[Effectivity of ultrasonics by the root canal instrumentation].

The investigative results showed that preparation of root canals is more effective with ultrasonic as compared to hand instrumentation. Areas like diverticula, canal enlargements or side canals were seen to be extremely clean. This is probably due to the effect of cavitation, implosion of small bubbles, the acceleration of minute particles and the formation of ultra sonic waves. The REM investigation showed no residual bacteria. The hand instrumented canals showed pulp remainders in the canal.