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1.
Int J Mol Sci ; 22(16)2021 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-34445228

RESUMEN

Recent advancements in medical imaging, virtual surgical planning (VSP), and three-dimensional (3D) printing have potentially changed how today's craniomaxillofacial surgeons use patient information for customized treatments. Over the years, polyetheretherketone (PEEK) has emerged as the biomaterial of choice to reconstruct craniofacial defects. With advancements in additive manufacturing (AM) systems, prospects for the point-of-care (POC) 3D printing of PEEK patient-specific implants (PSIs) have emerged. Consequently, investigating the clinical reliability of POC-manufactured PEEK implants has become a necessary endeavor. Therefore, this paper aims to provide a quantitative assessment of POC-manufactured, 3D-printed PEEK PSIs for cranial reconstruction through characterization of the geometrical, morphological, and biomechanical aspects of the in-hospital 3D-printed PEEK cranial implants. The study results revealed that the printed customized cranial implants had high dimensional accuracy and repeatability, displaying clinically acceptable morphologic similarity concerning fit and contours continuity. From a biomechanical standpoint, it was noticed that the tested implants had variable peak load values with discrete fracture patterns and failed at a mean (SD) peak load of 798.38 ± 211.45 N. In conclusion, the results of this preclinical study are in line with cranial implant expectations; however, specific attributes have scope for further improvements.


Asunto(s)
Benzofenonas , Sistemas de Atención de Punto , Polímeros , Impresión Tridimensional , Prótesis e Implantes , Cráneo/lesiones , Humanos , Procedimientos de Cirugía Plástica
2.
J Infect Dis ; 221(4): 608-617, 2020 02 03.
Artículo en Inglés | MEDLINE | ID: mdl-31854451

RESUMEN

BACKGROUND: No satisfactory canonical treatment is available for post-kala-azar dermal leishmaniasis (PKDL), clinical sequela of visceral leishmaniasis. Confined treatment options and substantial increase in relapse rate after miltefosine (MIL) treatment warrant the need to adapt resilient combination therapies. In this study, we assessed the safety and efficacy of combination therapy using liposomal amphotericin B (LAmB) and MIL for treating PKDL. METHODS: Thirty-two PKDL patients, confirmed by microscopy or quantitative polymerase chain reaction (qPCR), were included in the study. An equal number of cases (n = 16) were put on MIL monotherapy (100 mg/day for 90 days) or MIL and LAmB combination for 45 days (3 injections of LAmB, 5 mg/kg body weight, and 100 mg/day MIL). Parasite load in slit aspirate was monitored using qPCR. RESULTS: Patients treated with combination therapy demonstrated a rapid decline in parasite load and achieved 100% cure, with no reports of relapse. Those treated with MIL monotherapy attained clinical cure with a gradual decrease in parasite load; however, 25% relapsed within 18 months of follow-up. CONCLUSIONS: Liposomal amphotericin B and MIL combination for treating PKDL is efficacious and safe, with high tolerability. Furthermore, this study established the utility of minimally invasive slit aspirate method for monitoring of parasite load and assessment of cure in PKDL.


Asunto(s)
Anfotericina B/administración & dosificación , Anfotericina B/uso terapéutico , Antiprotozoarios/uso terapéutico , Leishmania donovani/genética , Leishmaniasis Cutánea/tratamiento farmacológico , Leishmaniasis Visceral/tratamiento farmacológico , Fosforilcolina/análogos & derivados , Adolescente , Adulto , Anfotericina B/efectos adversos , Antiprotozoarios/efectos adversos , Niño , ADN Protozoario/genética , Quimioterapia Combinada , Femenino , Humanos , Leishmaniasis Cutánea/parasitología , Leishmaniasis Visceral/parasitología , Liposomas , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Carga de Parásitos , Fosforilcolina/efectos adversos , Fosforilcolina/uso terapéutico , Reacción en Cadena en Tiempo Real de la Polimerasa , Recurrencia , Resultado del Tratamiento , Adulto Joven
3.
J Prosthet Dent ; 124(6): 780-786, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31955837

