April 2011 - Vol.5 139 European Journal of Dentistry AbstrAct Objectives: To evaluate the fluoride ion concentration in some fermented milks present in the market. Methods: Three brands of 6 fermented milks (Parmalat®-uva, Chamyto®, Paulista®, Batavito®, Yakult®, Vigor Club®) were analyzed. Fluoride concentration was evaluated after facilitated micro- diffusion by HDMS. Results: Parmalat® products ranged from 0.022 μgF/g to 0.031 μgF/g, Chamyto® from 0.228 μgF/g to 0.272 μgF/g, Paulista® from 0.182 μgF/g to 0.220 μgF/g, Batavito® from 0.028 μgF/g to 0.030 μgF/g, Yakult® from 0.115 μgF/g to 0.206 μgF/g and Vigor Club® from 0.808 μgF/g to 1.171 μgF/g. Conclusions: The presence of fluoride could be observed in all of the fermented milks analyzed which can contribute with the total fluoride daily intake. (Eur J Dent 2011;5:139-142) Key words: Fluoride; Dental fluorosis; Milk–fermentation; Children. Carolina Simonetti Lodia Michele Maurício Manarelia Kikue Takebayashi Sassakib Alberto Carlos Botazzo Delbema Cleide Cristina Rodrigues Martinhona Fluoride Concentration of Some Brands of Fermented Milks Available in the Market a Department of Pediatric Dentistry, Araçatuba School of Dentistry, Paulista State University (UNESP), São Paulo, Brazil. b Department of Basic Sciences, Araçatuba School of Dentistry, Paulista State University (UNESP), São Paulo, Brazil. Corresponding author: Carolina Simonetti Lodi Department of Pediatric Dentistry, Araçatuba School of Dentistry, Paulista State University (UNESP) Rua José Bonifácio, 1193 16015-050-Araçatuba, São Paulo, Brazil. Phone: +55 18 3636 3235 E-mail: carol_lodi@yahoo.com.br The role of fluoride in dental caries prevention is well established. However, ingestion of exces- sive fluoride during tooth development can cause dental fluorosis.1 Dental fluorosis is a deficiency in enamel min- eralisation due to excessive daily fluoride intake during tooth development and its severity is di- rectly related to the absorbed dose of this ion. Since the dose-effect relationship is not precisely known, the dose of 0.07 mg F/day/kg of body weight IntroductIon European Journal of Dentistry 140 has been accepted as the upper limit in terms of the clinically acceptable risk of dental fluorosis.2 The main sources of fluoride intake are fluo- ridated water, powdered milk reconstituted with fluoridated water, inadvertent ingestion of fluo- ridated toothpaste, inappropriate use of dietary supplements, as well as foods and beverages pro- cessed with fluoridated water.3-5 During infancy and childhood (36-48 months), the fluoride intake in diet deserves special atten- tion. This period coincides with the calcification of different stages of the developing permanent teeth crowns. This is also a critical time for ensur- ing that the optimal levels of ingested fluoride are not exceeded.3 Several previous studies have determined the fluoride content of children’s foods, such as milk,6,7 dinners and desserts8-11 and beverages.5,12,13 How- ever, the fluoride concentration in many child ad- dressed products remains unknown. Thus, the aim of this study was to evaluate the fluoride ion concentration in some fermented milks present in the market. MAtErIALs And MEtHods Three lots of six different brands of ferment- ed milks, with 80 g each bottle, were analyzed: Parmalat®-uva, Chamyto®, Paulista®, Batavi- to®, Yakult®, Vigor Club®. The products were opened on the day of the analysis and 2 mL of each fermented milk was used in this experiment. Fluoride concentrations were determined after overnight hexamethyldisi- loxane (HMDS)-facilitated diffusion14 as modified by Whitford, using a fluoride ion-specific electrode (model 9409, Thermo Electron Corporation, Bev- erly, MA, USA) and a miniature calomel reference electrode (Accumet, #13-620-79: Fischer Scientif- ic, Pittsburgh, PN, USA), coupled to a potentiom- eter (290A, Orion Research