Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Original Paper Caries Res 2010;44:135–140 DOI: 10.1159/000302902 Effect of Different Fluoride Concentrations of Experimental Dentifrices on Enamel Erosion and Abrasion M.J. Moretto   a A.C. Magalhães   c K.T. Sassaki   b A.C.B. Delbem   a C.C.R. Martinhon   a   Departments of a  Pediatric Dentistry and b  Basic Science, Unesp – Universidade Estadual Paulista, Araçatuba, and c  Department of Biological Science, Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil using a 2-way ANOVA test followed by a Bonferroni correc- tion (p ! 0.05). In in vitro conditions, the 5,000 g F/g and 500 g F/g plus 3% TMP dentifrices had a greater protective ef- fect when compared with the 1,100 g F/g dentifrice, under both ERO and ERO + ABR conditions. The results suggest that dentifrices alone are not capable of completely inhibiting tooth wear. Copyright © 2010 S. Karger AG, Basel Dental erosion is defined as the loss of tooth substance due to chemical processes (acid exposure) not involving bacteria [Amaechi and Higham, 2005; Wiegand et al., 2007]. Erosive lesions have a multifactorial etiology in which the extrinsic (mainly dietary) and/or intrinsic (gastric) acid exposures are related [Imfeld, 1996]. Nowa- days, the extrinsic factor is gaining importance due to an increase in the consumption of acid drinks, such as car- bonated beverages, sports drinks, iced teas and fruit juic- es [Lussi et al., 2004]. The acidic attack leads to an irreversible loss of dental hard tissue, which is accompanied by a progressive soft- ening of the surface [Amaechi and Higham, 2001]. This softened zone is more susceptible to mechanical forces such as abrasion [Attin et al., 2001; Rios et al., 2006]. Key Words Dental enamel, abrasion  Dental enamel, erosion  Dentifrice, fluoride  Trimetaphosphate Abstract It has been suggested that fluoride products are able to re- duce erosive tooth wear. Thus, the purpose of this in vitro study was to evaluate the effect of dentifrices with different fluoride concentrations as well as of a low-fluoridated denti- frice supplemented with trimetaphosphate (TMP) on enam- el erosion and abrasion. One hundred twenty bovine enam- el blocks were assigned to the following experimental den- tifrices: placebo, 1,100 g F/g, 500 g F/g plus 3% TMP and 5,000 g F/g. The groups of enamel blocks were additionally subdivided into conditions of erosion (ERO) and of erosion plus abrasion (ERO + ABR). For 7 days, the blocks were sub- jected to erosive challenges (immersion in Sprite  4 times a day for 5 min each time) followed by a remineralizing period (immersion in artificial saliva between erosive challenges for 2 h). After each erosive challenge, the blocks were exposed to slurries of the dentifrices (10 ml/sample for 15 s). Sixty of the blocks were additionally abraded by brushing using an electric toothbrush (15 s). The alterations of the enamel were quantified using the Knoop hardness test and profilometry (measurements in micrometers). The data were analyzed Received: September 9, 2009 Accepted after revision: January 27, 2010 Published online: April 2, 2010 Cleide Cristina Rodrigues Martinhon Unesp – Universidade Estadual Paulista Department of Pediatric Dentistry, Rua José Bonifácio 1193 Araçatuba, SP 16015-050 (Brazil) Tel. +55 18 3636 3235, Fax +55 18 3636 3332, E-Mail cleidecristina  @  foa.unesp.br © 2010 S. Karger AG, Basel 0008–6568/10/0442–0135$26.00/0 Accessible online at: www.karger.com/cre