veneers: Can we be
Ross W. Nash, DDS
WHEN PERFORMING ELECTIVE PROCEDURES for cosmetic improvement of
natural teeth, I prefer to take a conservative approach and reduce as little tooth
structure as possible. I have found direct composite resin to provide the best
opportunity for this philosophy when elective veneers are desired. The materials
can be applied directly, allowing for them to be “paper thin” in areas and still work.
Indirect veneers usually need to have a certain thickness in order to be fabricated
in the dental laboratory, carried to the mouth, and bonded to place without
breakage. In addition, preparation for indirect restorations must have “draw” so that
the restorations can be fully seated. In my experience, most indirect ceramic
veneers last longer than direct veneers. I think that porcelain is the most durable,
long-lasting, and stain-resistant material we have for use with bonded veneers.
One philosophy for preparation for elective porcelain
veneers is to remove no tooth structure at all. An impression is taken of the unprepared teeth and a cast is fabricated from the impression. On this cast, conventional
feldspathic porcelain, pressed ceramics, or milled ceramics
can be used to fabricate the veneers. I prefer pressed or
milled lithium disilicate (IPS e.max, Ivoclar Vivadent)
because it can be made very thin, yet has high strength.
When bonded to the tooth structure with composite resin,
the lamination effect of the bonding processes strengthens
the veneer even more.
MINIMAL PREPARATION VENEERS
While no-preparation veneers satisfy my desire to conserve
tooth structure, I have found that some veneers placed
with this technique look too bulky, have margins that are
too thick, and are sometimes monochromatic in appearance. It is often difficult to hide all of the margins without
tooth preparation. Minimal preparation is my goal, but
once the patient has decided on elective veneers, the
desired end result dictates the amount of preparation that
The following is an example of a patient who desired elective veneers to improve the appearance of her smile. She
stated that her maxillary anterior teeth were spaced and
rotated. Her lateral incisors were “pegged” and smaller
than normal. The previous dentist was well meaning and
did not prepare the teeth at all before taking a final impression for fabrication of porcelain veneers. In Figure 1, you
can see the result that was obtained with six no-preparation
veneers from canine to canine. Though the spacing was
closed, the teeth still appeared malaligned and the shade
was monochromatic. The close-up view in Figure 2 shows
thick margins, some short of the tissue line. In Figure 3,
you can see where there had been marginal leakage of the
veneer on the lateral incisor evidenced by the black color.
The incisal view in Figure 4 shows overcontouring of proximal areas and less-than-ideal tooth-veneer interfaces.
Overlapping of proximal surfaces can be seen in Figure 5.
SCIENCE & TECH
Figure 1: Six no-preparation veneers
placed by the
Figure 2: Margins
in the previous
Figure 3: Marginal
leakage of the
veneer in the