ABSTRACT
Abstract Objective To clinically assess the effect of desensitizing gels and dentifrices on the reduction in pain sensitivity and color variation during tooth bleaching. Methodology A total of 108 volunteers were randomly separated into the following groups of n=12: GT/S-glycerine and thickener/sucralose; NF/S-potassium nitrate and sodium fluoride/sucralose; NA/S-potassium nitrate and arginine/sucralose; GT/AC-glycerine and thickener/arginine and calcium carbonate; NF/AC-potassium nitrate and sodium fluoride/arginine and calcium carbonate; NA/AC-potassium nitrate and arginine/arginine and calcium carbonate; GT/PN-glycerine and thickener/potassium nitrate; NF/PN-potassium nitrate and sodium fluoride/potassium nitrate; and NA/PN-potassium nitrate and arginine/potassium nitrate. Sensitivity was assessed with the numerical analogue scale, and color variation (ΔE) was measured with a spectrophotometer. The sensitivity values obtained were subjected to a multivariate analysis of variance (MANOVA) and color variation values were subjected to a randomized analysis of variance (p<0.05). Results The NF/AC, NA/AC, NF/PN, and NA/PN groups presented lower sensitivity values and reduced sensitivity compared to those of the other groups throughout the clinical sessions. None of the groups showed sensitivity at the 24-week assessment. Statistically, no significant difference were observed in the color values among the groups four weeks after the beginning of bleaching (p=0.074). Additionally, the color assessment of all groups was statistically similar four weeks (p=0.084) and 24 weeks (p=0.118) after the beginning. Conclusion Our results indicate that adding NF/S, NA/S, NF/AC, and NA/AC desensitizers to tooth bleaching protocols reduces pain sensitivity without affecting its effectiveness.
Subject(s)
Humans , Tooth Bleaching , Dentin Sensitivity , Dentin Desensitizing Agents , Tooth Bleaching Agents , Pain , Follow-Up Studies , Treatment Outcome , Potassium CompoundsABSTRACT
Abstract The objective of this study was to evaluate the influence of hydrofluoric acid (HF) concentration, etching time, and application of phosphoric acid (PA) followed by neutralization with sodium bicarbonate on the bond strength between a feldspar ceramic and resin cement. Thus, 80 blocks (10 x 12 x 2 mm) of glass ceramic (VM - Vita Mark II - Vita Zahnfabrik) were made and randomly assigned to eight groups (n = 10) according to the factors: HF concentration (5 and 10%), etching time (60 and 120 s), and use of phosphoric acid (PA) (with and without). According to the experimental group, 37% PA (Condac, FGM) was applied after HF etching for 60s. Afterwards, samples were immersed in sodium bicarbonate for 1 min then in an ultrasonic bath in distilled water (5 min) for cleaning. After surface bonding treatment, cylinders (Ø = 2 mm; h = 2 mm) of dual resin cement (AllCem / FGM) were made in the center of each block. The samples were then stored in water (37ºC) for 90 days and submitted to the shear bond test (50 KgF, 1 mm/min). Failure analysis was performed by stereomicroscope and scanning electron microscopy. Data (MPa) were analyzed with 3-way ANOVA and Tukey's test. Only the factor "HF concentration" was significant (p = 0.02). Most failures were of cohesive in ceramic (40%) and mixed types (42.5%). The 10% HF resulted in higher shear bond strength value than the 5% HF. Surface cleaning with phosphoric acid followed by sodium bicarbonate and HF time (60 or 120 seconds) did not influence the resin bond strength to feldspar ceramic.
Subject(s)
Phosphoric Acids/chemistry , Dental Bonding/methods , Potassium Compounds/chemistry , Aluminum Silicates/chemistry , Hydrofluoric Acid/chemistry , Reference Values , Silanes/chemistry , Surface Properties , Time Factors , Materials Testing , Microscopy, Electron, Scanning , Reproducibility of Results , Analysis of Variance , Resin Cements/chemistry , Shear Strength/drug effects , Dental Porcelain/chemistry , Methacrylates/chemistryABSTRACT
Abstract This study evaluates the shear bond strength (SBS) of various resin cements to different ceramics. Composite resin cylinders of Z100 were fabricated and cemented to disks of feldspathic ceramic (Creation), leucite-reinforced feldspathic ceramic (Empress I), and densely sintered aluminum oxide ceramic (Procera AllCeram) using five resin cements: Panavia F (PAN), RelyX ARC (ARC), RelyX Unicem (RXU), RelyX Veneer, and Variolink II. SBS was measured after three days of water storage (baseline) and after artificial aging (180 days of water storage along with 12,000 thermal cycles). Failure mode of fractured specimens also was evaluated. Data were analyzed with Kruskal-Wallis and Mann-Whitney tests (α=0.05). RXU showed 1) the lowest baseline median SBS to feldspathic ceramic, which was not statistically different from PAN; 2) the lowest median baseline SBS to leucite-reinforced feldspathic and densely sintered aluminum-oxide ceramics. All cements performed similarly after aging, except for ARC (median 0.0 MPa) and PAN (median 16.2 MPa) in the densely sintered aluminum-oxide ceramic group. Resin cements perform differently when bonded to different ceramic substrates. While all test resin cements worked similarly in the long-term to feldspathic and leucite-reinforced feldspathic ceramics, only the MDP-containing resin cement provided durable bonds to densely sintered aluminum-oxide ceramic.
