Attaining Consistent Aesthetic Success With Veneers
By Irwin Smigel, DDS
I have had the privilege of being closely involved with porcelain veneers since their inception.
Even before Dr. Robert Weller developed the prototype preparation technique, the main concern was attaining a natural effect. The original veneers placed over unprepared teeth generated bulbous, overcontoured end products, which too often appeared unnatural. Today, the natural 'befitting" shape is our aesthetic barometer. The shade of a veneer is critical to its success, but when the veneer shape is unnatural, even a perfect shade cannot compensate the deficiency.
Dentists have come quite a ways since the early days of veneer design. Tooth preparation was the catalyst with proper reduction of tooth structure opening the doors to consistent natural aesthetics. Since those early days, continuing technique and material improvements, including the ultimate aesthetic breakthrough - bonding to dentin - have paved the way to unlimited aesthetic possibilities. But before dentists can achieve success with porcelain veneers, they must first learn how to tap into the aesthetic potential of dentistry.
Clinicians should be a participant in the final shaping of the veneers they are placing. Every case I undertake is returned overbuilt by my technician. With the veneers overcontoured and overlengthened, the responsibility for the final appearance is solely with me. With extensive cases in particular, I'm often uncertain of the exact result desired. I have a conception of the ideal outcome, but there are many variables, such as the precise tooth length and width and flow of each tooth into the next (the harmony of the smile). If I cannot envision the result I desire until working with the veneers in the mouth, how can I expect the technician to envision it?
Patients are appreciative and responsive to suggestions for improving their appearance. There is no intraoral camera in my office because I prefer to provisionally bond the areas intended for alteration, which dramatically demonstrates tooth realignment and color alterations. The old adage, "seeing is believing" still works in aesthetic dentistry.
To determine the best aesthetic treatment, dentists should observe patients with mouth smiling and mouth at rest. They should explain their intentions, ask patients for comments, listen attentively, and incorporate those that are beneficial, always bearing in mind that they are responsible for the results.
The following are two concepts that need to be reinforced before showing cases demonstrating them.
PROPER PREPARATION
Proper preparation is paramount. If the undersurfaces are not properly prepared, no amount of improvisation will attain the desired result. Midlines can be moved, overlaps straightened, and diastemas closed only if the teeth have been prepared to allow it.
SHAPING VENEERS
Shaping the veneers should be the clinician's responsibility. Control of length, width, angles, and inclinations provides dentists with the power to create illusions. They can make teeth appear wider or narrower, longer or shorter, masculine or feminine, and straighten an entire smile by altering tooth inclinations.
VENEERS
Straightening a Smile
A woman presented with concerns about the shape of her teeth. Her protruding lateral incisors overlapped her centrals, which distorted her smile (Figure 1). A closer observation showed that the lateral protrusion was exaggerated by the lingual leaning of her canines and first premolars (Figure 2).
I wanted to create a normal anterior alignment and if the teeth were prepared properly, a dramatic improvement could be achieved. The centrals were mostly reduced at the gingival one third of the facial surface, narrowed distally, and slightly shortened (Figure 3). The gingival reduction provided the veneer with a gradual gingival-to-incisal protrusion, eliminating the original top-heavy effect. Narrowing eliminated the distal flare and created space for norirnal width laterals, and the incisal shortening allowed better control of the final incisal length. The facial surfaces of the laterals were significantly reduced and the mesial overlaps were eliminated. This reduction was vital, but the realignment was also dependent on overcontouring the canines and first premolars (Figure 3).
The canines and first premolars had lingual inclinations, so again, most of the reduction was at the gingival thirds (Figure 2). They were also shortened incisally particularly the left canine. The shortened teeth provided the veneers with a better path of insertion and a more natural gingival-to-incisal protrusion. The basic preparation essentials (mesial, distal, and gingival chamfers) and incisal butt joints were adhered to in each situation (Figure 3).
The technician's responsibility was carefully outlined in the prescription. He was advised to overcontour and overlengthen the veneers, adhere to the margins, and follow the instructions regarding the shade: an A2 neck and Al body and incisal shade was indicated. The completed veneers were returned as requested, making the aesthetic responsibility completely mine (Figure 4).
