Oral Health Group
Feature

The magic combination: Dentist, Laboratory, & Patient

June 1, 2005
by Elliot Mechanic, DDS, and Camille Halaby, CDT


The appearance of a person’s teeth can dramatically influence how they are perceived by others. By altering tooth shape, size, length, and color it is possible to influence perception of age, personality, and projected self-confidence.

In the past, we simply took an impression, sent it off to the dental lab, and hoped for the best. When we referred a patient to a specialist, we left the treatment up to the specialist and accepted the result as being all that was possible.

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By the 1980s, however, not everybody was content with “Austin Powers teeth”; they actually wanted nice-looking natural teeth, and dentists began learning how to properly diagnose, treatment-plan, and communicate exactly what they required to their dental labs and various dental specialists.

Today we constantly think “outside the box,” working intensely, committed to pushing the barriers of esthetic dentistry to new heights. By acknowledging that we don’t know everything, we always manage to learn more. We strive to achieve completely natural-looking esthetic dentistry, aiming for “asymmetric symmetry” (harmony without symmetry), as natural teeth are not perfectly symmetrical.

Early recognition

Early recognition of a dental problem and a logical treatment plan allows subsequent treatment to correct the situation in an orderly, efficient manner with extremely predictable results.

It became apparent when the patient was 11 years that her four upper incisors were misshapen, as well as crowded (Fig 1). The lateral incisors were not the correct size and shape and the central incisors did not have the form and fullness to enhance her facial features.1 Rather, the teeth were very narrow and the interproximal form was very straight. We had recently placed four porcelain veneers in the patient’s mother’s mouth; this had made her very attuned to dental issues and enabled her to see what we were observing in her daughter’s mouth.

The patient and her mother decided that these were not the shape of teeth that the girl would go through the rest of her life with; and that orthodontics alone was not the answer, as the shape, form, and texture of her teeth would have to be altered. Communication is much easier when everyone is on the same page.

Treatment-planning

It was decided to begin orthodontic treatment when the patient was 14 and her canines were fully erupted. Unlike the four anteriors, her canines, in our opinion, were dimensionally and esthetically correct. By the general principals of tooth proportions,2 we were able to predetermine the ideal approximate width and length of the four anterior teeth, using the measurements of the canine’s height and width as our guide.3-5 We know that if the width of our canine is X, then the width of the central should be 1.15X, and the lateral 0.9X. The height of a central for a female should be 1.16 its width and the lateral 1.27 its width.

The patient’s canine being 10.22 X 8.25 determined that her centrals should be approximately 10.9 X 9.4 and the laterals 9.4 x 7.4. Knowing the probable dimensions of her teeth enabled us to accurately communicate to her orthodontist how much space was required from canine to canine to predictably achieve the final esthetic result that we envisioned.

Esthetic orthodontic set-up

The patient’s orthodontic treatment was straightforward and uneventful, as her orthodontist had been instructed exactly how much space to leave between each anterior tooth to accommodate the projected porcelain veneers (Fig. 2). He was then able to establish cuspid guidance and a stable occlusion.

When the patient was 16 and it appeared that her orthodontic treatment was near completion, a diagnostic wax-up was fabricated to preview the shape and size of the projected anteriors and to ensure that enough space had been created to accommodate them (Figs. 3 & 4). We were able to immediately envision that with just a little bit of gingival laser recontouring, we would attain the desired result.2

A clear vacuum-form stent was made of the projected tooth form. This was placed over the patient’s teeth to ensure that they were centered with the future restoration so that we would achieve congruent crown-to-root anatomy.

It was critical to recreate the interdental papilla between the central incisors, especially in light of the patient’s youth. Knowing that a distance from the crest of the alveolar bone to the contact point of the teeth of 5 mm or less would recreate interdental papilla 100% of the time (no black triangle), a contact point 5 mm from the bone was incorporated into the wax-up.7

As the patient did not want to remove her orthodontic brackets and have spaces showing between her teeth, and because her orthodontist did not want her teeth to drift, it was decided that we would remove the brackets and immediately place four joined anterior provisional restorations that would serve as the upper retainer. A lingual wire was to be used to retain the lower teeth.

