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1.
São Paulo; s.n; 20210219. 78 p.
Tesis en Portugués | LILACS, BBO - Odontología | ID: biblio-1147715

RESUMEN

A resina acrílica é usada em larga escala nos mais diversos setores inclusive na odontologia. Apesar dessa difusão, esse material sofre um problema sério frente a adesão de microrganismos em sua superfície. Visando isso, o presente trabalho elaborou um biomaterial baseado na incorporação do biocida Poli (cloreto de dialildimetilamônio) (PDADMAC) na massa de resinas acrílicas auto e termopolimerizável, avaliou suas propriedades antifúngicas e citotoxicidade. O PDADMAC foi incorporado nas resinas acrílicas e sua atividade antifúngica foi testada frente aos fungos Candida albicans (ATCC 10231) e Aspergillus niger (ATCC 16404) seguindo os protocolos padrão G21-15 e E2149-13. Além disso, cepas isoladas da mucosa oral de pacientes sem doenças sistêmicas foram identificadas e a partir disso foram realizados os estudos de protease e de potencial antifúngico frente a essas cepas. Foram realizados também os testes de citotoxidade utilizando o ensaio de redução de MTT em células-tronco de polpa dentária cultivadas em contato com meio de cultura condicionado pelas resinas. Os resultados demostraram que ambas as resinas com PDADMAC exibiram eficácia significativa contra Candida albicans. Já com relação ao fungo Aspergillus niger, ficou evidente que esse material possui apenas eficácia fungistática. Com relação às cepas isoladas da mucosa oral de pacientes sem doenças sistêmicas, foi observado que a Candida albicans foi a mais prevalente e que independente da produção de protease produzidas por essas cepas as resinas acrescidas de PDADMAC são eficazes. Nos exames de citotoxidade a adição do biocida nas resinas não afetou a viabilidade celular quando comparada às células cultivadas em condições ideais. Portanto, conclui-se que a incorporação de PDADMAC nas resinas acrílicas foi determinante para alcançar o efeito antifúngico desejado, mantendo a biocompatibilidade. Este estudo encontrou resultados promissores para o uso futuro deste biocida em materiais odontológicos.


Asunto(s)
Resinas Acrílicas , Materiales Dentales , Antifúngicos
2.
AAPS PharmSciTech ; 22(1): 44, 2021 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-33438107

RESUMEN

Among the great number of poorly soluble drugs in pharmaceutical development, most of them are weak bases. Typically, they readily dissolve in an acidic environment but are prone to precipitation at elevated pH. This was aimed to be counteracted by the preparation of amorphous solid dispersions (ASDs) using the pH-dependent soluble polymers methacrylic acid ethylacrylate copolymer (Eudragit L100-55) and hydroxypropylmethylcellulose acetate succinate (HPMCAS) via hot-melt extrusion. The hot-melt extruded ASDs were of amorphous nature and single phased with the presence of specific interactions between drug and polymer as revealed by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), and Fourier-transform infrared spectroscopy (FT-IR). The ASDs were milled and classified into six particle size fractions. We investigated the influence of particle size, drug load, and polymer type on the dissolution performance. The best dissolution performance was achieved for the ASD made from Eudragit L100-55 at a drug load of 10%, whereby the dissolution rate was inversely proportional to the particle size. Within a pH-shift dissolution experiment (from pH 1 to pH 6.8), amorphous-amorphous phase separation occurred as a result of exposure to acidic medium which caused markedly reduced dissolution rates at subsequent higher pH values. Phase separation could be prevented by using enteric capsules (Vcaps Enteric®), which provided optimal dissolution profiles for the Eudragit L100-55 ASD at a drug load of 10%.


Asunto(s)
Antifúngicos/química , Cetoconazol/química , Tamaño de la Partícula , Resinas Acrílicas/química , Rastreo Diferencial de Calorimetría , Composición de Medicamentos/métodos , Liberación de Fármacos , Concentración de Iones de Hidrógeno , Metacrilatos , Metilcelulosa/análogos & derivados , Metilcelulosa/química , Preparaciones Farmacéuticas/química , Polímeros , Difracción de Polvo , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier
3.
Chemosphere ; 262: 128072, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33182132

