ABSTRACT
OBJECTIVE@#To analyze the effect of ceramic onlay to repair serious defects in young permanent molars.@*METHODS@#Sixty patients with defects in young permanent molars were selected. The patients were randomly divided into two groups. One group was restored with ceramic onlay, and the other used resin composite to direct filling. Follow-up visit was conducted at 3, 6, 12, and 24 months after treatment. Modified USPHS/Ryge criteria were used to evaluate the effect of restoration. The occlusal courses were recorded by the T-Scan Ⅲ system in intercuspal position. Gingival and food impaction were recorded. The effect of the two restorative methods, the recovery of occlusal function, and the gingival and approximal conditions were analyzed.@*RESULTS@#At 12 months after restoration, the marginal fitness in the onlay group was significantly better than that in the resin group (P0.05). The gingival and approximal conditions also demon-strated no stati-stical differences (P>0.05).@*CONCLUSIONS@#The ceramic onlay repair method is better than resin composite filling in marginal fitness, surface smoothness, and recovery of the occlusal function when restoring young permanent molars with serious defects.