Effectiveness of glass-ionomer surface protection treatments: a scanning optical microscope study

Due to their complex setting reaction, glass-ionomer cements require careful control of hydration during the initial 48-hour maturation period. This in vitro study was designed to evaluate the efficacy of three surface protection treatments (copal varnish, unfilled bonding resin and a dentine bonding agent) in preventing water penetration into 40 restorations placed in recently extracted third molars. The sealing ability was analysed using confocal light microscopy to visualise dye penetration into the samples. The results indicate that the dentine bonding agent, in vitro, provides a comprehensive barrier to water movement.