Surface roughness and weight loss of esthetic restorative materials related to fluoride release and uptake

The objective of this study was to assess the surface roughness of eight esthetic restorative materials and the relationship with weight changes during fluoride release and uptake. Five specimens each of ChemFil Superior, Fuji IX Dyract, Fuji II LC, Vitremer, Photac-Fil, Ketac-Silver, and Z100 (control) were prepared and immersed in 2 ml of artificial saliva at 37 degrees C. The changes in specimen weight and fluoride release were monitored for 12 weeks. This protocol was repeated after recharging the specimens with 1.23% APF gel for 12 more weeks. The immersed and fresh specimens for each material were then examined with SEM and surface profilometry. There was a significant weight loss for all glass ionomer cements following APF gel application (P < 0.01), which correlated with fluoride release (r = 0.89-0.98). Mean roughness (Ra) measurements and SEM showed that roughness increased from the resin composite to the conventional glass ionomer cements. The marked erosive effect of APF gel on glass ionomer restorations could increase surface colonization by plaque micro-organisms, and reduce the longevity of the restorations.