Occlusal wear of a resin-modified glass ionomer cement following three surface treatments.

Unacceptable occlusal wear has been reported for resin-modified glass ionomer cements (RMGICs) placed in permanent molar teeth. Three different surface treatments of a RMGIC were evaluated over periods of up to 2 years for their effects on restoration wear behaviour: (a) sealing with a thin layer of low viscosity unfilled resin (sealed restoration), (b) sealing with a thicker layer of a lightly-filled pit and fissure sealant (sealant restoration), and (c) co-curing the RMGIC with a posterior resin composite (co-cured restoration). After 2 years the cumulative median (quartiles) wear was for (a) 100 (50-150) microns, (b) 25 (0-50) microns, and (c) 25 (25-38) microns. Although method (b) effectively reduced the surface wear of the RMGIC, this treatment required frequent re-sealing, involving 52% of the restorations. Sealing the surface of a RMGIC placed in permanent molars was not a satisfactory method for reducing occlusal wear. However, co-curing the RMGIC with a posterior resin composite reduced occlusal wear significantly (P < 0.0001), without the need for frequent reapplications of a pit and fissure sealant to the RMGIC.