RESUMEN

A new synthesis method was developed to prepare an aluminum-based metal organic framework (MIL-96) with a larger particle size and different crystal habits. A low cost and water-soluble polymer, hydrolyzed polyacrylamide (HPAM), was added in varying quantities into the synthesis reaction to achieve >200% particle size enlargement with controlled crystal morphology. The modified adsorbent, MIL-96-RHPAM2, was systematically characterized by SEM, XRD, FTIR, BET and TGA-MS. Using activated carbon (AC) as a reference adsorbent, the effectiveness of MIL-96-RHPAM2 for perfluorooctanoic acid (PFOA) removal from water was examined. The study confirms stable morphology of hydrated MIL-96-RHPAM2 particles as well as a superior PFOA adsorption capacity (340 mg/g) despite its lower surface area, relative to standard MIL-96. MIL-96-RHPAM2 suffers from slow adsorption kinetics as the modification significantly blocks pore access. The strong adsorption of PFOA by MIL-96-RHPAM2 was associated with the formation of electrostatic bonds between the anionic carboxylate of PFOA and the amine functionality present in the HPAM backbone. Thus, the strongly held PFOA molecules in the pores of MIL-96-RHPAM2 were not easily desorbed even after eluted with a high ionic strength solvent (500 mM NaCl). Nevertheless, this simple HPAM addition strategy can still chart promising pathways to impart judicious control over adsorbent particle size and crystal shapes while the introduction of amine functionality onto the surface chemistry is simultaneously useful for enhanced PFOA removal from contaminated aqueous systems.


Asunto(s)
Aluminio/química , Caprilatos/análisis , Fluorocarburos/análisis , Dietilamida del Ácido Lisérgico/análogos & derivados , Estructuras Metalorgánicas/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Resinas Acrílicas/química , Adsorción , Carbón Orgánico/química , Dietilamida del Ácido Lisérgico/química , Tamaño de la Partícula , Solubilidad , Propiedades de Superficie
4.
Food Chem ; 335: 127631, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-32736157

RESUMEN

In this work, sodium 4-styrenesulfonate functionalized polyacrylonitrile nanofibers mat (SS/PAN NFM) was firstly prepared and applied as 96-well plate solid-phase extraction adsorbent for quantitative determination of seven ß-agonists residues in pork samples. The functional modification endowed the SS/PAN NFM with superior adsorption performance for target ß-agonists. The adsorption process is spontaneous (ΔG < 0), the initial adsorption rate can reach 6.03-9.09 mg/g/min and the maximum adsorption capacity is calculated to be 48.3 mg/g at 298 K. Moreover, SS/PAN NFM can be reused for 12 times without degradation in adsorption capability. Combined with UPLC-MS/MS, the limits of detection can reach 0.006-0.24 µg/kg, the recoveries ranged from 87.2% to 111% and the relative standard deviations of intra-day and inter-day precisions were in the scope of 1.75%-11.6% and 5.08%-13.5%, respectively. The obtained results fully demonstrated the practicability of this method in preventing the hazard of ß-agonists residues.


Asunto(s)
Agonistas Adrenérgicos beta/análisis , Agonistas Adrenérgicos beta/aislamiento & purificación , Análisis de los Alimentos/métodos , Nanofibras/química , Poliestirenos/química , Carne Roja/análisis , Extracción en Fase Sólida/métodos , Resinas Acrílicas/química , Agonistas Adrenérgicos beta/química , Adsorción , Animales , Contaminación de Alimentos/análisis , Límite de Detección , Porcinos
5.
Chemosphere ; 263: 127875, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32835968

RESUMEN

Nanoscale zero-valent iron (nZVI) settled slowly and incompletely in a nano-iron reactor (NIR) in wastewater treatment, and the effluent quality and processing capacity of nZVI were degenerated. Herein, three types of polyacrylamide (PAM), anionic-APAM (nZVIAPAM), cationic-CPAM (nZVICPAM), and nonionic-NPAM (nZVINPAM)) were applied to modify the nZVI (nZVIPAM), which were proved to enhance aggregation and sedimentation in the gravity settling clarifier of NIR. PAM modification lead to aggregate by forming large agglomerates. The median sizes of aggregates were 32, 194, 168 and 133 µm respectively for nZVI, nZVICPAM, nZVINPAM, and nZVIAPAM. Under quiescent conditions, bare nZVI needed 5 min to reach sedimentation equilibrium, while nZVIPAM just within 1 min nZVICPAM settled more quickly and completely than nZVINPAM and nZVIAPAM. The Fe concentration in the dynamic flow NIR effluent could keep a low level for 8 h for nZVIPAM, while bare nZVI for 6 h. Iron concentration was 3.11, 0.037, 0.93, and 1.20 mg·L-1 for nZVI, nZVICPAM, nZVINPAM, and nZVIAPAM after 8-h-reaction. Meanwhile, the reactivity of nZVIPAM was kept much longer for lead removal in the NIR. Results demonstrated PAM modifications (especially CPAM) provided a reliable solution for nZVI aggregation and sedimentation in wastewater treatment.


