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UNLABELLED: The value of aesthetic dentistry has precipitated several developments in the investigation of dental materials related to this field. The free marketing of these products is a problem and it is subject to various interpretations regarding its legality. There are several techniques for tooth whitening, the most used one being the external bleaching. It is the later version of such technique that poses the greatest danger of ingesting the product. The present study analysed the systemic effect of these products when they are swallowed. OBJECTIVE: This experimental study aimed to observe the effects of a tooth whitening product, whose active agent is 6% hydrogen peroxide, on the gastric mucosa of healthy and non-tumour gastric pathology animals. MATERIAL AND METHODS: Fifty Wistar-Han rats were used and then distributed into 5 groups, one for control and four test groups in which the bleaching product was administered in animals with and without non-tumour gastric pathology (induced by the administration of 1 sample of 50% ethanol and 5% of drinking water during 6 days) at different times of study by gavage. There was a decrease in body weight in animals of groups handled during the study period, which was most pronounced in IV and VA groups. Changes in spleen weight relative to body weight revealed no statistically significant changes. An analysis of the frequency was performed on the results of macroscopic observation of the gastric mucosa. RESULTS: The gastric mucosa revealed lesions in all manipulated groups, being more frequent in groups III and IV. It appears that there is a synergism when using hydrogen peroxide and 50% ethanol in the same group. CONCLUSION: Therefore, it seems that there are some signs of toxicity 3 to 4 days after administration of 6% hydrogen peroxide. The prescription of these therapies must be controlled by the clinician and the risks must be minimized.

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The value of aesthetic dentistry has precipitated several developments in the investigation of dental materials related to this field. The free marketing of these products is a problem and it is subject to various interpretations regarding its legality. There are several techniques for tooth whitening, the most used one being the external bleaching. It is the later version of such technique that poses the greatest danger of ingesting the product. The present study analysed the systemic effect of these products when they are swallowed.Objective This experimental study aimed to observe the effects of a tooth whitening product, whose active agent is 6% hydrogen peroxide, on the gastric mucosa of healthy and non-tumour gastric pathology animals.Material and Methods Fifty Wistar-Han rats were used and then distributed into 5 groups, one for control and four test groups in which the bleaching product was administered in animals with and without non-tumour gastric pathology (induced by the administration of 1 sample of 50% ethanol and 5% of drinking water during 6 days) at different times of study by gavage. There was a decrease in body weight in animals of groups handled during the study period, which was most pronounced in IV and VA groups. Changes in spleen weight relative to body weight revealed no statistically significant changes. An analysis of the frequency was performed on the results of macroscopic observation of the gastric mucosa.Results The gastric mucosa revealed lesions in all manipulated groups, being more frequent in groups III and IV. It appears that there is a synergism when using hydrogen peroxide and 50% ethanol in the same group.Conclusion Therefore, it seems that there are some signs of toxicity 3 to 4 days after administration of 6% hydrogen peroxide. The prescription of these therapies must be controlled by the clinician and the risks must be minimized.

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Objective - To evaluate the effect of calcium hydroxide premedication on the apical seal of White MTA, placed as an apical barrier in permanent teeth with simulated immature apices. Furthermore, we intended to compare potential changes, under the influence of calcium hydroxide, in the apical seal of MTA over time. Methods - Thirty-four single-rooted extracted teeth were prepared in order to simulate a divergent open apex. Two experimental groups of 10 teeth were created: group 1 (G1) and group 2 (G2) with and without calcium hydroxide intracanal medication previous to the placement of MTA apical plug. Two control groups, positive and negative, each with 7 teeth were created. On the 7th and on the 28th day after placement of the MTA apical plug, the apices of the teeth were submersed in a solution of sodium pertechnetate (99mTcO4Na) for 3 hours. The radioactivity was measured using a gamma camera. Results - Results revealed statistically significant differences between the 2 control groups and the 2 experimental groups with respect to the microleakage. Within the experimental groups no statistically significant differences were found; nor between the two observed periods. Conclusion - Based on the results obtained in this study, it was concluded that intracanal medication with calcium hydroxide did not affect the sealing ability of WMTA, placed as an apical plug, neither on the 7th, nor on the 28th day.

Objetivo - Avaliar o efeito do hidróxido de cálcio como medicação intracanal, no selamento apical do MTA branco, colocado como uma barreira apical em dentes permanentes com ápices imaturos simulados. Métodos - Trinta e quatro dentes unirradiculares extraídos foram preparados para simular um ápice aberto divergente. Foram separados em dois grupos experimentais (n=10): G1 e G2 com e sem medicação intracanal de hidróxido de cálcio antes da colocação do tampão apical com o MTA e dois grupos controle, positivos e negativos (n=7 em cada). Em 7 e 28 dias após a colocação do tampão apical de MTA, os ápices dos espécimes foram submersos em uma solução de pertecnetato de sódio (99mTcO4Na) por 3 horas. A radioatividade foi medida usando uma câmara gama. Resultados - Os resultados revelaram diferenças estatisticamente significativas entre os grupos controle e os grupos experimentais com relação a microinfiltração. Não houve diferença entre os grupos experimentais nos dois períodos. Conclusão - Com base nos resultados obtidos neste estudo, concluiu-se que a medicação intracanal com hidróxido de cálcio não influenciou na capacidade seladora do MTA.

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Objetivo: o objetivo desse trabalho foi comparar, qualitativa e quantitativamente, a presença de matéria orgânica em limas endodônticas depois de utilizadas, descontaminadas e esterilizadas. Métodos: foram usadas 30 limas tipo K #30, das quais 5 serviram como grupo controle positivo e 5 como negativo. Instrumentaram-se 10 molares suínos pela técnica Crown-Down, inserindo uma lima por canal num total de 25 limas. As limas do grupo 1 (n=10) foram esterilizadas em autoclave. As limas do grupo 2 (n=10) foram colocadas em banho de ultrassom com solução enzimática e posteriormente esterilizadas em autoclave. As do grupo 3 (n=5) foram utilizadas, mas não foram esterilizadas; e as do grupo 4(n=5) não foram utilizadas nem esterilizadas. As limas experimentais e de controle foram posteriormente coradas com solução de Van Gieson, observadas ao microscópio óptico e atribuído um valor representativo da quantidade de matéria orgânica ainda existente na lima, de acordo com uma escala previamente estabelecida. Essa quantificação foi realizada nos terços apical, médio e cervical da parte ativa de cada lima, e foram elaboradas tabelas comparativas entre os diferentes grupos. Resultados:os resultados demonstraram que ambos os grupos experimentais apresentaram resultados significativamente inferiores aos das limas do grupo controle positivo.Conclusão: comparando-se os grupos experimentais,as limas imersas em banho de ultrassom com solução enzimática apresentaram valores inferiores aos daquelas que não foram submetidas a esse procedimento.

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