[Scanning electron microscopic studies on the efficacy of irrigated, hand root canal preparation].

The effectiveness of hand preparation and irrigation of 48 root canals of upper anterior teeth was evaluated by scanning electron microscopy. Independently of instrument (K reamer or combination K reamer and H file), irrigating solution (sodium chloride) and root canal dressing a similar degree of preparing and cleaning effectiveness of root canals was detected. In all groups a homogeneous or inhomogeneous smear layer of different thickness and extent dominated. A scale of preparing and cleaning effectiveness is recommended.