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CLINICAL
SECTION
A bonding technique for fixed
maxillary retainers
Raphael Patcas and Guido Pedroli
Center of Dental Medicine, Department for Orthodontics and Pediatric Dentistry, Zu¨rich, Switzerland
Maintaining incisor alignment is an important goal of orthodontic retention and can only be guaranteed by placement of an
intact, passive and permanent fixed retainer. Here we describe a reliable technique for bonding maxillary retainers and
demonstrate all the steps necessary for both technician and clinician. The importance of increasing the surface roughness of the
wire and teeth to be bonded, maintaining passivity of the retainer, especially during bonding, the use of a stiff wire and correct
placement of the retainer are all discussed. Examples of adverse tooth movement from retainers with twisted and multistrand
wires are shown.
Key words: Fixed retainer, passivity, maxilla, bonding technique, adverse tooth movement
Received 7 May 2012; accepted 1 July 2012
Introduction
Most orthodontists believe that a truly stable treatment
outcome is a myth and conclude that the only definitive
way of maintaining ideal alignment after treatment
is with some form of permanent retention.1 In fact,
as early as 1934 Professor Albin Oppenheim stated:
‘retention is the most difficult problem in orthodontia,
in fact, it is the problem’.2 Maintaining incisor align-
ment is especially important from the patient’s perspec-
tive and fixed bonded retainers have been advocated in
order to avoid relapse (Figure 1).3
Scientific contributions regarding bonded retainers
in the maxilla are scarce and only 5% of orthodontists
in the US routinely use fixed maxillary retention.4 In
the UK, between 1–4% reportedly use fixed maxillary
retainers, depending on their practice environment.5
Nevertheless, the fixed maxillary retainer is a reliable
method of achieving permanent retention in the
maxilla without relying on long-term compliance.6
The reasons why clinicians may remain apprehensive
when recommending the use of fixed maxillary
retainers might be related to the absence of a reliable
indirect bonding technique and the increased difficul-
ties associated with placing a fixed retainer in the
upper arch.7
Even in the presence of a fixed retainer, in rare cases
adverse movement of the bonded teeth can still be
observed. Most clinicians use a flexible wire, which is
sometimes only slightly adapted to the teeth and in
some cases not at all. The use of flexible twisted or
multistrand wire may result in unwanted tooth
movement owing to the lack of passivity of the wire.
This adverse tooth movement has not only been
observed in vivo, but has also been verified in vitro.8
Indeed, the use of a round rigid wire has been
advocated in the upper jaw9 and has demonstrated
convincing long-term results.10 In the light of evidence
of adverse tooth movement associated with multi-
stranded wires in the lower jaw, the use of rigid wires
has been advocated.12,13
This article presents evidence of adverse tooth move-
ment associated with fixed retainers constructed from
twisted and multistranded wires in the maxillary incisor
region. We present a dependable technique for the
indirect bonding of maxillary retainers using a rigid wire
and demonstrate how to guarantee passivity when
bonding the wire.
Fabricationof the retainer
Instructions for technician
Alginate impressions of the upper and lower jaw and a
wax bite in maximum intercuspation (MI) are needed to
produce the plaster models. After trimming the models
in MI, mark the desired position of the retainer. Viewing
the models in MI from the lingual side, the ideal location
of the wire will become evident, as it should be placed
more cranial than the palatal surface covered by the
Journal of Orthodontics, Vol. 39, 2012, 317–322
Address for correspondence: R. Patcas, Center of Dental Medicine,
Department for Orthodontics and Pediatric Dentistry Zu¨rich,
Switzerland.