Subject(s)
Ceramics/chemistry , Dental Bonding/methods , Resin Cements/chemistry , Reference Values , Surface Properties , Materials Testing , Reproducibility of Results , Potassium Compounds/chemistry , Statistics, Nonparametric , Shear Strength , Aluminum/chemistry , Aluminum Silicates/chemistryABSTRACT
Abstract Objective: To analyze color change, microhardness and chemical composition of enamel bleached with in-office bleaching agent with different desensitizing application protocols. Materials and Methods: One hundred and seventeen polished anterior human enamel surfaces were obtained and randomly divided into nine groups (n = 13). After recording initial color, microhardness and chemical composition, the bleaching treatments were performed as G1: Signal Professional White Now POWDER&LIQUID FAST 38% Hydrogen peroxide(S); G2: S+Flor Opal/0.5% fluoride ion(F); G3: S+GC Tooth Mousse/Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) paste(TM); G4: S+UltraEZ/3% potassium nitrate&0.11% fluoride(U); G5: S+Signal Professional SENSITIVE PHASE 1/30% Nano-Hydroxyapatite (n-HAP) suspension(SP); G6: S-F mixture; G7: S-TM mixture; G8: S-U mixture; G9: S-SP mixture. Color, microhardness and chemical composition measurements were repeated after 1 and 14 days. The percentage of microhardness loss (PML) was calculated 1 and 14 days after bleaching. Data were analyzed with ANOVA, Welch ANOVA, Tukey and Dunnett T3 tests (p<0.05). Results: Color change was observed in all groups. The highest ΔE was observed at G7 after 1 day, and ΔE at G8 was the highest after 14 days (p<0.05). A decrease in microhardness was observed in all groups except G6 and G7 after 1 day. The microhardness of all groups increased after 14 days in comparison with 1 day after bleaching (p>0.05). PML was observed in all groups except G6 and G7 after bleaching and none of the groups showed PML after 14 days. No significant changes were observed after bleaching at Ca and P levels and Ca/P ratios at 1 or 14 days after bleaching (p>0.05). F mass increased only in G2 and G6, 1 day after bleaching (p<0.05). Conclusions: The use of desensitizing agents containing fluoride, CPP-ACP, potassium nitrate or n-HAP after in-office bleaching or mixed in bleaching agent did not inhibit the bleaching effect. However, they all recovered microhardness of enamel 14 days after in-office bleaching.
Subject(s)
Humans , Tooth Bleaching/methods , Dental Enamel/drug effects , Dentin Desensitizing Agents/chemistry , Tooth Bleaching Agents/chemistry , Reference Values , Saliva, Artificial/chemistry , Spectrometry, X-Ray Emission , Spectrophotometry , Surface Properties/drug effects , Time Factors , Materials Testing , Calcium Phosphates/chemistry , Microscopy, Electron, Scanning , Caseins/chemistry , Random Allocation , Reproducibility of Results , Analysis of Variance , Potassium Compounds/chemistry , Color , Statistics, Nonparametric , Dental Enamel/chemistry , Hardness Tests , Hydrogen Peroxide/chemistry , Nitrates/chemistryABSTRACT
La exposición de dentina radicular asociada a una recesión gingival puede producir dolor ante distintos estímulos, situación que puede difi cultar la vida cotidiana de los pacientes que lo padecen, además de presentar complicaciones estéticas que pueden afectar la autoestima. La hipersensibilidad dentinaria tiene una etiología asociada a múltiples factores, siendo el principal factor de riesgo la recesión gingival, situación clínica común que se observa en gran parte de la población. El propósito de esta revisión es reunir distintos conceptos que expliquen la asociación que mantienen estas dos patologías, sus etiologías, el cuadro clínico que presenta la hipersensibilidad dentinaria para poder realizar un diagnóstico diferencial y las distintas opciones de tratamiento para realizar un adecuado manejo de esta condición que incluyen desde recursos terapéuticos que buscan resolver la sintomatología hasta procedimientos quirúrgicos que resultan más invasivos y que se enfocan en tratar el factor predisponente como es la recesión gingival misma (AU)
Dentin exposure level periodontal tissues can cause pain to diff erent stimuli, a situation which can hinder the daily lives of patients who suff er, in addition to having aesthetic complications that can damage self-esteem. Dental hypersensitivity has a multifactorial etiology associated being the main risk factor gingival recession, the common clinical situation observed in much of the population. The purpose of this review is to bring together various concepts that explain the association that maintain these two pathologies, their etiologies, clinical picture presented dentine hypersensitivity to perform a diff erential diagnosis and treatment options for proper management of this condition ranging from therapeutic procedure seeking to resolve the symptoms to surgical procedures that are more invasive and that focus on treating the predisposing factor such as the gingival recession itself (AU)
Subject(s)
Humans , Dentin Sensitivity/diagnosis , Dentin Sensitivity/etiology , Dentin Sensitivity/therapy , Gingival Recession/complications , Potassium Compounds , Diagnosis, Differential , Laser Therapy , Gingival Recession/classificationABSTRACT
Abstract Objective: The present study aimed the functional recovery evaluation after long term of cardiac arrest induced by Custodiol (crystalloid-based) versus del Nido (blood-based) solutions, both added lidocaine and pinacidil as cardioplegic agents. Experiments were performed in isolated rat heart perfusion models. Methods: Male rat heart perfusions, according to Langendorff technique, were induced to cause 3 hours of cardiac arrest with a single dose. The hearts were assigned to one of the following three groups: (I) control; (II) Custodiol-LP; and (III) del Nido-LP. They were evaluated after ischemia throughout 90 minutes of reperfusion. Left ventricular contractility function was reported as percentage of recovery, expressed by developed pressure, maximum dP/dt, minimum dP/dt, and rate pressure product variables. In addition, coronary resistance and myocardial injury marker by alpha-fodrin degradation were also evaluated. Results: At 90 minutes of reperfusion, both solutions had superior left ventricular contractile recovery function than the control group. Del Nido-LP was superior to Custodiol-LP in maximum dP/dt (46%±8 vs. 67%±7, P<0.05) and minimum dP/dt (31%±4 vs. 51%±9, P<0.05) variables. Coronary resistance was lower in del Nido-LP group than in Custodiol-LP (395%±50 vs. 307%±13, P<0.05), as well as alpha-fodrin degradation, with lower levels in del Nido-LP group (P<0.05). Conclusion: Del Nido-LP cardioplegia showed higher functional recovery after 3 hours of ischemia. The analysis of alpha-fodrin degradation showed del Nido-LP solution provided greater protection against myocardial ischemia and reperfusion (IR) in this experimental model.
