What do people use now?

Like W_B mentioned, current local anesthetics do not include novocaine.
I'm sure that you really used the name to include any local anesthetic
that dentists currently use.

IME, delivery and effectiveness of local anesthetics can make or break
a private practice (I'm in the US where anyone can go to the guy down
the street if they don't think I am better.)  Comfort during injection
is important, but if the anesthetic is not truly effective, the
injection
comfort is fast forgotten.  Like real estate, location, location,
location!

Many dentists try and improve injection comfort by using 30 gauge
needles.  These are not appropriate for most nerve blocks.  With
*sharp*, quality needles the patient cannot tell the difference between
a 30, 27, or 25 gauge needle.  Small 30 gauge needles deflect and often
leave the anesthetic deposited too far from the nerve to achieve
effective anesthesia.

If you're trapped in a government run health care system or an DMO,
there is less of an incentive for the dentist to really *care*.  Also,
the cost of supplies often dictates the cheapest materials available.
Cheap needles are usually not as sharp as more expensive needles.

After leaving dental school, the last thing I worried about was my
local anesthetic technique, but after a few years I figured out that
it was more important than I had first imagined.  I needed to get
better.

I ran into an opportunity to take a course with an expert in local
anesthesia techniques.  I took the course once, and then I took it
again 2 years later.  There's a lot of stuff that dental school doesn't
teach (and I'm still not perfect).

JMO,
Fawks

Nope, its simple. There is what we call LD50. A lethal dose. Some
procedures require additional injections along the way, so we meter
out how much we initially give, to not run short near the end.

Can one OD on xylocaine? You bet.

Joel

**

OVERDOSE

Acute emergencies from local anesthetics are generally related to high
plasma levels encountered during therapeutic use of local anesthetics
or to unintended subarachnoid injection of local anesthetic solution
(see , WARNINGS , and PRECAUTIONS).

Management of Local Anesthetic Emergencies:   The first consideration
is prevention, best accomplished by careful and constant monitoring of
cardiovascular and respiratory vital signs and the patient's state of
consciousness after each local anesthetic injection. At the first sign
of change, oxygen should be administered.



The first step in the management of convulsions, as well as
underventilation or apnea due to unintended subarachnoid injection of
drug solution, consists of immediate attention to the maintenance of a
patent airway and assisted or controlled ventilation with oxygen and a
delivery system capable of permitting immediate positive airway
pressure by mask. Immediately after the institution of these
ventilatory measures, the adequacy of the circulation should be
evaluated, keeping in mind that drugs used to treat convulsions
sometimes depress the circulation when administered intravenously.
Should convulsions persist despite adequate respiratory support, and
if the status of the circulation permits, small increments of an
ultra-short acting barbiturate (such as thiopental or thiamylal) or a
benzodiazepine (such as diazepam) may be administered intravenously.
The clinician should be familiar, prior to the use of local
anesthetics, with these anticonvulsant drugs. Supportive treatment of
circulatory depression may require administration of intravenous
fluids and, when appropriate, a vasopressor as directed by the
clinical situation (e.g., ephedrine).

If not treated immediately, both convulsions and cardiovascular
depression can result in hypoxia, acidosis, bradycardia, arrhythmias
and cardiac arrest. Underventilation or apnea due to unintentional
subarachnoid injection of local anesthetic solution may produce these
same signs and also lead to cardiac arrest if ventilatory support is
not instituted. If cardiac arrest should occur, standard
cardiopulmonary resuscitative measures should be instituted.

Endotracheal intubation, employing drugs and techniques familiar to
the clinician, may be indicated, after initial administration of
oxygen by mask, if difficulty is encountered in the maintenance of a
patent airway or if prolonged ventilatory support (assisted or
controlled) is indicated.

Dialysis is of negligible value in the treatment of acute overdosage
with lidocaine.

The oral LD 50 of lidocaine HCl in non-fasted female rats is 459
(346-773) mg/kg (as the salt) and 214 (159-324) mg/kg (as the salt) in
fasted female rats.



CONTRAINDICATIONS

Lidocaine is contraindicated in patients with a known history of
hypersensitivity to local anesthetics of the amide type.