THE USE OF A REINFORCED GLASS-IONOMER CERMET FOR THE RESTORATION OF PRIMARY MOLARS - A CLINICAL-TRIAL

The development of adhesive restorative materials has led to more cons ervative cavity design with greater reliance being placed upon the bon d of a material with tooth tissue for retention of the restoration. Gl ass-ionomer cements may offer particular advantages but have yet to ac hieve the durability reported for amalgam. This study reports on the r esults of a 2.5-year prospective clinical trial comparing the durabili ty of two glass-ionomer cements, a conventional material (Ketac Fil) a nd a metal reinforced cermet (Ketac Silver) in the restoration of Clas s II lesions in primary molars. Forty-six pairs of restorations were a ssessed in 37 children. The failure rate of Ketac Fil, 23%, was signif icantly lower than that of Ketac Silver, 41% (P < 0.05). The median su rvival time of the Ketac Fil restorations was significantly greater, 2 5.3 months, than that of the Ketac Silver restorations, 20.3 months (P < 0.05). These values may be an underestimate of the true longevity o f both restoration types as many of the restorations survived intact a t the censor date. Neither the age of the child nor the tooth restored influenced the durability of the restoration. The deterioration in bo th marginal integrity and anatomic form of the Ketac Silver restoratio ns was significantly greater than the Ketac Fil restorations (P < 0.05 ). The durability of Ketac Silver was such that it cannot be recommend ed for use in restoring carious primary molars.