Sunday, October 18, 2009
Thermoplastic Materials:An Alternative to Gutta-Percha
Obturation of the cleaned and shaped root canal space has been performed for many years using a core of gutta-percha rubber cones combined with various formulations of sealer cements. This step in root canal treatment is an effort to create a root canal system that is sealed from reinfection resulting from coronal leakage, and to entomb residual bacteria and their by-products remaining in the roots following cleaning and shaping procedures. The gutta-percha cones can be manipulated into the root canal with either cold lateral condensation, or through a method which involves softening the core filling material with the application of heat, which was introduced more than 40 years ago by Dr. Schilder. The gutta-percha and sealer filling material has been the most popular and most tested filling material throughout the history of nonsurgical endodontic procedures.
Despite significant advances in materials science over the past 50 years, it was just recently that an alternative filling material for root canal obturation was introduced and studied in an attempt to improve upon the successful history of gutta-percha. A new a polycaprolactone resin-based thermoplastic filling material (Resilon [Resilon Research LLC]) has been introduced that differs from gutta-percha—the rubber in the gutta-percha material has been replaced with a urethane-based resin. A dual-cured methacrylate resin sealer cement (Epiphany [Pentron Clinical Technologies]) was developed to be utilized with a self-etching primer in association with Resilon in an attempt to create a root filling material that is of a single, solid, bonded material. This system differs from the gutta-percha sealer-based obturation material because it has the ability, through dentin adhesive resin-bonding technology, to bond the root canal walls to the sealer cement, which in turn bonds to the core filling material. This has the potential to strengthen roots and to improve the leakage resistance of the obturated root, hopefully improving nonsurgical endodontic outcome success over the long term. The Resilon and Epiphany obturation material is available under different names: Resilon/Epiphany (Pentron Clinical Technologies), Resinate (Obtura Spartan), and RealSeal (SybronEndo).
In the past 4 years, sponsored and independent research has been busy determining if the new Resilon material is an acceptable alternative to the time-tested gutta-percha and sealer. Factors that have been tested include the cement’s cellular toxicity, bacterial leakage in filled roots, fluid filtration leakage comparisons, microscopic bonding visual analyses, bond strength to root dentin studies, periapical inflammation evaluations, and clinical outcome comparisons. Based on the majority of the current research covering the various aspects of the new material, studies show that the new filling material is a viable alternative to the gutta-percha-sealer technique for filling roots in nonsurgical endodontic treatment. Furthermore, future research and development may eventually reveal that it has the potential to be a better material than gutta-percha.
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.