RESUMEN

STATEMENT OF PROBLEM: Comparisons of the material qualities of pressed, milled, and 3D-printed occlusal devices are sparse, complicating informed decisions on material choice. PURPOSE: The purpose of this in vitro study was to compare the material properties of pressed, milled, and 3D-printed resins, as well as how these are affected by thermal aging. These data were then used to estimate the likely clinical performance of the tested materials. MATERIAL AND METHODS: Three pressed (ProBase Cold; Ivoclar Vivadent AG, Palapress clear; Kulzer GmbH, Aesthetic Blue clear; Candulor), 3 milled (Temp Premium Flexible Transpa; Zirkonzahn, idodentine PMMA transparent; Unión Dental S.A., Yamahachi PMMA clear; Yamahachi Dental MFG), and three 3D-printed (Freeprint splint; DETAX GmbH, LuxaPrint Ortho Plus; DMG GmbH, Nextdent Ortho Clear; Vertex-Dental B.V.) resin materials were evaluated. Flexural strength, Martens hardness (HM), Vickers hardness (HV), water sorption, water solubility, and surface topography were analyzed. The tests were carried out after 50 hours of water storage at 37 °C (baseline) and after simulated aging (50 hours of water storage at 37 °C, followed by 20 000 thermocycles [TC] at 5 °C and 55 °C). RESULTS: At baseline, the mean flexural strength values were 92.8 to 99.5 MPa for pressed, 95.1 to 122.0 MPa for milled, and 19.5 to 91.3 MPa for 3D-printed materials. After aging, these values were 87.6 to 93.5 MPa for pressed, 93.1 to 116.0 MPa for milled, and 13.0 to 63.3 MPa for 3D-printed resins. The mean HM values were 130.1 to 134.1 N/mm for pressed and 130.3 to 158.5 N/mm for milled resins. After aging, the mean HM ranged from 121.6 to 124.2 N/mm for pressed and 116.2 to 149.7 N/mm for milled resins. The mean HV values were 18.2 to 19.9 for pressed and 18.4 to 23.0 for milled resins before aging and 16.9 to 18.7 for pressed and 17.3 to 22.3 N/mm for milled resins after aging. Printed resins could not be measured. At baseline, the mean modulus of elasticity ranged from 4.6 to 4.8 GPa for pressed and from 4.7 to 5.3 GPa for milled resins. For 3D-printed resins, only 1 material could be measured (3.7 GPa). The mean sorption values were 8.6 to 9.2 µg/mm3 for pressed, 7.9 to 10.5 µg/mm3 for milled, and 9.2 to 21.2 µg/mm3 for additive resins. After aging, these values were 21.1 to 22.6 µg/mm3 for pressed, 20.5 to 23.7 µg/mm3 for milled, and 19.4 to 45.5 µg/mm3 for 3D-printed resins. The mean solubility values ranged from 0.3 to 1.4 µg/mm3 for pressed, 0.4 to 1.7 µg/mm3 for milled, and -3.5 to 11 µg/mm3 for 3D-printed materials. CONCLUSIONS: Pressed and milled resins can be considered equivalent in terms of their material properties. Relative to the pressed and milled resins, the 3D-printed resins had lower flexural strength and hardness values and higher water sorption and solubility.


Asunto(s)
Resinas Compuestas , Estética Dental , Materiales Dentales , Resistencia Flexional , Dureza , Ensayo de Materiales , Impresión Tridimensional , Estrés Mecánico , Propiedades de Superficie
4.
J Contemp Dent Pract ; 19(9): 1140-1146, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-30287718