Using a chipless stone (Shofu), the left central, lateral, and canine were shaped into an alignment, which was duplicated as close as possible on the right side (Figure 5). It was important that the patient and I felt very comfortable with the alignment. I then fine tuned and balanced both sides (Figure 6).
To eliminate the scratch markings and roughness left by the chipless stone, ceramic polishing wheels were used on a slow-speed handpiece until the veneers were completely smooth. A diamond impregnated polishing paste, Diaglaze (Antraco Inc.), was used for the final glaze-simulating finish. A small amount of the paste on a felt wheel was applied with medium pressure for 20 seconds on each veneer. This, in my opinion, yielded a finish at least as effective and natural as a conventional oven-produced glaze. The lateral overlaps were eliminated, and the lighter shade made the smile brighter. Nonetheless, the effort expended shaping the veneers is mainly responsible for the final vibrant and straight effect (Figure 7).
VENEERS AND SEXUAL IDENTIFICATION
Most first permanent teeth erupt at age 6. Of course, the teeth did not care if they were piercing a male or female mandible - the shapes would not have varied in any event. Evolution has not yet reached a plateau of that sophistication. Nonetheless, some people make much ado about a perceived difference between male and female teeth. This is because understanding that difference is essential to the proper performance of aesthetic dentistry.
People striving to enhance their appearance are luscious to the importance of emphasizing their sexuality. Most women attempt to project a feminine image, while men strive to enhance their masculinity. Men and women use everything from makeup and perfume to weight training and beards. Why not their teeth? There are distinct differences between masculine and feminine teeth. Differences that affect an identity and influence the ways others see us. I've seen too many otherwise acceptable veneer cases considered aesthetic failures because the veneers projected an incorrect sexual identification. Figure 8 illustrates the fundamental male/female differences.
The obvious difference is that female teeth are lighter and smoother, and male teeth are darker and more textured. The curved incisal edges are an important feminine feature. Flat or straight incisal edges indicate wear (possibly from a powerful bite), a strong male indication. The most significant sexual indicators are the maxillary lateral incisors. Large, prominent laterals similar to maxillary centrals are an important male characteristic, while narrow laterals dehneate femininity. The canines are comparable. Strong bold canines project manhood, while delicate canines are feminine. Men can carry a diastema, often appearing more natural, while the same can upset the symmetry in women. The step where maxillary laterals are distinctly and incisally shorter than the centrals is a female trait. Male central and lateral incisal edges should be similar. A slight step is acceptable, but a "powerful" male supposedly wears down his teeth uniformly.
A female patient can appear attractive and feminine except for her smile. It's contrary to everything she is trying to project. A closer view clearly shows why her smile is masculine (Figure 9). Her teeth are too dark and textured, and the anterior incisal edges are flat and straight. The important lateral incisors are wide, and the canines are much too prominent. The only male characteristic missing is a diastema. The first step in her transformation was the diagnosis.
To offset the prominence of her canines and broaden her smile, her four premolars were included into the treatment. Proper preparation was essential. The central and premolar preparations were routine, but her laterals and canines were complicated. Beyond the normal reduction, the laterals were narrowed, and the canines were shortened and significantly reduced facially (Figure 10).
Her new lighter and smoother veneers have curved incisal edges and a step between the centrals and laterals (Figure 11). The laterals are more delicate, and (because of the overcontoured premolars) her canines no longer dominate the smile. The before-and-after close-ups of her right side demonstrate a narrower lateral and gentler canine (Figures 12 and 13). The new veneers have given the patient a smile complimenting her natural feminine persona.
VENEERS AND ILLUSIONS
Success in aesthetics frequently depends on the ability to create illusions. The patient did not believe her large diastema could be closed without making her central incisors excessively wide (Figure 14). Figure 15 shows that it could be done, while making her new centrals appear slightly narrower than the originals. All this was done via illusions. The following was how the result was achieved.
- Four teeth were employed (instead of two) to better balance the tooth widths.
- The shortest distance between two points (the canines) is a straight line. So, by reducing the labial flare of the centrals, the space between the canines was reduced. And with less space to fill, the veneers could be made narrower.
- Lengthening makes teeth appear narrower. The patient's new, longer veneers exaggerated the illusion of narrowness.
- The mesial and distal gingival corners of the veneers were tapered and stained. This exposed less facial surface and created the illusion narrower veneers.
