttria-stabilized zirconia (YTZP), and titanium discs were produced under appropriate and similar conditions to achieve controlled surface features. Human osteoblasts and human gingival fibroblasts were cultured on discs for 14 days. Cell viability and proliferation were evaluated using a resazurin-based method. Morphology and cellular adhesion were observed using field emission gun-scanning electron microscopy (FEG-SEM). Alkaline phosphatase (ALP) activity and bone cell mineralization were evaluated on osteoblasts. Confocal laser scanning microscopy (CLSM) images of fluorescent-stained fibroblasts were obtained at 7 and 14 days of the culture. Results were presented as mean and standard deviation (SD). Group comparisons were tested using analysis of variance (ANOVA) (Tukey's post hoc) with appropriate statistical software, and significance was set at P < .05. RESULTS: Cell viability and proliferation were higher in PEEK and YTZP groups compared with titanium on osteoblast cells (P < .05, all time points) and on fibroblasts (P < .05, 7 and 14 days). All groups showed an increase in ALP activity over time, which was not significant. Mineralization patterns demonstrated an increase in mineral content over time, which was more apparent in the YTZP group. Cell spreading was more evident on PEEK and YTZP specimens. CONCLUSION: The results suggest increased adhesion, viability, and proliferation of osteoblasts and gingival fibroblasts on zirconia and PEEK surfaces compared with titanium. These results are correlated with the increased wettability of these materials.
Asunto(s)
Materiales Dentales , Fibroblastos/fisiología , Cetonas , Osteoblastos/fisiología , Polietilenglicoles , Titanio , Circonio , Análisis de Varianza , Benzofenonas , Adhesión Celular , Proliferación Celular , Supervivencia Celular , Células Cultivadas , Fibroblastos/citología , Encía/citología , Humanos , Microscopía Electrónica de Rastreo , Osteoblastos/citología , Polímeros , Propiedades de SuperficieRESUMEN
The aim of this study was to analyze the osteogenic cell behavior on the surface of novel functionally graded titanium-based composites containing bioactive ceramics. Titanium grade V discs (8 × 3 mm) embedding gradual content of hydroxyapatite (TiAlV-HA) or beta-tricalcium phosphate (TiAlV-ßTCP) were produced by hot-pressing technique. Titanium-ceramic composite discs and Ti grade V (control group) were placed in contact with human osteoblast culture assays. The morphology and adhesion of osteoblasts were inspected by field emission guns scanning electron microscopy (FEGSEM) while cell viability was assessed by fluorometric method. Alkaline phosphatase (ALP) activity and fluorescent microscopic analyses were used to evaluate mineralization on the test and control discs. FEGSEM images showed cells adhered to Ti6Al4V-ceramic and Ti6Al4V surfaces over a period of 24 h, and therefore, an intense proliferation of osteoblasts and spreading cells was noticed for 7 days. Cell viability increased with time on all the surfaces although TiAlV-ßTCP revealed significant higher percentage of cell viability than that recorded for TiAlV-HA (p < 0.01). TiAlV-ßTCP also showed the highest hydrophilic character. ALP levels increased on the Ti6Al4V-ceramic surfaces when compared to the control group. Also, a qualitative analysis of mineralization evidenced an increase in mineral content on TiAlV-HA or TiAlV-ßTCP groups. Novel functionally graded composites based on Ti grade V and hydroxyapatite or ßTCP showed a higher bioactivity in presence of osteoblasts than that recorded on Ti grade V. Also, such functionally graded materials can prevent risks of failures by detachment of bioactive ceramic materials during implant placement. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1923-1931, 2018.
