Intracanal placement of calcium hydroxide: a comparison of techniques, revisited

The goal of this in vitro study was to compare the effectiveness of three different placement techniques of calcium hydroxide paste in a curved canal. An acrylic resin block with a 44-degree curvature was instrumented to a #40 Flex-R file. The canal was filled with radiopaque calcium hydroxide paste using the following techniques: group 1, the paste was injected with an Ultradent tip; group 2, the paste was injected as in group 1 and followed by a size 35 Lentulo to working length; and group 3, the paste was placed with a size 35 Lentulo only, to working length. Each technique was performed 25 times. The radiodensity of the simulated canal was measured at 1, 3, 5, and 7 mm from the canal terminus. At 1 mm, the Lentulo was significantly better than the other two techniques. At 3 mm, the Lentulo technique and the combined technique were better than the Ultradent tip alone.