This next case could not have been successful without using illusions. A man presented an unbalanced and off-center smile. His major concern was the shade of his teeth; I envisioned greater dividends. Lengthening his teeth to be more visible and overcontouring his canines and premolars to broaden his smile were suggested. This was helpful until a closer observation disclosed the crux of the imbalance.
All his anterior teeth, from first premolar to first premolar leaned noticeably to the left, creating an asymmetry distorting the smile (Figure 16). It had to be reversed, so his eight anterior teeth were prepared for veneers. The preparations were definitely not routine. On the left, the distal halves of the facial surfaces of teeth Nos. 9 through 12 were overreduced. On the right, the mesial halves of teeth Nos. 5 through 8 were overprepared. These were the first steps in eliminating the leftward imbalance.
The key to this case, however, would be the configuration of the veneers. On the patient's left, the mesial ledges were overbuilt to lean the teeth mesially, fostering the illusion that the teeth were moved to the right. On the right, the distal ledges were overbuilt, further enhancing the illusion of rightward movement. Figure 17 illustrates the completed procedure. A close-up of the midline shows it is exactly as it was originally, yet,the smile has been normally realigned.
Reversing the inclinations altered the perception of the smile. Lengthening the teeth and building out the canines and premolars embellished the smile, but the overall effect could not have been accomplished without illusions.
VENEERS AND COLOR
The most difficult assignment in shade duplication is matching one central veneer to the exact shade of the adjacent natural anteriors. This is complicated when the veneer has to be placed over a discolored tooth. Duplication in this case requires effort, an understanding of the basic tenets of color, and affiliation with a technician with similar values.
He came to the office concerned about his discolored maxillary left central (Figure 18). Because his other anterior teeth were normal, I -inquired if he had ever suffered an injury to the discolored area. He said he had not, and the area was always that color.
After the tooth tested vital and the radiograph revealed everything was normal, treatment options were discussed. A porcelain crown was viable and might have been an easier shade match, but with his gingival tissue sound and the adjacent teeth normal, I believed a veneer would be the most tissue tolerant and conservative option (Figure 19). I told the patient the aesthetics would be difficult, but achievable. The first step was preparation. The shade of the adjacent teeth could be taken any time, but with discolored teeth, the shade should be finalized following tooth preparation. It is important to include a photo or detailed drawing of the completed preparation with the prescription. This enables the technician to accommodate the veneer to the underlying situation.
To compensate the discoloration, the facial surface required more than the normal reduction. The broadly stained distal half was reduced almost 0.75 mm; the mesial half was reduced slightly less. The gingival, mesial, and distal chamfer finishes and incisal reduction are illustrated in Figure 20.
The major concern was the orange-brown stains on a large area of the distal and a small area of the mesial. Over a sketch of the left central, I marked the specific areas I wanted opaqued, and specified the intensity. Because a too-powerful opaque can make a veneer appear unnatural, a relatively mild 1-part opaque to 35-parts porcelain was used. Stronger opaques range up to 1-part opaque to 25-parts porcelain. In the technique developed by my technician, the opaque intensity varies depending on the depth of the stain it is masking.
The incisal area of the right central was unusual (Figure 20). Except for the mesial and distal corners, there was no incisal translucence. In the center, there was a semicircle of A1 body color. The gingival area had a similar but inverted semicircle of A1 gingival color (Figure 19). The body shade was more difficult to match because it was to be placed over opaque. I saw it as a combination of D2 and D3. Th complement the underlying light opaque, two-thirds D2 and one-third D3 was prescribed (Figure 19). I then duplicated the mesial and distal incisal translucence of the right central onto the veneer. The mesial incisal area of the right central had a longer, wider, and lighter translucence than the smaller and slightly more concentrated translucent area on the distal incisal comer (Figure 20). I put them into the sketch with a T2 arrow pointing to the distal incisor, which indicated the translucence had to be more accentuated (Figure 19). The finished veneer clearly shows the A1 body and gingival colors and the mesial and distal incisal translucence (Figure 21). Less apparent, but nonetheless present, is the combination of D2 and D3 body and hints of the 1:35 opaque. The finished veneer matched its right central counterpart so closely that no color assistance was required from the composite, Ultrabond (DenMat) employed to bond it. A neutral color was used to achieve final matching.