Determination of rpm, time, and load used in oral prophylaxis polishing in vivo.

Clinically relevant values for revolutions per minute (rpm), time, and load should be used when one evaluates effects of abrasive slurries on teeth. However, in the past, these variables have not been measured in vivo to determine clinical means. This study describes an instrument and computer software which monitored rpm, time, and load used by 29 clinicians during routine oral prophylaxes performed on 76 patients. Grand means and standard deviations determined for the three variables were: rpm, mean = 2571 (s = 739): time per tooth surface, mean = 4.5 sec (s = 2.9); and load, mean = 145 g (s = 66). Mean rpm, time, and load used on facial and lingual surfaces of the 32 teeth were also determined. Statistical tests showed that rpm was not altered significantly by tooth location, surface, or type and amount of deposit, but time was affected significantly by tooth location, surface, and amount of calculus; load was affected by tooth location, surface, and amount and intensity of stain.