Orthotown October 2016 - 42


time-consuming in the daily schedule-and
also can be unpleasant for the patient, because
these changes typically are done keeping the
patient in rectangular nickel titanium wire
or larger, less-flexible arch wires.
In the end, total treatment time and
efficiency are dramatically affected by the
initial bracket placement.

The indirect approach

Fig. 1: Brackets positioned.

indirect bonding systems vary greatly. Lab
procedures are required to produce a transfer
tray that holds the brackets precisely for the
clinical bonding.
The patient preparation procedure for
indirect bonding is much the same as for
direct bonding: An isolated, clean, dry field is
required. Teeth are sealed with unfilled resin,
composite is applied to the bracket bases, and
the tray is inserted into position and held
firmly in place. Light curing or chemical
curing bonds the bracket to the tooth. The
tray is removed, and if all has gone according
to plan, the brackets stay firmly attached to
the teeth and the wires can be placed. Simple
and efficient, if all goes well.
Depending upon state laws, the clinical
time required by the orthodontist is minimal.
Indeed, it's possible to have multiple full-mouth
bonding procedures occurring at the same
time, which is a key benefit to the indirect
bonding technique.

Indirect bonding was developed in an
effort to improve initial bracket placement.
The primary benefit of indirect bonding is
eliminating or minimizing bracket repositioning, and finishing bends in the final arch
wire. The greatest benefit of indirect bonding
is the gain in treatment efficiency. Taking the
most direct path from Point A to Point B has
to be the primary consideration in minimizing
treatment time. Time spent rebonding brackets
Fig. 2: CAD virtual alignment allows evaluation
or bending wires increases overall treatment
and modification of bracket placement.
time and reduces efficiency. While the benefit
is obvious, the challenges are many.
Implementing a system of indirect bonding adds a number of
Drawbacks and limitations
variables to the bonding equation. Unlike direct bonding brackets,
In all fairness to direct bonding, the indirect system has some
limitations, as well.
There are multiple opportunities for error to be introduced
into the system. Ultimately, any error can result in a suboptimal
bracket position at best, and at worst a failure to bond the bracket
to the tooth at all. The latter often results in the need to resort to
direct bonding to place the bracket.
The inability to place the bracket in the ideal position
due to gingival interference is common. Short clinical crowns
are especially prone to this. When this happens, the gum tissue
has to be relieved on the stone model, or the bracket pad has to
be altered. Both of these require additional time to finalize the
bracket placement, which is often done by the orthodontist. Many
times the orthodontist won't take the additional time and accepts
a less-than-ideal bracket position, which defeats the original
purpose altogether.
The difficulty of including second molars in the bonding
trays. Often, the upper second molars are difficult to access and
don't allow the bonding tray to be placed without moving the jaw to
one side or the other, which leads to poor and inaccurate bonding.
The mandibular second molars are hard to isolate and keep dry,
and many times the tongue will quickly become the enemy of an
otherwise perfect bonding routine. As a result, many orthodontists
will direct bond some or all of the first and second molars.
By far the biggest obstacle to achieving ideal bracket position is the
inability to project the final position of the teeth once the straight
wire has done its magic. Any "static" indirect bonding setup is relying
on our ability to visualize the resultant tooth movement once the
brackets have been applied to the model.

42

OCTOBER 2016 // orthotown.com
http://www.orthotown.com
Table of Contents for the Digital Edition of Orthotown October 2016