Asunto(s)
Nanopartículas del Metal , Contaminantes Químicos del Agua , Resinas Acrílicas , Hierro , Contaminantes Químicos del Agua/análisis
6.
Food Chem ; 337: 127763, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-32791431

RESUMEN

In this work, water-resistant poly (vinyl alcohol) (PVA)/poly (acrylic acid) (PAA) electrospun fibers encapsulating tangeretin (Tan) were fabricated by emulsion-electrospinning. To optimize the electrospinning condition, the size and morphology of electrospun fibers were characterized by dynamic light scattering (DLS), optical light microscope, fluorescence microscopy, and scanning electron microscopy (SEM), respectively. The optimized initial concentration of PVA/PAA was 10% (w/w) with a mass ratio of 3:7. The time and temperature of optimized thermal crosslinking treatment were 2 h and 145 °C, respectively. The results of XRD and SEM showed that the Tan was successfully incorporated into smooth PVA/PAA electrospun fibers and those fibers possessed nano-diameter size and high porosity. The encapsulation of Tan had no significant impact on the antioxidant activity of PVA/PAA/Tan crosslinking electrospun fibers. The in vitro release test showed the PVA/PAA/Tan crosslinking electrospun fibers achieved durable release profiles and lower burst release rates than that from the pure Tan emulsion. Based on these results, it is concluded that PVA/PAA/Tan crosslinking electrospun fibers prepared by emulsion-electrospinning serve as a promising technique in the fields of water-insoluble drug delivery and slow-release.


Asunto(s)
Resinas Acrílicas/química , Antioxidantes/química , Portadores de Fármacos/química , Electricidad , Flavonas/química , Alcohol Polivinílico/química , Liberación de Fármacos , Emulsiones
7.
Chemosphere ; 262: 127836, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32805657

RESUMEN

Polyacrylonitrile fiber was successfully modified with triazine-based dendrimer via grafting method as a promising adsorbent for removal of mercury species from aqueous media. The prepared adsorbent was characterized by elemental analysis, scanning electron microscope, Fourier transform infrared spectroscopy, porous structure analysis and X-ray photoelectron spectroscopy, providing the evidence of successful fabrication. The adsorption conditions were found via varying pH, dosage, coexisting substances, contact time, temperature and concentration. Adsorption performance, described better by the pseudo-second-order kinetics with intraparticle diffusion as rate controlling step and Langmuir isotherm model, indicated a chemisorption process with the maximum Langmuir adsorption amount of 227.64 mg g-1 for mercury ions. Thermodynamically, adsorption of mercury ions was spontaneous and endothermic. Desorption and regeneration experiments demonstrated that it could be reused in five successive adsorption cycles without significant loss of its original performance. Experimental data and density functional theory calculation disclosed the coordination geometries and chelating mechanism between the adsorbent and mercury ions. The proposed study would provide a new prospect for the purification of mercury in aqueous system by functionalizing commercial polyacrylonitrile fiber with dendrimers.


Asunto(s)
Resinas Acrílicas/química , Dendrímeros/química , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Adsorción , Difusión , Concentración de Iones de Hidrógeno , Iones/análisis , Cinética , Mercurio/análisis , Temperatura , Termodinámica , Aguas Residuales/química , Agua/química , Contaminantes Químicos del Agua/análisis
8.
Food Chem ; 338: 128144, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33092004

RESUMEN

A weak ion-exchange membrane (P-COOH) was synthesized by alkaline hydrolysis of a polyacrylonitrile nanofiber membrane prepared by electrospinning process. The P-COOH membrane was characterized for its physical properties and its application for purification of lysozyme from chicken egg white was investigated. The lysozyme adsorption efficiency of the P-COOH membrane operating in a stirred cell contactor (Millipore, Model 8010) was evaluated. The effects of key parameters such as the feed concentration, the rotating speed, the flow rate of feed and the operating pressure were studied. The results showed successful purification of lysozyme with a high recovery yield of 98% and a purification factor of 63 in a single step. The purification strategy was scaled-up to the higher feedstock loading volume of 32.7 and 70 mL using stirred cell contactors of Model 8050 and 8200, respectively. The scale-up processes achieved similar purification results, proving linear scalability of the purification technique adopted.


