AVALIAÇÃO DO pH DE AGENTES CLAREADORES
Palavras-chave:
Concentração de Íons de Hidrogênio, Peróxido de carbamida, Agente ClareadorResumo
O objetivo deste estudo foi avaliar o pH de agentes clareadores a base de carbamida a 10% e 16% disponíveis comercialmente Whiteness Standard (FCM), Review (SSWhite) e Whiteness Perfect (FCM) e manipulados em farmácia de manipulação. A analise do pH foi conduzida utilizando um pHmetro Micronal B474, calibrado em 4,00 e 7,00 com soluçao tampao acido cítrico l hidrogênio fosfato de sódio, empregando-se soluçao RCl 3 mol L-¹. Três gramas de cada amostra foram depositadas em tubo de ensaio recobrindo todo bulbo do eletrodo. O processo foi repetido 8 vezes para cada agente clareador. O eletrodo era lavado entre cada amostra usando água corrente e acido acético a 4% para remoção completa do agente clareador. O eletrodo foi lavado com água destilada, seco com papel absorvente e a calibração conferida. Aguardava-se 3 minutos para cada leitura, em temperatura ambiente de 34±1ºC. O pH dos produtos clareadores variou de 4,060 (agente manipulado 10%) a 6,313 (Whiteness Standard 10%). Para os agentes clareadores comerciais a 10 e 16%, o pH variou de 6,079 a 6,313 e de 5,774 a 6,040, respectivamente e para os agentes clareadores manipulados a 10 e 16%, de 4,060 e 5,006, respectivamente. ANOVA de dois fatores e teste de Tukey (pF0,05) mostraram haver diferença significativa entre os produtos e as diferentes concentrações. Conclui-se que nenhum dos agentes clareadores avaliados apresentou pH neutro; os menores pHs foram encontrados para os agentes clareadores manipulados; os agentes clareadores com concentração de 10% de peróxido de carbamida apresentaram pH mais alto do que o mesmo produto na concentração de 16%.
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