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One of the most challenging aspects of direct posterior
resin restorations is achieving good proximal contacts
with proper contours. This can become especially challenging
when the resulting proximal preparation is wide and
the adjacent tooth leaves a large space interproximally.
The goals of posterior direct restorations include:
- Tight contact with the adjacent tooth's proximal
surface
- Contour gingival to the contact that fills the
space without food traps
- Buccal and lingual contours that prevent food
impaction interproximally
These goals often are not met routinely as circumferential
matrices tend to constrict the buccal and lingual contours,
resulting in inadequate contacts and poor anatomical
form.
Sectional matrix and ring retainers were introduced
in an attempt to combat this and allow the practitioner
to achieve better contacts and contours. But those also
had some challenges when the proximal preparation resulted
in a box that extended to include a portion of the buccal
and lingual walls or space was present between the tooth
being treated and the adjacent tooth. The proximal tines
of most rings would jump into the preparation and have
no tooth structure to brace against. This resulted in
a const ricted contact and narrowed anatomy of the restoration.
fig.1.Triodent
V3 Ring straddling the wedge placed interproximally.
The newest generation rings, such as the V3 (Triodent,
Katikati, New Zealand), were developed to overcome the
negatives of the prior rings available. These rings
have wider tines that are able to contact more tooth
structure even when preparation has eliminated portions
of the buccal and lingual cusps interproximally or there
is a greater distance with the adjacent tooth. As with
its predecessor the V-Ring, the tines are designed to
straddle the wedge instead of sitting adjacent to it,
making placement easier. (Figure 1)
Fig.2.The
Triodent V3 Rings, molar (green) and premolar (yellow).
The added benefit is that proximal separation
is greater, making for a tighter final contact. As all
teeth are not created equal, no single ring is ideal
for every situation and what fits a molar proximal may
not be ideally suited for a premolar contact. With that
in mind, Triodent provides two different sized V3 Rings,
a green for molar contacts and a yellow for premolar
contacts. (Figure 2)
An added improvement from their original ring is
that the tines have an increased angle to the ring's
loop making it easier to stack the rings for placement
on adjacent proximals when both the mesial and distal
will be restored on the same tooth. (Figure 3)
Fig.3.Stacked
Triodent V3 Rings allowing placement at adjacent proximals.
Case report:
A typical clinical situation involves the need to
restore both proximal surfaces on the same tooth. This
as discussed can be challenging. especially when caries
removal requires more of the interproximal to be removed.
The goal in today's restorative dentistry is to conserve
as much tooth structl lre as possible and only remove
carious dentin and enamel. But th is can still resu
lt in challenges to restoring the interproximals.
The patient presented with an open contact between
the first and second molars with resulting interproximal
caries as a result of chronic food impaction. Following
caries removal it was noted that the distal box was
relatively wide, but the mesial box preparation was
narrow due to the minimal caries in this area. (Figure
4)
Fig.4.Preparation
for a MOD direct restoration on a mandibular first molar
with an open contact on the distal
Fig.5.Sectional
matrix placed on the mesial/distal along with wedges and V3 retainer rings are
stacked.
Sectional matrices were placed at both the
mesial and distal of the tooth to be restored. A medium
Wave-Wedge (pink) was placed at the mesial and a large
(purple) distally. Triodent V3 Rings were placed at
both the interproximals. (Figure 5).
The preparation was rinsed and lightly dried to eliminate
any pooled water. A solvent-free self-etch adhesive
(Bond1-SF, Pentron Clinical Technologies, Wallingford,
CT) was vigorously rubbed into the prepared dentin and
enamel surfaces for 20 seconds. (Figure 6 and 7)
Fig.6.Application
of Bond1-SF adhesive applied with the frocked tip on
the syringe to all prepared surfaces and scrubbed for
20 seconds.
Fig.7.Application
of Bond1-SF adhesive applied with the frocked tip on
the syringe for 20 second and vigorous rubbing of the
prepared surfaces.
Fig.8.The
appearance of the prepared surface following application
of Bond1-SF demonstrates a glistening surface on the
dentin.
Fig.9.The
adhesive is light cured for 10 seconds
The resulting surface should have a glistening
surface (figure 8) and is then light-cured for 10 seconds
(figure 9)
A layer of Artiste dentin shade B3 (Pentron
Clinical Technologies, Wallingford, CT) a nano composite
was adapted to the pulpal floor, proximal boxes and
over all prepared dentin surfaces. Lobes were formed
and pits/fissures developed with a cone burnisher then
light-cured. (Figure 10 and 11)
Fig.10
Cone burnisher used to adapt Artiste shade B3 Dentin
to preparation.
Fig.11
First layer of Artiste following light curing, showing
development of lobes within the dentin layer.
To replicate a more natural esthetic appearance,
a brown tint, Artiste Maverick posterior pit tint (Pentron
Clinical Technologies, Wallingford, CT), was applied
with a #8 endodontic hand file to the pits and fissures
created in the dentin layer of composite and light-cured.
(Figure 12) A layer of Artiste enamel nano composite,
shade B (Pentron Clinical Technologies, Wallingford,
CT) was placed over the dentin composite and an acorn
burnisher was used to adapt it and create the anatomy.
(Figure 13)
Fig.12
Artiste Maverick posterior pit tint applied with an
endodontic file to accent the pits and fissures then
light cured.
Fig.13
Acorn burnisher being used to adapt the Artiste shade
B enamel layer.
The restoration was light¥cured from the buccal,
followed by the lingual and finally the occlusal surfaces.
(Figure 14).
Fig.14
Restoration is light cured.
The restoration is now ready for fini shing
and polishing. (Figure 15)
Fig.15
Direct resin restoration following placement of Artiste
nano composite prior to finishing.
The Triodent V3 Rings, wedges and matrices are removed.
(Figure 16) As the proximal contacts are often very
tight as a result of this ring system, it may be necessary
to use a locking hemostat to remove the matrix. Needle-shaped
finishing carbides and diamonds are used to remove any
f lash on the buccal and lingual. This was followed
by football shaped carbides and diamonds to contour
the cavosurface margin. (Figure 16) Final polisl1ing
was performed by Fini polishing disks (Pentron Clinical
Technologies, Wallingford,Cl) followed by polisl1ing
paste on a felt point (Pentron Clinical Technologies,
Wallingford, Cl).
Fig.16
Retainers, wedges and sectional matrices removed.
Fig.17
Direct resin restoration following contouring with finishing
carbides and diamonds.
Fig.18
Direct resin restoration following finishing and polishing,
which was accomplished with Fini finishing system.
Conclusion: Posterior direct resin restorations
can be accomplished resulting in good proximal contours
and tight contacts with the Triodent V3 Ring, matrices
and wedges. Combined with a simple layering technique
using Artiste composite, this allows replication of
natural esthetics and anatomy.
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