An in vitro evaluation of the irrigating characteristics of ultrasonic and subsonic handpieces and irrigating needles and probes.

The objective of this in vitro study was to evaluate the efficacy of a variety of endodontic irrigating devices. This study utilized plastic blocks with artificial canals to simulate the clinical setting. The canals were instrumented, and red food dye was introduced into each canal. The blocks were placed in a jig to simulate maxillary and mandibular arch orientation. Irrigation was performed with: (a) B-D 22-gauge needle; (b) Monoject Endodontic Needle 23 and 27 gauge; (c) Max-i-Probe 25-, 28-, and 30-gauge probes; (d) Cavi-Endo ultrasonic handpiece; and (e) Micromega 1500 subsonic handpiece. A Sony Camcorder was used to record the effect of irrigation on the simulated canal contents. Tape review enabled the investigators to observe dye clearance effected by each modality. The Max-i-Probe probes were the most effective instrument used to clear dye from the simulated canals in both the mandibular and maxillary positions.