When standard anesthetic techniques are not working, you
need something more, a “go to” cascading series of alternative
techniques to provide profound anesthesia and visual and
tactile control over the case. While opinions differ with regard to
materials, methods and the time required to create excellent clinical
results, the procedure must be executed efficiently.
Unnecessary steps and inefficiency are a waste of time and, more
importantly, create the environment for clinical and emotional
harm. The best clinical events are highly planned, well executed
and move in a straight line from the first injection to the placement
of the coronal seal.
Profound anesthesia and attainment of patency are the two
most vital components of modern endodontic procedures. Master
these two foundational components, and a stable platform has been
built for the rest of the procedure. Alternatively, less than profound
anesthesia leaves the patient uncomfortable, and the clinician
twitchy. Never a good combination. A lack of patency is the harbinger
of all manner of iatrogenic misadventure.
Of the local anesthetic techniques available for irreversible pulpitis,
two techniques have proven indispensible in my hands: the
STA Wand (Aseptico) and intraosseous techniques. It provides
numerous advantages over a standard syringe. First, a positive aspiration
is more definitive with the wand and easier to confirm in the
handpiece. It is extremely rare to have an inadvertent intravascular
injection. To date, in three years of full time clinical use of the STA,
no epinephrine reactions have resulted. Because the injection is
much slower than a typical syringe injection and the tactile “feel”
of the handpiece is more sensitive, in my experience, there have
been no “electric shock” reactions where the needle has grazed the
nerve bundle (Fig. 1).
Second, the wand has three injection speeds: extremely
slow, very slow and slow. It is simply more comfortable for
the patient than a traditional syringe. There is no more-comfortable
way to administer local anesthetic. The wand tells
you a lot about your patient. For example, if the patient has
an exaggerated response to the infiltration of local anesthetic
at the slowest speed (four minutes per cartridge) used for initiating
injections, you are treating a phobic individual that
will be harder to get numb in any case than a patient who is
less responsive. Translated, even with profound anesthesia,
you are potentially in for a “rougher ride” than someone who
tolerates the wand without a blink.
Third, another impressive feature of the wand is the ability
to give a PDL injection predictably and comfortably, and
without tissue or bone necrosis. Some clinicians do their
restorative dentistry with only the PDL injection, which is a
valid technique for restorative dentistry, but not useful for
the vast majority of endodontic procedures. Having the
PDL injection capability clearly reduces the number of
intraosseous injections that might otherwise subsequently be
required. Again, the tactile control of the wand to give PDL
injections is very sensitive and precise.
Fourth, the handpieces are very reasonable in price at just
over $2 per cannula. For an irreversibly inflamed lower
molar, I use the 27 ga 1 1/4” inch handpiece for the inferior
alveolar block, the 27 ga 1” handpiece for a buccal infiltration
of articaine and the 30 ga 1/2” handpiece for the PDL
injection. Generally, I will use all three injections for irreversibly
inflamed lower molar teeth.
In my practice, occasionally I need intraosseous anesthesia.
Three methods of providing intraosseous anesthesia are
clinically available: the X-tip (DENTSPLY), Stabident
(Fairfax Dental) and the Anesto (W&H). In my hands, the X-tip is the most cumbersome, but does have the advantage of a
guiding sleeve for needle insertion after cortical perforation.
Stabient, with no guide sleeve, is more “bare bones” and finding
the entry into cortical bone is slightly more challenging. The
Anesto uses the same needle for the cortical perforation as the
injection. The Anesto is simple, practical and ergonomic (Fig.
2). Intraosseous anesthesia is discussed in the dental literature
and a representative sample of the available articles are referenced
Regardless of which intraosseous system one uses, it is important
for the clinician to be able to seamlessly move between standard
injections to PDL to intraosseous calmly and efficiently.
Profound anesthesia allows immediate and confident canal
exploration and negotiation. The method of initial canal negotiation
has significant implications for the treatment that follows.
If the wrong hand file or too large of a hand file is inserted
too forcefully, the canal can become blocked, ledged or otherwise
transported quickly and without warning. Many iatrogenic
events have, to one degree or another, their source in a lack of
straight-line coronal access, lack of adequate canal negotiation
and glide path preparation, and inaccuracy in the determination
of true working length (TWL). While a comprehensive determination
of each of these steps is beyond the scope of this article,
using the correct stainless steel hand file, both sequentially and
tactilely, is essential for both optimization of negotiation and
avoidance of iatrogenic events.
