RS 7 Reliability of apical dye sealability studies with and without vacuum removal of air inclusions

Abstract

The reliability of two commonly used methods of sealability testing, dye leakage under normal atmospheric pressure and dye leakage in a vacuum, was tested using a repeated studies design. Forty extracted teeth were instrumented and obturated using lateral condensation of gutta-percha and Sealapex® sealer. One half of the teeth were placed in India ink under normal atmospheric pressure and the other half underwent air evacuation before immersion in the ink. After 24 hours the teeth were removed from the ink and rendered transparent for linear leakage analysis. A second study, repeated within the exact parameters of the first, was performed approximately one month later. MannWhitney U tests indicated that there was no significant difference between the air and vacuum groups or within each group (air or vacuum) between trials, indicating that the methodology is repeatable and that application of vacuum did not enhance the reliability. Most of the teeth placed under vacuum showed evidence of vacuum induced artifacts that may negate the vacuum's value as a research tool.