RESUMEN

INTRODUCTION: Rendering quality care to the patient, dentists needs to update their skills and knowledge with latest diagnostics and treatment modalities. Evidence-based dentistry can provide best-known treatments. AIM: To assess knowledge, attitude, and practice of oral healthcare professionals toward evidence-based dentistry among dental professionals. MATERIALS AND METHODS: A cross-sectional study was conducted for a period of 3 months from April 2017 to June 2017 in Jodhpur city, Rajasthan, India. The data were collected by using closed-ended questionnaires. A total of 240 study subjects participated in the survey, which include dental practitioners and dentists attached to the two private dental colleges in the Jodhpur. Chi-square test was used to determine significant difference among the three groups. RESULTS: Statistically significant difference among the three groups (academicians, practitioners, and academicians into dental practice) was found with regard to awareness of dentists about extracting journals, review publications, and databases relevant in carrying out evidence-based practice (EBP); 72.4% of academician felt lack of personal time was one of the major perceived barriers and about 50.7% of academician believe that learning skills of evidence-based dentistry helps them to utilize evidence-based dentistry in daily practice. CONCLUSION: Majority of the oral health practitioners were not aware about the concept of evidence-based dentistry. The regulatory body of dental sciences in India should make some necessary changes in the dental curriculum to include the concept of evidence-based dentistry in detail. CLINICAL SIGNIFICANCE: To improve the clinical expertise of the dental professional, to aid dental professional to reach best decision regarding dental treatment of the patient, to improve patient safety, and to improve the success rate of dental treatments, evidence-based dentistry should be the integral part of everyday dental practice.


Asunto(s)
Odontólogos/psicología , Odontólogos/estadística & datos numéricos , Odontología Basada en la Evidencia , Conocimientos, Actitudes y Práctica en Salud , Adulto , Anciano , Concienciación , Competencia Clínica , Estudios Transversales , Curriculum/tendencias , Educación en Odontología/tendencias , Odontología Basada en la Evidencia/educación , Femenino , Humanos , India/epidemiología , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Adulto Joven
5.
J Environ Manage ; 162: 37-45, 2015 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-26217888

RESUMEN

Conducting hydrogels possessing antibacterial activity were developed using a two-step free-radical aqueous polymerization method to incorporate polyaniline chains into an adsorbent Guar gum/acrylic acid hydrogel network. The material properties of the synthesized samples were characterized using FTIR spectroscopy, thermal analysis and scanning electron microscopy techniques. Conducting hydrogels were tested for antibacterial activities against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria and demonstrated antibacterial activity. Synthesized hydrogel samples can be potential adsorbent materials for dye removal applications.


Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Galactanos/química , Hidrogeles/química , Mananos/química , Gomas de Plantas/química , Polisacáridos Bacterianos/química , Acrilatos/química , Antibacterianos/síntesis química , Materiales Biocompatibles , Colorantes/aislamiento & purificación , Escherichia coli/efectos de los fármacos , Hidrogeles/síntesis química , Azul de Metileno/aislamiento & purificación , Microscopía Electrónica de Rastreo , Polimerizacion , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus/efectos de los fármacos
6.
Int J Pharm ; 651: 123768, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38176477

RESUMEN

Chronic inflammation is a leading cause of neurodegeneration and vision loss in hyperglycemia-associated conditions such as diabetic retinopathy. Corticosteroid injections are widely used for treatment but suffer from limitations such as rapid drug clearance, short drug half-lives and frequent administration. While drug release from biomaterial carriers can overcome these shortcomings, evaluating the combined effects of corticosteroids and polymeric matrices under hyperglycemic stress is an important step towards aiding translation. In this study, we investigated the effects of dexamethasone (DEX) and electrospun mesh combination on primary human mixed retinal cells under normal and hyperglycemic culture conditions. DEX-incorporated poly(lactide-co-glycolide) (PLGA) meshes were prepared and characterized for architecture, chemistry, drug distribution and in vitro release. The meshes exhibited cumulative in vitro drug release of 39.5 % over 2 months at a near constant rate. Under normal culture conditions, DEX-PLGA meshes promoted significantly higher viability of mixed retinal cells than the control groups but without adverse phenotypic activation. Under hyperglycemic conditions, DEX supplementation resulted in higher viability than the control, although the highest viability was achieved only when DEX was added to cells cultured on PLGA fibers. The combination of DEX and PLGA fibers also promoted higher mRNA expression of the antioxidant GSH under hyperglycemia. Importantly, the largest reduction in the production of pro-inflammatory cytokines viz., MMP-9, IL-6, IL-8 and VEGF-R1 was observed for the DEX and PLGA combination. Our study reveals a combined effect of DEX and electrospun fibers in combating hyperglycemia-driven pro-inflammatory responses, which can aid the development of DEX-loaded electrospun implants for diabetes-driven retinal conditions.


