Restorative dentistry has developed significantly in the are of esthetics since the
advent of acid-etch bonding. As bonding materials, laminates and porcelains continue to be
refined dental esthetic consideration more and more often focus on the relationship of the
gingival tissues to the teeth. In a recent interview, Dr. Gordon Christenson, restorative
and clinical research dentist, noted fifty percent of his newly diagnosed esthetic cases
are referred to the Periodontist for management of gingival esthetic factors. In this
newsletter, gingival factors which may influence the results of your esthetic dentistry as
well as some of the periodontal corrective measures which are available are discussed.
The first step in creating a harmonious relationship between tooth and gingival tissue
is the elimination of marginal inflammation of the periodontal tissues. Reddened marginal
tissue draws the attention of the casual observer due to the stark contrast with the
tooth’s color and adjoining tissue. Edematous tissue produces a shadow effect on the
gingival one-third of the tooth increasing the perception that the tooth is yellow or
brown. Rolled gingival margins encourage more rapid growth of plaque in the
"stagnation area", the triangular shaped depression between the bulky, inflamed
gingival margin and the tooth’s gingival height of contour. A healthy, knife-edge
gingival margin minimizes this stagnation area.
Thin, delicate gingival tissues are more demonstrative of the inflammatory response and
undergo significant gingival recession after root preparation and restorative procedures
if they are highly inflamed. Bluish hues in the marginal gingiva may represent subgingival
calculus, vascular stagnation or the presence of restorative margins too deep or too wide
within the sulcular area. Responsible efforts at plaque control by the patient are
critical in the immediate and long term success of esthetic dentistry cases. In patients
with pre-existing subgingival restorative margins and bluish tissue responses, adjustment
of the gingival margin’s relationship to the restorative margin is required.
Provisional restorations may be needed to maximize gingival esthetics and assess margin
placement.
Color is readily recognized for its influence on appearance. To understand and assess
other esthetic values, our profession has looked at those individuals considered most
esthetically pleasing and extracted dental parameters that define the "ideal"
smile. Although every smile is different, a recent article in the ADA journal by Dzierzak
has summarized these parameters.
Esthetic Values
- Tooth color matches age and complexion
- Tooth to face size ratio is acceptable
- No visual defects catch the eye
- Curvature of the maxillary incisal edges mimics lower lip line
- If displaced, midlines are harmonious with each other
- No gingival inflammation
- Adequate attached gingiva
- Harmony of cervical and interproximal gingival contours
- Upper lip covers all but interproximal gingiva
- No open cervical embrasures
It should be noted that these values are applicable to individual patients when the
patient believes that esthetics is an issue. Any diagnosis and therapy begins then
with questioning the patient about the personal impact of differences the dentist may note
from his concept of an esthetic smile and the existing smile. To some patients, esthetics
will not be an issue and to some it will. It should also be added that these societal
esthetic values are often subconsciously applied by the patient and alter lip and jaw
posture during smiles, as well as other facial expressions. A good example is the teenager
with a retrognathic mandible who subconsciously protrudes the lower jaw to make the facial
profile acceptable.
The position, contour, and bulk of the gingiva on the crown of the tooth determines the
perception of tooth length and width. The esthetic value of the tooth’s length is,
however, related not just to its physical length, but to the relationship of that length
to the width, height, and shape of the face. The maxillary central incisor has been found
to be one-fifteenth the width and height of the face. Multiple teeth shorter than this
ratio may indicate the presence of altered passive eruption. Additional tooth exposure
through periodontal surgery will have a marked impact on esthetics.
Assessment of the amount of gingiva which shows during the smile is an aid in
determining if additional tooth length is desirable. Under normal circumstances, only the
interdental papillae are exposed by the smile. The presence of lip insufficiency with
normal tooth length should alert the practitioner to a possible skeletal discrepancy.
Although gingival surgery might improve the esthetic value, orthodontic evaluation is
indicated in this case. Contour in the interproximal region and bulk of tissue in a
buccolingual direction impact esthetics. When the normal scalloped curvature of the
interproximal region is interrupted by hyperplastic tissue, attention is drawn to the area
just as enamel hypoplasia draws attention. Gingivoplasty is very effective at recreating
harmonious curvature.
A single tooth with much less tooth length than adjoining teeth poses an esthetic value
problem. Often such a tooth will be in linguoversion and shorter than the adjoining teeth.
Such a tooth is a candidate for orthodontics. In short teeth with incisal heights
compatible esthetically with the adjoining teeth, periodontal surgery will be more
beneficial. In the case of a tooth which has supraerupted, the alveolar housing as well as
the gingival tissue height will have to be reduced to produce esthetic gingival contours.
Uneven gingival recession also produces discrepancies in contour and poor esthetics.
When the individual tooth exhibits recession, the amount of tooth structure exposed is out
of proportion to the remaining teeth and the eye is drawn to the area. The ability to
achieve an esthetic result rests upon root coverage of the affected tooth. Several
surgical procedures are possible to correct this situation, but all are dependent on the
amount of labial tooth malposition. The more the root surface is located to the facial of
the facial bone the more difficult it is to achieve root coverage. If the root prominence
can be mechanically reduced or reduced by tooth movement, the process of root coverage is
enhanced.
Another evaluation of esthetics involves the assessment of the lower lip line and the
incisal edges of the upper anterior teeth. The upper incisal edges should be parallel to
this line which increases the sense of balance. All of us have seen the unesthetic
appearance of a periodontally involved maxillary lateral incisor whose incisal edge hangs
over the lower lip line. In a similar way, those individuals who show gingival tissue
during a smile may have a gingival line which runs at an angle to the lower incisal edge
line and reduces the esthetics of the smile. Gingival modification is a potential solution
to this problem as well.
Frustrating to patients and dentists alike are the presence of spaces produced by the
loss of interdental papillae to periodontal disease and surgical therapy. Our advancing
understanding of the disease process has made surgical intervention less common in the
maxillary anterior segment, reducing root exposure. In addition, approaches to anterior
surgery have more and more emphasized the retention of the interdental papilla. Recently,
Beagle described a technique for reconstruction of the maxillary midline papilla using a
lingual approach, split thickness flap. The tissues obtained from the area lingual to the
papilla are folded coronally to fill the interproximal space. Procedures such as this may
help reduce the problem of the "black triangle", the open anterior interproximal
space. At this time, anterior esthetic restorative dentistry remains the primary means of
anterior interproximal space closure.
We would be happy to consult with you regarding gingival esthetics and its role in your
restorative plan, both in the initial planning stages and in the provisional restorations
phase.