Subject(s)
Animals , Male , Cardioplegic Solutions/pharmacology , Myocardial Reperfusion/methods , Potassium Compounds/pharmacology , Pinacidil/pharmacology , Heart Arrest, Induced/methods , Lidocaine/pharmacology , Time Factors , Vascular Resistance/physiology , Cardioplegic Solutions/chemistry , Carrier Proteins/analysis , Blotting, Western , Rats, Wistar , Coronary Vessels/physiopathology , Glucose/pharmacology , Glucose/chemistry , Heart/drug effects , Mannitol/pharmacology , Mannitol/chemistry , Microfilament Proteins/analysisABSTRACT
Objetivo: Determinar el grado de confiabilidad de un modelo de dentina humana para evaluar la calidad de oclusión de los túbulos dentinarios luego del uso de dos agentes desestabilizantes que contienen oxalato de potasio. Materiales y métodos: Se obtuvieron dos secciones horizontales en forma de discos de dentina de 0,8 mm de espesor de cada uno de 21 terceros molares sanos extraídos por razones periodontales, ortodóncicas o quirúrgicas. El barro dentinario de las superficies coronaria y pulpar de los discos se eliminó con ácido fosfórico al 35% y posterior lavado con suero fisiológico y secado. De cada molar se separó un disco para el grupo 1 (n=20). Los segundos discos de cada molar se destinaron al grupo 2 (n=20). Y los dos discos del molar restante no recibieron tratamiento (controles negativos). El ensayo se realizó en dos etapas. En la primera, las superficies coronarias de los discos del grupo 1 se trataron con Klepp Desensitizer, mientras que en el grupo 2 se empleó BisBlock Desensitizer. Posteriormente, se metalizaron con oro-paladio y se observaron en un microscopio electrónico de barrido. En la segunda etapa, los discos se retiraron del microscopio, se invirtieron de posición, y la superficie pulpal ubicada en posición superior se lavó con suero, se secó, se metalizó y se observó nuevamente con el microscopio. Con el objeto de realizar el análisis químico de los agentes desestabilizantes, se obtuvieron otros dos discos a partir de un molar adicional y se prepararon ambos siguiendo el mismo protocolo que en los discos experimentales. Uno de ellos se trató con Klepp Desensitizer, y el otro, con BisBlock Desensitizer. Finalmente, las superficies pulpares de ambos discos adicionales se metalizaron con carbón y se examinaron mediante un análisis de energía dispersiva de rayos X. Resultados: En la primera etapa del ensayo, la superficie coronaria de los 20 discos de cada grupo se encontraba cubierta por una capa uniforme de cristales precipitados a partir de ambos agentes desestabilizantes. En la segunda etapa, la superficie pulpar de los 20 discos del grupo 1 reveló que todos los túbulos dentinarios estaban totalmente ocluidos por los cristales en nueve (n=9) casos. Lo mismo ocurrió en ocho (n=8) discos del grupo 2. En ambos casos los cristales ocluyeron totalmente los túbulos hasta una profundidad de 0,8 mm. En 11 (n=11) y 12 (n=12) discos de los grupos 1 y 2 respectivamente se observaron túbulos parcialmente ocluidos o bien una combinación de estos con túbulos vacíos. Las diferencias entre grupos no fueron significativas (P>0,05). En los controles negativos todos los túbulos se encontraban vacíos. El análisis de energía dispersiva de rayos X reveló que los cristales precipitados a partir de ambos agentes desestabilizantes dentro de los túbulos contenían importantes concentraciones de calcio y trazas de potasio. Conclusiones: El modelo ensayado parecería ser adecuado para comparar ex vivo la calidad de protección de la superficie dentinaria producida por los agentes desestabilizantes a base de oxalato de potasio (AU)
Subject(s)
Humans , Dentin Sensitivity , Oxalates , Potassium Compounds , Dental Pulp , Dentin Permeability , Microscopy, Electron, Scanning , Data Interpretation, StatisticalABSTRACT
Abstract This study evaluated the effect of the accelerated artificial aging (AAA) on feldspar ceramic strength and the reinforcing effect promoted by adhesive cementation with resin luting agent. One hundred twenty feldspar ceramic disks were obtained. Sixty disks were acid-etched, silanized, and coated with an experimental resin luting agent simulating the adhesive luting procedures. Four groups were created (n=30): uncoated ceramic (control group), uncoated ceramic submitted to AAA, ceramic coated with resin luting agent, and coated ceramic submitted to AAA. Biaxial flexural testing with ball-on-ring setup was carried out. Biaxial flexural strength (s bf , MPa), characteristic strength (s 0 , MPa), and Weibull modulus (m) were calculated for axial positions z=0 (ceramic surface) and z=−t2 (luting agent surface). Data of s bf at positions z=0 and z=-t2 were separately submitted to statistical analyses (a=0.05). The uncoated ceramic submitted to AAA had no significant difference in s bf and s 0 compared with the control group. Resin coating of the ceramic increased s bf and s 0 at z=0. The AAA increased the s bf and s 0 for the resin-coated ceramic specimens at z=0 and also the s 0 at axial position z=-t2. The structural reliability at z=0 and z=-t2 was not influenced by the variables tested. In conclusion, resin coating improved the mechanical strength of the feldspar ceramic. The AAA procedure was not effective in aging the uncoated or resin-coated feldspar ceramic specimens.
Resumo Este estudo avaliou o efeito do envelhecimento artificial acelerado (EAA) na resistência da cerâmica feldspática e o reforço promovido pela cimentação adesiva com cimento resinoso. Cento e vinte discos de cerâmica feldspática foram obtidos. Sessenta discos foram condicionados com ácido, silanizados, e recobertos com um cimento resinoso experimental simulando os procedimentos de cimentação adesiva. Quatro grupos foram criados (n=30): cerâmica sem recobrimento (grupo controle), cerâmica sem recobrimento submetida ao EAA, cerâmica recoberta com cimento resinoso, cerâmica recoberta com cimento resinoso submetida ao EAA. O teste de resistência à flexão biaxial foi realizado utilizando o dispositivo pistão-anel. Resistência à flexão biaxial (s fb , MPa), resistência característica (s 0 , MPa), e módulo de Weibull (m) foram calculados para as posições axiais z=0 (superfície da cerâmica) e z=−t2 (superfície do cimento). Os dados de s fb em z=0 e z=−t2 foram submetidos a análises estatísticas separadamente (a=0,05). A cerâmica não recoberta submetida ao EAA não teve diferença significante na s fb e s 0 comparada com o grupo controle. O recobrimento com cimento resinoso da cerâmica aumentou a s fb e s 0 em z=0. O EAA aumentou a s fb e s 0 para os espécimes de cerâmica recobertos com cimento resinoso em z=0 e também a s 0 em z=−t2. A confiabilidade em z=0 e z=−t2 não foi influenciada pelas variáveis testadas. Concluindo, o recobrimento com cimento resinoso melhorou a resistência mecânica da cerâmica feldspática. O procedimento de EAA não foi efetivo em envelhecer os espécimes de cerâmica feldspática recobertos ou não com cimento resinoso.