Asunto(s)
Materiales Biocompatibles/farmacología , Cerámica/farmacología , Osteoblastos/citología , Titanio/farmacología , Fosfatasa Alcalina/metabolismo , Aleaciones , Calcificación Fisiológica/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Fluorescencia , Dureza , Humanos , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , AguaRESUMEN
Abstract Adding a biological apatite layer to the implant surface enhances bone healing around the implant. Objective This study aimed to characterize the mechanical properties and test human gingival fibroblasts behavior in contact with Zirconia and Titanium bioactive-modified implant materials. Methodology 6 groups were considered: Titanium (Ti6Al4V), Ti6Al4V with 5% HA and 5% ßTCP, Zirconia (YTZP), YTZP with 5% HA and 5% ßTCP. For each group, we produced discs using a novel fabrication method for functionally graded materials, under adequate conditions for etching and grit-blasting to achieve equivalent surface microroughness among the samples. Surface roughness (Ra, Rz), water contact angle, shear bond strength, and Vickers hardness were performed. Human gingival fibroblasts immortalized by hTERT gene from the fourth passage, were seeded on discs for 14 days. Cell viability and proliferation were assessed using a resazurin-based method, and cellular adhesion and morphology using field emission gun scanning electron microscopy (FEG-SEM). After 3 days of culture, images of fluorescent nucleic acid stain were collected by confocal laser scanning microscopy (CLSM). Results Results were presented as mean ± standard deviation (SD). We compared groups using one-way ANOVA with Tukey's post-hoc test, and significance level was set at p<0.05. After 14 days of culture, cell viability and proliferation were significantly higher in YTZP group than in other groups (p<0.05). Samples of YTZP-ßTCP presented significantly higher wettability (p<0.05); yet, we observed no improvement in cell behavior on this group. Fibroblast spreading and surface density were more evident on YTZP specimens. Adding calcium-phosphate bioactive did not alter the tested mechanical properties; however, Ti6Al4V material shear bond strength was statistically higher than other groups (p<0.05). Conclusion Adding bioactive materials did not improve soft-tissue cell behavior. When compared to other zirconia and titanium groups, pure zirconia surface improved adhesion, viability and proliferation of fibroblasts. Cell behavior seems to depend on surface chemical composition rather than on surface roughness.
Asunto(s)
Humanos , Titanio , Circonio , Implantes Dentales , Fibroblastos , Propiedades de Superficie , Microscopía Electrónica de RastreoRESUMEN
To promote a healthy diet, the dietary guidance should consider socio-cultural factors as they influence both the food standards and preferences of each population. The aim of this study was to describe the socio-cultural contexts of pregnancy and feeding in the domestic arena, using a qualitative approach. In-depth interviews were conducted using the data saturation technique with six women experiencing high-risk pregnancy. The interviews were transcribed and analyzed in accordance with the Bardin method and the IT Atlas program. The following aspects were identified: uncertainty due to unplanned pregnancy and limited partner support; a few dietary changes to improve health; perception of bad and good feeding habits, although it did not comply with the characteristics of a good diet; omission of fruit and vegetable group from dinner. The people in charge of preparing and serving food were not always the pregnant woman; food products perceived as being harmful were consumed and beneficial products were rarely consumed. This highlighted the need to train professionals to consider the socio-cultural context when providing dietary guidance.
Asunto(s)
Características Culturales , Dieta , Conducta Alimentaria , Adolescente , Adulto , Femenino , Humanos , Embarazo , Factores de Riesgo , Factores Sociológicos , Adulto JovenRESUMEN
Gestational diabetes mellitus (GDM) is a public health problem in Mexico and diet therapy is the main form of treatment. Self-management abilities are required to control the disease. Five women with GDM were studied to assess GDM risk perception and experiences related with self-management practices. Sociodemographic data were obtained and in-depth interviews were conducted and subsequently analyzed using Atlas ti V.5 software. The results revealed that women were conscious regarding the role of diet and physical activity in improving GDM control, and about the perinatal risks associated with the disease. Adherence to diet recommendations was partial, but gradual and positive lifestyle changes were observed. Emotionally, perception about having GDM was a key factor with respect to adhering to the diet. In conclusion, the medical and dietary treatment influences the cultural food behavior of women with GDM. Health professionals should consider sociocultural determinants when designing and implementing treatment strategies.
Asunto(s)
Actitud Frente a la Salud , Diabetes Gestacional/terapia , Sobrepeso/terapia , Complicaciones del Embarazo/terapia , Autocuidado , Adulto , Femenino , Humanos , Paridad , EmbarazoRESUMEN
Para favorecer una alimentación correcta la orientación alimentaria debe considerar factores socioculturales que condicionen patrones y preferencias del consumo de alimentos propios de cada población. El objetivo de esta investigación fue describir el contexto sociocultural del embarazo y su alimentación en el ámbito doméstico, mediante un enfoque cualitativo. Se realizaron entrevistas en profundidad a 6 mujeres con embarazo de alto riesgo bajo la técnica de saturación de la información. Las entrevistas se transcribieron y analizaron de acuerdo a Bardín con ayuda del programa Atlas TI. Se identificó: incertidumbre por el embarazo no planeado y poco apoyo de la pareja; ciertos cambios en la alimentación para mejorar la salud; percepción de una mala y buena alimentación, aunque ésta no cumplía con las características de una dieta correcta; omisión de la cena y del grupo de verduras y frutas. Las encargadas de preparar y servir los alimentos no siempre fueron las mujeres embarazadas; los alimentos percibidos peligrosos fueron consumidos y los benéficos presentaron consumo escaso. Resaltó la necesidad de capacitar a los profesionales de la salud para considerar al contexto sociocultural en la orientación alimentaria que proporcionen.
