Effects of bleaching using 10% carbamide peroxide with calcium or amorphous calcium phosphate on enamel mineral content and hardness / Asociación entre la severidad de Hipomineralización Incisivo-Molar (HIM) y lesiones cavitadas de caries en escolares

ABSTRACT This study evaluated enamel mineral content and surface microhardness before and after bleaching treatment using 10% carbamide peroxide (CP) containing calcium (Ca) or amorphous calcium phosphate (ACP). Thirty-six bovine slabs were randomly allocated into 3 groups (n = 12) according to bleaching treatment: G1 - Opalescence PF 10% (CP), G2 -NiteWhite ACP (CP+ACP), and G3 - Opalescence PF (10%) with calcium (CP+CA). The bleaching agent was applied on enamel surface for 6 h/day over a period of 21 days. Enamel surface was evaluated by Knoop microhardness (KNH) and micro energy-dispersive X-ray fluorescence spectrometry (p-EDXRF) at baseline and at after bleaching treatment. Data were statistically analyzed by repeated measures ANOVA and Tukey's test (a = 0.05). There was a significant decrease in microhardness after bleaching treatments for all study groups, but no difference between bleaching gels. There was no difference in the Ca/P ratio measured by p-EDXRF for all groups at the study times, but the mean value was lower in group CP+CA than in group CP+ACP. Group CP was similar to both CP+ACP and CP+CA. It can be concluded that enamel microhardness decreased after the bleaching process, regardless of the presence of calcium or ACP, but there was no significant change in the Ca/P ratio of enamel after bleaching for each tested gel. This indicates that the bleaching gels have erosive potential, causing softening of enamel without promoting surface loss, regardless of the presence of calcium of ACP ions.

RESUMO Este estudo avaliou o conteúdo mineral do esmalte e a microdureza superficial antes e após o tratamento clareador, utilizando peróxido de carbamida 10% (PC) contendo cálcio (Ca) ou fosfato de cálcio amorfo (ACP) em sua composigao. Trinta e seis espécimes de esmalte bovino foram alocados aleatoriamente em 3 grupos (n = 12) de acordo com os tratamentos clareadores: G1 - Opalescence PF 10% (CP), G2 -NiteWhite (CP+ACP); e G3 - Opalescence PF (10%) com cálcio (CP + CA). O agente clareador foi aplicado na superficie do esmalte por 6 h/dia por um periodo de 21 dias. A superficie do esmalte foi avaliada por microdureza Knoop (KNH) e espectrometria de fluorescencia de raios X micro-dispersiva (p-EDXRF) no inicio e após o tratamento clareador. Os dados foram analisados estatisticamente pelo teste ANOVA de medidas repetidas e Tukey (a = 0,05). Houve uma diminuigao significativa da microdureza após os tratamentos clareadores para todos os grupos estudados, mas nao houve diferenga entre os diferentes géis. Nao houve diferenga da relagao Ca/P mensurada por p-EDXRF para todos os grupos nos tempos estudados; no entanto, o grupo CP+CA apresentou menor valor comparado ao grupo CP+ACP. O grupo CP foi similar aos grupos CP+ACP e CP+CA. Portanto, pode-se concluir que houve redugao significativa da microdureza do esmalte após o clareamento, independente da presenga de cálcio ou APC na composigao dos géis, embora nao tenha havido alteragao significando na relagao Ca/P do esmalte após o clareamento. Isto indica um potencial erosivo dos géis clareadores, causando o amolecimento sem perda da estrutura do esmalte, independente da presenga dos íons cálcio e ACP.

Uso de N-acetilcisteína tópica en ictiosis: experiencia clínica en una serie de casos / Use of topical N-acetylcysteine ​​in ichthyosis: clinic experience in a series of cases

Las ictiosis son trastornos generalizados de la queratinización, que se caracterizan por presentar hiperqueratosis y/o descamación. El tratamiento es sintomático e incluye terapias tópicas y sistémicas. La N-Acetilcisteína (NAC) tópica ha mostrado utilidad en algunos reportes. Se describirá la experiencia con el uso de NAC 10% y urea 5% en novobase II (NB II) en 6 pacientes con distintos tipos de ictiosis hereditarias. Caso Nº1: Escolar masculino de 7 años con Ictiosis lamelar (IL) en tratamiento con fórmula de NAC hace 4 años con buena respuesta. Caso N°2, 3 y 4: Escolar masculino de 7 años, escolar masculino de 5 años y lactante masculino de 1 año 8 meses con Ictiosis recesiva ligada a X (IRLX), en tratamiento con fórmula de NAC con buena respuesta. Caso N°5: Mujer de 18 años con Eritrodermia ictiosiforme congénita (EIC), inicia tratamiento con fórmula de NAC, pero se suspende por mala tolerancia. Caso N°6: Preescolar femenina de 3 años, con Ictiosis epidermolítica (IE), inicia tratamiento con fórmula de NAC con mala tolerancia por lo que también se suspende. Se evaluaron los efectos de la fórmula de NAC en diferentes tipos de ictiosis, mostrando un buen perfil de seguridad y eficacia en IL e IRLX, sin embargo, en EIC e IE su uso estuvo restringido por efectos adversos. El tratamiento con fórmula de NAC presenta buena respuesta y tolerancia en pacientes con IL e IRLX, por lo que podría considerarse en el tratamiento habitual de estos pacientes.

