Simulates craze lines
Decreases value or brightness
Simulates craze lines
Simulates enamel hypocalcifications; white spots
Masks yellow spots
Masks blue tetracycline stains
Yellow and yellow-brown
They can also be used to simulate craze lines. Because yellow is the complementary color of violet, it is effective in neutralizing and masking blue-gray tetracycline stains (see Chapter 2). Yellow can also be used in combination with white to mask brown tetracycline stains.
Blue, gray, or violet
Blue, gray, or violet shades are used on the incisal third of the tooth to simulate translucency (compare Fig. 4-2). They can also be used to reduce value (brightness).
White is used to increase the value (brightness) of any color modifier. It can be effectively used to simulate craze lines and enamel hypocalcifications (Fig. 4-3) and to mask yellow stains (Fig. 4-4).
Red or pink
Red or pink simulates gingival tones, enhances vitality, and can neutralize blue tetracycline stains (see Chapter 2).
Class III and class IV restorations
Truly “invisible” Class III and Class IV restorations are possible only through proper cavity preparation in conjunction with proper color matching (Fig. 4-5). Blending the color of the restorative resin into the color of the tooth is essential. Color modifiers are indispensable in fine tuning the definitive color.
In Class III or Class IV cavity preparations involving a through-and-through loss of both the facial and lingual enamel, the definitive restoration can exhibit undesirable “shine-through” (Fig. 4-5 C).
This shine-through occurs because the missing lingual tooth structure is replaced by a composite resin that is more translucent than the original dentin. The result is a visible outline of the restoration. Shine-through can be prevented by careful cavity preparation, the judicious use of color modifiers and opaquers, and a “sandwich” of various types of composite resins.
• Bonding agent of choice (see Chapter 3)
• Hybrid composite resin of choice (see Chapter 5)
• Microfilled composite resin of choice (see Chapter 5)
• For microfilled composite resins, low-speed, water-cooled diamond burs are best for trimming and finishing. For small-particle hybrid composite resins, high-speed tungsten carbide burs and low-speed, water-cooled diamond burs are recommended.
• Medium-grit rubber wheels for prepolishing (e.g., Burlew, Jelenko), or complete systems (e.g., CompoMaster/ CompoMaster Coarse Polishers, Shofu Dental Corp.; OR Astropol , Ivoclar Vivadent; ET Illustra Composite Polishers, Brasseler USA; Venus Supra Polishing System Heraeus Kulzer Inc., USA; Top Finisher System, Cosmedent, Inc.; Enhance Finishing System L.D. Caulk Co.
• Color modifiers: yellow, yellow-brown, white, blue, gray, violet (e.g., Effect Color Heraeus Composite Tints and Opaquers, Heraeus Kulzer, Inc.; Creative Color, Cosmedent Inc.; Kolor + Plus Kerr Corp; Artiste Maverick Tints, Pentron Clinical Technology; Bisco’s Characterization Tints, Bisco, Inc.
5. Prepare the cavity in a conventional manner (Fig. 4-6 A).
6. Round the cavosurface angle and place a long bevel to create an invisible transition from resin to tooth (Fig. 4-6 B).
10. If necessary, place custom tinting resins over this layer and blend the background color of the resin with the color of the tooth (Fig. 4-6 C).
A microfilled composite resin is the material of choice for diastema closure because of its excellent polishability and enamel-like luster (Figs. 4-7 A and B). If the diastema is very large, the lingual surface of the composite resin could be subjected to high functional stress in patients with heavy centric contacts. In these situations, the dentist may elect to use a hybrid composite resin for the entire restoration or a hybrid on the lingual portion overlaid on the facial surface with a microfilled composite resin. Shine-through is usually not a problem in diastema closure because of the labiolingual thickness of the add-on composite resin in the body area of the clinical crown. In many situations some translucency is desirable because the composite resin thins out at the incisal edge. If shine-through is a problem, follow the procedure described for the Class III and Class IV restorations.