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Class II Composite
Restorations and Proximal
Concavities: Clinical
Implications and
Management
M Patras !S Doukoudakis
Clinical Relevance
Proper configuration of the proximal surface of a Class II composite restoration is essential
for the preservation of dental and periodontal tissues and subsequent long-term success.
Adequately customized or designed wedges can assist in reproducing an imitation of
natural form in the interproximal area and ensure sufficient contact tightness with the
adjacent tooth.
SUMMARY
Clinical experience supports the notion that
the restoration of MOD cavities may pose a
challenge to the practitioner. Proper place-
ment of precontoured matrices and commer-
cial wedges help the clinician to establish an
optimal emergence profile and sufficient con-
tours. However, the presence of proximal con-
cavities in premolars or molars can turn the
reproduction of previous cervical architecture
into an even more demanding task. Wedges
with customized form or adequate design can
precisely conform the matrix to the cavosur-
face area and prevent any gap formation. This
article presents two different options that
allow for successful and predictable reestab-
lishing of anatomically correct contours and
optimal proximal contacts in posterior teeth
with proximal concavities.
INTRODUCTION
Recent technological advances in adhesive dentistry
along with the increasing patient demand for tooth-
colored restorations have forced the routine use of
contemporary resin composites for the restoration of
carious lesions. However, especially in Class II
composite restorations, among the most difficult
challenges to clinicians is achieving perfect adapta-
tion of resin composite to the margins and the
internal walls of the cavity or the prevention of
*Michael Patras, CDT, DDS, University of Florida, Center for
Implant Dentistry, Gainesville, FL, USA
Spyridon Doukoudakis, DDS, MSc, PhD, Assistant Professor,
Department of Operative Dentistry, School of Dentistry,
University of Athens, Department of Operative Dentistry,
Athens, Attiki 11527, Greece
*Corresponding author: University of Florida, Center for
Implant Dentistry, 1600 SW Archer Rd, Gainesville, FL
32608, USA; e-mail: michpatras@yahoo.gr
DOI: 10.2341/11-224-T
!
Operative Dentistry, 2013, 38-2, 119-124
overhangs at the cavosurface margin. Unlike amal-
gam, composite resins cannot easily be condensed
into all regions of the prepared cavity, which in turn
affects the establishment of sufficient proximal
contacts. In addition to that, the cervical proximal
margins in Class II restorations are often considered
to be the Achilles’ heel, as dentin bonding is often
less predictable.
Established United States Public Health Services
(USPHS) criteria evaluate anatomic form and mar-
ginal characteristics of restorations, implying that
marginal and internal adaptation are crucial for the
longevity and good prognosis of resin composite
restorations.
1–3
Moreover, it is well documented
4,5
that the formation of overhangs provokes food
impaction, subsequent recurrent caries, and peri-
odontal problems. Consequently, clinical experience
supports the notion that the proper placement of the
matrix and wedge are of paramount importance in
order to achieve ideal form, function, and esthetics
for the success of posterior resin composite restora-
tions.
6
In recent decades numerous developments have
been made in the field of matrices and wedges that
are used in posterior teeth. As resin composite is
becoming the most frequently used restorative
material, many of these products are specifically
targeted for improved results with those restora-
tions.
6
The constant search for the ‘‘perfect’’ system
is ongoing, as the diversity of clinical cases seems to
be endless. One of the most demanding clinical
challenges is the restoration of concave proximal
cervical areas, which are most commonly located in
the mesial aspect of the upper first premolars and
first lower molars as well as the distal side of the
upper first molars.
7
These prominent concavities
occupy an area located cervical to the mesial contact
area and extend to the corresponding tooth depres-
sion (Figure 1).
7
When the cervical margin of a Class
II restoration is located in the area of proximal root
invaginations, tooth contour seems ‘‘incompatible’’
with the convex shape of most matrices, as the latter
are commonly used for the restoration of convex-
shaped proximal areas.
As concave-shaped matrices have not been devel-
oped for such distinct clinical situations, the dental
clinician has to rely on the proper shape of the
wedge. Dental wedges usually serve to compress the
matrix to the remaining healthy tooth structure
across the entire buccolingual length, apical to the
gingival cavosurface line angle.
8
A review of the
literature revealed limited references on that topic,
suggesting molding the wedge with compound,
9
light-cured resin,
10
the utilization of elastic cords,
11
or the use of two wedges to seal the cavity.
12
PURPOSE
The purpose of this article is to recommend two
different options that will enable the clinician to
solve one of the main aforementioned issues regard-
ing Class II composite restorations, that is, the
adequate sealing of the gingival cavosurface margin
when a proximal concavity exists. The following two
clinical cases will illustrate two ways of conforming
the matrix to the proximal concavity of the tooth,
thus preventing an overhang and securing ideal
contours of the restoration.
DESCRIPTION OF TECHNIQUES
Case 1: Customization of Wooden Wedge
A 35-year-old female patient presented with a
carious lesion on the mesial aspect of her first upper
Figure 1. Proximal concavity at the mesial aspect of an extracted
upper first premolar.
120 Operative Dentistry
premolar. A conventional wooden wedge of adequate
dimensions was placed during the preparation of the
cavity (pre-wedging technique) in order to protect
the soft tissues, separate the adjacent teeth, and
ensure proper proximal contacts.
13
During the cavity
preparation, special care was given so that the
cavosurface margin finished on enamel, in order to
minimize the microleakage (Figure 2). Upon com-
pletion, a proximal concavity made it impossible for
the precontoured sectional matrix (Contact Matrix,
Danville Materials, San Ramon, CA, USA) to
maintain precise contact with the cavosurface
margin. Therefore, a larger wedge (Kerr, Bioggio,
Switzerland) than that needed was selected and
customized with a #15 blade in a corresponding
convex shape to accommodate the interproximal
space (Figure 3).
