For many clinicians, creating artistically esthetic direct composite restorations poses a challenge. Replicating natural anterior esthetics using a recipe of various shades and opacities of composite materials becomes complicated because of the difficulty in blocking out the darkness of the oral cavity while creating a naturally translucent restoration. In the posterior areas of the oral cavity, the blend or chameleon effect of the composite material with the adjacent tooth structure proves more important than the opacity of the restoration’s dentin layers. In this article, the composite system (Ceram X: Dentsply Caulk) used in the clinical cases offers a simple, unique approach to shade selection. The system has two components: Ceram X Duo has five dentin shades (D1 through D4, and D Bleach) and three enamel shades that are used to create all of the popular Vita Shades by layering the appropriate enamel over the dentin material. Ceram X Mono offers seven basic shades to cover all Vita shade possibilities. Either component can be used for both anterior and posterior applications.

DIASTEMA CLOSURE USING DIRECT COMPOSITE

Diastema closure using direct composite resin can be a deceptively difficult restoration to perform, because one needs to exaggerate emergence angles from below the gingival crest to create natural eruptive tooth form. Most attempts result in building a “supragingival shelf” that closes the space, but does not reproduce a balanced, convex gingival embrasure profile that supports the papillae without leaving a “black triangle.” To further complicate matters, potential soft-tissue damage or bleeding during the restorative procedure can hinder the process. The patient shown in Fig. 1 presented with a Class IV mesioincisal fracture on tooth No. 9, and a small diastema between tooth Nos. 8 and 9. A Vita Lumin shade guide (Vident) is used to select a B1 shade for the restoration. According to the Ceram X Duo shade conversion chart (Figs. 2 and 3), using D1 for the dentin layer and E1 for the enamel layer duplicates a Vita B1 overall shade. The operative plan is to bevel the enamel from the mesiofacial line angle of the facial surface to the lingual proximal line angle, proximally. It is easier to create an “invisible seam” or margin if the restorative material ends directly on the intersection of the mesial and facial surfaces (Fig. 4).

Next, the enamel beveled surfaces are etched using 37% phosphoric acid for 15 seconds, then thoroughly rinsed and air dried (Fig. 5). A single-bottle dentin adhesive (XP Bond: Dentsply Caulk) was chosen, and applied with a microapplicator per the manufacturer’s instructions. XP Bond (Fig. 6) was selected because when it comes to adversely affecting bond strength, this adhesive reportedly is less sensitive to moisture or over-drying. Because the gingival crevice can be a difficult place to use adhesives, it’s critical that the restorative material starts to exaggerate the emergence profile of the tooth from this intracrevicular position.  After saturation of the prepared enamel surfaces (Fig. 7), the excess is air-thinned and light cured.

Once the preparation is completed and the adhesive is applied and light cured, the gingival tissues are deflected away from the tooth surface at the periodontal-tooth interface and also impregnated with a hemostatic agent by using Expasyl (Kerr Corp.) (Fig. 8). The material is expressed, then “tapped” to place using a dry cotton pellet held in a cotton forceps. After about 2 minutes, the Expasyl is rinsed away with a combined air-water spray, leaving the gingival tissue deflected away from the tooth surface and allowing access to the gingival sulcus. Facilitate creating the intracrevicular portion of the restoration by using a dead soft matrix strip. Carefully place the strip into the opened gingival crevice and create a convexity using a plastic filling instrument (Flexi-Thin Mini 4: HuFriedy). The matrix is stabilized from the lingual aspect of the tooth being operated upon with the index finger, while the thumb is used to stabilize the matrix from the facial aspect of the adjacent central incisor (Fig. 9). The dentin increment of composite (Ceram X Duo) is placed to form the lingual shelf of the first central incisor restoration. This lingual shelf should fill about one-half of the diastema, and may be slightly overcontoured when placed. Place a plastic matrix next to the adjacent proximal surface to keep composite off this surface (Fig. 10). Once cured, the shelf can be contoured using a flexible composite contouring disc (OptiDisc:Kerr Hawe) (Fig. 11). When completed, the proximal surface should close one-half of the space.