To promote a healthy diet, the dietary guidance should consider socio-cultural factors as they influence both the food standards and preferences of each population. The aim of this study was to describe the socio-cultural contexts of pregnancy and feeding in the domestic arena, using a qualitative approach. In-depth interviews were conducted using the data saturation technique with six women experiencing high-risk pregnancy. The interviews were transcribed and analyzed in accordance with the Bardin method and the IT Atlas program. The following aspects were identified: uncertainty due to unplanned pregnancy and limited partner support; a few dietary changes to improve health; perception of bad and good feeding habits, although it did not comply with the characteristics of a good diet; omission of fruit and vegetable group from dinner. The people in charge of preparing and serving food were not always the pregnant woman; food products perceived as being harmful were consumed and beneficial products were rarely consumed. This highlighted the need to train professionals to consider the socio-cultural context when providing dietary guidance.
Asunto(s)
Adolescente , Adulto , Femenino , Humanos , Embarazo , Adulto Joven , Características Culturales , Dieta , Conducta Alimentaria , Factores de Riesgo , Factores SociológicosRESUMEN
La diabetes mellitus gestacional (DMG) es un problema de salud pública en México, cuya primer línea de tratamiento es la dietoterapia. Se requieren habilidades de automanejo para el control de la enfermedad. En este trabajo se estudiaron cinco mujeres con DMG, quienes manifestaron su percepción de riesgo de la presencia de la DMG y vivencias en algunas prácticas del autocuidado. Se obtuvieron datos sociodemográficos; se realizaron entrevistas en profundidad, las cuales se analizaron con el paquete Atlas ti V.5. Los resultados demuestran que las mujeres están conscientes del papel que juega la alimentación y la actividad física en mejorar el control de su enfermedad, además de los riesgos perinatales a los que se asocia la DMG. El cumplimiento de las recomendaciones dietéticas en su mayoría fue parcial, pero se demuestran cambios positivos y graduales en el estilo de vida. Las percepciones desde las emociones que les produce la DMG, fue factor clave para que llevaran a cabo la dieta. En conclusión, el tratamiento médico y dietético influye en el comportamiento cultural alimentario de las mujeres con DMG. Los profesionales de la salud deben tomar en cuenta los determinantes socioculturales al diseñar e implementar estrategias de tratamiento.
Gestational diabetes mellitus (GDM) is a public health problem in Mexico and diet therapy is the main form of treatment. Self-management abilities are required to control the disease. Five women with GDM were studied to assess GDM risk perception and experiences related with self-management practices. Sociodemographic data were obtained and in-depth interviews were conducted and subsequently analyzed using Atlas ti V.5 software. The results revealed that women were conscious regarding the role of diet and physical activity in improving GDM control, and about the perinatal risks associated with the disease. Adherence to diet recommendations was partial, but gradual and positive lifestyle changes were observed. Emotionally, perception about having GDM was a key factor with respect to adhering to the diet. In conclusion, the medical and dietary treatment influences the cultural food behavior of women with GDM. Health professionals should consider sociocultural determinants when designing and implementing treatment strategies.
Asunto(s)
Adulto , Femenino , Humanos , Embarazo , Actitud Frente a la Salud , Diabetes Gestacional/terapia , Sobrepeso/terapia , Complicaciones del Embarazo/terapia , Autocuidado , ParidadRESUMEN
El presente trabajo tiene como objetivo conocer la experiencia del Hospital San Juan de Dios en relación a las diferentes técnicas quirúrgicas utilizadas en la reparación de la hernia inguinal, evaluando sus complicaciones y ventajas. Se realizó un estudio descriptivo entre técnicas clásicas abiertas, técnica libre de tensión utilizando prótesis de polipropileno (Lichtenstein) y técnica laparoscópica transabdominal pre-peritoneal (TAPP). Se intervinieron 208 hernias en 170 pacientes (38 bilaterales) de las cuales 104 corresponden a técnicas abiertas clásicas (Bassini, Mc Vay y Shouldice), 73 a técnicas de Lichtenstein y 31 a técnica laparoscópica TAPP. Se operaron indistintamente pacientes primarios y recidivas. Se evaluaron resultados de acuerdo a dolor postoperatorio, utilizando escala de categoría numérica (0 a 10), tipo de anestesia, alta quirúrgica, reintegro laboral y complicaciones de cada una de las diferentes técnicas