Deterioration of the keeper surface has decreased retentive force of the magnetic attachment. However, there have been few reports of the restorative retentive force on the roughed surface of using keeper in the oral cavity.
The purpose of this study is to research relevance of the surface condition and retentive force, and to elucidate the used keeper polishing method that can restore of retentive force. The retentive force of extracted coping with attachment keepers were measured in a universals testing machine. Surface roughness and weivness were measured using a laser microscope. At first, the new keeper surface roughed by sandblasting was analyzed. Roughed keepers polished by using silicone point and waterproof abrasive paper after tried to weigh that analyzed surface condition and measured retentive force.
The restoration of retentive force by waterproof abrasive paper was higher than that of silicon point.
In conclusion, waterproof abrasive paper was valid and feasible way to polishing for the keepers have roughed surface.