I use only precurved Mani D Finders, Mani K files, and
Mani Safe ended K files (Mani SEC O K files) for canal negotiation
and glide path creation. D Finders are used for curved and
calcified canals. They are stiffer than standard K files. Safe ended
K files are especially valuable in canals that are highly curved,
apically complex and in which the risk of blockage or iatrogenic
events is extreme. Aside from the standard ISO sizes (#6, 8, 10,
15, etc.) I also commonly use medium sizes in the above file
types (#12, 17, etc.).
It is noteworthy that stainless steel hand files are a commodity
and relatively inexpensive; there is no economy in using
them for multiple cases. They lose
their sharpness quickly, hence in my
hands these are a single use item.
For an average case, even one of
modest curvature, I will generally
use at least three to four packs of Mani hand files, in a severely
curved and calcified case, often many more. Mani (Japanese) is
a global leader in the dental industry. Mani has excellent manufacturing
quality at approximately half the cost of competitive
products (Fig. 3).
In vital (irreversibly inflamed) cases, in the initial presence of
EDTA gel (ChelCream, MetaBiomed) the orifice is shaped with
orifice openers (for example, MounceFile .08/25 Controlled
Memory). In non-vital cases,
in the initial presence of
either ChelCream or sodium
hypochlorite, the orifice is
similarly shaped. After orifice
shaping, the chosen Mani
stainless steel hand file is precurved
and inserted in every
orientation necessary with
gentle pressure (watch winding)
to make apical progress.
Irrigation is copious and frequent
Irrespective, vital or non
vital, starting with a #6 hand
file is invaluable because in
many cases, if the clinician
starts with a larger hand file (#10 or #15, etc.) and cannot make apical progress, they will
never know if the canal might have been patent and negotiable
with a #6 hand file, if used first.
Once the #6 reaches the estimated working length (EWL)
taken from the initial radiographs, the electronic apex locator
is used (Foramatron Parkell, iRoot Meta Biomed) to determine
the position of the TWL. Using copious amounts of
sodium hypochlorite between each hand file, the next larger
hand file (#8, #10, #12, #15, #17) is used to the TWL successively
until the glide path is prepared, approximately to the
size of a #15 or #20 stainless steel hand file.
One useful adjunct for glide path preparation with stainless
steel hand files is a reciprocating hand piece (ER-10
NSK, MounceEndo.com). The ER-10 can save minutes per
case as it replicates the manual watch winding of stainless
steel hand files during glide path preparation. Many clinicians
reciprocate safe ended K files for reciprocation as a precaution,
although this is an empirical preference. The ER-10
has an E-type coupling that fits on any endodontic motor
using this coupling (all corded endodontic motors). I use my
ER-10 every tooth, every patient, every day for reciprocation.
Along with the STA, it is an indispensible part of my
armamentarium (Figs. 4-5).
Once the glide path is created, in my hands, the canal is
ready for shaping with nickel titanium in the Controlled
Memory (MounceFiles CM, Typhoon CM Clinicians
Choice) via either a crown down, step back or hybrid technique
I’ve reviewed methods for obtaining profound anesthesia
and glide path creation. Emphasis has been placed on moving
rapidly to a successful conclusion while avoiding iatrogenic
events using needed anesthetic techniques confidently. Once
profound anesthesia and straight-line access are obtained, the
glide path is created using an increasingly sized sequence of
stainless steel hand files starting with a precurved #6, possibly
aided by a reciprocating handpiece in the presence of copious
irrigation. I welcome your feedback.
- Med Oral Patol Oral Cir Bucal. 2013 Jan 1;18(1) Root damage induced by intraosseous anesthesia. An in vitro investigation. Graetz C1, et al.
- J Am Dent Assoc. 2003 Nov;134(11):1476-84. A comparison of two intraosseous anesthetic techniques in mandibular posterior teeth. Gallatin J1, et al.
- Dent Res J (Isfahan). 2013 Mar;10(2):210-3. X-tip intraosseous injection system as a primary anesthesia for irreversible pulpitis of posterior mandibular teeth: A randomized clinical trail. Razavian H1, et al.
- J Conserv Dent. 2013 Mar;16(2):162-6. Anesthetic efficacy of X-tip intraosseous injection using 2% lidocaine with 1:80,000 epinephrine in patients with irreversible pulpitis after inferior alveolar nerve block: A clinical
study. Verma PK1, et al.
- J Endod. 2009 Jan;35(1):15-8. The use of intraosseous anesthesia among endodontists: results of a questionnaire. Bangerter C1, et al.
- J Endod. 2012 Apr;38(4):421-5. A prospective randomized trial of different supplementary local anesthetic techniques after failure of inferior alveolar nerve block in patients with irreversible pulpitis in mandibular teeth.
Kanaa MD1, et al.