Asunto(s)
Fraccionamiento Químico/instrumentación , Clara de Huevo , Membranas Artificiales , Muramidasa/aislamiento & purificación , Nanofibras/química , Resinas Acrílicas/química , Adsorción , Animales , Intercambio Iónico , Muramidasa/química
9.
Vestn Oftalmol ; 136(6. Vyp. 2): 133-141, 2020.
Artículo en Ruso | MEDLINE | ID: mdl-33371641

RESUMEN

The search for optimal design and material of the intraocular lens (IOL) that would prevent posterior capsule opacification (PCO) is still a relevant problem. PURPOSE: To compare the influence of three models of hydrophobic acrylic IOLs on the development of PCO within one year after phaco surgery. MATERIAL AND METHODS: The study included 72 patients (91 eyes) who were followed up for 12 months after implantation of one of three models of posterior chamber hydrophobic acrylic IOLs: MIOL-2 (Reper-NN, Russia, 24 eyes, 1st group), SA60AT and US60MP (Alcon, USA, 41 and 26 eyes, 2nd and 3rd groups, respectively). Posterior capsule images were taken and then processed with the EPCO 2000 (Evaluation of Posterior Capsular Opacification) software. The area of posterior capsule adjacent to the center of IOL's optic of 4.0 mm in diameter was estimated. PCO score was calculated as the weighted sum of opacification areas multiplied by the degree (from 0 to 4). RESULTS: Within 1 year of the follow-up, mean visual acuity was at least 1.0 (20/20). Significant PCO progression was observed as early as 3 months after surgery. Despite that, opacification density in all three groups at every follow-up visit did not exceed grade 2; maximal PCO score (0.0315, median) was seen 12 month after surgery in the 1st group. At the same time, differences in PCO score between the groups were not significant. Nd:YAG laser posterior capsulotomy was performed only in one patient from the 1st group 12 month after surgery. Difference in the percentage of clear posterior capsules was significant only 12 month after surgery between the 1st and 3rd groups (p=0.024). CONCLUSION: All three models of hydrophobic acrylic IOLs showed comparably high vision outcomess during 12 months of the follow-up with somewhat better PCO score and percentage of clear posterior capsules in eyes with US60MP.


Asunto(s)
Opacificación Capsular , Catarata , Lentes Intraoculares , Facoemulsificación , Resinas Acrílicas , Opacificación Capsular/diagnóstico , Opacificación Capsular/etiología , Opacificación Capsular/prevención & control , Catarata/diagnóstico , Catarata/etiología , Humanos , Implantación de Lentes Intraoculares , Lentes Intraoculares/efectos adversos , Facoemulsificación/efectos adversos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Estudios Prospectivos , Diseño de Prótesis , Federación de Rusia
10.
PLoS One ; 15(12): e0228828, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33362254

RESUMEN

This study evaluated the effect of green propolis extract on the adhesion and biofilm formation of Candida species in dentistry materials. Phytochemical analysis of green propolis extract was performed by high-performance liquid chromatography. Adhesion was quantified by counting the number of yeast cells adherent to dental material fragments in a Neubauer chamber. Biofilm formation was determined by counting colony-forming units recovered from dental material fragments. The intensity of biofilm adhesion was classified as negative, weak, moderate, strong, or very strong. Fifteen compounds, mainly flavonoids, were identified in green propolis extract. All strains adhered to and formed biofilms on the surfaces of the orthodontic materials studied. On steel and resin, yeast cell adhesion intensities were weak at all incubation times, except for those of Candida parapsilosis and C. tropicalis, which were moderate at 12 h. At 24 and 48 h, C. albicans formed biofilms on steel with moderate adhesion affinities; at 24 and 48 h, C. parapsilosis formed biofilms with very strong affinities. C. tropicalis formed biofilms with strong and very strong affinities at 24 and 48 h, respectively. On resin, all species displayed strong affinity for biofilm formation at 24 and 48 h, except for C. tropicalis, which displayed very strong affinity at only 48 h. Green propolis extract displayed antifungal activity and inhibited both adhesion and biofilm formation at 2.5 µg/mL. This study reinforces the idea that green propolis has antifungal activity and interferes with the virulence of Candida species.


