How to place posterior composites

Separation rings can be used as a predictable method to place Class II composite resins and obtain tight, well-contoured, interproximal restorations.

Separation rings can be used as a predictable method to place Class II composite resins and obtain tight, well-contoured, interproximal restorations.

Use of a separating ring, such as the Garrison Composi-Tight 3D system, when restoring Class II composite restorations has a greater influence on the obtained proximal contact tightness compared to the influence of the consistency of the composite resin.1 Ceramic inserts or pre-polymerized resin particles have been used, which can wedge contacts interproximally as well as decrease the overall amount of composite used, thereby reducing overall shrinkage.2,3

What it’s made of

The Garrison Composi-Tight 3D sectional matrix system has a Soft-Face (Fig. 1). The circular ring is made of polished stainless steel, with the bow section encased in plastic that stiffens the ring (Fig. 2). The hard and soft plastic combination of the tine area creates separating pressure while entering the interproximal area to minimize flash and enhance the grip on the contoured matrix band, which comes in a number of sizes and shapes. The U-shaped gingival contour of the soft face allows the ring to be placed over the wedge.

The system has the option of using regular contoured bands or the new Slick bands (Fig. 3), which are designed to minimize adhesion to the matrix band. The Garrison Fender Wedge (Figs. 4 & 5) is an excellent way to protect the rubber dam, interproximal gingival tissues, and the tooth surface adjacent to the preparation.

Clinical predictability is assured using the following protocol.

Case presentation

A 20-year-old patient presented with four quadrants of failing composites due to open contacts, interproximal and occlusal decay and pain on chewing (Figs. 6 & 7). Tooth No. 15 had carious pulp exposure and required endodontic therapy. Rubber dam was applied to the lower left quadrant after anesthesia, interproximal wooden wedges were placed to begin the “pre-wedging” process and were advanced during the procedure.

Step 1: After removing the old restorations and caries in tooth Nos. 19 and 20, a BlueView Pinch Matrix (Garrison Dental Solutions) was applied to tooth No. 19 (Fig. 8) and new wedges inserted to stabilize the band, adapt it gingivally to minimize the chance for composite overhang, and to create interproximal pressure.

Step 2: To facilitate easy access, and because tooth Nos. 18 and 20 were going to be prepared and restored, no auxiliary separation was applied. Tooth No. 19 was etched with Ultra-Etch 35% phosphoric acid solution (Ultradent) by applying it to the enamel margins first, followed by placement within the cavity preparation, and washed and gently dried after 15 seconds, leaving a slightly moist surface.

Step 3: G5 desensitizer (Clinician’s Choice) a mixture of 5% Gluteraldehyde, 35% HEMA and water was carefully applied, and the excess removed by suction. By coagulating plasma proteins in the tubules, the G5 acts as a pre-primer and has residual antimicrobial effects.

Step 4: MPa (Clinician’s Choice), a fifth generation bonding agent, was placed in a single layer, air-thinned with the solvent evaporated and light cured with a Valo broad spectrum curing light (Ultradent) for 10 seconds.

Step 5: A thin layer of DeMark, a hyper-opaque, flowable hybrid lining composite (Cosmedent) was teased into the base of the proximal box, into the deeper carious excavation areas and lightly teased over the pulpal floor (Fig. 9), followed by light curing for 10 seconds. Its radiopacity can be seen clearly on the radiograph (Fig. 10), which minimizes the chance for erroneous diagnosis of caries under the composite due to radiolucent lining materials. Placement of a flowable liner also creates an “elastic cavity wall”4 interface which minimizes the effect of C-factor shrinkage.5

Step 6: An incremental insertion technique was used to restore the tooth with Cosmedent Nano A2 (Cosmedent), with each layer no more than 2 mm, laterally placed to reduce the C-Factor and light cured for 10 seconds. The restoration was shaped on the occlusal with a 7803 multi-fluted bur, and the mesial interproximal shaped with a 7901.

Step 7: On tooth No. 20 the Garrison contoured matrix was placed, followed by a G Wedge, and the Composi-Tight 3D ring applied to separate the teeth, and minimize interproximal flash (Fig. 11). After each placement of the contoured matrix band, a ball burnisher should be used to verify contact with the adjacent tooth.

Step 8: The DO restoration was placed following the previously described protocol.

Step 9: A final excellent contour and contact can be routinely achieved with this system (Fig. 12). Because of a tear in the rubber dam, a new dam was placed to adequately isolate tooth No. 18 and “pre-wedging” initiated.

Step 10: Even with the rubber dam clamp on the same tooth, if well-placed apically, Figure 11 shows the application of the Garrison contoured matrix and the Composi-Tight ring over the rubber dam clamp. The easy 90° direct access allowed by the shape and design of the Valo curing light allows maximum curing penetration (Fig. 13).

Step 11: After restoring tooth No. 18 as previously described and polishing the restorations with an occlusal diamond impregnated Groovy bristle brush (Clinician’s Choice), a post-operative photo was taken (Fig. 14).

About the author

Dr. Leendert (Len) Boksman DDS, BSc, FADI, FICD, is a part-time consultant to Clinical Research Dental acting as Director of Clinical Affairs, an Adjunct Clinical Professor at the Schulich School of Medicine and Dentistry and is in private practice in London, Ontario. He can be reached at lboksman@clinicalresearchdental.com. This article is a portion of one previously published in Oral Health November 2010.