Re: Porcelain Veneers: Providing Beautiful Aesthetics

[sushantpatel_doc]

CASE REPORT
Diagnosis and Treatment Plan
Allison, a 32-year-old female, presented with a history of existing restorations on her maxillary lateral and central incisors (Before Image and Figures 1 and 2). They were placed when she was a teenager due to the presence of “peg” laterals and a slight diastema that had existed between her central incisors. Allison disliked the way her restorations had discolored over the years and thought that her front teeth were disproportionately short. This made her self-conscious about smiling. She wanted a long-lasting solution that would address her “fang-like” canines, disproportionate teeth, and “dingy” appearing smile.

According to Allison, “It is time to start feeling good about my smile again!”

Other than the previously placed anterior restorations, Allison had very little old dentistry in her mouth and she demonstrated an unremarkable health history. Given her age and health history, the goals were simple: conservative preparations, a functional bite, and a “killer,” natural-looking smile.

Treatment Planning: Smile Design
When preparing the smile design, consideration must be given to the desires of the patient. However, a high degree of scrutiny needs to be placed on bite functionality as well. Allison presented with an atraumatic Class II Div II occlusal relationship and an overall healthy oral environment.

Further evaluation of her smile design (Figures 3 to 5), using the SMILES acronym developed at LVI (Las Vegas Institute for Advanced Dental Studies, Las Vegas, Nev), is as follows:

Size and Golden Proportion: Because we were considering only 4 teeth in this smile transformation, it is important to evaluate the proportionality of the teeth to be restored. They must look like they proportionally blend into the limited space with which we have to work. Considering size and proportion at this stage also helps develop an insight into the preparation design which will be utilized in the next step. In addition, it helps in our communication with the dental technician team regarding the diagnostic wax-up.

The central incisors were 8.3 mm wide and 9.5 mm long. Her current height/width proportion represented a 94% ratio. An acceptable height to width ratio is 75% to 80%. This means the current proportion of her front teeth appeared too wide and too short.

Because of the existing restorations on the anterior incisors, it was impossible to tell the size of the original teeth. Therefore, we had to consider the amount of space that was available to work with from the mesial of the left canine to the mesial of the right canine. The Golden Proportion of the central incisors could then be determined. The proportion of teeth Nos. 8 and 9 is 0.618 times the width of teeth Nos. 7 to 10. The width of teeth Nos. 7 to 10, in this case, was 31.0 mm. We multiplied 31.0 mm by 0.618 and then divided the result by 2. This approximated the width of teeth Nos. 8 and 9. In this case, the approximate width of Nos. 8 and 9 would be 9.5 mm. The length, therefore, was proportionally determined to be between 75% to 80% of the width; so a starting point for the length of the centrals would be 10.5 mm.

Midline and Canting: The midline and canting were within normal limits for this case.

Axial Inclination: Teeth Nos. 7 to 10 would be improved if they were axially inclined toward the mesial. Some axial inclination correction could also be accomplished by correcting the zenith of the soft tissue of these teeth. In addition, some inclination could be corrected by the dental technician. (This was communicated to the laboratory team in the instructions for the wax-up.)

Lip Line & Incisal Edge of Teeth: The lip line was found to follow the incisal edge of the teeth and did not need to be corrected.

Extra Hard Tissue Guidelines:

Contact Point—Contact points start from the mesial contact of the central incisors and gingivally migrate posteriorly; this requires improvement in the final restoration.

Gradation of Teeth Proper—This was to be addressed in the dental laboratory and would be dictated by the function on the teeth.

Arch Form Proper—The arch form in this case was within normal limits.

Soft Tissue Conditions:

Gingival Symmetry—The gingival symmetry in this case needed improvement in the lateral areas and the left central incisor.

Height and Contour—The height of the lateral gingivae needed to be addressed. (This would be accomplished using a diode laser at the time of preparation.)