Email: Raphael.Patcas@zzm.uzh.ch
# 2012 British Orthodontic Society DOI 10.1179/1465312512Z.00000000044
lower incisors, whilst respecting some distance from the
gingiva (Figure 2a). Ideally, the wire should be posi-
tioned half-way up the clinical crown, but placing the wire
more cervically is also acceptable, as long as sufficient
distance to the gingiva is guaranteed for later bonding. The
stainless steel wire should be stiff, a dimension of 0.0166
0.016 inches (0.460.4 mm) (Dentaurum, Ispringen,
Germany) will provide enough rigidity. The wire should
fit closely to the tooth surface. Bending optional v-bends
may provide an increased wire surface for bonding
(Figure 2b,c). Fix the wire with sticky wax on the model
in the desired position. To enable transfer of the well-
defined position of the wire to the clinician and to guarantee
passivity, two s-shaped auxiliary hooks of 0.017560.0175
inches (0.4560.45 mm) (Dentaurum) are welded inter-
dentally. The two hooks are fixed on the retainer with the
two hand electrodes of a welding machine (Figure 2d). It is
important to choose the right welding current: high enough
Figure 1 A fixed maxillary retainer bonded on all four incisors.
Optionally, the canines can be included
Figure 2 Fabrication of the retainer. (a) Viewing the models from inside will provide the necessary information needed for the vertical
position of the wire. (b) The 0.01660.016 inch stainless steel wire with optional v-bends. The areas to be bonded are sandblasted and two
s-shaped auxiliary hooks are welded interdentally to facilitate the repositioning. (c) Note the close-fitting devolution of the wire. (d)
Welding the auxiliary hooks on the retainer fixed with wax to the model. This set-up facilitates bonding the stiff wire with the required
passivity
318 Patcas and Pedroli Clinical Section JO December 2012
to avoid a detachment during the transfer, but not too firm
to render removal difficult. Ultimately, the wire sections to
be bonded are sandblasted with aluminum oxide (Al2O3,
particle size 80–125 mm; Dentaurum) to increase mechan-
ical retention (Figure 3).
Instructions for clinician
It is important to clean and optionally sandblast
(Al2O3, particle size of 80–125 mm) the palatal aspect
of the teeth to be bonded in order to increase
mechanical retention.14 Rinse the sand off and etch
with 35% phosphoric acid for 30 seconds (Figure 4a).
Rinse again, dry thoroughly and keep a dry oral
environment. Apply the sealant (TransbondTM XT; 3M
Unitek, Monrovia, CA, USA) (Figure 4b) and light
cure for 20 seconds. Lay a base of composite to prevent
undercuts, then position the wire and lay if needed,
additional composite (Transbond LR; 3M Unitek).
Shaping the composite with a microbrushH (Microbrush
International, Grafton, WI, USA) (see Figure 4b)
previously moistened with sealant will make subsequent
finishing and contouring in most cases unnecessary
(Figure 4c). Make sure the composite covers the wire,
does not create undercuts and provides enough distance
to the palatal gingiva. Light cure the composite for
40 seconds at every site. After removing the auxiliary
hooks with a scaler (Figure 4d) check the bite with
occlusal foil for any unwanted primary contacts and
eliminate them by reducing and reshaping the compo-
site, if necessary. In contrast to lingual retainers in the
mandible, instructing a special flossing method is not
required in the maxilla due to the anatomical difference
of the upper incisors.
Discussion
Relapse may occur many years after treatment.15,16 A
bonded retainer placed in the upper jaw will secure
alignment achieved during treatment. We present an
indirect bonding technique for a fixed retainer that can
be left inplace permanently, provided the oral hygiene is
adequate. Fixed retention reportedly causes less gingi-
vitis than removable, although slightly more plaque
accumulation can be observed (both not significant).17
We consider the fixed retainer to be superior for the
following reasons:
N independence of a patient’s long-term compliance;
N patient’s have a preference for ‘invisible’ retainers;
N no adverse effects on gingival health.
For long-term success, clinicians should concern them-
selves with some important aspects when fabricating and
bonding the retainer.
1. Surface roughness is crucial for good mechanical
retention. Sandblasting a stainless steel wire will
result in a 24-fold increase in the wire-composite
Figure 3 Scanning electron microscope (SEM) images of a 0.032-
inch round (0.8 mm) stainless steel wire (RemaniumH; Dentaurum):
(a) untreated, (b) surface roughened with a carbon silicide bur and
(c) surface roughened with sandblast (particle size 80–125 mm).