Asunto(s)
Biopelículas/efectos de los fármacos , Candida/efectos de los fármacos , Própolis/química , Resinas Acrílicas , Antibacterianos/farmacología , Antifúngicos/farmacología , Ascomicetos/efectos de los fármacos , Adhesión Celular/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Própolis/farmacología , Virulencia/efectos de los fármacos
11.
Oral Health Prev Dent ; 18(1): 999-1010, 2020 11 20.
Artículo en Inglés | MEDLINE | ID: mdl-33215491

RESUMEN

PURPOSE: This study investigated the effect of long-term daily chemical disinfection on the topographic and Candida albicans biofilm formation on a denture base resin and a reline acrylic resin. MATERIAL AND METHODS: Circular samples (14 × 1.2 mm) were fabricated from a denture base (Vipi Wave) and reline acrylic resins (Tokuyama Rebase Fast II). Samples were kept in 50 ml of distilled water (48 h at 37°C). Subsequently, the samples were immersed in five different solutions: 0.5% sodium hypochlorite; 3.8% sodium perborate; 2% chlorhexidine gluconate; apple vinegar containing 4% maleic acid; and distilled water (control group). The specimen was immersed in the solutions for 8 h daily and transferred to distilled water at 37°C for more 16 h. The surface topographic and Candida albicans (ATCC 90028) biofilm formation were evaluated at baseline (before chemical disinfection) and after 1, 3 and 6 months of immersion. The surface topographic was evaluated by arithmetical roughness average (Ra) and scanning electron microscope (SEM), while the biofilm formation was evaluated by colony-forming units (CFU/ml) method and Alamar Blue assay (cell metabolism). The results were evaluated by three-way analysis of variance (ANOVAs) and post-hoc tests (α = 0.05). RESULTS: The results showed statistically significant effects from the type of acrylic resin (p = 0.029) and time (p <0.001) on the roughness of the specimen. In general, the reline resin had higher roughness than the denture base resin. In addition, the roughness of the samples after 1, 3 and 6 months of immersion in the cleaning solutions was higher than at baseline. In relation to the microbiological assays, there were no statistically significant differences (p >0.055) in the CFU/ml values of the biofilms among the different resins, periods of time and cleaning solutions. Considering the metabolism of the cells within the biofilms, the results showed that, at baseline, it was statistically significantly higher (p <0.05) than after 1, 3 and 6 months of storage. The SEM images showed that all disinfectant solutions provided surface changes of both acrylic resins (base and reline) after 1, 3 and 6 months of immersion. CONCLUSIONS: The roughness of both acrylic resins was affected by the disinfection in all cleaning agents, increasing over time, and this effect was more evident in the reline acrylic resin group. This surface change was also observed in the SEM images. While the number of cells within the biofilms was not affected by immersion in the cleaning agents, their metabolism was lower after 1, 3 and 6 months of immersion.


Asunto(s)
Candida albicans , Desinfección , Resinas Acrílicas , Biopelículas , Bases para Dentadura , Limpiadores de Dentadura/farmacología , Ensayo de Materiales , Propiedades de Superficie
12.
Braz Dent J ; 31(5): 511-515, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33146335

RESUMEN

This study aimed to assess the physicochemical properties of a repair material in the Brazilian market, BioMTA, in comparison to other two materials currently in use (Biodentine and MTA Angelus). The initial setting time was evaluated using Gillmore needle. The pH was measured with a pH-meter after 24 h, 3, 7, 14 and 21 days. The radiopacity was determined using the equivalence in millimeters of aluminum (mm Al) from digitized occlusal radiographs. Solubility was determined after immersion in water for 7 days. The data were analyzed by one-way ANOVA and Tukey tests (a=0.05). The BioMTA initial setting time (5.2 min) was lower than the other materials (p<0.05). All materials showed an alkaline pH at 21 days. At 24 h, BioMTA was the most alkaline material (p<0.05); and at 3, 7, 14 and 21 days there was no difference between BioMTA and Biodentine (p>0.05), both being more alkaline than MTA Angelus (p<0.05). The radiopacity of BioMTA (4.2 mm Al) was significantly higher compared to Biodentine (p<0.05) and lower than MTA Angelus (p<0.05). The solubility of the materials was -4.2%, -1.6% and 4.1% for BioMTA, MTA Angelus and Biodentine, respectively, with a significant difference between them (p<0.05). Therefore, it can be concluded that BioMTA displayed a shorter setting time, an alkaline pH, a higher radiopacity, and a gain in mass.


