[Application of an air-powder abrasive system in periodontal therapy and its effect on root surfaces].

An air-powder abrasive device used to remove stain and debris adherent to tooth surface is now available for use by dentist. Air Flow was evaluated for its effectiveness in removing stains and debris from teeth. Split design in anterior was used, and half was treated with the device and the contralateral side with a brush cone and tooth polishing paste. Time required by each method to remove stain and debris completely was recorded and compared. A gingival trauma index was assessed according to the method of Weaks L.M. et al. (1984). Air-powder abrasive system removed stain and debris in less time than brush cone technique (P less than 0.001). The system was also most effective in removing stains in pit, fissure and contact areas. The device caused a significant increase (P less than 0.01) in gingival irritation immediately posttreatment, but there was no statistically and clinically significance in the effect on the gingiva at 7 days posttreatment between two techniques. In vitro study, the effect of the device on root surfaces was also assessed. 5, 10, 20, 40 and 60 seconds exposure of a fixed point on root surfaces to the device produced defects 137, 245, 308, 945 and 1,394 microns in depth, respectively. The resulting surface was smooth and all cementum was removed. And the average loss of root structure as a function of the exposure time was also assessed. The average losses were 0.2, 0.6, 1.7, 1.8, 2.0, 2.1, 2.3 and 2.4 mg by 5, 10, 15, 20, 30, 40, 50 and 60 seconds exposures, respectively. Root surface roughness, resulting from hand curette, ultrasonic curette and air-powder abrasive system was examined histologically. The hand curette produced smooth root surface. The ultrasonic instrument produced a surface characterized by irregular ridges. The air powder abrasive system was found to produce a root surface favorably comparable to manual root planing and remove cementum from areas of difficult treatment, such as furcations.