April 1, 2004
by K. William Mopper, DDS
Restoring the cervical area of teeth is a frequent encounter of the restorative dentist. The causes of these lesions may result from caries, erosion, abrasion, and abfractions.
Modern composite resins offer high polishability, ease of handling, and optimal shade matching for ultimate esthetics. When combined with the new generation bonding agents, composite resins provide excellent bonding to tooth structure with a minimum amount of tooth loss.
Chairside composite restorations provide the clinician with greater control by allowing incremental buildup and sculpting of the final restoration to the desired morphology and color.
Microfill composite is the ideal restorative material for cervical restorations. Teeth can flex under occlusal loading, therefore you would like a material that will have some flexure in order to prevent failure. Its physical properties allows for long lasting polishable restorations.
The cervical of a tooth usually exhibits a higher chroma than the body or incisal area. Therefore a microfill with opacity is desirable. In order to increase the chroma of the cervical, tints may be used in conjunction with the microfill composite.
Figure 1 shows a lower right quadrant with cervical erosion on the facial of the bicuspids and first molar. In order to provide the most esthetic restorations, the teeth were prepared with the Mopper Micro bur kit from Brasseler. A long bevel is placed on the enamel towards the incisal and blends into the tooth. No bevel is needed on the gingival area, especially if it is subgingival (Figs. 2-4).
The total etch technique is used for increased bond strength. The adjacent teeth are protected from the etch with metal matrix bands. Thirty-seven percent phosphoric acid is placed on the teeth for 15 second. (Fig. 5). The teeth are rinsed with water and air dried for 2-3 seconds. A moist surface is desirable (Fig. 6).
A fourth generation bonding agent was chosen, Power Bond (Cosmedent, Inc.). This has a primer component and a resin component. The A & B primer are mixed and placed in numerous coats for 20 seconds. This layer is air thinned. The bonding resin is then placed, air blown lightly, and light cured for 20 seconds (Fig. 7). Be careful not to allow the bonding resin to pool.
In order to get the material to easily adhere to the preparation, a small amount of flowable microfill (Cosmedent, Inc.) is placed and light cured (Fig. 8). This will allow the microfill to be sculpted easily without tug back.
Due to the increased chroma at the cervical, a light brown tint from the Creative color kit (Cosmedent, Inc.) is placed and light cured. Only a small amount of tint is needed to provide the chroma desired. This is light cured for 20 seconds (Fig. 9).
A small amount of microfill is placed with a titanium coated instrument (8A Cosmedent, Inc.) and sculpted to place (Fig. 10). It is not necessary to fill the cavity preparation with one increment. The excess is cleaved off and condensed into the outline form. The material should not stop on the bevel, but go over the bevel. This will allow the material to blend into the tooth and have a disappearing margin (Fig. 11).
Once the material has been sculpted to the ideal form, it is light cured for 40 seconds. The gingival margin is sealed by taking a small piece of microfill resin and forming a cylindrical shape and forcing it into the marginal area (Fig. 12). This final layer is light cured for 60 seconds with a conventional halogen lamp.
Finishing is initiated using Brasseler ET finishing carbide burs. The rotation of the bur is from composite to tooth, thus helping to eliminate any open margins caused by finishing (Fig. 13). Course Flexi discs with a plastic mandrel will help hone the material into the tooth, creating perfect margins with no overhangs. The flexi disc system is used through out the process to achieve ideal polishability (Fig. 14).
The final polish is achieved by using a Flexi buff with enamelize polishing paste (Fig. 15) (Cosmedent, Inc.). The final restorations are shown in Figure 16.
By following the protocol in this article, an invisible Class V restoration can easily be attained.
Dr. Mopper is a pioneer of dental esthetic education. He is the director of CEE at Cosmedent.
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