Endodontic brushing: The secret to mastering rotary safety

John West, DDS, MSD

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Every dentist wants to be in control of his or her technique. All patients want their dentistry to be safe.

"Endodontic brushing" makes both control and safety not only possible but highly predictable. Endodontic brushing is a "skill within a skill" that has been widely recognized by master endodontic clinicians as the most efficient, simple, and sustainable way to make rotary endodontics safer, easier, and more enjoyable.

Technique
This master endodontic skill has been divided into four questions and answers:

» What is brushing?
» First prepare the glide path, which can be defined as a "smooth No. 15 file size tunnel or a super loose No. 10 file size from orifice to radiographic terminus." The glide path can be long or short, narrow or wide, curved or more curved. Brushing is defined as "selectively carving away coronal radicular restrictive dentin using a painting motion." Classically, this distinction is called "early coronal enlargement."

» Why do I need brushing?
» Brushing moves the endodontic radicular preparation away from "furcal danger" so that finishing files can produce the final endodontic shape safely within dentin walls, which prevents apical transportation. And because dentin is not needlessly removed, it preserves coronal ferrule.

» How do I do brushing?
» Gently "follow" the glide path with a rotary file until the blades just barely begin to engage dentin. Short of maximum apical cutting resistance, arch pressure away from furcal direction and carve toward access cavity as if brushing the dentin walls with a paintbrush. The handpiece is held at the butt end in order to increase delicacy and eliminate the urge to push or peck with the handpiece head. The handpiece should be cradled and allowed to float in the palm of the operating hand rather than gripping like a pen, allowing it to randomly and easily slide down the glide path. Once the desired depth is reached, the withdrawal should be performed using the same painting motion. This action is deliberately made against the most robust dentin walls and away from potentially fragile furcal walls. Brushing strokes continue as the file follows deeper toward the physiologic apex or until the shaper blades are loaded with dentin, in which case the file is removed, cleaned, and the "float, follow, and brushing" motions continue until brushing is finished. The canal preparation is now ready for finishing files that can safely carve the final shape by "connecting the outline preparation dots" from the apical constriction to the coronal constriction. The brushing motion has literally paved the way for the rotary finishers by intentionally and specifically removing the restrictive dentin. Removal of restrictive dentin reduces rotary file taper lock along the dentin surface and, at the same time, allows a significant increase in apical tactility. The dentist experiences a new level of freedom, confidence, and control.

» Is there an endodontic system dedicated to brushing?
» While any rotary system's smaller files can be used in a brushing motion, one system actually does have designated files that are designed with the shaping motion in mind. The ProTaper Universal system (DENTSPLY Tulsa Dental Specialties) promotes brushing and puts the operator in control. The dentist tells the file what to do just as the dentist tells the bur what to do during a veneer preparation. The dentist directs the movement; the movement does not direct the dentist. The specific shapers designed for brushing in the ProTaper technology are SX, S1, and S2. Typically, S1 is followed by S2 and then brushing is finished. In shorter canals, due to increased progressive geometries, or where significant coronal brushing is required, the SX is useful for improving efficiency and accuracy.

The difference in endodontics

Endodontics is different from other dental disciplines. In all other dental techniques, the dentist can see and do simultaneously. In endodontics, radicular cleaning and shaping are accomplished blind. The dentist is literally in the dark. While microscopes have enabled dentists to find most canal entrances, there is no technology to see the radicular preparation as it is being prepared. Unlike a crown prep, there is no way to precisely direct the design of the preparation, and there is no way to directly inspect the preparation to confirm proper finishing. Brushing gives the dentist a clear and unrestricted path to fine-tune the desired continuously tapering funnel radicular preparation. The brushed convenience form allows for successful cleaning and shaping. And, the dentist is back in the driver's seat: in control, efficient, effective, and above all, safe.