Note the increase of retentive relief
JO December 2012 Clinical Section Bonding technique for fixed maxillary retainers 319
bond strength.18 Additionally, the tooth surface can
be roughened correspondingly.14
2. Passivity of the retainer is of primary importance: it
has been reported that forces generated from
retainer wires can be large enough to cause
unwanted tooth movement.19 Previous techniques
to stabilize the wire for bonding fail to guarantee
the required passivity.20 We introduce the use of
auxiliary hooks to overcome this clinical difficulty
and facilitate repositioning.
3. A stiff wire should be used and twisted or
multistrand retainers avoided. Negative effects
have been associated with the use of these
retainers11 and these can occur in the maxillary
arch as well (Figures 5 and 6 ). This adverse tooth
movement of bonded teeth cannot be referred to
as relapse, since it is caused by forces generated
from the lack of passivity of the retainer wire
itself. The use of five-stranded wires rather than
three-stranded has been advocated to avoid the
side effects associated with wire distortion.21 It
indeed seems that the incidence of wire breakage
decreases with increasing wire diameter.22 Yet, a
recent publication has demonstrated that 0.2 mm
tooth movement can generate forces in multi-
stranded wires great enough to move teeth, regard-
less of whether the wire is three- or six-stranded. This
finding has two implications: that passive adaptation
of retainers is crucial (here five-stranded wires are
definitely superior to three-stranded wires) and
physiological movement of teeth bonded to the
retainer might be reason enough to produce forces in
the wire large enough for adverse tooth movement.8
It is this second concern that makes us believe that
even five-stranded wires might be affected by these
adverse tooth movements, since all multistranded
wires allow physiological tooth movement. Rigid
wires will provide the security to avoid adverse
Figure 4 Clinical steps necessary to bond the retainer. (a) After cleaning the palatal aspects of the teeth, the enamel is etched with
phosphoric acid. (b) The acid is rinsed off and the teeth dried before the sealant is applied with a microbrushH and light cured. (c) A base
of composite is placed to prevent undercuts, the retainer is positioned passively and the composite shaped with a microbrushH. (d) The
auxiliary hooks are easily removed after light curing the composite
320 Patcas and Pedroli Clinical Section JO December 2012
Figure 5 (a–d) Adverse effect of a multistrand retainer on the upper left incisors: unwanted tooth movement generated by forces in the wire
Figure 6 (a–d) Adverse effect of a twisted retainer on the upper right incisor and canine: unwanted tooth movement generated by forces
in the multistrand wire causing a buccal crown-tip of the canine and a buccal root-tip of the lateral incisor. Note that the apex of the
lateral incisor is exposed. The figure was reported by Dr. Reto Fa¨h, University of Zurich
JO December 2012 Clinical Section Bonding technique for fixed maxillary retainers 321
tooth movement by diminishing physiological
tooth movement. However, a possible drawback
of this approach might be an increase of bonding
failures due to the rigidity of the system. The rate
of bonding failure has reportedly been higher in
mandibular retainers when all the teeth are
bonded. But our clinical observation is that
bonding all incisors in the maxilla is far less
problematic. This might be due to the greater
inter-bonding distances and the fact that the
bonding sites are further away from the centre of
resistance of upper incisors, all this allowing some
play in the system.
4. The retainer should ideally be positioned approxi-
mately half-way or in the cervical part of the clinical
crown and the avoidance of occlusal interferences
from opposing teeth should be guaranteed.21 The
resin margin should respect a minimal distance to
the gingiva in order to avoid permanent gingival
irritation.
Conclusion
Maintaining incisor alignment is an important goal
during retention and only a permanent fixed retainer can
guarantee this. Bonded retainers in the maxilla are,
however, not so widely used and the use of twisted or
multistrand wires can in rare cases cause serious adverse
tooth movement due to a lack of passivity. A depend-
able technique for indirect bonding of maxillary
retainers with a rigid wire is therefore presented to
achieve this required passivity.
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