Asunto(s)
Hiperglucemia , Mallas Quirúrgicas , Humanos , Materiales Biocompatibles , Polímeros , Dexametasona , Hiperglucemia/tratamiento farmacológico
7.
Chemosphere ; 360: 142312, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38761824

RESUMEN

Lignocellulosic waste generation and their improper disposal has accelerated the problems associated with increased greenhouse gas emissions and associated environmental pollution. Constructive ways to manage and mitigate the pollution associated with lignocellulosic waste has propelled the research on biochar production using lignocellulose-based substrates. The sustainability of various biochar production technologies in employing lignocellulosic biomass as feedstock for biochar production not only aids in the lignocellulosic biomass valorization but also helps in carbon neutralization and carbon utilization. Functionalization of biochar through various physicochemical methods helps in improving their functional properties majorly by reducing the size of the biochar particles to nanoscale and modifying their surface properties. The usage of engineered biochar as nano adsorbents for environmental applications like dye absorption, removal of organic pollutants and endocrine disrupting compounds from wastewater has been the thrust areas of research in the past few decades. This review presents a comprehensive outlook on the up-to-date research findings related to the production and engineering of biochar from lignocellulosic biomass and their applications in environmental remediation especially with respect to wastewater treatment. Further a detailed discussion on various biochar activation methods and the future scope of biochar research is presented in this review work.


Asunto(s)
Biomasa , Carbón Orgánico , Lignina , Carbón Orgánico/química , Lignina/química , Restauración y Remediación Ambiental/métodos , Aguas Residuales/química , Adsorción , Contaminantes Ambientales/química , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/análisis
8.
Protoplasma ; 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38607379

RESUMEN

Globodera pallida, an obligate sedentary endoparasite, is a major economic pest that causes substantial potato yield losses. This research aimed to study the effects of gene silencing of three FMRFamide-like peptides (FLPs) genes to reduce G. pallida infestation on potato plants by using kaolinite nanoclay as a carrier to deliver dsRNAs via drenching. A dsRNA dosage of 2.0 mg/ml silenced flp-32c by 89.5%, flp-32p by 94.6%, and flp-2 by 94.3%. J2s incubated for 5 and 10 h showed no phenotypic changes. However, J2s of G. pallida efficiently uptake dsRNA of all targeted genes after 15 h of incubation. On the other hand, J2s that had been kept for 24 h had a rigid and straight appearance. Under fluorescence microscopy, all dsRNA-treated nematodes showed fluorescein isothiocyanate (FITC) signals in the mouth, nervous system, and digestive system. The untreated population of J2s did not show any FITC signals and was mobile as usual. The drenching of potato cultivar Kufri Jyoti with the dsRNA-kaolinite formulations induced deformation and premature death of J2s, compared with untreated J2s that entered J3 or J4 stages. This study validates that the nanocarrier-delivered RNAi system could be employed effectively to manage G. pallida infestations.

9.
Dent Mater ; 40(4): 674-688, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38388252

RESUMEN

OBJECTIVE: Polyetheretherketone (PEEK), a biomaterial with appropriate bone-like mechanical properties and excellent biocompatibility, is widely applied in cranio-maxillofacial and dental applications. However, the lack of antibacterial effect is an essential drawback of PEEK material and might lead to infection and osseointegration issues. This study aims to apply a natural antibacterial agent, totarol coating onto the 3D printed PEEK surface and find an optimized concentration with balanced cytocompatibility, osteogenesis, and antibacterial capability. METHODS: In this study, a natural antibacterial agent, totarol, was applied as a coating to fused filament fabrication (FFF) 3D printed PEEK surfaces at a series of increasing concentrations (1 mg/ml, 5 mg/ml, 10 mg/ml, 15 mg/ml, and 20 mg/ml). The samples were then evaluated for cytocompatibility with L929 fibroblast and SAOS-2 osteoblast using live/dead staining and CCK-8 assay. The antibacterial capability was assessed by crystal violet staining, live/dead staining, and scanning electron microscopy (SEM) utilizing the oral primary colonizer S. gordonii and isolates of mixed oral bacteria in a stirring system simulating the oral environment. The appropriate safe working concentration for totarol coating is selected based on the results of the cytocompatibility and antibacterial test. Subsequently, the influence on osteogenic differentiation was evaluated by alkaline phosphatase (ALP) and alizarin red staining (ARS) analysis of pre-osteoblasts. RESULTS: Our results showed that the optimal concentration of totarol solution for promising antibacterial coating was approximately 10 mg/ml. Such surfaces could play an excellent antibacterial role by inducing a contact-killing effect with an inhibitory effect against biofilm development without affecting the healing of soft and hard tissues around FFF 3D printed PEEK implants or abutments. SIGNIFICANCE: This study indicates that the totarol coated PEEK has an improved antibacterial effect with excellent biocompatibility providing great clinical potential as an orthopedic/dental implant/abutment material.


