Fluoride stability in dentifrices stored in schools in a town of northern Brazil

Abstract

The aim of this study was to analyze fluoride stability in dentifrices stored during nine months in schools from Careiro da Várzea, State of Amazonas, Brazil. Analysis of total fluoride concentration, total soluble fluoride, and ionic fluoride in the dentifrice samples was performed in four different time periods: at the time of purchase (baseline); after three months, after six months, and after nine months of storage. Fluoride concentration was determined using a specific electrode (Orion 96-09) connected to an ion analyzer (Orion A-720) and calibrated with fluoride standard solutions containing 2.0 to 32.0 ppm F. The results obtained during the measurements were analyzed by analysis of variance (one-way ANOVA), followed by Tukey's test for comparison of the means. After nine months of storage, total soluble fluoride, the active form of fluoride, decreased by 21.9%. As total soluble fluoride was below the minimum required for anticaries efficacy (1,000 ppm F) in the fourth analysis, it may be concluded that anticaries potential decreased with storage time.

Availability and stability of soluble fluoride content in commercial fluoride dentifrices available in Uruguay

“…In most toothpastes analyzed in the present study, the TF concentration of fresh and aged samples did not vary. It is expected that the TF concentration should remain stable after one year, although there may be variations in the other fluoride forms such as TSF, due to its instability [18,19].…”

“…This variation can be explained by the formulation as part of the chemically active F can bind with Ca ions in the abrasive [11]. Although MFP is more compatible with a CaCO 3 or DCPD (dicalcium phosphate dihydrate) abrasive [10,11], later studies showed that part of F can bind with Ca in the abrasive, reducing the amount of soluble F [18][19][20][21]. These decreases occur during product storage due to the release of F ions from the hydrolysis of MFP [18,19].…”

“…Although MFP is more compatible with a CaCO 3 or DCPD (dicalcium phosphate dihydrate) abrasive [10,11], later studies showed that part of F can bind with Ca in the abrasive, reducing the amount of soluble F [18][19][20][21]. These decreases occur during product storage due to the release of F ions from the hydrolysis of MFP [18,19]. Even toothpaste I has a concentration of TF (> 2,000 ppmF) higher than all other dentifrices, only 32.8% of its TF concentration corresponded to TSF and this value was lower than that found to other tested fluoride toothpastes (table 2).…”

Dentifrícios Fluoretados E O Sus-Brasil: O Que Precisa Ser Mudado?

“…Entretanto, a Resolução nº 79 da ANVISA não regulamenta o quanto de fluoreto solúvel um dentifrício deveria conter e manter pelo seu prazo de validade. Diante disso, diversos estudos têm sido publicados na perspectiva de ratificar a necessidade de revisão da norma brasileira sobre dentifrícios fluoretados10,15,17,[23][24][25]31,32 .O relatado nessa discussão não é uma especificidade do Brasil, mas sim um problema mundialsinalizado pela World Dental Federation (FDI)8 . As regulamentações de diversos países do mundo não garantem que um dentifrício tenha uma concentração mínima de fluoreto solúvel para o controle da cárie dentária, como atestado em publicações internacionais11,[33][34][35][36][37][38] .…”