Inc., Boston, MA, EUA). During the diffusion process, which was con- ducted at room temperature, the solutions in the nonwetable Petri dishes (J.Prolab Ind. e comércio de produtos para laboratório LTDA., São José dos Pinhais, PR, Brazil) were gently swirled on a rota- ry shaker. Fluoride standards (0.4, 0.8, 1.6, 3.2 and 6.4 μgF/mL) were prepared by serial dilution of a stock-standard containing 100 μgF/mL of fluoride (Orion 940907 – Thermo Orion, Beverly, MA, USA) in triplicate and diffused in the same manner as the samples. Comparison with identical non-dif- fused fluoride standards showed that recovery af- ter diffusion was > 99%. The standard curve had a correlation coefficient 0.99. All samples were ana- lyzed in duplicate. The mean repeatability of the fluoride readings, based on the duplicate samples was 94.9%. rEsuLts Fluoride concentrations (μgF/g) in the differ- ent brands of fermented milk analyzed are shown in the Table 1. The fluoride concentration in the fermented milk of Parmalat® ranged from 0.022 μgF/g to 0.031 μgF/g, Nestlé® from 0.228 μgF/g to 0.272 μgF/g, Paulista® from 0.182 μgF/g to 0.220 μgF/g, Batavo® from 0.028 μgF/g to 0.030 μgF/g, Yakult® from 0.115 μgF/g to 0.206 μgF/g and Vig- or® from 0.808 μgF/g to 1.171 μgF/g. dIscussIon It is important to know all sources of fluoride ingestion that contribute to the total intake once the dental fluorosis is systemic caused by the excessive fluoride ingestion. Although the exact relationship between the consumption of industri- alized beverages and dental fluorosis is not clear their ingestion contribute for the total fluoride in- take specially the high fluoride content products, which never always highlight its content in the la- bels. Many studies have demonstrated that it is nec- essary to know the fluoride concentration of infant foods, foodstuffs and beverages to estimate the total fluoride ingestion by children.8,12,15 Although the total fluorine intake from the diet is difficult to be precisely determined, it is clear that there is substantial variation on the intake of different foods, foodstuffs and beverages, and in the fluoride content of these products. Since products are not required to have their fluoride content displayed, only a fluoride assay is possible to determine the dietary fluoride intake.3 All of the fermented milks analyzed in this study presented varied concentra- tions of fluoride, although none of the packages indicated that information. The optimal level of systemic fluoride intake where it is believed to be active against caries and is not related to the development of dental fluoro- sis is not accurately known. Using rough estima- tive of the types and quantities of foods and drinks Fluoride concentration of fermented milks April 2011 - Vol.5 141 European Journal of Dentistry ingested and a technique less sensitive than the fluoride electrode to measure levels of fluoride, McClure16 estimated that the 'average daily diet' provided no more than 0.05 to 0.07 mg fluoride/ kg body weight/day and that it did not exceed 0.10 mg fluoride/kg body weight/day for children aged 1 to 12 years. This figure has been extrapolated by some to be the 'optimal' level of intake,9,17 while others2,18 have considered it to be the 'threshold' level of intake beyond which dental fluorosis may occur. In this study, most of the fermented milks ana- lyzed presented low concentrations of fluoride, less than 0.3 μgF/g. However, the products of the brand Vigor® showed higher fluoride concentra- tion ranged from 0.808 μgF/g to 1.171 μgF/g. Con- sidering that the ‘optimal’ level of fluoride intake ranges from 0.05 to 0.07 mgF/Kg body weight, those analyzed products can contribute signifi- cantly to the total ingestion of fluoride increasing the risk of the dental fluorosis development. In this sense, the consumption of 80 g of a fermented milk containing 1.171 μgF/g a day