A Smile From Within
Placing veneers to correct deficiencies in tooth size, shape, and color
Justin Chi, DDS, CDT
Today's patients have expectations that reach beyond traditional preventive and restorative dentistry. Now, patients arrive at their dentists' offices with some knowledge of cosmetic dentistry, and they have desires that are informed by online information and the experiences of friends. Therefore, dentists are often called upon to overhaul a smile and improve upon the esthetics, contours, morphology, and proportions of a patient's natural teeth in the process.
A patient presented to the office with a dental concern that she had had for most of her life: she did not like the size, shape, or color of her teeth. Upon examination, it was evident that this patient had a wide smile, characterized by the visibility of her first molars (Figure 1). The preoperative evaluation also showed that her maxillary teeth were a bit short and somewhat uniform in length across the arch-a look that presents a more aged appearance. In addition, this patient presented with some interproximal composite bonding between teeth Nos. 8 and 9, Class III restorations on teeth Nos. 7 and 10, and various diastemas on the upper arch. The patient reiterated her lifelong desire for a more esthetic smile and a lighter tooth shade. After the evaluation, the patient accepted the treatment recommendation to place veneers on teeth Nos. 4 through 13.
To begin, a preliminary anterior, triple-tray impression was taken with a vinyl polysiloxane (VPS) impression material (Capture® Impression Material, Glidewell Direct) and sent to the laboratory to be used as the basis for a diagnostic wax-up (Figure 2).
A bis-acryl material was back-filled into a putty matrix that was created from the diagnostic wax-up received from the lab (Figure 3). The putty matrix was then slowly seated over the patient's teeth to minimize the inclusion of bubbles, and the bis-acryl material was allowed to set, transferring a mock-up of the proposed restorations to the patient's mouth.
Once the mock-up was placed and polished, the patient was able to get a realistic glimpse of what could be achieved with the final restorations (Figure 4). When you lengthen patients' teeth, the difference is particularly noticeable to them, so it is important to evaluate their speech patterns and comfort.1
The patient confirmed that she was satisfied with the proposed designs, and at the next appointment, the preparation was initiated through the temporary bis-acryl mock-up. Having a clear vision of where to go esthetically is important, and using a mock-up based on a diagnostic wax-up can also help to guide preparation. Vertical depth cuts were placed through the mock-up, ensuring that the tip of the bur, which was about 0.8 mm in diameter, was buried entirely into the temporary restorations along the gingival margin (Figure 5).
A minimal thickness of 0.7 mm was required for the final restorations to achieve optimal strength and esthetics. To allow for a chamfer, once the preparations were completed, the gingival margins were traced with a periodontal probe, placing a little pressure apically, to confirm a complete stop. With that apical stop, it is possible to create a restoration that has a nice chamfer margin at the gingival area of the preparation.
The next critical element was tissue management for the final impression. Placing size No. 1 retraction cord all around the gingival margins created the necessary tissue displacement (Figure 6).2 The cord was allowed to remain in place for at least 5 minutes to provide the retraction that was needed. Meanwhile, the edges of the facial and incisal line angles were rounded over a bit more, creating rounded internal angles so that the restorations could adapt well to the preparation. Once this was completed, the cord was removed and the impression was taken.
Next, an intraoral scanner (iTero® Element™ Scanner, iTero) was used to scan the preparations, the surrounding structures, the opposing dentition, and the bite-essentially creating a digital triple tray. Everything was digitally sent to the laboratory with the push of a button. Following impression taking, the provisional restorations (BioTemps® Provisionals, Glidewell Laboratories), which were fabricated from the preoperative impression, were seated. The provisional restorations were relined intraorally to serve as temporary restorations until the final veneers were ready for delivery.
The design of the final restorations was created based on the digital impression and some minor adjustments requested by the patient after seeing the bis-acryl mock-up (Figure 7). Ten veneers were fabricated from zirconia (BruxZir® Esthetic Solid Zirconia, Glidewell Laboratories) to achieve a combination of high strength and beautiful, lifelike esthetics in the smile zone. For the delivery, a light-cured resin cement (NX3 Nexus® Third Generation Cements, Kerr) was used. After decontaminating the restorations with a universal cleaning paste (Ivoclean, Ivoclar Vivadent), the veneers were bonded into place following the recommended protocol (Figure 8).
The patient's reaction in cases like these can be tremendously rewarding and satisfying. As a dentist, it is gratifying to be able to change patients' lives in a way that makes an emotional impact-building their confidence and giving them smiles that they are proud to show off. The smile is one of the most recognizable facial expressions, and it has been said that it can even be spotted from 300 feet away; so, even at long distances, it is easy to see the happiness on this person's face.
About the Author
Justin Chi, DDS, CDT
Director of Clinical Technologies
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1. Besimo CE, Rohner HP. Three-dimensional treatment planning for prosthetic rehabilitation. Int J Periodontics Restorative Dent. 2005;25(1):81-87.
2. Chandra S, Singh A, Gupta KK, et al. Effect of gingival displacement cord and cordless systems on the closure, displacement, and inflammation of the gingival crevice. J Prosthet Dent. 2016;115(2):177-1782.