Asunto(s)
Abietanos , Benzofenonas , Implantes Dentales , Osteogénesis , Polímeros , Polietilenglicoles/farmacología , Polietilenglicoles/química , Cetonas/farmacología , Cetonas/química , Antibacterianos/farmacología , Antibacterianos/química , Impresión Tridimensional , Propiedades de Superficie
10.
Chemosphere ; 352: 141453, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38364916

RESUMEN

Polyethylene Terephthalate (PET) is a polymer which is considered as one of the major contaminants to the environment. The PET waste materials can be recycled to produce value-added products. PET can be converted to nanoparticles, nanofibers, nanocomposites, and nano coatings. To extend the applications of PET nanomaterials, understanding its commercialization potential is important. In addition, knowledge about the factors affecting recycling of PET based nanomaterials is essential. The presented review is focused on understanding the PET commercialization aspects, keeping in mind market analysis, growth drivers, regulatory affairs, safety considerations, issues associated with scale-up, manufacturing challenges, economic viability, and cost-effectiveness. In addition, the paper elaborates the challenges associated with the use of PET based nanomaterials. These challenges include PET contamination to water, soil, sediments, and human exposure to PET nanomaterials. Moreover, the paper discusses in detail about the factors affecting PET recycling, commercialization, and circular economy with specific emphasis on life cycle assessment (LCA) of PET recycled nanomaterials.


Asunto(s)
Nanocompuestos , Nanopartículas , Humanos , Tereftalatos Polietilenos , Reciclaje , Polímeros
11.
Bioengineered ; 14(1): 2242124, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37548430

RESUMEN

Recently, the development of sustainable and environmentally friendly biomaterials has gained the attention of researchers as potential alternatives to petroleum-based materials. Biomaterials are a promising candidate to mitigate sustainability issues due to their renewability, biodegradability, and cost-effectiveness. Thus, the purpose of this study is to explore a cost-effective biomaterial-based delivery system for delivering fertilizers to plants. To achieve this, rice straw (agro-waste) was selected as a raw material for the extraction of cellulose. The cellulose was extracted through alkali treatment (12% NaOH), followed by TEMPO-based oxidation. The cellulose nanofibers were characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, and transmission electron microscopy. In scanning electron microscopy, a loosening of the fibrillar structure in cellulose nanofibers (CNFs) was observed with a diameter of 17 ± 4 nm. The CNFs were loaded with nitrogen-based fertilizer (ammonium chloride) in 1:1, 1:2, and 2:1 (w/w) proportions. The loading was estimated through surface charge variation; in the case of the 1:1 sample, maximum reductions in surface charge were seen from -42.0 mV to -12.8 mV due to the binding of positive ammonium ions. In the release kinetics study, a controlled release pattern was observed at 1:1, which showed a 58% cumulative release of ammonium ions within 8 days. Thus, the study paves the way for value-added uses of rice straw as an alternative to the current environmentally harmful practices.


Bio-based cellulose nanofibers (CNFs) from rice straw via circular economy approach.Controlled release fertilizers for sustainable agriculture.Nanotechnology for precision agriculture and decarbonization via agricultural waste management.


