clinical report _ shaping system I Well, for one we have the presentation of cases. Secondly, we offer free two- to three-hour workshops for anyone interested in trying our system, so they can decide for themselves on the validity of these assertions. Below are some examples of fairly challenging cases that were treated recently in our office using the SafeSiders. Please understand that the instruments are not simply placed into the reciprocating handpiece and then the canals are shaped. Rather, the reamers—both relieved and non-relieved—give excellent tactile feedback so we know when we are in the canal and when we are encountering a wall. With this knowledge, we know when to bend an instrument to negotiate manually around any blockage. Once patency has been achieved, the instruments used either manually or in the handpiece give us the ability to widen most often apically to a #35 without distortion and then obturate most often with a single medium point in a canal flooded with epoxy resin cement. The case pictured in Figures 1 and 2, treated by Dr Young Bui, displays several important features of the system. Dr Bui was able to shape the canals to a #35 to the apex, ensuring enough irrigation to open up whatever lateral canals were present so they too could be obturated with the epoxy cement. While shaping to these dimensions, distortion is avoided because the instruments are fed apically using either a tight manual watchwinding motion or the reciprocating handpiece. If a wall had been encountered, the instruments would have been pre-bent, fed manually around the blockage and then reattached to the reciprocating handpiece. Please note the density of the fills. These radiographs were originally generated from film, not a digital source, which tends to exaggerate the density of gutta-percha and cement. The original negotiation of the canal was fairly straightforward because, despite the curves negotiated, the reamers (both relieved and nonrelieved) produce far less resistance along length than K-files. After the #20, the coronal curves of the canals were straightened with a Pleezer, which has a tip size of 0.75 mm and a 0.03 mm taper. Figures 3 to 5 demonstrate the maintenance of canal anatomy while shaping canals to a minimum of #35 and an overlayed taper of 25/.06, producing conditions that allow for adequate irrigation and the placement of a 3-D fill in a predictable manner. Again, the canals were initially negotiated with instruments that are inherently less engaging along the walls of the canal, provid- Fig. 8 Fig. 9 Fig. 10 ing for less resistance as they negotiate apically. All apical negotiation is achieved with the same manual watch-winding motion or the 30° arc produced by the reciprocating handpiece. Either way, maintaining patency assures a non-distorted canal preparation. Figures 6 and 7 present an extreme case of canal curvature, treated by my partner Dr Doug Kase. The curve on the distal root could not be roots 4 _ 2009 I 15