The Broach- An Underutilized Time Saver
In its rush to move to mechanization, Endodontic clinicians sometimes neglect one of the most primitive, yet effective instruments for gross debridement of the pulp. Efficient broaching of the canal space allows the clinician to quickly remove the majority of the pulp with the minimum of effort and time. This speeds cleaning and shaping, allows deeper initial penetration of irrigation and most importantly prevents "balling up" of the canal contents at the apex. This phenomenon is one of the most common reasons for canal transportation (both external and internal) as well as the inability to reach the apex after previously obtaining an accurate working length.
A broach is really nothing more than a small piece of barbed wire that is used to engage the pulp and attempt to remove it in its entirety. As simple as it sounds, the "art" (and it IS truly an art) of snagging a pulp in this manner is analogous to that of setting a hook when catching a trophy bass. Many initially try but it takes practice and skill to decide when the barbs are set and when to pull out the broach.
The technique is as follows:
- Establish straight-line access to the canal. This means removal of all coronal obstructions, ledges, lips and overhangs that prevent direct and unobstructed insertion of the broach into the canal. It is important that broaches are not "negotiated" into the canal. They must fit directly and easily into the canal orifice. When in doubt, either refine the access or do not use a broach.
- Select the proper size broach. This is extremely important. Schilder is fond of remarking that many clinicians have "the" office broach i.e./ one size fits all. Broaches are available in sizes from Coarse (Black) to XXXXF (Purple). Proper broaching of canals means that the clinician must have a good selection in all size ranges. If a practice treats younger patients or mostly single canals of larger size, appropriately larger size broaches must be purchased. Clinicians with an aging practice or those who treat molars routinely should have a good selection of smaller sizes available for use.
- Irrigate the orifice with NaOCl to remove bleeding. Suction to allow visibility of the orifice.
- Insert the broach into the orifice. Do not insert more than one half or two thirds of the canal length. NEVER insert a broach around the curved part of the canal. Turn the broach a full 360 degrees and withdraw quickly. With proper technique, the pulp will be removed almost entirely as it becomes entangled in the barbs of the broach. REMEMBER, the idea is to entangle, not macerate the pulp. Repeatedly inserting the broach into the canal and turning it against the canal walls will only chop the pulp into pieces like a blender and possibly break some of the barbs. These broken barbs may become obstructions if they are forced to the apical portions of the canal. The goal is to remove the pulp in its entirety. (Fig.1)
Fig. 1 - Palatal canal maxillary molar pulp removed intact.
Fig.2 - Pulp removed intact from pulpitic tooth. Note pink appearance
(normal) of apical section and darker red portion of coronal pulp.
- In unusually large canals (such as in adolescent anterior teeth), a "Braiding" technique may be used. Usually a single Coarse broach is still too narrow to sufficiently engage the pulp. In that case several Coarse broaches are inserted one at a time and then the instruments are turned as a unit. This "braids" them together to form one large broach and is a very effective method for removing large pulps.
- One of the most critical skills that need to be developed is that of broach size selection. In many cases, you only get one or two tries before the pulp is severed into pieces. It is important to select a broach that is smaller than the diameter of the canal but not too small that it merely punctures the pulp and does not engage it. If that happens, go to a larger size and repeat the procedure. If the broach is too large, generally it will not fit very far into the canal without resistance. Forcing the broach at this point risks loss of the barbs or fracture of the instrument. Broaches are notoriously difficult to remove in deeper sections of the canal because of their barbs. If you are unsure, always select a smaller size. You can always move up a size if the pulp does not engage.