Asunto(s)
Nanofibras , Oryza , Celulosa/química , Fertilizantes , Oryza/química , Nanofibras/química , Desarrollo Sostenible , Preparaciones de Acción Retardada , Espectroscopía Infrarroja por Transformada de Fourier , Materiales Biocompatibles , Iones
12.
J Pharm Bioallied Sci ; 15(Suppl 1): S151-S155, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37654268

RESUMEN

Introduction: An instrumented and endodontically treated tooth may sometimes impede disinfection by trapping hard tissue as well as the other canal contents at the isthmus level of the canal. Thus, the current in vitro study was piloted to assess the competence of two irrigating systems. Methods: Twenty mandibular with two mesial canals convergent into a single foramen and joined by an isthmus of the human permanent teeth were compared for the two irrigation systems of continuous and intermittent ultrasonic (US) motions of the irrigation. The teeth were prepared by a single rotary system and were imaged using the "Scanning electronic microscopy-SCM". The parameters were compared before and after the irrigation of the canal with the intended US systems for the removal of hard tissue debris. The appropriate statistical tools were used to find the significance, the value of which was kept at P < 0.05. Results: Significant percentage reduction of the hard tissue debris was achieved after the application of the supplemental irrigation protocols (P < 0.05). However between the groups, there was no significant difference. Conclusions: Comparable removal of the hard tissue debris was obtained in both the irrigation systems. Though not significant, the GentleWave performed better than the Irrisafe.

13.
J Pharm Bioallied Sci ; 15(Suppl 1): S137-S140, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37654291

RESUMEN

Introduction: There are numerous chances for pulpal irritation during the placement of a crown on a tooth. This study's goal was to find and examine the variables that influence the prevalence of routine root canal therapy after the teeth were restored with full coverage crowns. Methods: The hospital records were retrospectively evaluated from 2000 to 2010 for a decade. The demographics as well as the various variables that caused for the intervention with the root canal therapy for the teeth with the full crowns were evaluated. The values were compared for the significance. Results: The total number of the teeth that were finalized in the study was 4308. Of the total teeth that were treated with full coverage crowns, 50% were metal ceramic, 42% were full ceramic, and 9% were full metal crowns. After 10 years, possibility that every tooth with a crown would survive was 91%. The most frequent adverse incident was the intervention with the RCT. Metal ceramic crowns had poor survival rates and needed the maximum intervention. Younger age-group had least survival rate than the older age-groups. Conclusions: Endodontic therapy is unlikely to be necessary after crown installation. As the patient's age declines and all-ceramic or PFM crowns are used, this risk rises.

14.
Cureus ; 15(2): e35210, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36960257

RESUMEN

Background and purpose Implant-supported mandibular overdentures are a good alternative for patients having poor retention of mandibular conventional dentures. The aim of this prospective study was to evaluate and compare the results between early loading and delayed loading of mandibular overdentures on two unsplinted implants. Materials and methods  A total of 14 completely edentulous male patients in the age group of 50-60 years were selected for the study. Two 3.5×13 mm implants were placed in the mandibular interforaminal region. The patients were divided into two groups: (i) the test group in which the overdenture was connected after one week of surgery, and (ii) the control group, in which the overdenture was connected three months after surgery. Marginal bone levels were evaluated at baseline (during loading), three months, and six months post loading. Unpaired 't' test was used for the comparison of intergroup measurements.  Results No implants were lost. Marginal bone resorptions showed no statistically significant differences between the two groups over six months period after loading. Conclusion The results of this prospective clinical study suggested that there was no significant difference in the clinical and radiographic state of patients treated with implant-supported mandibular overdentures loaded either one week or three months after implant surgery.