can contribute with about 0.008 mgF/Kg body weight for a child weighing 12 Kg (approximately 2 years old). It is worth emphasizing that this dose (0.008 mgF/Kg) would be reached with the ingestion of only this beverage, without considering the other foods and beverages consumed during the day. Several reports have been showed high fluoride concen- trations in foods typically consumed by children, such as powdered milks, ready-to-drink juices and chocolate milks, cereals and snacks.3,5,6,19,20,21 The variation in fluoride concentrations among the lots is another issue that should be observed. In the present study, the lots of different brands presented variations ranged 16% to 44%. In the brand Yakult®, it was observed the largest dif- ference among the analyzed lots. For beverages with low fluoride concentrations, these variations may have little impact on total fluoride intake. However, for products with high fluoride levels, such as the lot 2 of the brand Vigor®, this varia- tion can contribute significantly for the total intake of this ion. On the other hand, the bioavailability of milk is another point to be considered. Due to Manufacturer Brand Production site Lot Mean Bottle total fluoride SD* Parmalat Fermented Milk skimmed sweeten - grape Carambeí-PR T3 0.031 2.48 0.0043 M1 0.029 2.32 0.0038 N1 0.022 1.76 0.0012 Nestlé Fermented Milk skimmed sweeten Chamyto- vanilla Araras–SP 7078132315 0.228 18.24 0.0007 7071132315 0.272 21.76 0.0114 7068132312 0.238 19.04 0.0057 Paulista Fermented Milk skimmed sweeten - vanilla Poços de Caldas-MG L 13:03 S3 0.185 14.80 0.0254 L 15:48 S3 0.220 17.60 0.0046 L04:52 S3 0.182 14.56 0.0060 Batavo Fermented Milk skimmed sweeten Batavito - orange and citric fruits Carambeí-PR L094 0.030 2.40 0.0029 L103 0.030 2.40 0.0007 L063 0.028 2.24 0.0022 Yakult Fermented Milk skimmed sweeten Yakult São Paulo-SP 57 0.115 9.20 0.0024 26 0.122 9.76 0.0040 90 0.206 16.48 0.0089 Vigor Fermented Milk skimmed sweeten Vigor Club - vanilla Lorena-SP 3 0.808 64.64 0.0300 2 1.171 93.68 0.0980 4 0.894 71.52 0.0294 Table 1. Fluoride concentration (μg/g) of the three lots in the different brands of fermented milk. *: Standard Deviation Lodi, Manareli, Sassaki, Delbem, Martinhon European Journal of Dentistry 142 the high calcium concentrations in milk, there is a possibility of diminution of fluoride absorption from gastro-intestinal tract.22,23 Thus, the calcula- tions made for these products could be overesti- mated. Milk is also rich in fats, what are known to increase the lag time of the food or beverage in the stomach.23 Although milk interferes with the rate of fluoride absorption, it was demonstrated that 67 to 82% of total fluoride in milk is absorbed.24 Another crucial factor when the association between fluorosis and infant foods is the critical period of fluoride exposure to develop fluorosis. Enamel fluorosis can occur following acute or chronic exposure to fluoride during tooth forma- tion assuming a significant relevance and em- phasizing the importance of monitoring fluoride intake by little children. concLusIons In this study the presence of fluoride could be observed in all of the fermented milks analyzed which can contribute with the total fluoride daily intake. rEFErEncEs 1. Aoba T, Fejerskov O. Dental fluorosis: chemistry and biol- ogy. Crit Rev Oral Biol Med 2002;13:155-170. 2. Burt BA. The changing patterns of systemic fluoride intake. J Dent Res 1992;71:1228-1237. 3. Buzalaf MAR, Granjeiro JM, Cardoso VE da S, Silva TL da, Olympio KPK. Fluorine content of several brands of choco- late bars and chocolate cookies found in Brazil. Pesqui Odontol Bras 2003;7:223-227. 4. Buzalaf MAR, Whitford GM, Cury JA. Fluoride exposures and dental fluorosis: a literature review. Rev Fac Odontol Bauru 2001;9:1-10. 5. Lodi CS, Ramires I, Pessan JP, Neves LT das, Buzalaf MAR. 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