The XP-3D Shaper
New NiTi alloy expands with temperature to adapt to anatomy
Allen Ali Nasseh, DDS, MMSc
Instrumenting a root canal while considering its original natural shape is referred to as anatomical shaping. The objective of this process is to enlarge the natural shape in all dimensions and try to preserve its original integrity. Historically, achieving this objective with conventional NiTi rotary instruments has been a challenge. Much of the difficulty has stemmed from the use of instruments that create a round-shaped cross section while working in an oval-shaped cross section of a root canal. This discord between instrumentation shapes and natural canal shapes can result in some areas of the canal being underprepared while other areas are over-instrumented. And while the success rate of root canal therapy as a whole has been excellent, primarily because of improved irrigation and disinfection protocols, clinicians have long known that outcomes could be further improved if we could somehow reach into the oval areas of canals and touch more surfaces during shaping.
Recently, a proprietary NiTi alloy with remarkable clinical characteristics was introduced to the market. This alloy, MaxWire® from Brasseler USA, was designed to go through a phase transition from a martensite crystalline structure to an austenite crystalline structure at 35 degrees Celsius or above. This means that a file designed with this alloy will exhibit martensitic characteristics at room temperature and austenitic characteristics in a root canal at body temperature.
The XP-3D Shaper from Brasseler USA combines this temperature-induced phase transition with a unique file design, which expands from a lightly curved, ductile wire at room temperature to a highly robust, serpentine shaped instrument when inside the root canal. When the file is rotated, three "virtual bulbs" spring up that have an envelope of motion much greater than the actual diameter of the file (30/.01). The flexibility and design of the instrument provides an adaptive, spring-like contact to the root canal walls that, when combined with long up and down strokes by the operator, can clean and shape root canals like an abrasive bottle brush.
The XP-3D Shaper demonstrates a promising and novel method of instrumenting a root canal. This instrument requires some space to operate properly; therefore, basic root canals should be prepared to at least a size 15/.02 taper, and advance canals should be prepared to at least a size 15/.04 taper prior to its introduction. Thereafter, operating the 3D file at 800 to 1000 RPM using long up and down strokes will safely and efficiently enlarge the majority of root canals anatomically. Employing this method will provide superior anatomical shaping, while reducing the number of files needed and increasing the efficacy of instrumentation.
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About the Author
Allen Ali Nasseh maintains a private endodontic practice in Boston, Massachusetts, and holds a staff position in Harvard's postdoctoral endodontic program. He is also the CEO and President of Real World Endo® and has lectured extensively nationally and internationally on surgical and non-surgical endodontic topics.