Tarnow, D.D.S., is a professor and Chairman of the Ashman Department
of Implant Dentistry
and Science Editor Dr. Max Gomez (left) interviewed Dr. Tarnow recently
about breakthroughs in implant therapy.
The new scalloped
aesthetic implant design has patent pending.
aesthetics of implant-supported restorations have been a focus of
interest for the Ashman Department of Implant Dentistry for many
years. The original work done by our group and published in 1992
focused on the presence or absence of the interdental papilla. In
that seminal study, we found that the papilla was present 100 percent
of the time when the distance from the base of the contact point
to the crest of bone was 5 mm’s or less. When the distance
was 6 mm’s, only one mm more, the papilla was present only
55 percent of the time. When the distance was 7 mm’s, the
papilla was present 25 percent of the time, and when it was 8 mm’s,
it was present only 10 percent of the time. Since its publication,
this paper has helped clinicians determine how to construct restorations
in the aesthetic zone between teeth.
We next focused on what happens to the papilla
when an implant is placed next to a tooth. The question was whether
or not the 5-mm rule would hold up. In collaboration with a group
of Belgian researchers, we demonstrated that the same 5-mm rule
was in fact also true when an implant was placed next to a tooth.
This explains why single-tooth replacements supported on implants
can look aesthetically normal, including in the papilla area, and,
since normal anatomy can be expected around the final restoration,
why most lecturers like to show single-tooth implant patients.
The single most difficult problem facing clinicians
occurs when two implants are to be placed next to each other in
the aesthetic zone. If the other teeth have normal papillae heights,
it becomes a challenge for the clinician to re-form the papilla
between these two implants. In fact, it rarely fills in to the original
level that existed before the natural teeth were extracted. Accordingly,
our faculty began to investigate the amount of tissue that could
be expected to cover the inter-implant bone—the area within
which most clinicians find it difficult, if not impossible, to get
a papilla to look normal. Our findings, which have recently been
submitted for publication, show that only about 3 mm of papilla
height can be expected between two adjacent implants in the aesthetic
zone. Indeed, almost 90 percent of the papilla heights were only
2 mm, 3 mm, or 4 mm. Virtually none of the papillae reach the 5-mm
or 6-mm distance that we normally see between two teeth. This means
that normal, beautiful aesthetics can be expected when a single
tooth implant is placed next to periodontally healthy teeth. However,
if two implants are placed adjacent to each other in the aesthetic
zone, the papilla will tend to be about 2 mm’s shorter than
the papilla between the natural teeth in the same area.
Based on this knowledge, we revised our treatment
plan to no longer place two implants next to each other in patients
with high smile lines. Instead, we now recommend that one implant,
along with an ovate pontic, be utilized in such cases. If three
teeth are missing, then only two implants should be placed along
with an ovate pontic between them.
In other research, our faculty have shown that
wide body implants cause more recession than normal diameter implants.
This is clinically significant because it suggests that wide body
implants may not be indicated for use in the aesthetic zone. Once
again, our findings have changed the way practitioners develop treatment
plans when beautiful, normal contoured restorations are the goal
in the aesthetic zone.
It is a point of pride that the Ashman Department
of Implant Dentistry is an international leader in the field, and
that it has made substantial progress in the area of aesthetics
with implant support restorations. Currently we are working on a
new implant design that will help maintain papilla height in the
aesthetic zone. This project is spearheaded by Dr. Nicholas Elian,
Assistant Professor of Implant Dentistry. Dr. Elian has a patent
pending for an implant top that is scalloped instead of flat. All
implants today are straight across at the abutment implant interface.
If the implant is placed properly for mid-buccal aesthetics it will
cause a violation of the inter-implant bone, which helps support
the papilla. Violation of this point is a major factor in bone loss
between two adjacent implants. The new, scalloped design will allow
the implant to be placed supracrestally in the aesthetic zone, an
approach that promises important patient benefits.