industry report _ obturation I Fig. 2a Fig. 2b Fig. 2c Fig. 2d Fig. 2a_The appropriate DownPak tip is selected to extend 3 to 5 mm from the apical terminus. A silicone stop on the tip is adjusted as a reference point. Fig. 2b_Canal walls are coated with sealer and a master gutta-percha (or Resilon) cone is placed in the canal to working length. Using the tip of the heated DownPak, excess coronal gutta-percha is removed to the level of the orifice. Fig. 2c_The DownPak tip is introduced into the canal to the predetermined binding point with the heat and vibration modes activated for two to four seconds. The tip is rotated rapidly 180 degrees clockwise/counterclockwise two or three times and heated for two seconds. Fig. 2d_The tip is removed quickly along with any excess gutta-percha. Remaining voids are sealed coronally with additional accessory cones by applying vertical compaction as described above. Fig. 3a_Pre-op radiograph of maxillary right second pre-molar: note apical dilacerations and peri-radicular bone loss. Fig. 3b_Immediately after obturation: note the lack of voids and the lateral canal filled on the mesial. Fig. 3c_Five months post-endodontic treatment: note the re-mineralisation in the area of the peri-radicular bone. imise this problem, Dr Howard Martin developed a self-contained electronically heated spreader for warming and laterally compacting gutta-percha (Endotec, Medidenta International). This device significantly enhanced the compaction of guttapercha.7 A 1993 study found that the Endotec device increased the density of the obturation by approximately 15 per cent.8 Although this obturation device is no longer commercially available, it demonstrated that electrically induced heat on a spreader or plugger tip is an efficient way of delivering heat to gutta-percha, producing a denser obturation as a result. Subsequently designed obturation heating systems, the Touch ’n Heat (SybronEndo) and the System B (SybronEndo), expanded on this concept and were found to be successful for creating a more homogenous obturation of gutta-percha.9 The EndoTwinn (MDCL) is another such device that has been used throughout Europe for many years. Like the Endotec, the EndoTwinn is a hand-held, selfcontained, heat-carrying instrument with spreader and plugger tips. Sonic vibration was also incorporated into this device to augment the compaction and obturation effectiveness of EndoTwinn’s heated tips. Several studies have reported that by simultaneously combining the efficacy of heating the obturating material with sonic vibration to help the plasticised gutta-percha flow, the average percentage of gutta-percha in the canal space could increase significantly, especially in the more narrowly tapered canals.10–12 In early 2007, efforts to improve and refine the EndoTwinn led to the introduction of the DownPak (Hu-Friedy). The DownPak enables the clinician to employ variable temperature settings and to turn the vibration feature on or off as desired.13 The variable temperature settings become useful when different obturation materials are used. For example, Resilon softens at a lower temperature than gutta-percha. The DownPak is cordless and lightweight, with an ergonomically balanced handheld grasp; all of the switches and adjustments are easily accessible on the handle (Fig. 1). _Technique The use of the DownPak is similar to a combined vertical and lateral compaction of gutta-percha, so the clinician familiar with these techniques should find the device very user-friendly. First, the appropriate DownPak tip is selected so that it reaches a depth in the canal that is 3 to 5 mm from the apical terminus. A silicone stop can be adjusted on the tip as a reference point for this measurement (Fig. 2a). Next, the canal walls are coated with sealer and a master gutta-percha (or Resilon) cone is placed in the canal to working length. Using the tip of the heated DownPak, excess coronal gutta-percha is removed to the level of the orifice (Fig. 2b). With a sustained push, the DownPak tip is introduced into the canal with the heat and vibration modes activated. The tip is then extended down the canal space to the predetermined binding point, 3 to 5 mm from Fig. 3a Fig. 3b Fig. 3c roots 4 _ 2009 I 39