NEW MATERIAL CHALLENGES: HANDLING
Despite significant amounts of published research, there is little information about the handling difference between this new root-filling material compared to its traditional alternative. While the dispensing of the Resilon/Epiphany system comes in similar standardized (ISO) cone forms, or pellet form for use in heated syringable dispensing systems (ie, Obtura II [Obtura Spartan] or the Hot Shot [Discus Dental]); the newer material handles differently in several ways. The Resilon core-filling material has less body stiffness and cohesion when compared to a standard gutta-percha cone. This translates into a cone that is softer (less stiff) and can be pulled apart easier. For example, if a master cone does not match the instrumentation size precisely, a cone that fits 0.5 mm short of the desired length cannot be “pushed” that extra distance with pressure on the cone itself. This is because the softer cone will buckle under pressure and will not slide apically like a gutta-percha cone might have a tendency to do. Additionally, if a Resilon cone is placed into a canal where it has very firm “tug-back,” if the cone is pulled on to withdraw it, there is a risk that the cone can be pulled apart upon withdrawal leaving the firm-fitting apical fragment in place. Of course, the flipside of this situation is that less tugback is required to successfully perform various obturation procedures. For example, when using a single master cone warm vertical obturation technique and there is inadequate tug-back present, the master cone could be withdrawn attached to the heated plugger. This is more difficult to do with a softer Resilon cone. Although the cone feels different in this subtle way, its flow characteristics and adaptability to the root canal walls have been studied and found to perform comparably to heated gutta-percha with sealer techniques in replicating anatomic depressions and filling lateral canals.In lateral condensation filling techniques, the softer cone does lead to an increased spreader-depth penetration versus gutta-percha cones. As a result, this permits further spreader penetration, which is essential for better master cone adaptation.