Subject(s)
Materials Testing , Potassium Compounds/chemistry , Resin Cements/chemistry , Dental Cements/chemistry , Dental Porcelain/chemistry , Aluminum Silicates/chemistry , Dental Bonding , Composite Resins/chemistry , Dental Stress AnalysisABSTRACT
RESUMEN: Objetivo: Comparar la eficacia clínica de dentífricos en base a arginina al 8%/ monofluorfosfato de sodio 1450 ppm versus nitrato de potasio al 5%/fluoruro de sodio 2500 ppm en la terapia de la hipersensibilidad dentinaria (HSD). Materiales y método: Ensayo clínico, aleatorio, controlado, doble ciego, de grupos paralelos. Treinta y cuatro voluntarios de 18 a 70 años, con HSD en escala Visual Análoga (EVA) ≥4 en 2 ó más dientes no molares, fueron distribuidos aleatoriamente en 2 grupos: grupo T1 (n=16): dentífrico de Arginina al 8%/ monofluorfosfato de sodio 1450 ppm; y grupo T2 (n=18): dentífrico de nitrato de Potasio al 5%/fluoruro de sodio 2500 ppm. Se evaluó HSD en EVA con estímulos evaporativos y térmicos, y se compararon sus valores, así como el grado promedio de HSD y su reducción (∆HSD), intra e intergrupal, al inicio y a las 4 semanas de tratamiento. Resultados: Ambos dentífricos disminuyeron el grado promedio de HSD entre el inicio y las 4 semanas de tratamiento (T1: 5.03 ± 1.23 versus 2.60 ± 1.27, p<0.05; T2: 4.73 ± 1.51 versus 2.71 ± 1.17, p<0.05). No hubo diferencias estadísticamente significativas entre ambos dentífricos al comparar el grado promedio de reducción de HSD durante la terapia (∆HSD T1: -2.43 ± 1.22 versus ∆HSD T2: -2.27 ± 1.42). Los datos fueron analizados en Stata versión 11. Conclusiones: Ambos dentífricos fueron clínicamente eficaces en reducir la HSD a las 4 semanas, sin existir diferencias estadísticamente significativas entre ambos.
ABSTRACT: Aim: To compare the clinical efficacy of 8% arginine/1450ppm sodium monofluorophosphate and 5% potassium nitrate/2500 ppm sodium fluoride dentifrices in the treatment of dentin hypersensitivity (DH). Methods: Parallel-design, double-masked, randomized controlled clinical trial. Thirty four volunteers aged 18 to 70 years, with DH and a visual analog scale (VAS) score ≥4 at least in two or more non-molar teeth, were randomized in two groups: T1 (n=16): 8% arginine/1450 ppm sodium monofluorophosphate dentifrice; and T2 (n=18): 5% potassium nitrate/2500 ppm sodium fluoride dentifrice. DH was assessed with evaporative and thermal stimuli; and their VAS measurements, mean DH value and DH reduction (∆DH) were compared, inside and between the groups at baseline and 4-week follow-up. Data were analysed through Stata® V11 program. Results: Both toothpastes decreased mean DH value between baseline and 4 weeks (T1: 5.03 ± 1.23 versus 2.60 ± 1.27, p<0.05; T2: 4.73 ± 1.51 versus 2.71 ± 1.17, p<0.05). There were no statistical differences between both dentifrices in mean DH reduction values during therapy (∆HSD T1: -2.43 ± 1.22 versus ∆HSD T2:-2.27 ± 1.42). Conclusions: Both dentifrices had clinical efficacy in decreasing DH in a 4- week therapy, without statistical differences between both of them.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Aged , Young Adult , Arginine/therapeutic use , Dentifrices/therapeutic use , Dentin Sensitivity/drug therapy , Dentin Desensitizing Agents/therapeutic use , Nitrates/therapeutic use , Sodium Fluoride/therapeutic use , Pain Measurement , Double-Blind Method , Potassium Compounds/therapeutic useABSTRACT
Abstract Purpose: To establish and compare protocols of alkaline cauterization for inducing corneal angiogenesis in murine models. Methods: Twenty-four adult Wistar rats were distributed into four groups (G1, G2, G3, and G4). The right eye cornea from each rat was cauterized using filter paper (3 mm), soaked in a solution of silver and potassium nitrates (3:1). Cauterization times were 10 (G1 and G4), or 20 seconds (G2 and G3). Cauterized corneas were washed with Ringer's lactate solution. The filter paper was either removed before washing (G1 and G2), or kept on the corneas (G3 and G4). Corneas were photographed at multiple time points (2, 4, 6, 8, 11, 13, and 15 days after the procedure), and neovascularization parameters were assayed. Results: Neovascularization was observed in 66% of G1 corneas, and 100% of G2, G3, and G4 corneas. On day 15, G1 corneas showed smaller vascularized areas (12.63 ± 12.59%) compared to those in the G3 (41.95 ± 17.32%) and G4 (33 ± 11.74%) (P < 0.05) groups. Conclusions: The silver and potassium nitrate solution effectively induced corneal angiogenesis. The G2, G3, and G4 protocols showed excellent reproducibility, and induced vascularization in 100% of corneas.
