Effects of APF gel on the physical structure of compomers and glass ionomer cements

This study assessed the effect of an acidulated phosphate fluoride (APF) ge l on the surfaces of eight modern esthetic restorative materials, Five spec imens each of three high powder: liquid ratio conventional glass ionomer ce ments (ChemFlex, Fuji M GP, Ionofil Molar), four polyacid-modified resin co mposites (compomers) (Compoglass F, Dyract AP, Freedom, F2000) and an alkal ine glass filled resin composite (Ariston pHc) were prepared and immersed a t 37 degreesC in 2 mt of artificial saliva for six weeks, The aged specimen s were then coated with 1.23% APF gel for four minutes, rinsed and again im mersed in artificial saliva for another six weeks, The immersed, fresh spec imens for each material were then examined with SEM and surface profilometr y, After APF gel application, mean surface roughness (R-a) measurements and SEMs showed that roughness increased significantly, generally from the res in composite and compomers to the conventional glass ionomer cements (p <0. 05).