Asunto(s)
Materiales de Obturación del Conducto Radicular , Silicatos , Resinas Acrílicas , Compuestos de Aluminio , Brasil , Compuestos de Calcio , Combinación de Medicamentos , Ensayo de Materiales , Óxidos , Solubilidad , Agua
13.
Indian J Dent Res ; 31(4): 589-592, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33107462

RESUMEN

Aim: Nano-sized metal particles exhibit special biological, chemical, and physical properties. The aim of this study was to evaluate the effect of incorporating silver nanoparticles into a resin-modified glass ionomer (GI) on its antimicrobial property. Materials and Methods: Antibacterial action of GI samples containing 0, 40, 80 ppm silver nanoparticles against standard strains of Streptococcus sanguinis and Streptococcus mutans were assessed by agar diffusion and direct contact tests. Data were analyzed using analysis of variance and Duncan test (P < 0.05). Results: Agar diffusion test showed no bacterial inhibition zone, but direct contact test exhibited significant antimicrobial activity against S. sanguinis and S. mutans in resin containing 80 ppm of nanosilver. Conclusion: Incorporation of a certain amount of silver nanoparticles into GI can increase its antimicrobial activity compared to the original material.


Asunto(s)
Nanopartículas del Metal , Streptococcus mutans , Resinas Acrílicas , Antibacterianos/farmacología , Dióxido de Silicio , Plata/farmacología
14.
J Adhes Dent ; 22(5): 465-474, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33073778

RESUMEN

PURPOSE: This sub-analysis of our multicenter trial was to assess the long-term periodontal health (PH) of teeth, esthetically reshaped by means of direct composite buildups. MATERIALS AND METHODS: 198 patients who received 667 direct composite buildups on 585 treated teeth (TT) between 01/2001 and 12/2013 were included. PH was assessed for each TT and for an untreated control tooth (CT) by recording the pocket probing depths (PPD), clinical attachment level (CAL), sulcus bleeding index (SBI), and Turesky's modification of the Quigley Hein plaque index (PI). Statistical analysis was performed using the two-sample Student's t-test and Mann-Whitney U-test. Regression models were performed to check for associations between PH and patients' age, gender, age of the buildups, enlargement range, jaw, and tooth type. The level of significance was set at α = 0.05. RESULTS: PI scores were significantly (p < 0.001) higher in TT (1.60 ± 0.81) than in CT (1.41 ± 0.81). Differences between TT and CT regarding PPD (TT: 2.14 ± 0.56/CT: 2.18 ± 0.56), CAL (TT: 2.34 ± 1.05/CT: 2.33 ± 0.92), and SBI (TT: 0.41 ± 0.60/CT: 0.41 ± 0.65) were not statistically significant (p > 0.05). The enlargement range of the TT and the tooth type were not associated with PH. Male patients had significantly higher PPDs, CAL, and SBI values than did female patients. CAL and SBI values increased over time for both the TT and CT. CAL, SBI, and PI values were significantly higher in the mandible and the PPD values in the maxilla. CONCLUSION: Direct composite buildups made for reshaping, change of color or position of teeth did not impair PH in the long term.


Asunto(s)
Resinas Acrílicas , Resinas Compuestas , Dentición , Poliuretanos , Color , Femenino , Humanos , Masculino
15.
Indian J Ophthalmol ; 68(11): 2486-2489, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33120649

RESUMEN

Since the emergence of COVID pandemic, health workers have been facing major challenges every day. Ophthalmology practice has encountered countless modifications in the practice pattern not to jeopardize patient care and at the same time maintain all safety measures to reduce transmission. One such modification we made was the Safe Slit-Lamp Shield (SSS) which has been found to be extremely protective in differentiation to other available shield. Although SSS has a larger surface area when compared to already available shields, it won't compromise the comfort of the clinician at the same time gives satisfactory protection.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/transmisión , Seguridad de Equipos , Ergonomía , Transmisión de Enfermedad Infecciosa de Paciente a Profesional/prevención & control , Neumonía Viral/transmisión , Equipos de Seguridad , Microscopía con Lámpara de Hendidura/instrumentación , Resinas Acrílicas , Aerosoles , Diseño de Equipo , Humanos , Pandemias , Lámpara de Hendidura
16.
Water Sci Technol ; 82(7): 1350-1369, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33079715

RESUMEN

A hydrophobically associating cationic polyacrylamide (HACPAM) was prepared by using a micellar polymerization method with V-50 (azobisisobutyramidine hydrochloride) as the initiator and acrylamide, acryloyloxyethyl trimethylammonium chloride and butyl methacrylate as substrates under ultraviolet light irradiation. Structural analysis using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance and X-ray photoelectron spectroscopy analyses showed that the substrates were successfully polymerized. HACPAM was used to condition sludge to improve its dewatering performance, and the results showed that as the amount of HACPAM increases, the sludge dewatering performance is significantly improved, and 3.532 kg/t dry solids of HACPAM is regarded as the optimal amount. Compared with the commercially available cationic polyacrylamide (CPAM), HACPAM has a stronger hydrophobic group association effect, with better promotion of the conversion of bound water in sludge flocs into free water, thereby improving the sewage dewatering performance. The 3D spatial structure of dewatered sludge cakes analyzed by computed tomography technology showed that the number of pores of the dewatered sludge cake treated by HACPAM 3 was smaller than that of the cake treated by CPAM, with a reduction in the porosity of 68.8%, resulting in a better hydrophobic effect. In addition, the mechanism of HACPAM improving the dewatering performance is discussed.