15.
J Mech Behav Biomed Mater ; 144: 105948, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37348171

RESUMEN

Only a few mandibular bone finite element (FE) models have been validated in literature, making it difficult to assess the credibility of the models. In a comparative study between FE models and biomechanical experiments using a synthetic polyamide 12 (PA12) mandible model, we investigate how material properties and boundary conditions affect the FE model's accuracy using the design of experiments approach. Multiple FE parameters, such as contact definitions and the materials' elastic and plastic deformation characteristics, were systematically analyzed for an intact mandibular model and transferred to the fracture fixation model. In a second step, the contact definitions for the titanium screw and implant (S-I), implant and PA12 mandible (I-M), and interfragmentary (IF) PA12 segments were optimized. Comparing simulated deformations (from 0 to -5 mm) and reaction forces (from 10 to 1'415 N) with experimental results showed a strong sensitivity to FE mechanical properties and contact definitions. The results suggest that using the bonded definition for the screw-implant contact of the fracture plate is ineffective. The contact friction parameter set with the highest agreement was identified: titanium screw and implant µ = 0.2, implant and PA12 mandible µ = 0.2, interfragmentary PA12 mandible µ = 0.1. The simulated reaction force (RMSE = 26.60 N) and surface displacement data (RMSE = 0.19 mm) of the FE analysis showed a strong agreement with the experimental biomechanical data. The results were generated through parameter optimization which means that our findings need to be validated in the event of a new dataset with deviating anatomy. Conclusively, the predictive capability of the FE model can be improved by FE model calibration through experimental testing. Validated preoperative quasi-static FE analysis could allow engineers and surgeons to accurately estimate how the implant's choice and placement suit the patient's biomechanical needs.


Asunto(s)
Fracturas Mandibulares , Humanos , Fracturas Mandibulares/cirugía , Análisis de Elementos Finitos , Titanio , Fijación Interna de Fracturas/métodos , Fenómenos Biomecánicos , Mandíbula , Placas Óseas , Estrés Mecánico
16.
Environ Toxicol Pharmacol ; 98: 104045, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36572198

RESUMEN

Microplastics are the small fragments of the plastic molecules which find their applications in various routine products such as beauty products. Later, it was realized that it has several toxic effects on marine and terrestrial organisms. This review is an approach in understanding the microplastics, their origin, dispersal in the aquatic system, their biodegradation and factors affecting biodegradation. In addition, the paper discusses the major engineering approaches applied in microbial biotechnology. Specifically, it reviews microbial genetic engineering, such as PET-ase engineering, MHET-ase engineering, and immobilization approaches. Moreover, the major challenges associated with the plastic removal are presented by evaluating the recent reports available.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Plásticos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Biodegradación Ambiental , Ecosistema
17.
Int J Biol Macromol ; 234: 123733, 2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-36801274

RESUMEN

The exponential increase in the use and careless discard of synthetic plastics has created an alarming concern over the environmental health due to the detrimental effects of petroleum based synthetic polymeric compounds. Piling up of these plastic commodities on various ecological niches and entry of their fragmented parts into soil and water has clearly affected the quality of these ecosystems in the past few decades. Among the many constructive strategies developed to tackle this global issue, use of biopolymers like polyhydroxyalkanoates as sustainable alternatives for synthetic plastics has gained momentum. Despite their excellent material properties and significant biodegradability, polyhydroxyalkanoates still fails to compete with their synthetic counterparts majorly due to the high cost associated with their production and purification thereby limiting their commercialization. Usage of renewable feedstocks as substrates for polyhydroxyalkanoates production has been the thrust area of research to attain the sustainability tag. This review work attempts to provide insights about the recent developments in the production of polyhydroxyalkanoates using renewable feedstock along with various pretreatment methods used for substrate preparation for polyhydroxyalkanoates production. Further, the application of blends based on polyhydroxyalkanoates, and the challenges associated with the waste valorization based polyhydroxyalkanoates production strategy is elaborated in this review work.


Asunto(s)
Petróleo , Polihidroxialcanoatos , Ecosistema , Biopolímeros/química , Plásticos
18.
Dent Mater ; 38(7): 1083-1098, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35562293