Ichthyosis are generalized disorders of keratinization, characterized by hyperkeratosis and/or scaling. Treatment is symptomatic and includes topical and systemic therapies. Topical N-acetylcysteine (NAC) has shown utility in some reports. We describe the experience using 10% NAC and 5% urea in novobase II (NB II) in 6 patients with different types of hereditary ichthyosis. Case N°1: 7-year-old boy with lamellar Ichthyosis (IL) in treatment with NAC formula 4 years ago, with good response. Case N°2, 3 and 4: 7-year-old boy, 5-year-old boy and 1-year-8-month-old male infant, with X-recessive recessive Ichthyosis (IRLX) in treatment with NAC formula with good response. Case N°5: An 18-year-old woman with congenital ichthyosiform erythroderma (EIC) begins treatment with NAC formula but is discontinued because of poor tolerance. Case No. 6:3-year-old girl, with epidermolytic Ichthyosis (IE), starts treatment with NAC formula with poor tolerance and is also suspended. The effects of the NAC formula on different types of ichthyosis were evaluated, showing a good safety and efficacy profile in IL and IRLX, however, in EIC and IE, its use was restricted by adverse effects. Treatment with NAC formula has a good response and tolerance in patients with IL and IRLX, so it could be considered in the usual treatment of these patients.

Comparative clinical study of the effectiveness of different dental bleaching methods - two year follow-up

This study evaluated color change, stability, and tooth sensitivity in patients submitted to different bleaching techniques. MATERIAL AND METHODS: In this study, 48 patients were divided into five groups. A half-mouth design was conducted to compare two in-office bleaching techniques (with and without light activation): G1: 35% hydrogen peroxide (HP) (Lase Peroxide - DMC Equipments, São Carlos, SP, Brazil) + hybrid light (HL) (LED/Diode Laser, Whitening Lase II DMC Equipments, São Carlos, SP, Brazil); G2: 35% HP; G3: 38% HP (X-traBoost - Ultradent, South Jordan UT, USA) + HL; G4: 38% HP; and G5: 15% carbamide peroxide (CP) (Opalescence PF - Ultradent, South Jordan UT, USA). For G1 and G3, HP was applied on the enamel surface for 3 consecutive applications activated by HL. Each application included 3x3' HL activations with 1' between each interval; for G2 and G4, HP was applied 3x15' with 15' between intervals; and for G5, 15% CP was applied for 120'/10 days at home. A spectrophotometer was used to measure color change before the treatment and after 24 h, 1 week, 1, 6, 12, 18 and 24 months. A VAS questionnaire was used to evaluate tooth sensitivity before the treatment, immediately following treatment, 24 h after and finally 1 week after. RESULTS: Statistical analysis did not reveal any significant differences between in-office bleaching with or without HL activation related to effectiveness; nevertheless the time required was less with HL. Statistical differences were observed between the results after 24 h, 1 week and 1, 6, 12, 18 and 24 months (intergroup). Immediately, in-office bleaching increased tooth sensitivity. The groups activated with HL required less application time with gel. CONCLUSION: All techniques and bleaching agents used were effective and demonstrated similar behaviors.

In vitro study on tooth enamel lesions related to whitening dentifrice.

Background: The tooth whitening substances for extrinsic use that are available in Brazil contain hydrogen peroxide or carbamide peroxide. Several studies have attributed the appearance of lesions in the enamel morphology, including hypersensitivity, to these substances. Such lesions justify fluoride therapy and application of infrared lasers, among other procedures. However, there is no consensus among researchers regarding the relevance of the severity of lesions detected on the tooth surface. Objectives: The present study was carried out with an aim of evaluating in vitro the effects of the hydrogen peroxide, carbamide peroxide and sodium bicarbonate contained in dentifrice formulations, on human tooth enamel. Materials and Methods: After darkening process in laboratory, human premolars were brushed using dentifrice containing the two whitening substances (Rembrandt - carbamide peroxide and Mentadent - hydrogen peroxide) and the abrasive product (Colgate - sodium bicarbonate). The degree of specimen staining before and after this procedure was determined using spectrophotometry. Scanning electron microscopy (SEM) was used to obtain images, which were analyzed to show the nature of the lesions that appeared on the enamel surface. Results: The effectiveness of the whitening caused by hydrogen peroxide and carbamide peroxide and the abrasion caused by bicarbonate were confirmed, given that the treated test pieces returned to their original coloration. Based on SEM, evaluation of the enamel surfaces subjected to the test products showed that different types of morphologic lesions of varying severity appeared. Conclusions: Whitening dentifrice containing hydrogen peroxide and carbamide peroxide produced lesions on the enamel surface such that the greatest sequelae were associated with exposure to hydrogen peroxide.