Subject(s)
Animals , Male , Cautery/methods , Corneal Neovascularization/etiology , Potassium Compounds , Disease Models, Animal , Neovascularization, Pathologic/etiology , Nitrates , Reference Values , Time Factors , Reproducibility of Results , Rats, Wistar , Cornea/surgery , Cornea/blood supplyABSTRACT
ResumenPoblaciones endémicas de Hechtiaperotensis se han descrito en Puebla y Veracruz, México. La recolección de semillas de buena calidad permite su uso en conservación, investigación y restauración ecológica. Algunos compuestos para evaluar la calidad de las semillas silvestres y endémicas, como nitrato de potasio (KNO3) y ácido giberílico (AG3), se utilizan para incrementar la germinación de las semillas y disminuir la latencia. La prueba de cloruro de trifeniltetrazolio (tetrazolio) se correlaciona con la viabilidad de las semillas porque se basa en la actividad de las deshidrogenasas de tejidos vivos que catalizan la respiración mitocondrial. El objetivo de este estudio fue conocer el tamaño y el peso de las cápsulas y las semillas y la germinación y viabilidad de las semillas de H. perotensis recolectadas en Veracruz en 2012 y 2015. Las hipótesis fueron (1) que la germinación y la viabilidad de las semillas son independientes del año de recolecta, (2) que hay una concentración adecuada de tetrazolio para identificar la viabilidad de las semillas y (3) que el pretratamiento con KNO3 o AG3 incrementa la germinación de las semillas. La germinación se evaluó con un diseño completamente al azar con tres tratamientos (testigo y promotores de la germinación KNO3 0.2 % y AG3 500 mg/L), cuatro tratamientos para la prueba de viabilidad (testigo, 0.2, 0.5 y 1.0 % de tetrazolio) y seis repeticiones de cada tratamiento. La germinación se evaluó en 100 semillas y la viabilidad en 25. Los resultados entre y dentro de años se analizaron con ANDEVA y prueba de comparación múltiple de medias de Tukey. La proporción de semillas no germinadas se cuantificó junto con el número de plántulas normales y anormales, semillas con embrión viable o sin él, y con viabilidad baja o sin viabilidad. En promedio la muestra recolectada en 2012 tuvo 36 % de semillas con embrión viable, 7 con viabilidad baja, 24 % no viables y 33 % sin embrión. Este resultado fue significativamente diferente al de 2015, que presentó 87 % de embriones viables, 10 % con viabilidad baja, 0 % no viables y 3 % sin embrión. La germinación también fue significativamente diferente entre los años (22 y 92 %). Los tratamientos pregerminativos no modificaron la germinación. La germinación y la viabilidad de las semillas de H. perotensis varían significativamente entre los años de recolecta.
Abstract:Endemic populations of Hechtiaperotensis have been described in Puebla and Veracruz, Mexico. Good quality seed collections can be used in conservation, research and ecological restoration. To evaluate seed quality of wild and endemic species, some compounds are used as effective promoters of germination, such as potassium nitrate (KNO3) and gibberellic acid (AG3), because they increase seed germination capacity and reduce latency. The triphenyl tetrazolium chloride (tetrazolium) test correlates seed viability because it is based on the activity of dehydrogenases in live tissues that catalyze mitochondrial respiration. The objective of this study was to obtain information on size and weight of capsules and seeds and seed germination and viability of H.perotensis, collected in Veracruz in the year 2012 and 2015. The hypotheses were 1) that seed germination and viability are independent of the year of collection, 2) that there is a tetrazolium concentration that can identify seed viability better than others, and 3) that pretreatment with KNO3 or AG3 improves seed germination. Seed germination was assessed using a completely randomized design with three treatments (control and the germination promoters 0.2 % KNO3 and 500 mg/L AG3), four treatments for the viability test (control, 0.2, 0.5 and 1.0 % of tetrazolium) and six replicates for each treatment. A total of one hundred seeds for germination experiments, and 25 seeds for the viability test were used. The results between and within years were analyzed with ANOVA and multiple comparison with the Tukey test. The proportion of non-germinated seeds was quantified along with the number of normal and abnormal seedlings, seeds with viable embryo, seeds without embryo, and seeds with low or no viability. On average, for the 2012 collected sample, 36 % had viable embryos, 7 % had low viability, 24 % were not viable and 33 % had no embryo. This result was significantly different from the 2015 sample, for which 87 % of seed showed viable embryos, 10 % had low viability, 0 % was not viable and 3 % had no embryo. Seed germination was also significantly different between years (22 and 92 %) Pregerminative treatments did not improve germination. Seed germination and viability of H. perotensis significantly varied between years of seed collection. Rev. Biol. Trop. 65 (1): 153-165. Epub 2017 March 01.
Subject(s)
Seeds/physiology , Germination/physiology , Bromeliaceae/physiology , Reference Values , Temperature , Time Factors , Reproducibility of Results , Analysis of Variance , Potassium Compounds/pharmacology , Statistics, Nonparametric , Biomass , Bromeliaceae/drug effects , Mexico , Nitrates/pharmacologyABSTRACT
Abstract Resin cements have led to great advances in dental ceramic restoration techniques because of their ability to bond to both dental structures and restorative materials. Objective The aim of this study was to assess the performance of resin cements when different curing modes are used, by evaluating the degree of conversion and bond strength to a ceramic substrate. Material and Methods Three resin cements were evaluated, two dual-cured (Variolink II and RelyX ARC) and one light-cured (Variolink Veneer). The dual-cured resin cements were tested by using the dual activation mode (base and catalyst) and light-activation mode (base paste only). For degree of conversion (DC) (n=5), a 1.0 mm thick feldspathic ceramic disc was placed over the resin cement specimens and the set was light activated with a QTH unit. After 24 h storage, the DC was measured with Fourier transform infrared spectroscopy (FTIR). For microshear bond strength testing, five feldspathic ceramic discs were submitted to surface treatment, and three cylindrical resin cement specimens were bonded to each ceramic surface according to the experimental groups. After 24 h, microshear bond testing was performed at 0.5 mm/min crosshead speed until the failure. Data were submitted to one-way ANOVA followed by Tukey test (p<0.05). Scanning electron microscopy (SEM) was used for classifying the failure modes. Results Higher DC and bond strength values were shown by the resin cements cured by using the dual activation mode. The Variolink II group presented higher DC and bond strength values when using light-activation only when compared with the Variolink Veneer group. Conclusion The base paste of dual-cured resin cements in light-activation mode can be used for bonding translucent ceramic restorations of up to or less than 1.0 mm thick.
