Comparison of apical extrusion of NaOCl using the EndoVac or needle irrigation of root canals

The purpose of this study is to compare extrusion of irrigants delivered with a 27-G needle or the EndoVac system (Discus Dental, Culver City, CA) during instrumentation and final irrigation of teeth.

Matched paired single canal teeth were divided into four sample groups and controls. The experimental groups were needle irrigation International Standards Organization (ISO) size #40 (N40) and #60 (N60) and EndoVac ISO size #40 (E40) and #60 (E60). Teeth were secured and embedded in 0.2% agarose gel (ph = 7.3-7.4) containing 1 mL 0.1% m-cresol purple, which changes color at a pH of 9.0. Teeth received NaOCl and EDTA irrigation with the 27-G slot needle or the EndoVac system. The amount of irrigation was controlled for each sample. Standardized digital photographs were taken 20 minutes after the first irrigant was used. Photographs were analyzed by using Adobe Photoshop 7 (Adobe, San Jose, CA) to determine the amount of extrusion expressed as percent of total pixels.

Data from sample groups show the following: N40 with 50% extrusion (6/12), E40 with 8.33% extrusion (1/12), N60 with 58.33% (7/12), and E60 with 8.33% (1/12). The overall extrusion frequency, regardless of apical preparation size, was 54.17% (13/24) for needle and 8.33% (2/24) for EndoVac. Analysis of N40 and E40 revealed p < 0.03. Analysis of N60 and E60 revealed p < 0.01. Comparison of needle irrigation versus EndoVac showed a significant p value of 0.0007.

This study showed significantly less extrusion risk using the EndoVac system compared with needle irrigation.