TREATMENT SEQUENCE
Pretreatment Protocol
Prior to initiation of this case, a standard protocol of information was gathered. This included a photo release and informed consent. These were reviewed with, and signed by, the patient. Pretreatment photographs were taken. Tooth shape and shade were discussed with her. High quality pretreatment vinyl polysiloxane (VPS) impressions (Flextime [Heraeus Kulzer]) and bite registration were taken. A symmetry bite [CLINICIAN’S CHOICE]) was also taken in order to evaluate the case and to construct a lab-fabricated pretreatment wax-up, temporary stent, and reduction guide that followed the smile design that we had selected.

One of Allison’s goals in pursuing her smile rehabilitation was to have whiter teeth. Since we were veneering only the maxillary central and lateral incisors, whitening prior to initiation of veneering needed to be considered. Customized take-home whitening trays were fabricated and a 16% take-home carbamide peroxide gel (Venus White [Heraeus Kulzer]) was used to obtain the final desired shade. It took approximately 3 weeks to reach the whiter shade that Allison loved. Allison was instructed to discontinue whitening 2 weeks prior to the preparation appointment in order to account for any rebound that often occurs after the whitening process is completed. During the last whitening check, we showed the lab-fabricated diagnostic wax-up to Allison (Figure 6). She approved of the design and was excited to go to the next stage of preparation.

Preparation, Impressions, and Temporization
Prior to initiation, topical gel (FTP Gel [Flourish Pharmacy]) was placed on the buccal tissue to optimize comfort when administering the local anesthetic. Injection of 2 carpules of lidocaine (1:100,000 epinephrine) was given using an anesthetic delivery system (The Wand [Milestone Scientific]). A final shade was then taken of the still hydrated teeth and recorded prior to initiation of the preparation (Figure 7).

Next, gingival recontouring was performed with the diode laser (BIOLASE) prior to removing the existing restorations (Figures 8 and 9) and following the guidelines set in the smile design (SMILES). By conservatively recontouring the gingivae, the gingival zeniths of all of the incisors were corrected. Also, Allison’s concern about her “gummy” appearing smile was addressed by conservatively reshaping both lateral incisor areas, giving a more elongated appearance of the lateral incisors and a more pleasing overall look.

In preparing teeth that have already been restored, care must be given in removing the existing restorations, so as to conserve tooth structure and to maintain the proper preparation design (Figure 10). After the existing restorations were removed, it was necessary to prepare a 360º preparation around the 2 laterals. Both centrals were prepared both mesially and distally with interproximal slice preps so the laboratory technicians could proportionalize the restorations to the space available (Figure 11). The lingual portion of the natural tooth of the central incisors was left unaltered.

After final review of the preparations, a symmetry bite (Figure 12), a VPS check bite, and VPS full-arch maxillary final impression were taken, making sure to capture both hamular notch areas. For the maxillary impression, a Sure-Lock Full Arch Tray (Pearson Dental Supply) was used. A mandibular impression was not taken because no alteration took place in the lower arch. A lower VPS impression (Flextime [Heraeus Kulzer]) was taken only as part of the pretreatment protocol.

Photos of the prepared teeth were taken with the stumpf shade guide and desired final shade (Figures 13 and 14). A photo disc was created and sent into the dental laboratory with the prescription for review.

Prior to temporization, the teeth were cleaned (Consepsis [Ultradent Products]), and Gluma (Heraeus Kulzer) desensitizer was applied. Immediately after this, the temporary stent (Sil-Tech [Ivoclar Vivadent]) was loaded with a bleach white temporary bis-acrylic material (Temp C&B [Heraeus Kulzer]) and placed in the mouth for 2 minutes. Then, the silicone stent was taken out and the temporary restorations remained on the prepared teeth. Flash was removed and the material was custom stained and glazed at the chair (Figure 15). Finally, the bite was checked/slightly adjusted, and the patient was given instructions for care and released.