If the direct composite restorations your patients have were placed by the dentist you work with, it would be best to find out the brand of direct composite that he/she is using. Manufacturers of composite restorative materials include in their package information specific instructions as to how they recommend that particular brand of composite be polished. If those directions are available, it is best to follow them. For direct composites that do not have package information on product(s) to use for polishing, you should be use the least abrasive agent possible. If there is no stain on the composite, a cleaning agent is ideal, as it contains no abrasives that will leave irregular scratches or grooves that will corrupt the surface characterization of the direct composite material. Another polishing agent is made specifically for dental hygienists to use on esthetic restorations. It is formulated so that it does not leave scratches or grooves in the composite surface.
To be clear, direct composites are polished by the dentist upon completion. The dentist may use polishing disks or a polishing agent that comes with the direct composite material. This is not the same polishing that is typically performed by dental hygienists who are treating patients at initial or maintenance appointments.