Shade Matching with Light-Diffusing Composite in Anterior Restorations
Single- and dual-shade selection methods provide esthetically pleasing results
The introduction of light-diffusion technology has improved the quality of anterior composite resins, (eg, Clearfil Majesty™ ES-2, Kuraray America, Inc., www.kuraraydental.com). By refracting light in a way that is similar to dentin, these composites exhibit the opacity and fluorescence of the natural tooth. As a result, the finished restoration blends into the existing tooth structure invisibly, masking the darkness behind front teeth and matching the hue, chroma, and value of the restored tooth.
Simplified Shade Taking
Many dentists have long-term, extensive experience with, and can easily recall, the VITA Classical Shade Guide (eg, A1, B2, etc) (Vident, www.vident.com). However, a new method based on relative lightness, in which the A shade within each value grouping falls midway between the other two, enables fast and accurate shade taking. A single shade of light-diffusing composite, such as Clearfil Majesty™ ES-2 Classic (Kuraray America, Inc.), or multiple shades in the dual-shade technique may be used for the restoration. By selecting the appropriate value, the shade choice is narrowed down to one of the three shades within each grouping. The single-shade and dual-shade techniques are described in the cases that follow.
In the dual-shade technique, one material replaces the enamel and another replaces the dentin (Clearfil Majesty™ ES-2 Premium, Kuraray America, Inc.). This technique is useful when dentists are faced with complex esthetic requirements, such as a color gradient. The enamel and dentin shades of the composite are A shades, and each grouping contains different color intensities. For example, if the final shade match was B2 and the clinician elected to use the dual-shade technique, he or she would use shade A1D to replace dentin, and shade A1E to replace enamel.
For either single- or dual-shade restorations, a facial 2- to 3-mm bevel of approximately 60° serves as a functional/esthetic bevel that facilitates the blending of the composite to match the adjacent tooth structure. At the edge of the bevel, the composite picks up the adjacent tooth color and diffuses the light like dentin. In certain cases, the edge can be scalloped rather than straight by holding the diamond in different directions so as to blend the composite into the transition zone.
Case 1: Single-Shade Technique
A 17-year-old male patient came into the office for a routine visit and was found to have multiple areas of decay (Figure 1) contributing to gingival inflammation from plaque retention. During this visit, teeth No. 9 (distal), No. 10 (mesial), and No. 11 (buccal cervical) were treated.
Following local anesthesia, the shade of Clearfil Majesty ES-2 Classic composite was selected, the tooth isolated using cotton rolls, and the salivary pellicle removed using coarse pumice with a prophy cup, then rinsed. Next, a 40% phosphoric acid gel (K-Etchant gel, Kuraray America, Inc.) was applied for 15 seconds to the unprepared enamel surfaces, and then rinsed.
Following the outline and caries removal, the dentin was tested for residual decay with a caries-detecting solution (Caries Detector, Kuraray America, Inc.) (Figure 2) and all red-stained dentin was completely removed from within 2 mm of the dentinoenamel junction. In the deeper areas of the preparation, the “pink haze” was left so as to avoid an unwanted pulp exposure. The bonding system chosen was Clearfil™ SE Protect (Kuraray America, Inc.), an antibacterial, fluoride-releasing self-etch adhesive, which was applied according to the manufacturer’s instructions.
A polyester film strip was used to establish the proximal contour and the appropriate shade of Clearfil Majesty ES-2 Classic composite (shade A2) was used on tooth No. 10 until the preparation was completely filled, then contoured. The procedure was repeated for tooth No. 9, and the buccal cervical lesion on tooth No. 11.
The occlusion was adjusted and the case contoured using a fine diamond (Two Striper®, Premier, www.premusa.com) and a sandpaper disc (coarse Sof-Lex™ Contouring Disc, 3M ESPE, www.3mespe.com). Polish was achieved using coarse pumice followed by a slurry of polishing compound. After the restoration was completed, the patient was given oral hygiene instructions. Pleasing esthetics were maintained and the gingival health of the patient had improved at the 1-month follow-up appointment (Figure 3).
Case 2: Dual-Shade Technique
In this case, use of a dual-shade technique with Clearfil Majesty ES-2 Premium composite shade A3D (to replace dentin) and shade A3E (to replace enamel) achieved results that successfully blended into the adjacent tooth structure and masked the darkness of the mouth. A 30-year-old woman came into the office desiring an esthetic repair of the fractured incisal edge of tooth No. 8 (Figure 4).
The dual-shade technique was chosen due to the restoration’s more complex esthetic requirement. First, the shade was determined using Clearfil Majesty ES-2 Shade Guide (Figure 5; Kuraray America, Inc.). The shade chosen was A3, so the treatment plan involved using shade A3E (enamel shade) over shade A3D (dentin shade). The pre-etching of enamel was employed as in Case 1, followed by a class IV preparation, hiding the transition zone with an undulating bevel (Figure 6). The self-etching adhesive (Clearfil SE Protect) was used and the dentin composite was “sandwiched” between two enamel layers, then contoured and polished, leaving a conservative, esthetically pleasing restoration (Figure 7). Figure 8 shows the simplified shade taking guide.
Anterior restorations can be accomplished using an esthetic composite resin and a simplified shade-taking system. Clearfil Majesty ES-2 composites can be used with a single-shade technique (using Clearfil Majesty ES-2 Classic composite) or a dual-shade technique (using Clearfil Majesty ES-2 Premium composite). Simplified finishing completes each case, resulting in an esthetic blend into the adjacent tooth structure.
The author received an honorarium from Kuraray.
About the Author
Randall G. Cohen, DDS