Effects of finishing/polishing time on surface characteristics of tooth-coloured restoratives

This study compared the effects of immediate and delayed finishing/polishing procedures on the surface characteristics (surface roughness and hardness) of tooth-coloured restoratives including a microfilled, a heavily filled and a polyacid-modified composite resin and a resin-modified glass-ionomer cement. Eighty-four specimen discs were made for each material; the first 12 were used as controls and the remaining 72 specimens were randomly divided into two equal groups. The first group was finished/polished immediately after light polymerization and stored for 1 week in distilled water at 37 degrees C while the second group was finished/polished after 1 week storage in distilled water at 37 degrees C. Finishing and polishing was carried out using the following systems: Enhance(R) system, white stones with Vaseline(R) and Super-snap(R) disks system. The finished/polished surfaces were subjected to profilometric evaluation and microhardness testing. The effects of delayed finishing/polishing procedures on surface roughness and hardness appear to be both material and technique dependent. Delayed finishing/polishing of polyacid-modified composite resins and resin-modified glass-ionomer cements generally resulted in a smoother surface. The surface roughness of composite resins after finishing/polishing procedures were generally not influenced by the finishing/polishing time. For all materials, delayed finishing/polishing viith the various techniques generally resulted in a surface of similar hardness to or harder than that obtained with immediate finishing/polishing and the control group.