After five minutes of curing, the change in the organic matrix of the resin composite using silorane has a positive effect on controlling the cumulative cuspal deflection. SUMMARYObjective: To investigate the effect of using two resin-composite materials for restoring conservative mesio-occluso-distal (MOD) cavities on the changes (incremental and cumulative) in cuspal deflection.Methods: Forty extracted sound human maxillary second premolars were subjected to standardized MOD cavity preparation and then divided into two groups (n=20).