8
After the wedge was inserted in the proximal
space, securing the matrix in place, proper marginal
fit was verified (Figure 4).
8
A ring maintained their
positions, held the matrix against the tooth surfaces,
and added to the wedge’s separation capacity.
6,14
Subsequent burnishing of the matrix provided
adequate configuration and contact with the adja-
cent tooth.
6
The total etch technique was used and
the composite (Tetric EvoCeram, Ivoclar Vivadent
AG, Liechtenstein) was preheated, then applied by
incremental layering and polymerized in a soft-start
mode (Figure 5) in order to improve adaptation and
reduce shrinkage at the cervical interface.
15,16
Case 2: Plastic Wave-Wedge
A 40-year-old female patient presented to the clinic
with a failing composite restoration that also had
clinically unacceptable contours (Figure 6). After a
rubber dam was placed the old restoration and
secondary caries were removed and the outline form
of the cavity preparation was assessed (Figure 7).
Upon insertion of the conventional wooden wedge a
Figure 2. Occlusal view of the cavity preparation. Note the existence
of a proximal concavity.
Figure 3. A selected wooden wedge was properly contoured with the
use of a surgical blade.
Figure 4. The insertion of the customized wedge ensures adequate
matrix adaptation.
Figure 5. Postoperative view of the final restoration.
Patras & Doukoudakis: Management of Proximal Concavities 121
misfit between the matrix and the cavosurface
margin was verified (Figure 8). A plastic wedge
(Wave-Wedge, Triodent Ltd, Katikati, New Zealand)
(Figure 9) that has been lately introduced
17
was
selected in the case in order to aid in the adaptation
of the matrix. This wedge is designed with a wave
curvature that allows for an optimal adaptation to
the anatomy of the cervix of the tooth. Furthermore,
its elasticity enables the wedge to expand after
entering the critical interproximal area. For that
reason, the wedge was forced beyond its central
concavity to ensure proper sealing (Figure 10), to
prevent any gap formation in the cavosurface area,
and to facilitate composite layering (Figure 11). All
the subsequent steps were carried out as mentioned
above, and a radiograph verified the acceptable
contours at the mesial aspect of the restoration
(Figure 12).
Potential Problems
The potential problems identified included the
following: 1) difficulty in establishing sufficient
contours of the wooden wedge (in the first case)
Figure 6. Preoperative occlusal view of the existing restoration.
Figure 7. After the removal of the restoration, a proximal concavity
could be observed.
Figure 8. Placement of a conventional wooden wedge results in
incomplete sealing of the cavosurface margin.
Figure 9. The Wave-Wedge (Triodent Ltd) in three different, color-
coded sizes.
Figure 10. The Wave-Wedge’s design allows for adequate sealing.
122 Operative Dentistry
and 2) potential displacement of the plastic wedge or
inadequate tooth separation (in the second case)
DISCUSSION
Resin composites are considered to be the state-of-
the-art materials with which to facilitate direct
posterior restorations. However, the restoration of
a MOD cavity is often a concern for the clinician,
who has to overcome problems associated with
adequate handling of interproximal areas as a result
of constraints in clinical access.
6
Given the afore-
mentioned inherent limitations, the presence of any
proximal anatomical variations in premolars or
molars can pose a challenge to the practitioner.
6
Proper reproduction of the proximal concavity is
largely dependent on the shape and relation of the
sectional matrix and corresponding wedge.
6,8
Among the basic requirements, a dental wedge
must be able to cause tooth separation, provide
resistance against the matrix, and precisely conform
it to the anatomical surfaces of the tooth to be
restored. Loose fit of the matrix allows oral fluids to
contaminate both the cavity and the restorative
materials. Therefore, this improper adaptation com-
promises the longevity of the restoration and induces
its potential failure in the future. Furthermore, any
gap formations will develop overhangs and unac-
ceptable contours of the tooth in the interproximal
space, leading to plaque accumulation.
4,5
This is
even more important as the finishing burs and strips
cannot approximate concave gingival margins,
6
and
the difficulty in gaining access can definitely endan-
ger the integrity of the adjacent teeth and the
periodontium.
As the restoration’s success lies in meeting the
fundamental prerequisites, the custom wedge mod-
ifications with a bur or blade
8
or the utilization of
precontoured wedges can present viable alternatives
to conventional wedges and enhance the clinician’s
armamentarium.
Summary of Advantages and Disadvantages
From a clinician’s perspective, the two options
illustrated above represent very effective ways of
addressing such clinical situations, thus providing
the practitioner with sufficient comfort at the same
time.
6
Both wedge designs reflect the shape of the
proximal concavities; thus, they may offer various
advantages in an efficient and simplified manner.
Their customized shape can easily be adapted to
tooth contours, create a tight seal, and ensure
matrix manipulation. In such a clinical situation
the adequate transition from the concave cervical
area to the convex shape of the contact area is
mandatory. This individual reproduction of previous
cervical architecture prevents any overhang forma-
tion and minimizes the need for lengthy finishing
procedures.
In the authors’ experience, the potential disad-
vantages of the present approaches could be the time
needed for the techniques to be well adopted and
Figure 11. Occlusal view of the completed restoration showing
optimal contours and proximal contact with the adjacent tooth.
Figure 12. The radiograph verifies the absence of an overhang at the
cavosurface margin.
Patras & Doukoudakis: Management of Proximal Concavities 123
distortion of the matrix during the insertion of the
wedge, as well as the cost of the plastic wedges.
Conflict of Interest
The authors of this manuscript certify that they have
no proprietary, financial, or other personal interest
of any nature or kind in any product, service, and/or
company that is presented in this article.
(Accepted 21 February 2012)
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