Asunto(s)
Resinas Acrílicas , Aguas del Alcantarillado , Cationes , Polimerizacion
17.
Medicine (Baltimore) ; 99(33): e21516, 2020 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-32871998

RESUMEN

INTRODUCTION: Breast filler injections are less commonly used due to their associated complications, such as pain and foreign body reactions. Yet, these fillers are often administered illegally, resulting in aesthetic or life-threatening complications. These are treated by removing the foreign material, and the breasts are reconstructed using silicone implants or autologous tissue/fat injection. PATIENT CONCERNS: Case 1. A 45-year-old woman with polyacrylamide gel injections in both breasts visited our clinic for breast pain and tenderness. Grade I ptosis was observed in each breast, without skin necrosis and discoloration. Case 2. A 51-year-old woman, with unknown breast filler injections, visited our clinic for painful masses. Intraoperatively, massive amounts of foreign material had severely infiltrated the nearby tissues; thus, an immediate breast reconstruction could not be performed. Three months later, severe deformities including shrinkage and irregular breast skin surfaces were observed. DIAGNOSIS: Case 1. Multiple cystic lesions, fluid collection in the retromammary spaces, and diffuse infiltration were observed on mammography, computed tomography, and ultrasonography. Case 2. Multiple cystic lesions, calcified areas, and diffuse infiltrations in the axillae and retromammary spaces were observed on mammography, computed tomography, and ultrasonography. INTERVENTIONS: Case 1. The foreign material was removed and the breasts were reconstructed using silicone implants into subpectoral pocket with acellular dermal matrices (Alloderm, Lipocell Corporation). Case 2. A delayed reconstruction was undertaken using silicone implants covered by latissimus dorsi muscle flaps, 3 months after the foreign material removal. OUTCOMES: Case 1. The foreign material was removed and there were no complications such as foreign body reaction, capsular contracture. Ptosis was corrected and both breasts were symmetric with proper projection. Case 2. Residual foreign material was removed and there were no complications such capsular contracture, implant malposition. CONCLUSION: Massive injections of foreign materials into the breast can cause severe infiltration and associated foreign body reactions. By a near-complete removal of the foreign materials and breast reconstruction using silicone implants, we achieved satisfactory results, without complications such as wound disruption, capsular contracture, and implant malposition.


Asunto(s)
Resinas Acrílicas/efectos adversos , Rellenos Dérmicos/efectos adversos , Reacción a Cuerpo Extraño/cirugía , Mamoplastia/métodos , Mastodinia/cirugía , Femenino , Reacción a Cuerpo Extraño/inducido químicamente , Humanos , Mastodinia/inducido químicamente , Persona de Mediana Edad
18.
Braz Oral Res ; 34: e110, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32876123

RESUMEN

Acrylic resin has been used in the manufacture of prostheses, however, in the oral cavity, this material starts to retain microorganisms capable of causing gingival inflammation due its porosities. The aim of this study was to evaluate the influence of the use of silicon dioxide as a coating layer applied onto acrylic resin, on the adhesion of Candida albicans (Ca). After the incubation period in Sabouraud Dextrose Broth, a total of 1 ml of the Ca suspension was added to plate wells, each well containing a specimen of acrylic resin. The adhesion ability of Ca on acrylic resin was determined by counting colonies. Three groups (n = 6) of acrylic resin were assessed: with polishing (RP); without polishing (RW); with polishing and coating layer of silicon dioxide (RPC). Ca deposited on the surface of the acrylic resin was also observed using Scanning Electron Microscopy (SEM). Statistical assessment by Kruskal-Wallis and Student-Newman-Keuls Method were done (α = 2%). There was significant difference among the groups. The RPC group showed the lowest growth, with an average of 5.59 Log CFU/cm 2 ; there was a statistically significant difference in relation to group RW, which presented a growth of 6.07 Log CFU/cm 2 and to group RP with 5.91 Log CFU/cm 2 (p < 000.1). SEM images demonstrated that in the RP and RPC group, the surface of the resin had greater regularity, and smaller number of microorganisms. The application of silicon dioxide coating on acrylic resin appears to be a promising alternative, and its use can help in reducing the adhesion of Ca in prostheses.