Micromorphology and microhardness of enamel after treatment with home-use bleaching agents containing 10 percent carbamide peroxide and 7.5 percent hydrogen peroxide

OBJECTIVE: The purpose of this study was to assess the effect of home-use bleaching agents containing 10 percent carbamide peroxide and 7.5 percent hydrogen peroxide on enamel microhardness and surface micromorphology. MATERIAL AND METHODS: Enamel slabs (n=10) received the bleaching agents for 1 h/day and remained in artificial saliva solution for 23 h/day, during a total period of 21 days. Control group was composed of enamel slabs that were not subjected to treatment with the agents and were maintained in artificial saliva solution. Microhardness tests were performed before treatment application, 21 days of treatment and 14 days after the end of treatment. Scanning electron microscopy analyses were performed after 14 days after the end of bleaching treatment by 3 calibrated observers who attributed scores. RESULTS: The Tukey's test (á=0.05) showed no significant differences in microhardness values among bleaching agents, at 21 days of treatment and a significant increase in microhardness for different agents after 14 days from the end of treatment. Fisher's exact test showed differences in micromorphology of enamel between control and experimental groups (p=0.0342). CONCLUSIONS: Bleaching agents containing 10 percent carbamide peroxide and 7.5 percent hydrogen peroxide may change surface micromorphology of enamel, although no changes in microhardness were observed.

Efectividad de la pomada de urea en las verrugas plantares / Effectiveness of the urea ointment in the feet warts

Se hizo un ensayo clinicoterapéutico en 60 pacientes atendidos en la consulta de Dermatología del Hospital Provincial Docente Dr Joaquín Castillo Duany de Santiago de Cuba, durante el 2008, con el fin evaluar la efectividad de la pomada de urea en las verrugas plantares. Se conformaron 2 grupos (de estudio y control): los primeros recibieron pomada de urea al 20 por ciento y los segundos pomada salicílica al 40 por ciento. La pomada de urea resultó más eficaz para eliminar las manifestaciones clínicas de esa lesión, en un período de 6 a 8 semanas y no hubo reacciones adversas.

A clinical therapeutical trial was made in 60 patients assisted at the Dermatology department of Dr Joaquín Castillo Duany Teaching Provincial Hospital from Santiago de Cuba, during 2008, aimed at evaluating the effectiveness of the urea ointment in the feet warts. They conformed to 2 groups (study and control): the first group received urea ointment at 20 percent and the second one salicylic ointment at 40 percent. The urea ointment was more effective to eliminate the clinical manifestations of that lesion, in a period of 6 to 8 weeks and there were not adverse reactions.

El valor de la urea en el cuidado y tratamiento de la piel / The urea in the treatment and care of skin

La urea es uno de los humectantes naturales más efectivos y su disminución da lugar a alteraciones de la piel en algunas afecciones dermatológicas. Se revisa brevemente sus propiedades farmacológicas así como sus indicaciones principales.

Urea is one of more effective moisturizer of skin and its disminution is the cause of some dermatologic diseases. Its pharmacologic properties as well its indications are briefly revised.

Spectrophotometric assessment of the effects of 10 percent carbamide peroxide on enamel translucency

Tooth shade results from the interaction between enamel color, enamel translucency and dentine color. A change in any of these parameters will change a tooth’s color. The objective of this study was to evaluate the changes occurring in enamel translucency during a tooth whitening process. Fourteen human tooth enamel fragments, with a mean thickness of 0.96 mm (± 0.3 mm), were subjected to a bleaching agent (10 percent carbamide peroxide) 8 hours per day for 28 days. The enamel fragment translucency was measured by a computer controlled spectrophotometer before and after the bleaching agent applications in accordance with ANSI Z80.3-1986 - American National Standard for Ophthalmics - nonprescription sunglasses and fashion eyewear-requirements. The measurements were statistically compared by the Mann-Whitney non-parametric test. A decrease was observed in the translucency of all specimens and, consequently, there was a decrease in transmittance values for all samples. It was observed that the bleaching procedure significantly changes the enamel translucency, making it more opaque.

