Figure 4: Significant caries and tooth decay indicated that the best decision for these six maxillary anterior teeth was lithium bisilicate crowns.
Need for orthodontic treatment-The overall need for orthodontic treatment should be carefully analyzed. If orthodontic treatment is a viable alternative for correcting any of the described clinical conditions, this treatment should be performed instead of veneers. Patients should have in-depth informed consent regarding the various methods for correcting their functional and esthetic needs before choosing a veneer.
Matching the color of veneers and crowns-This work should be taken seriously in treatment planning. If many adjacent teeth in a treatment plan require crowns and some adjacent teeth could have veneers, color matching can be difficult. If all veneers and crowns are made of lithium bisilicate or similar materials, the challenge is reduced. If esthetic demands are high, a better result will be achieved by placing crowns on all involved teeth, rather than the more radical removal of enamel required for the less needy teeth.
Treatment of one or multiple teeth-Every dentist knows the difficulty of matching the color of a tooth to the adjacent teeth. Crowns block the color of the stump of the tooth, while with few exceptions, veneers take some of the color of the stump of the tooth. The final color of a veneer is related to the rest of the tooth structure, the cement used and the color of the ceramic. This combination of three colors makes it very difficult to match a veneer to adjacent teeth. Although matching a crown to the surrounding teeth is difficult, in my opinion, matching a veneer to the surrounding teeth is more difficult.
Difficulty placing veneers versus crowns-Most clinicians agree that the veneer procedure is more difficult than the crown procedure. Preparing teeth for veneers is usually fairly simple, but placing them requires meticulous attention to proper placement and color, as well as avoiding chipping of the veneers during cementation. This difference in difficulty has caused some dentists to charge higher fees for veneers than for crowns. With experience and repetition, veneer placement becomes relatively easy and predictable, and the results can be excellent.
Type of veneer material-Lithium bisilicate is currently the most popular material for ceramic veneers. Other similar materials are in development stages and will soon be on the market. Fabricating veneers using lithium bisilicate is a relatively easy job for lab technicians, and the aesthetics and durability are excellent. However, a recent survey of clinicians by the Clinicians Report Foundation shows that the use of feldspathic ceramics and leucite-reinforced ceramics (eg IPS Empress) is still popular but declining. Zirconia has revolutionized the profession and full contour zirconia crowns are more popular than PFM. As the esthetic characteristics of zirconia continue to improve, there is no doubt that zirconia veneers will gain acceptance.
Advantages of ceramic veneers when appropriate-In mature adults, teeth are usually fixed in positions related to masticatory contacts, muscle and tongue activity, chewing habits, and the presence of particular oral habits. When veneers are placed on permanent teeth, there is minimal post-treatment tooth movement or occlusal change. Every dentist has seen significant tooth movement that occurs for several weeks after crowns are placed.
Veneers, where indicated and properly constructed, technically have near-optimal aesthetic appearance for many years (figures 5, 6). This is not the case with many PFM crowns, which often show unsightly marginal exposure and loss of surface stains after only a few years. With the popularity and increased use of lithium bisilicate restorations, which do not have a metal substructure, this veneer advantage may not be as apparent in the future.