Next, apply the enamel layer (Ceram X Duo) into place using the plastic filling instrument (Flexi-Thin Mini 4). Dip an artist’s brush (#4 Keystone Ceramic Brush Flat: Patterson Dental) into the adhesive, wipe off any excess with a 2x2 gauze, leaving the bristles supple, and use the brush to blend and contour the enamel surface of the restoration (Fig. 12). After light curing, use an 8-fluted composite finishing bur to complete the facial contouring and finish the restoration using rubber abrasive discs (Enhance: Dentsply Caulk). Next, use a celluloid matrix strip to protect the first restoration on the mesial aspect of tooth No. 8. Repeat the steps described to build up the mesial aspect of tooth No. 9 and complete the diastema closure. Use a celluloid matrix to build the lingual shelf for the restoration on tooth No. 9 (Fig. 13).

The enamel layer then is freehanded into place without a matrix against the polished surface of the adjacent tooth to ensure a closed contact. This layer is contoured using the 8-fluted composite finishing bur (Fig. 14). The flexible polishing disc (OptiDisc) is again used to polish and refine the facial proximal line angles of both restorations (Fig. 15). Final contouring of the critical intracrevicular areas is accomplished using 30- and 50-micron diamond abrasive strips (Gateway Strips: Brasseler USA) (Fig. 16). Figure 17 shows the completed diastema closure prior to final polishing. The rubber abrasive disc (Enhance) is used to create the final finish to the restorations (Fig. 18). The final step: Place a surface sealant using an artist’s brush and light cure (Lasting Touch: Dentsply Caulk). Due to the “self-leveling properties” reported for this particular surface sealant, the brush marks will be less visible after application. It is recommended, however, to apply this sealant using horizontal brush stokes across the tooth, instead of brushing it in a vertical direction. Fig. 19 shows a post-operative view of the completed diastema closure.

POSTERIOR OCCLUSAL RESTORATION

Posterior direct composite restorations are the new “bread and butter” restorations in the esthetic/restorative practice. Many may argue that we are not there yet in the search for the true tooth-colored amalgam replacement. However, materials science has taken leaps and bounds toward that lofty goal within the past decade. Challenges with technique sensitivity still plague many dentists and their patients, but newer materials may provide some answers. Completing the total-etch technique using fourth- and fifth-generation bonding adhesives can provide excellent clinical service, and sixth- and seventhgeneration bonding agents (self-etch systems) have helped many clinicians deal with the sensitivity issues sometimes reported with total-etch systems. The singlebottle system, XP Bond, is reported by themanufacturer to reduce some of the technique sensitivity by performing well with “extended windows of wetness”…that is, when the dentin substrate is too wet or too dry. This can prove beneficial. Fig. 20 shows a pre-operative occlusal view of tooth No. 19, which needs an occlusal restoration due to caries surrounding an old sealant. This tooth is prepared and isolated in preparation for the restorative process. After etching the enamel and dentin surfaces, then thoroughly rinsing and air drying, a single-bottle dentin adhesive (XP Bond) is placed using a microapplicator (Fig. 21), then is air-thinned and light cured. The appropriate shade of composite material (Ceram X Mono) is selected for the restoration using the shade guide provided. The chameleon effect allows the restorative material to blend without using complex layering techniques. The facial increment is placed using a unidose compule, angling the material so that it is extruded against the vertical wall of the preparation. A plastic filling instrument (Flexi-thin Mini 4: HuFriedy) is used to sculpt the parabolic cusp forms to coincide with the resident anatomic tooth form. After light curing the facial increment, the process is repeated on the lingual aspect of the preparation (Fig. 22).

Note: Before light curing the lingual increment, smooth it with the artist’s brush to soften the composite contours and refine the marginal interface (Fig. 23). The restoration then is finished at the marginal interfaces with rubber abrasive discs (Enhance), and a surface sealant is brushed on and light cured (Lasting Touch) Figure 24 is the occlusal view of the completed restoration of tooth No. 19.