Asunto(s)
Candida albicans , Resinas Acrílicas , Bases para Dentadura , Dióxido de Silicio , Propiedades de Superficie
19.
Oral Health Prev Dent ; 18(1): 747-756, 2020 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-32895658

RESUMEN

PURPOSE: This in vitro study evaluated the effectiveness of polyacrylic acid as an acid etchant similar to phosphoric acid and its effect on the microtensile bond strength of self-adhesive resin cement to enamel. MATERIALS AND METHODS: Ninety Te-Econom Plus resin blocks (11 x 4 mm) were cemented onto bovine enamel and distributed into 10 groups according to the surface treatments (no surface treatment; etching with 37% phosphoric acid; etching with 20% polyacrylic acid; etching with 37% phosphoric acid + dental adhesive, and etching with 20% polyacrylic acid + dental adhesive) and the self-adhesive resin cements used (RelyX U200 and MaxCem Elite) (n = 9). After bonding, the specimens were sectioned into sticks, subjected to thermocycling (5760 cycles, 5°C and 55°C) and microtensile bond strength testing (n = 6). Images of representative specimens were obtained using a scanning electron microscope. Enamel penetration evaluation of different surface treatments was analysed by confocal laser scanning microscopy (n = 3). Data on bond strength were subjected to 2-way ANOVA and Tukey's least significant difference test (α = 0.05). RESULTS: Both 37% phosphoric acid and 20% polyacrylic acid yielded the same microtensile bond strength between self-adhesive resin cement and enamel, independent of the application of dental adhesives (p > 0.05). MaxCem Elite showed higher bond strength values than RelyX U200 just for the 20% polyacrylic acid group (p = 0.001). CONCLUSION: Acid pre-conditioning of dental enamel may influence the bond strength of self-adhesive resin cement to enamel, and 20% polyacrylic acid showed efficacy similar to that of 37% phosphoric acid.


Asunto(s)
Recubrimiento Dental Adhesivo , Cementos de Resina , Grabado Ácido Dental , Resinas Acrílicas , Animales , Bovinos , Resinas Compuestas , Cementos Dentales , Esmalte Dental , Análisis del Estrés Dental , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Propiedades de Superficie , Resistencia a la Tracción
20.
Int J Prosthodont ; 33(5): 536-545, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32956435

RESUMEN

PURPOSE: To evaluate the shear bond strength (SBS) and color stability (ΔE) of four ceramic veneers (VITA VM 9; VITA VM 13; VITA VMK 95; and IPS e.max Ceram) following repair with three different self-adhesive composite resins (Fusio Liquid Dentin; Constic; and Vertise Flow) and BISCO Intraoral Repair Kit + Filtek Supreme (BC + FS). MATERIALS AND METHODS: A total of 96 specimens were prepared per ceramic material, and each ceramic group was divided into subgroups according to testing method (32 specimens for color stability analysis and 64 specimens for SBS testing). ΔE and SBS (SBS1 = non-aged, SBS2 = thermally aged) values of the repaired specimens were calculated. One specimen from each of the thermally aged groups was investigated under scanning electron microscopy (SEM). Two-way ANOVA was used to analyze the mean ΔE, SBS1, and SBS2 values. The differences between SBS1 and SBS2 values were analyzed using independent-samples t test. RESULTS: The lowest ΔE values were calculated for Constic (P ≤ .05). The SBS2 values among all groups were lower than the SBS1 values (P ≤ .05). The lowest SBS2 values were observed for Vertise Flow (2.3 ± 1.47 MPa) (P ≤ .05) and were below the acceptable limit of 5 MPa. CONCLUSION: All of the investigated repair materials in combination with the ceramic veneers exhibited ΔE values that were higher than the clinically acceptable limits. Thermal aging negatively affected the SBS values in all groups (P ≤ .05). All tested self-adhesive composite resins, with the exception of Vertise Flow, could be used instead of a repair kit with flowable composite resin, especially in noncooperative patients, for the purpose of repairing chipping fractures for VITA VM 9, VITA VM 13, and VITA VMK 95 (P > .05).


Asunto(s)
Recubrimiento Dental Adhesivo , Cementos Dentales , Resinas Acrílicas , Cerámica , Color , Resinas Compuestas , Porcelana Dental , Humanos , Ensayo de Materiales , Cementos de Resina , Resistencia al Corte , Propiedades de Superficie
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