Ionomeric materials release different proportions of fluoride and aluminum. Their simultaneous effect on the acidogenicity and composition of S. mutans biofilm is unknown. Six cylindrical specimens of each material (Ketac-fil, Vitremer, Fuji-Ortho LC, F-2000, and Z-100) were incubated with S. mutans GS-5 in culture media containing 5% sucrose (w/v). The media were changed daily for seven days, during which the pH and concentrations of fluoride and aluminum were determined. Furthermore, the concentrations of these ions and insoluble polysaccharide were determined in the biofilm formed at the end of the experimental period. The results showed that all the materials tested released fluoride. However, Vitremer released the highest amount of aluminum and was the most effective in reducing the acidogenicity of S. mutans biofilms. It also significantly affected both biofilm formation and composition. Thus, this study suggests that aluminum released by ionomeric materials may enhance the biological effects of fluoride.824267271Barkhordar, R.A., Kempler, D., Pelzner, R.R., Stark, M.M., Technical note: Antimicrobial action of glass-ionomer lining cement on S. sanguis and S. mutans (1989) Dent Mater, 5, pp. 281-282Benderli, Y., Ulukapi, H., Balkanti, O., Kulekci, G., In vitro plaque formation on some dental filling materials (1997) J Oral Rehabil, 24, pp. 80-83Benelli, E.M., Serra, M.C., Rodrigues Jr., A.L., Cury, J.A., In situ anticariogenic potential of glass ionomer cement (1993) Caries Res, 27, pp. 280-284Carvalho, A.S., Cury, J.A., Fluoride release from some dental materials in different solutions (1999) Oper Dent, 24, pp. 14-19Cury, J.A., Rebello, M.A., Del Bel Cury, A.A., In situ relationship between sucrose exposure and the composition of dental plaque (1997) Caries Res, 31, pp. 356-360Cury, J.A., Rebelo, M.A., Del Bel Cury, A.A., Derbyshire, M.T., Tabchoury, C.P., Biochemical composition and cariogenicity of dental plaque formed in the presence of sucrose or glucose and fructose (2000) Caries Res, 34, pp. 491-497Forss, H., Release of fluoride and other elements from light-cured glass ionomer in neutral and acidic conditions (1993) J Dent Res, 72, pp. 1257-1262Hamilton, I.R., Biochemical effects of fluoride on oral bacteria (1990) J Dent Res, 69 (SPEC. ISSUE), pp. 660-667Herrera, M., Castillo, A., Bravo, M., Liebana, J., Carrión, P., Antibacterial activity of resin adhesives, glass ionomer and resin-modified glass ionomer cements and a compomer in contact with dentin caries samples (2000) Oper Dent, 25, pp. 265-269Koo, H., Rosalen, P.L., Cury, J.A., Park, Y.K., Bowen, W.H., Effects of compounds found in propolis on Streptococcus mutans growth and on glucosyltransferase activity (2002) Antimicrob Agents Chemother, 46, pp. 1302-1309Lunardi, J., Dupuis, A., Garin, J., Issartel, J.P., Michel, L., Chabre, M., Inhibition of H +-transporting ATPase by formation of a tight nucleoside diphosphate-fluoroaluminate complex at the catalytic site (1988) Proc Natl Acad Sci USA, 85, pp. 8958-8962Nakajima, H., Komatsu, H., Okabe, T., Aluminum ions in analysis of released fluoride from glass ionomers (1997) J Dent, 25, pp. 137-144Nobre Dos Santos, M., Melo Dos Santos, L., Francisco, S.B., Cury, J.A., Relationship among dental plaque composition, daily sugar exposure and caries in primary dentition (2002) Caries Res, 36, pp. 347-352Oppermann, R.V., Rölla, G., Effect of some polyvalent cations on the acidogenicity of dental plaque in vivo (1980) Caries Res, 14, pp. 422-427Savarino, L., Cervellati, M., Stea, S., Cavedagna, D., Donati, M.E., Pizzoferrato, A., In vitro investigation of aluminum and fluoride release from compomers, conventional and resin-modified glass-ionomer cements: A standardized approach (2000) J Biomater Sci Polym Ed, 11, pp. 289-300Scherer, W., Lippman, N., Kaim, J., Antimicrobial properties of glass-ionomer cements and other restorative materials (1989) Oper Dent, 14, pp. 77-81Schilling, K.M., Bowen, W.H., Glucans synthesized in situ in experimental salivary pellicle function as specific binding sites for Streptococcus mutans (1992) Infect Immun, 60, pp. 284-295Seppä, L., Torppa-Saarinen, E., Luoma, H., Effect of different glass ionomers on the acid production and electrolyte metabolism of Streptococcus mutans Ingbritt (1992) Caries Res, 26, pp. 434-438Seppä, L., Forss, H., Ogaard, B., The effect of fluoride application on fluoride release and the antibacterial action of glass ionomers (1993) J Dent Res, 72, pp. 1310-1314Seppä, L., Korhonen, A., Nuutinen, A., Inhibitory effect on S. mutans by fluoride-treated conventional and resin-reinforced glass ionomer cements (1995) Eur J Oral Sci, 103, pp. 183-185Sturr, M.G., Marquis, R.E., Inhibition of proton-translocating ATPases of Streptococcus mutans and Lactobacillus casei by fluoride and aluminum (1990) Arch Microbiol, 155, pp. 22-27Wilson, A.D., McLean, J.W., (1988) Glass-ionomer Cement, , Chicago: Quintessence Publishing CoWunder, D., Bowen, W.H., Action of agents on glucosyltransferases from Streptococcus mutans in solution and adsorbed to experimental pellicle (1999) Arch Oral Biol, 44, pp. 203-214Yap, A.U., Khor, E., Foo, S.H., Fluoride release and antibacterial properties of new-generation tooth-colored restoratives (1999) Oper Dent, 24, pp. 297-305