The porcelain veneer has gained full acceptance in recent years as a primary restoration in esthetic dentistry. Since its introduction in the early 1980s, it has undergone an evolution in both techniques and materials. A significant number of long-term clinical studies confirm the excellent durability of the porcelain veneer restoration.
Porcelain veneers may be used to modify a tooth’s color, shape, length, or alignment, to close space, and to restore fractured and endodontically treated teeth.
The Patient should be informed, however, of the possible morbidity associated with a specific indication, as well as the generally accepted limitations. Informed consent should include, but not be limited to, the following potential complications:
- Postoperative sensitivity
- Marginal discoloration
- Wear of opposing teeth.
The Patient’s self-image must be considered during the initial patient interview. A key element in the diagnostic phase is a clarification of the Patient’s expectation. If it can be determined initially that the Patient’s expectations are unrealistic, future grief may be avoided.
Maintain Facial Aesthetics
When a treatment plan is being developed that includes the restoration of teeth in the esthetic zone, attention must be directed not only to the shape and color of the teeth, but to the shape of the face, the lips, the maxillary and mandibular lip lines, and the skin color.
The teeth can be used to accentuate a positive feature or de-emphasize a negative trait. For example, a patient with a narrow face may desire longer and narrower teeth to emphasize the facial shape or shorter, rounded teeth to soften the narrowness of the face.
It is also essential to evaluate skin color, especially if there is a possibility that it will change over time. For example, if porcelain veneers are being planned for a white patient with a dark tan, a determination must be made regarding the longevity of the tan before shade selection. If the dark tan is transient and skin color will revert to a lighter tone, this will significantly affect the decision on the color of the porcelain veneers.
Veneers that appear to be bright and high in value against the tan skin will look more yellow and lower in importance as the skin tone becomes lighter. All of these parameters must be consciously considered during the diagnostic phase if consistently excellent results are to be obtained.
After the facial features have been considered, attention must be directed to the smile and its components. During the initial interview, the dentist should pay close attention to the overall appearance of the Patient’s mouth as he or she speaks and is in repose.
The dentist should note the maxillary incisal edge position about the lower lip, the relationship of the maxillary incisal plane to the horizon, the amount of gingival display during smiling and speaking, the relationship of the anterior and posterior segments, and the overall quality of the smile.
If the interpupillary plane is parallel to the horizon, it may be used in the evaluation of the incisal plane. The dentist pulls the upper lip parallel to the interpupillary line and then uses the lip to evaluate the incisal plane for a cant. The acceptability of the incisal plane must be determined during the diagnostic phase, or discrepancies may be incorporated into the final restorations.
With an understanding of esthetic diagnostic parameters, the dentist can use several diagnostic methods to develop a treatment plan that will predictably result in success. Preparation and waxing on a diagnostic cast are sometimes helpful to the dentist, primarily when the veneers are intended to lengthen teeth, close spaces, or correct malaligned teeth. However, a diagnostic wax-up is not especially helpful in giving the Patient a preview of the expected aesthetic outcome.
Types of Veneer
Perhaps the most challenging procedure in esthetic restorative dentistry is to perfectly match a full-coverage restoration to an adjacent natural central incisor. Commonly, the porcelain veneer is the restoration of choice in this situation. If the tooth to be restored is not significantly discolored, the porcelain veneer is an excellent therapeutic option. The significant advantage of the single porcelain veneer restoration is the dentist’s ability to increase or decrease the value of the repair with the bonding resin cement.
When the clinician has the option of veneering multiple anterior teeth, the problem of shade matching is minimized. It is easier to deal with even numbers when veneers are placed on anterior teeth. It is much simpler to veneer two central incisors than to attempt to match a surface to a natural tooth.
Therefore, the chances of obtaining an optimally esthetic result are enhanced when two, four, six, or eight veneers are placed. An option that is commonly chosen is the placement of six veneers from canine to canine. The anterior teeth are brighter and bolder, while the buccal corridor appears to become darker. It accentuates the anterior teeth and commonly creates the unpleasant illusion that the anterior teeth are more extensive and longer as well as brighter.
It does not usually occur when only the four incisors are veneered. Therefore, when veneers are planned for the teeth, but there is no aesthetic or functional requirement for canine surfaces, the esthetic result is enhanced when the canines are left unrestored. However, when all six anterior teeth require.
The preparation of teeth for porcelain veneers is usu-ally uncomplicated when the basic principles are understood and followed. The amount of tooth structure removed during development is determined by the position of the tooth in the arch and the color of the tooth.
If the tooth is cardioverted, more tooth structure will be removed so that the final restoration will have the correct facial contours. If the tooth is lin-governed, very little preparation is required other than a peripheral finish line. In routine training, the facial enamel is reduced approximately 0.3 to 0.5 mm.
This can be accomplished with depth cut burs, which are available from several manufacturers. After the depth cuts are made, the enamel is uniformly removed with a round-ended, tapered diamond. However, if the underlying tooth color is dark, the preparation must be deepened to allow for increased porcelain thickness. With darker tetracycline-stained teeth, the development should be approximately 0.7 mm deep in the area of the stain.
The porcelain veneer has gained full acceptance in recent years as a primary restoration in esthetic dentistry. Since its introduction in the early 1980s,