Subject(s)
Polyethylene Glycols/chemistry , Polymethacrylic Acids/chemistry , Ceramics/chemistry , Bisphenol A-Glycidyl Methacrylate/chemistry , Potassium Compounds/chemistry , Resin Cements/chemistry , Light-Curing of Dental Adhesives/methods , Aluminum Silicates/chemistry , Reference Values , Surface Properties , Time Factors , Materials Testing , Microscopy, Electron, Scanning , Reproducibility of Results , Analysis of Variance , Shear Strength , Curing Lights, Dental , Photochemical Processes , PolymerizationABSTRACT
Coloprep is a bowel preparatory solution given before endoscopic procedures to get a unobscured internal vision. It has among its constituent's sodium sulphate, potassium sulphate and magnesium sulphate which produce an osmotic effect in the bowel. However, the use of such agents in hyponatremic and patients predisposed to seizures can have adverse ramifications. The current case outlines manifestation of absence seizure in a 52-year-old male patient who was administered Coloprep for colonoscopy. There was absence of other predisposing factors and the symptoms were ameliorated using timely identification and rectification of the underlying derangements.
Coloprep é uma solução preparatória intestinal administrada antes de procedimentos endoscópicos, com o objetivo de se ter uma visão interna não obscurecida. Entre os constituintes de Coloprep, observa-se sulfato de sódio, sulfato de potássio e sulfato de magnésio, que provocam efeito osmótico no intestino. Mas o uso de tais agentes em pacientes hiponatrêmicos e com predisposição para convulsões pode ter ramificações adversas. O caso em tela delineia uma manifestação de convulsão de ausência em paciente do gênero masculino com 52 anos e que recebeu Coloprep para colonoscopia. Não havia outros fatores predisponentes e os sintomas melhoraram graças à oportuna identificação e correção dos transtornos subjacentes.
Subject(s)
Humans , Male , Middle Aged , Seizures/complications , Sulfates/administration & dosage , Cathartics/adverse effects , Colonoscopy/adverse effects , Sodium Compounds/administration & dosage , Potassium Compounds/administration & dosage , Magnesium Sulfate/administration & dosage , Seizures , Sulfates/analysis , Sulfates/adverse effects , Sulfates/therapeutic use , Cathartics/administration & dosage , Cathartics/therapeutic use , Sodium Compounds/analysis , Sodium Compounds/adverse effects , Sodium Compounds/therapeutic use , Potassium Compounds/analysis , Potassium Compounds/adverse effects , Potassium Compounds/therapeutic use , Hyponatremia , Magnesium Sulfate/analysis , Magnesium Sulfate/adverse effects , Magnesium Sulfate/therapeutic useABSTRACT
Statement of Problem: Dentin hypersensitivity is one of the most common complaints of patients after periodontal treatments which occur after tissue shrinkage
Objectives: The aim of this study was to determine and compare the effectiveness of sensikin gel [10% potassium nitrate and 0.22% sodium fluoride] with sodium fluoride gel [2.7%] and fluoride varnish [5%] in reducing the dentin hypersensitivity after periodontal surgery
Materials and Methods: Twenty-two patients who, after full mouth periodontal surgery, had a complaint of dentin hypersensitivity [DH] in at least three quadrants were selected. Then a specific treatment was randomly selected for each quadrant which was applied once a day for one week and then stopped. A visual analog scale [VAS] was used to assess the subjects' responses to air blast and periodontal probe stimuli at baseline at one week, and one, three and 6 months after treatment. To analyze the data, repeated measures ANOVA test, Tukey test and variance analysis test were used
Results: At all given intervals, almost both sodium fluoride and sensikin gel significantly reduced the dental sensitivity caused by stimulants. There were no significant differences between sensikin gel and other two desensitizers in reducing the dentin hypersensitivity after 1 week, 1 month, 3 months, and 6 months with respect to air blast stimuli. Sensikin gel was more efficient than Fluoride varnish in reducing the sensitivity caused by periodontal probe after 1 month
Conclusions: Sensikin gel, sodium fluoride gel and fluoride varnish can all be prescribed to reduce dental sensitivity in patients who have undergone periodontal treatments. In the case of severe sensitivity to mechanical stimulations, a treatment with a long-run effectiveness such as sensikin and/or sodium fluoride gel is preferred
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Periodontium/surgery , Nitrates , Potassium Compounds , Sodium Fluoride , Fluorides, TopicalABSTRACT
Abstract Lignocellulose is the most abundant environmental component and a renewable organic resource in soil. There are some filamentous fungi which developed the ability to break down and use cellulose, hemicellulose and lignin as an energy source. The objective of this research was to analyze the effect of three nitrogen resources (ammonium sulfate, saltpetre, soybean) in the holocellulolitic activity of Lentinula edodes EF 50 using as substrate sawdust E. benthamii. An experimental design mixture was applied with repetition in the central point consisting of seven treatments (T) of equal concentrations of nitrogen in ammonium sulfate, potassium nitrate and soybean. The enzymatic activity of avicelase, carboxymetilcellulase, β-glucosidase, xylanases and manganese peroxidase was determined. The humidity, pH, water activity (aw) and qualitative analysis of mycelial growth in 8 times of cultivation were evaluated. The results showed negative effect on enzyme production in treatments with maximum concentration of ammonium sulfate and potassium nitrate. The treatments with cooked soybean flour expressed higher enzymatic activities in times of 3, 6 and 9 days of culture, except in the activity of manganese peroxidase. The highest production was observed in the treatment with ammonium sulfate, and soybean (83.86 UI.L–1) at 20 days of cultivation.