Effect of a carbamide peroxide bleaching gel containing calcium or fluoride on human enamel surface microhardness

Este estudo in vitro avaliou microdureza superficial do esmalte após o clareamento com peróxido de carbamida a 10% (PC) contendo cálcio ou flúor. Noventa e oito blocos dentais (5 x 5 mm2) com a superfície do esmalte polido foram divididos em sete grupos experimentais (n=14): sem clareamento e armazenado em saliva artificial; 10% (PC); (3) 10% PC + 0,05% cálcio; 10% PC + 0,1% cálcio; 10% PC + 0,2% cálcio; 10% PC + 0,2% flúor; e 10% PC + 0,5% flúor. Os géis clareadores foram aplicados por 6 h durante 14 dias e após cada dia de tratamento, os espécimes foram armazenados em saliva artificial. A microdureza superficial foi mensurada antes (baseline), durante (7º dia), imediatamente após o clareamento (14º dia) e 1 semana após o fim do tratamento clareador. Os dados foram analisados pela ANOVA (2 fatores) e teste de Tukey (p<0.05). Os tratamentos clareadores reduziram significativamente a microdureza durante (7º dia), imediatamente após o clareamento (14º dia) e 1 semana após o seu término, quando comparados aos valores iniciais (baseline) e aos do grupo controle. Os achados deste estudo sugerem que, a despeito da adição de cálcio e flúor, todos os géis clareadores afetaram a microdureza superficial do esmalte.

Qualidade de silagens de sorgo com aditivos / Quality of sorghum silages with additives

Um delineamento inteiramente ao acaso, com três repetições, foi utilizado para avaliar os efeitos da adição de 0,5 por cento de uréia, de 0,5 por cento de carbonato de cálcio (CaCO3), de 0,5 por cento de uréia mais 0,5 por cento de CaCO3 e de inoculante bacteriano sobre o pH, teores de matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), hemicelulose, celulose, lignina, carboidratos solúveis, ácido lático e ácido acético sobre a digestibilidade in vitro da matéria seca (DIVMS) de silagens de quatro híbridos de sorgo (BR700, BR701, BR601 e AG2002). Os híbridos ensilados sem a adição de aditivos constituíram o grupo-controle. De cada genótipo foram coletadas três amostras do material original (MOR). Foram utilizados 60 silos de PVC com 10cm de diâmetro interno e 50cm de comprimento, sendo três por tratamento. A abertura dos silos ocorreu depois de 56 dias de fermentação. As silagens contendo CaCO3 e inoculante bacteriano apresentaram, em geral, características muito semelhantes às do controle. A adição de uréia e de uréia mais CaCO3 às silagens resultou em aumento (P<0,05) nos teores de PB. A adição conjunta de uréia e CaCO3 não propiciou aumento (P<0,05) superior ao obtido nas silagens contendo apenas uréia. Uréia pura, como aditivo, pode ser recomendada na ensilagem dos híbridos BR700, BR601 e AG2002.

Consumo e digestibilidade de novilhos Nelore sob pastagem suplementados com misturas múltiplas / Intake and digestibility of Nelore steers grazing pasture and supplemented with multiple mixture

Estudou-se o efeito da suplementação com misturas múltiplas sobre o consumo, digestibilidade e desempenho de novilhos Nelore, em pastagens de Brachiaria brizantha Cv. Marandu, submetidos a quatro tratamentos. No tratamento um (T1), cada animal recebeu 800g/dia de suplemento contendo uréia como fonte de nitrogênio não protéico (NNP); no tratamento dois (T2), recebeu 800g/dia de mistura na qual a uréia foi substituída por amiréia como fonte de NNP; no tratamento três (T3), recebeu 1500g/dia de uma mistura com amiréia; e no tratamento quatro (T4= controle), recebeu sal mineral. Seis animais por tratamento foram utilizados para se medir o consumo pela técnica de indicador externo (óxido crômico), e 10 animais foram usados na avaliação de ganho de peso. Foram utilizados dois animais canulados no esôfago para coleta de amostra de extrusa. Os animais suplementados obtiveram ganhos de peso superiores (P<0,05) aos do tratamento-controle, 435, 419, 467 e 271 g/dia para os tratamentos T1, T2, T3 e T4, respectivamente. Os coeficientes de digestibilidade da matéria seca (MS) foram de 56,7, 49,8, 48,9 e 45,5 por cento para os tratamentos T1, T2, T3 e T4, respectivamente, sendo correlacionados positivamente com a digestibilidade in vitro da MS (P<0,05). A suplementação com misturas múltiplas promoveu aumento no consumo (P<0,05).

Avaliaçäo terapêutica do oticerim em pacientes portadores de cerumen rígido e excessivo / The therapeutic evaluation of OTICERIM in patients with hard excessive cerume

Trinta pacientes portadores de cerumen rígido e excessivo, foram avaliados com uso do OTICERIM em um estudo aberto, näo comparativo, na cidade de Caxias do Sul - RS, visando analisar a performance do produto na degradaçäo do cerumen rígido do conduto auditivo