Journal of Oral Rehabilitation 2001 28; 26–32 Fluoride release from glass – ionomer cements, compomers and resin composites G. VERMEERSCH, G. LELOUP & J. VREVEN Department of Operative Dentistry, Dental School, Universite ´ Catholique de Louvain, Brussels, Belgium SUMMARY The short and long-term fluoride release ever, it was impossible to correlate the fluoride release of the materials by their type (conventional of 16 products (seven conventional glass – ionomers, five light-activated glass – ionomers, two polyacid- or resin-modified glass – ionomers, polyacid- modified resin composites and two resin com- modified resin composite and resin composite) ex- posites) commercialized as fluoride-releasing cept if we compared the products from the same manufacturer. The link between fluoride release materials were measured. A potential link between the material type and its level of fluoride release and an acid–base reaction seems to be confirmed. was researched. The fluoride release was evaluated The glass – ionomer composition (glass particles and after different time intervals. Initial fluoride release polyacid’s type, powder/liquid ratio) should have more influence on fluoride release than material from all materials was highest during the first 24 h and decreased sharply over the first week. Some type. groups of materials appeared to be significantly different after, respectively, 7 and 91 days. How- KEYWORDS: compomer, fluoride, glass – ionomer Introduction The ability of a material to inhibit recurrent caries formation is an important clinical property. Glass – ionomer cements (GIC) have been used for more than 20 years and it is well known that a major advantage with this group is their potential caries inhibition (Hicks & Flaitz, 1992; Dunne et al., 1996) due to their release of fluoride (Forsten, 1990; Momoi & McCabe, 1993; Takahashi, Emilson & Birkhed, 1993; Diaz- Arnold et al., 1995; Miller et al., 1995; Tam, Chan & Yim, 1997) and their antibacterial activity (Feather- stone, 1994; Seppa ¨ , Korhonen & Nutinen, 1995; Friedl et al., 1997). However, those conventional glass – ionomer cements should be protected from both mois- ture contamination and dehydration during the early stages of setting to avoid a considerable reduction of physical properties. This led to the development of light-cured or resin-modified glass – ionomer cements, which contained the essential components of both an aqueous glass – ionomer and a light-curable resin. This kind of material combines some advantages of resin composites, longer working time and rapid setting, and some advantages of conventional glass – ionomer, spon- taneous adhesion to dental tissues (Mount, 1994; Sidhu & Watson, 1995; Vargas, Fortin & Swift, 1995) with a substantial fluoride release (Takahashi, Emilson & Birkhed, 1993; Diaz-Arnold et al., 1995; Forsten, 1995; Seppa ¨ et al., 1995; de Araujo et al., 1996; Friedl et al., 1997; Tam, Chan & Yim, 1997). Mitra (1991) reported that the fluoride release from a light-activated glass–ionomer cement was not hindered by the pres- ence of light-activated resin. Momoi & McCabe (1993) confirmed that resin-modified glass – ionomers had a potential for releasing fluoride equivalent to that of conventional cements. At the present time, with a preventive approach to the control of dental caries, manufacturers produce many dental materials which should be able to release fluoride to their environment. These new fluoride-releasing materials belong to the © 2001 Blackwell Science Ltd 26