Resumo Lignocelulose é o componente mais abundante do meio ambiente e recurso orgânico renovável no solo. Alguns fungos filamentosos têm desenvolvido a habilidade de degradar e utilizar celulose, hemicelulose e lignina como fonte de energia. O objetivo deste trabalho foi analisar o efeito de três fontes de nitrogênio (sulfato de amônio, nitrato de potássio e farelo de soja) na atividade enzimática de Lentinula edodes EF 50 utilizando como substrato serragem de E. benthamii. Foi aplicado um planejamento experimental de mistura com três repetições no ponto central constituído de sete tratamentos (T) de iguais concentrações em nitrogênio de sulfato de amônia, nitrato de potássio e farinha de soja cozida. Foram determinadas a atividade enzimática da avicelase, carboximetilcelulase, β-glicosidase, xilanases e manganês peroxidase. Foram avaliados o teor de umidade, pH, atividade de água (aw) e análise qualitativa do crescimento micelial em 8 tempos de cultivo. Os resultados mostraram efeito negativo na produção das enzimas nos tratamentos com máxima concentração de sulfato de amônia e nitrato de potássio. Os tratamentos com farinha de soja cozida expressaram maiores atividades enzimáticas, nos tempos de 3, 6 e 9 dias de cultivo exceto na atividade do manganês peroxidase. A maior produção foi observada no tratamento com sulfato de amônia e farinha de soja cozida (83.86 UI.L–1) em 20 dias de cultivo.
Subject(s)
Biomass , Lignin/pharmacology , Nitrogen/metabolism , Shiitake Mushrooms/enzymology , Shiitake Mushrooms/growth & development , Ammonium Sulfate/metabolism , Eucalyptus/chemistry , Nitrates/metabolism , Potassium Compounds/metabolism , Soybeans/chemistry , Wood/analysisABSTRACT
OBJECTIVE: To assess four different chemical surface conditioning methods for ceramic material before bracket bonding, and their impact on shear bond strength and surface integrity at debonding.METHODS: Four experimental groups (n = 13) were set up according to the ceramic conditioning method: G1 = 37% phosphoric acid etching followed by silane application; G2 = 37% liquid phosphoric acid etching, no rinsing, followed by silane application; G3 = 10% hydrofluoric acid etching alone; and G4 = 10% hydrofluoric acid etching followed by silane application. After surface conditioning, metal brackets were bonded to porcelain by means of the Transbond XP system (3M Unitek). Samples were submitted to shear bond strength tests in a universal testing machine and the surfaces were later assessed with a microscope under 8 X magnification. ANOVA/Tukey tests were performed to establish the difference between groups (α= 5%).RESULTS: The highest shear bond strength values were found in groups G3 and G4 (22.01 ± 2.15 MPa and 22.83 ± 3.32 Mpa, respectively), followed by G1 (16.42 ± 3.61 MPa) and G2 (9.29 ± 1.95 MPa). As regards surface evaluation after bracket debonding, the use of liquid phosphoric acid followed by silane application (G2) produced the least damage to porcelain. When hydrofluoric acid and silane were applied, the risk of ceramic fracture increased.CONCLUSIONS: Acceptable levels of bond strength for clinical use were reached by all methods tested; however, liquid phosphoric acid etching followed by silane application (G2) resulted in the least damage to the ceramic surface.
OBJETIVO: avaliar quatro métodos de condicionamento químico da superfície cerâmica, previamente à colagem de braquetes, e seu impacto sobre a resistência ao cisalhamento e a integridade da superfície ao descolamento.MÉTODOS: quatro grupos experimentais (n = 13) foram delineados de acordo com o método de condicionamento da superfície cerâmica empregado: G1 = ácido fosfórico a 37%, seguido da aplicação de silano; G2 = ácido fosfórico líquido a 37%, seguido da aplicação de silano sem lavagem prévia do ácido; G3 = ácido fluorídrico a 10%; e G4 = ácido fluorídrico a 10%, seguido da aplicação de silano. Após o condicionamento da superfície, braquetes metálicos foram colados à porcelana utilizando-se o sistema Transbond XP (3M Unitek). As amostras foram submetidas a ensaios de resistência ao cisalhamento, em máquina de ensaio universal, e as superfícies cerâmicas foram posteriormente avaliadas em microscópio, com magnitude de 8X. Testes ANOVA/Tukey foram realizados para verificar-se a diferença entre os grupos (α = 5%).RESULTADOS: os maiores valores de resistência ao cisalhamento foram encontrados nos grupos G3 e G4 (22,01 ± 2,15MPa e 22,83 ± 3,32Mpa, respectivamente), seguidos por G1 (16,42 ± 3,61MPa) e G2 (9,29 ± 1,95MPa). Quanto à avaliação da superfície após a descolagem do braquete, a utilização de ácido fosfórico líquido seguido da aplicação de silano, sem lavagem do ácido (G2), produziu menores danos à porcelana. Quando ácido fluorídrico e silano foram aplicados, o risco de fraturar a cerâmica aumentou.CONCLUSÕES: níveis aceitáveis de resistência de união para uso clínico foram alcançados por todos os métodos testados. No entanto, o condicionamento com ácido fosfórico líquido, seguido da aplicação de silano (G2), resultou em menor dano à superfície cerâmica.
Subject(s)
Acid Etching, Dental/methods , Dental Bonding , Orthodontic Brackets , Dental Porcelain/chemistry , Phosphoric Acids/chemistry , Silanes/chemistry , Stress, Mechanical , Surface Properties , Materials Testing , Orthodontic Appliance Design , Dental Debonding/methods , Potassium Compounds/chemistry , Composite Resins/chemistry , Resin Cements/chemistry , Dental Alloys/chemistry , Shear Strength , Dental Stress Analysis/instrumentation , Aluminum Silicates/chemistry , Hydrofluoric Acid/chemistry , MicroscopyABSTRACT
The aim of this study was to evaluate the efficacy of different surface conditioning methods on the microtensile bond strength of a restorative composite repair in three types of dental ceramics: lithium disilicate-reinforced, leucite-reinforced and feldspathic. Twelve blocks were sintered for each type of ceramic (n=3) and stored for 3 months in distilled water at 37 °C. The bonding surface of ceramics was abraded with 600-grit SiC paper. Surface treatments for each ceramic were: GC (control) - none; GDB - diamond bur #30 µm; GHF - hydrofluoric acid (10%); GT- tribochemical silica coating (45-μm size particles). Treatments were followed by cleaning with phosphoric acid 37% for 20 s + silane + adhesive. The composite resin was used as restorative material. After repair, samples were subjected to thermocycled ageing (10,000 cycles between 5 °C and 55 °C for 30 s). Thereafter, the samples were sectioned into 1.0 mm2 sticks and tested for microtensile bond strength with 0.5 mm/min crosshead speed. Data were compared by two-way ANOVA and Tukey's test (α=0.05). The superficial wear with diamond bur proved to be suitable for feldspathic porcelain and for leucite-reinforced glass ceramic while hydrofluoric acid-etching is indicated for repairs in lithium disilicate-reinforced ceramic; tribochemical silica coating is applicable to leucite-reinforced ceramic. Predominance of adhesive failures was observed (>85% in all groups). In conclusion, the success of surface treatments depends on the type of ceramic to be repaired.