Tooth preparation and provisionals:

The orthodontic brackets were removed (Fig. 5), the gingival height of the lateral incisors was adjusted with a diode laser, and the four incisors were prepared for IPS Empress (Ivoclar Vivadent; Amherst, NY) restorations.8

To reproduce natural dentition with ceramics, the material used should mimic the same optical properties as the natural teeth. IPS Empress was chosen primarily because it has a proven track record and can be extremely esthetic, as it can be cutback and layered with various shades of porcelain. It also allows the natural tooth color from within to blend seamlessly into the restoration.

Using our diagnostic wax-up and a silicon matrix, Luxatemp provisionals (Zenith/DMG; Englewood, NJ) were fabricated, the contours adjusted and then finished with Luxaglaze (Zenith/DMG). Luxatemp, with its patented 10:1 base:catalyst ratio provides the perfect blend of strength, esthetics, accuracy, and fast set time.

The patient loved her new temporaries at first sight (Fig. 6). After two-and-a-half years of orthodontic treatment, these provisionals gave her immediate gratification. She had no problem wearing these provisionals for the four months of retention that her orthodontist desired.

Restoration

The patient had four months to preview her new front teeth during orthodontic retention and was so satisfied with her provisionals that she desired no changes. We took photos and impressions of the temporaries to give the lab a reference as to exactly what we wanted. The temporaries were then removed, the preparations refined, and final impressions taken. The provisionals were then replaced.

The IPS Empress porcelain veneers were fabricated using a multilayering technique. A TC1 ingot was chosen as the basic shade, as the patient’s teeth were in the Vita A range. Some neutral and clear porcelain was fired around the margins to make them appear invisible.

As the patient was very young, the incisal edges were built up with super opal porcelain; and transparent blue was mixed with the super opal porcelain for the mesial and distal corners.

When the veneers were tried in the patient’s mouth it was immediately clear that we had gotten it perfectly; they looked just like her natural teeth. The teeth were treated with All Bond II (Bisco Dental Products; Schaumburg; IL), and the veneers luted with Variolink clear (Ivoclar Vivadent) (Fig. 7).

The restorations now appeared even more life-like, in total harmony with gingiva and underlying natural tooth structure (Fig. 8); and radiographs confirmed a near-perfect match of crown and root (Fig. 9). Notice the near-perfect symmetry of the central incisors. The lateral incisors, however, are not symmetric. One lateral has round incisal corners and a triangular gingival contour, while the other has square/round corners and a round gingival contour. The laterals give individual character to the smile with their asymmetric symmetry.

Conclusion

The results of this case speak for themselves. Early recognition, organized treatment-planning, and excellent chemistry between all the players made this case proceed smoothly and result in exactly what the patient desired.

Photography plays an integral role in our dental practice; the patient’s photo shoot clearly communicates the confidence and self-esteem that a beautiful smile can generate. The pictures are fun, refreshing, and convey the excitement of youth. The patient is not the shy little girl she used to be! She now feels good about herself and is ready to take on the world.

REFERENCES

1. Tjan AH, Miller GD. Some esthetic factors in a smile. J Prosthet Dent 51(28):24-28, 1984.

2. Weisgold AS. Contours of the full-crown restoration. Alpha Omegan 70(89):77-89, 1977.

3. McCann J, Burden DJ. An investigation of tooth size in Northern Irish people with bimaxillary dental protrusion. Eur J Ortho 18:617-621, 1996.

4. Otuyemi OD, Noar JH. A comparison of crown size dimensions of the permanent teeth in a Nigerian and British population. Eur J Ortho 18:623-628, 1996.

5. Gillen RJ, Schwartz RS, Hilton TJ, Evans DB. An analysis of selected normative tooth proportions. Int J Prostho 7:410-417, 1994.

6. Kois JC. Altering gingival levels: The restorative connection. Part I: Biologic variables. J Esthet Dent 6(1):3-9, 1994.

7. Tarnow DP, Magner AW, Fletcher P. The effect of the distance from the contact point to the crest of bone on the presence or absence of the interdental papilla. J Periodont 63:995-996, 1992.

8. Kois JC. New paradigm for anterior tooth preparation: Rationale and technique. Dental Learning Systems Special Edition: Contemp Esthet Dent 2 (8):1-8, 1996.

Dr. Elliot Mechanic practices esthetic dentistry in Montreal, Canada. Dr. Mechanic maintains membership in numerous professional organizations, including the AACD. He is the editorial board member for Oral Health.

Mr. Camille R. Halaby, CDT received his dental technician diploma from CGEP douard Montpetit in 1989. He them opened his own dental lab (CRH Oral Design) in Montreal in 1992. He has been an active member of the AACD since 1996.


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