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The XP-3D Shaper™ and XP-3D Finisher
True 3-dimensional root canal therapy is finally a reality
Martin Trope, DMD
Historically, the fact that endo-dontic instruments have a round diameter but canals are more ovoid in shape has served as a barrier to providing ideal root canal therapy. This resulted in untouched canal walls and unreachable microbes that increased the potential for failure.
Herbert Schilder from Boston University was one of the first practitioners to attempt to solve this problem in instrumentation. Schilder bent the last few millimeters of a stainless steel file, theorizing that when used in an up-and-down motion, this off-center file would create an "envelope of motion," allowing it to move into the hard-to-reach areas of the canal and improve cleaning. The primary problem with his method was that the stainless steel file would eventually restraighten while working in the canal. Additionally, the technique was very labor intensive and even when successful, the 2-dimensional periapical radiograph looked the same as when the technique was not used. These limitations hindered the technique from becoming "mainstream."
Today, technology has advanced to the point that Schilder's goal of cleaning and filling the canal in all dimensions can be a reality. Clinicians can now use 3D cone-beam computed tomography images to visualize the unseen dimensions of the canal, and NiTi instruments can be manipulated to make Schilder's "envelope of motion" actually work.
The XP-3D instruments (Brasseler, USA) feature MaxWire technology. With MaxWire, the instruments are malleable at room temperature (ie, martensitic phase) but expand to become more robust at body temperature (ie, austenitic phase), allowing them to bounce back to the parent state shape without becoming straightened. Because they are used in a handpiece, they are not labor intensive at all. The XP-3D Shaper has a serpentine shape with a thin core that allows it to adapt to the original shape of the canal, bouncing off the walls while preventing debris from being forced into any irregular areas. The XP-3D Finisher has a sickle shape that can reach areas in the canal to a radius of 600 mm. When used in combination, these two instruments will reach almost every part of the canal with minimal change to its original shape, achieving the ideal of improving cleaning while being more conservative with treatment.
In addition to instrumentation, obturation technology has caught up as well. Today, bioceramic sealers (EndoSequence® BC Sealer™, Brasseler USA) solve the problems of shrinkage and washing out. BC Sealer actually expands slightly, improving the seal, and does not wash out when in contact with tissue fluids. In addition, it is premixed and hydrophilic, which makes it very user-friendly. Finally, clinicians can employ a hydraulic filling technique in which one cold, dimensionally stable cone of gutta-percha is used to move the sealer into the irregular areas of the canal, improving the seal.
1. It has always been the goal of root canal therapy to thoroughly clean and obturate the canal in three dimensions
2. 3D cleaning is now possible through new adaptive NiTi instrumentation featuring "MaxWire"
3. 3D obturation is now possible at room temperature through bioceramic technology
About the Author
Martin Trope, DMD