RESUMEN

OBJECTIVE: The objective of this study was to determine the effect of two plasma surface treatments on the biologic responses of PEEK medical implants manufactured by fused filament fabrication (FFF) 3D printing technology. METHODS: This study created standard PEEK samples using an FFF 3D printer. After fabrication, half of the samples were polished to simulate a smooth PEEK surface. Then, argon (Ar) or oxygen (O2) plasma was used to modify the bioactivity of FFF 3D printed and polished PEEK samples. Scanning electron microscopy (SEM) and a profilometer were used to determine the microstructure and roughness of the sample surfaces. The wettability of the sample surface was assessed using a drop shape analyzer (DSA) after plasma treatment and at various time points following storage in a closed environment. Cell adhesion, metabolic activity, proliferation, and osteogenic differentiation of SAOS-2 osteoblasts were evaluated to determine the in vitro osteogenic activity. RESULTS: SEM analysis revealed that several spherical nanoscale particles and humps appeared on sample surfaces following plasma treatment. The wettability measurement demonstrated that plasma surface treatment significantly increased the surface hydrophilicity of PEEK samples, with only a slight aging effect found after 21 days. Cell adhesion, spreading, proliferation, and differentiation of SAOS-2 osteoblasts were also up-regulated after plasma treatment. Additionally, PEEK samples treated with O2 plasma demonstrated a higher degree of bioactivation than those treated with Ar. SIGNIFICANCE: Plasma-modified PEEK based on FFF 3D printing technology was a feasible and prospective bone grafting material for bone/dental implants.


Asunto(s)
Productos Biológicos , Implantes Dentales , Argón , Benzofenonas , Cetonas/química , Osteogénesis , Polietilenglicoles/química , Polímeros , Impresión Tridimensional , Estudios Prospectivos , Propiedades de Superficie
19.
Children (Basel) ; 9(8)2022 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-36010151

RESUMEN

Cleft lip and palate are one of the most common congenital craniofacial malformations. As an initial treatment, presurgical orthopedics is considered standard treatment at many cleft centers. Digital impressions are becoming feasible in cleft care. Computer-aided design (CAD) and three-dimensional (3D) printing are manufacturing standards in dentistry. The assimilation of these technologies has the potential to alter the traditional workflow for the fabrication of customized presurgical orthopedic plates. We present a digital workflow comprising three steps: 3D digital image acquisition with an intraoral scanner, open-source CAD modeling, and point-of-care 3D printing for the fabrication of personalized passive presurgical plates for newborns with cleft lip and palate. The digital workflow resulted in patient-related benefits, such as no risk of airway obstruction with quicker data acquisition (range 1-2.5 min). Throughput time was higher in the digital workflow 260-350 min compared to 135 min in the conventional workflow. The manual and personal intervention time was reduced from 135 min to 60 min. We show a clinically useful digital workflow for presurgical plates in cleft treatment. Once care providers overcome procurement costs, digital impressions, and point-of-care 3D printing will simplify these workflows and have the potential to become standard for cleft care.

20.
ACS Appl Mater Interfaces ; 14(46): 52289-52300, 2022 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-36349361

RESUMEN

Environmental contamination and energy shortage are among the most critical global issues that require urgent solutions to ensure sustainable ecological balance. Rapid and ultrasensitive monitoring of water quality against pollutant contaminations using a low-cost, easy-to-operate, and environmentally friendly technology is a promising yet not commonly available solution. Here, we demonstrate the effective use of plasma-converted natural bioresources for environmental monitoring. The energy-efficient microplasmas operated at ambient conditions are used to convert diverse bioresources, including fructose, chitosan, citric acid, lignin, cellulose, and starch, into heteroatom-doped graphene quantum dots (GQDs) with controlled structures and functionalities for applications as fluorescence-based environmental nanoprobes. The simple structure of citric acid enables the production of monodispersed 3.6 nm averaged-size GQDs with excitation-independent emissions, while the saccharides including fructose, chitosan, lignin, cellulose, and starch allow the synthesis of GQDs with excitation-dependent emissions due to broader size distribution. Moreover, the presence of heteroatoms such as N and/or S in the chemical structures of chitosan and lignin coupled with the highly reactive species generated by the plasma facilitates the one-step synthesis of N, S-codoped GQDs, which offer selective detection of toxic environmental contaminants with a low limit of detection of 7.4 nM. Our work provides an insight into the rapid and green fabrication of GQDs with tunable emissions from natural resources in a scalable and sustainable manner, which is expected to generate impact in the environmental safety, energy conversion and storage, nanocatalysis, and nanomedicine fields.


Asunto(s)
Quitosano , Grafito , Puntos Cuánticos , Puntos Cuánticos/química , Grafito/química , Lignina , Nitrógeno/química , Ácido Cítrico/química , Almidón , Fructosa
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