O objetivo deste estudo foi avaliar a eficácia de diferentes condicionamentos de superfície na resistência de união de reparos de compósitos restauradores em três tipos de cerâmicas odontológicas: reforçada por dissilicato de lítio, reforçada por leucita e feldspática. Foram confeccionados 12 blocos para cada tipo de cerâmica (n=3) e armazenados por 3 meses em água destilada a 37 oC. A superfície de união das cerâmicas foi regularizada com lixa de granulação 600 por 15 s e lavadas em ultrassom por 10 min. Os tratamentos de superfície para cada cerâmica foram: GC (controle) - nenhum; GPD - ponta diamantada com 30 µm de granulação; GAF - ácido hidrofluorídrico a 10%; GJ - jateamento com partículas de óxido de alumínio revestido por sílica (45 µm - tamanho das partículas). Após, foi realizada a limpeza da superfície com ácido fosfórico a 7% por 20 s, seguido de silano e adesivo. Como material restaurador foi utilizada resina composta. Após o reparo, as amostras foram submetidas a ciclagem térmica (10,000 ciclos entre 5 °C e 55 °C, por 30 s). Na sequência, as amostras foram seccionadas em palitos de aproximadamente 1,0 mm2 e levadas ao teste de tração em uma máquina de ensaios universal à velocidade de 0,5 mm/min. Os dados obtidos foram comparados estatisticamente por ANOVA de dois fatores e teste de Tukey (α=0,05). Sugere-se que o desgaste da superfície com ponta diamantada é mais indicado para a cerâmica feldspática e cerâmica reforçada por leucita, enquanto o condicionamento com ácido fluorídrico é indicado para reparos em cerâmica reforçada por dissilicato de lítio. O jateamento com partículas de óxido de alumínio revestido por sílica mostrou-se aplicável à cerâmica reforçada por leucita. Predominancia de fraturas adesivas acima de 85% foi observada para todos os grupos. Este estudo demonstrou que o sucesso dos tratamentos de superfície depende do tipo de cerâmica a que são aplicados.
Subject(s)
Humans , Adult , Middle Aged , Aged , Aluminum Silicates/chemistry , Ceramics/chemistry , Composite Resins/chemistry , Dental Porcelain/chemistry , Potassium Compounds/chemistry , Acid Etching, Dental , Dental Cements , Random Allocation , Surface Properties , Tensile StrengthABSTRACT
The study aimed to evaluate the effectiveness of in-office bleaching and associated tooth sensitivity on application of nano-calcium phosphate paste as desensitizing agent. Bleaching was performed with 35% hydrogen peroxide gel in 40 patients who were randomly divided into placebo and nano-calcium phosphate paste groups. Bleaching efficacy (BE) was evaluated using a value-oriented Vita shade guide. Tooth sensitivity was recorded using a numeric rating scale (0–4) during bleaching and up to 48 h after each session. The primary outcome of absolute risk of tooth sensitivity was compared using the Fisher’s exact test (α = 0.05). The intensity of tooth sensitivity and the efficacy of in-office bleaching were also statistically evaluated. No significant differences in absolute risk and intensity of tooth sensitivity were detected between the groups (p = 1.0 and p = 0.53, respectively). BE was also found to be similar between the groups (p = 0.67). Although the use of a nano-calcium phosphate paste associated with fluoride and potassium nitrate did not influence the whitening outcome, but it also did not reduce bleaching-induced tooth sensitivity.
Subject(s)
Adult , Female , Humans , Male , Young Adult , Calcium Phosphates/administration & dosage , Dentin Desensitizing Agents/administration & dosage , Dentin Sensitivity/chemically induced , Hydrogen Peroxide/administration & dosage , Nitrates/administration & dosage , Potassium Compounds/administration & dosage , Tooth Bleaching Agents/administration & dosage , Tooth Bleaching/adverse effects , Calcium Phosphates/adverse effects , Double-Blind Method , Hydrogen Peroxide/adverse effects , Nitrates/adverse effects , Potassium Compounds/adverse effects , Tooth Bleaching Agents/adverse effects , Tooth Bleaching/methods , Tooth Discoloration/drug therapyABSTRACT
To offer the reference and method for salt damage in the cultivation of Marsdenia tenacissima, the seeds of M. tenacissima collected from Maguan city ( Yunnan province) were taken as the test materials to study the effects of different priming materials on improving germination and growth under high-level salt stress condition. Four different treatments, which were GA3, KNO3-KH2PO4, PEG-6000, NaCl, combined with ANOVA were applied to test the performance of germination energy, germination percentage, germination index, MDA, SOD, and CAT. The results showed that the seed germination was obviously inhibited under salt stress and the soaked seeds with different priming materials could alleviate the damage of salt stress. Under these treatments, the activities of SOD, CAT the content of soluble protein significantly increased. While the content of MDA significantly decreased. The maximum index was obtained when treated with 1.20% KNO3-KH2PO4, the germination percentage increased from 52.67% to 87.33% and the activity of SOD increased from 138.01 to 219.44 respectively. Comparing with the treatment of 1.20% KNO3-KH2PO4, the germination percentage of treating with 300 mg x L(-1) GA3 increased from 52.67% to 80.67%, while the activity of SOD increased from 138.01 to 444.61.