Minimally Invasive Preps for Thin Porcelain Veneers

Ross W. Nash, DDS
0 Shares

By using minimally invasive techniques, clinicians can now give their patients the smile enhancements that they desire. With currently available modern dental materials, this can be done in many cases without aggressive tooth reduction. This article will present a case report about a patient for whom thin porcelain veneers were fabricated and adhesively bonded to minimally prepared teeth. In this particular case, no temporary restorations were required after preparation. In addition, no anesthetic was required to prepare for and deliver the aesthetic restorations that provided the beautiful new smile that she desired.

CASE REPORT
Diagnosis and Treatment Planning

A young woman presented to our office requesting smile enhancement. She was entering a career that would put her in front of the camera and she wanted the best smile possible. At the initial consultation, her smile and teeth were photographed so that we could jointly evaluate them. Our treatment coordinator entered the photographs into a file so the images could be displayed on a computer screen for easy viewing.

The patient’s smile, as she presented, is shown in Figure 1. The retracted facial view can be seen in Figure 2 and the maxillary incisal view in Figure 3. As we looked at the images together, the patient pointed out that she wanted slightly larger teeth, and she also stated that she wanted to have a considerably lighter shade. It was pointed out to her that her smile and teeth were already very attractive but that they could certainly be changed if that was her desire. I let her know that my philosophy is to offer elective treatment for cosmetic reasons only in the absence of dental disease, in the presence of excellent dental health.

She exhibited a Class I occlusion. Her incisors were slightly triangular in shape and the maxillary central incisors were wider than the ideal of 75% width-to-length ratio. The Golden Proportion (0.6 – 1.0 – 1.6) between the maxillary canines, lateral incisors, and central incisors was present. The right maxillary canine exhibited incisal wear, as did the opposing mandibular canine. In addition, both the maxillary central incisors exhibited incisal wear. There was a composite restoration at the mesio-incisal angle of the left maxillary central incisor. The mandibular anterior teeth exhibited crowding of less than 3.0 mm. The shade of her teeth was approximately B1 on the VITA shade guide. A clinical examination illustrated that she had excellent periodontal health, and there was no visual evidence of any caries.

Figure 1. The patient’s smile, before treatment. Figure 2. Retracted facial view, before treatment.
Figure 3. Maxillary incisal view, before treatment. Figure 4. Retracted facial view, after minimal preparation.
Figure 5. Incisal view, after preparation. Figure 6. Facial view of the lithium disilicate (IPS e.max Press [Ivoclar Vivadent]) veneers on the working model.
Figure 7. Incisal view of the veneers on the working model. Figure 8. Silane (BIS-SILANE [BISCO Dental Products]) was applied to etch the intaglio surfaces of the veneers.
Figure 9. Phosphoric acid-etching gel (UNI-ETCH w/BAC [BISCO Dental Products]) was left in place for 10 seconds, then rinsed and air-dried. Figure 10. A universal bonding adhesive (ALL-BOND UNIVERSAL [BISCO Dental Products]) was applied then thinned with oil-free air.

In discussing her goals, she indicated that she wanted longer upper front teeth and a wider smile-line. She was not interested in straightening her lower front teeth but would be satisfied if the upper teeth were whiter than the lower teeth. She felt that enhancing the appearance of the upper teeth alone would satisfy her needs. After presenting her with options, ranging from simple teeth whitening to direct composite bonding to porcelain veneers, she was interested in porcelain veneers. I told her that we would need radiographs to confirm whether or not she would be a good candidate for the treatment proposed, and she agreed. Evaluation of her full set of radiographs confirmed that she was indeed in excellent dental health.

It was explained to her that, without orthodontic treatment, her front teeth could still exhibit wear, so she was advised to wear a nightguard appliance, regardless of the treatment chosen. She was also told that porcelain veneers are not reversible, and that saving as much natural tooth structure as possible, by opting for minimally invasive procedures whenever possible, is the philosophy of care practiced in our office. She was informed that she would be an excellent candidate for minimal preparation porcelain veneers that would require no temporary restorations. That was the treatment chosen, and the patient made an appointment to begin the treatment.

Clinical Protocol
At the first operative appointment, no anesthetic was needed. It is sometimes possible to use no preparation at all. However, in this case, I wanted to decrease the triangular shape of the maxillary central and lateral incisors and prepare the teeth for draw from incisal to gingival. Fine diamond burs (Brasseler USA) in a high-speed handpiece with water spray were used to refine the shapes of the teeth. All preparation was completed in enamel. Figure 4 shows the prepared teeth from the retracted facial view. In the incisal view (Figure 5), one can see the conservative nature of the preparations and the draw that was created.

Light-body impression material (Pan­asil Extra Light [Kettenbach LP]) was injected around the margins at the gingival of each tooth while my assistant was mixing impression putty (Panasil Putty [Kettenbach LP]) and placing it into a full-arch maxillary tray. The tray was inserted, then held in place for 5 minutes before removing it. No retraction cord was required in this case. A full-arch opposing vinyl polysiloxane alginate substitute (Silginat [Kettenbach LP]) impression was taken. An occlusal bite registration (Futar [Kettenbach LP]) was also taken.

For home care following this appointment, the patient was given a Sonicare Toothbrush (Philips Oral Healthcare) along with Oxyfresh toothpaste and mouthwash. She was encouraged to become a “fanatic” about her oral hygiene, especially for the next 2 weeks. The patient was appointed for a try-in and placement appointment in 2 weeks and dismissed. (Note: The total appointment time for the impression appointment was less than 90 minutes.)

Lab Fabrication
The impressions, preoperative photographs, and bite registration were sent to our dental laboratory team. The stump shade was listed as B1 VITA shade, and the desired final restoration shade was listed as OM1 from the VITA 3D shade guide. The laboratory team was informed that the patient wanted longer teeth and a wider buccal corridor. Lithium disilicate (IPS e.max Press [Ivoclar Vivadent]) was chosen as the restorative material due to its excellent strength, fracture toughness, and aesthetics. Figure 6 shows the veneers on the working model from the facial view. The incisal view of the restorations on the model can be seen in Figure 7.

Try-In and Placement
The patient returned for the seating appointment, and the restorations were tried in. She was immediately excited about the appearance and wanted them bonded into place. My assistant thoroughly cleaned the internal surfaces of the veneers that had been hydrofluoric acid-etched by the lab team prior to their delivery to our office. Next, the veneers were dried with a stream of oil-free air. Silane (BIS-SILANE [BISCO Dental Products]) was painted onto the intaglio surfaces (Figure 8), allowed to dwell for 20 seconds, then air-dried. Retractors (3M Unitek Ortho [3M]) were placed, and then the 6 anterior teeth were isolated from the premolars using metal matrix strips. Phosphoric acid-etching gel (UNI-ETCH w/BAC [BISCO Dental Products]) was applied to the facial surfaces of the 6 anterior teeth (Figure 9). The etching gel was allowed to stay in place for 10 seconds, then thoroughly rinsed and lightly dried with oil-free air. Next, a universal bonding agent (ALL-BOND UNIVERSAL [BISCO Dental Products]) was liberally applied (Figure 10) and then air-thinned. The bonding agent was light-cured for 10 seconds with an LED light-curing unit (SmartLite [Dentsply Sirona Restorative]) (Figure 11).

Figure 11. The bonding adhesive was light-cured (SmartLite [Dentsply Sirona Restorative]). Figure 12. Luting composite (Choice 2 [Milky Bright shade] [BISCO Dental Products]) was then applied to the intaglio surfaces of the lithium disilicate veneers (IPS e.max Press).
Figure 13. The 6 veneers, as seated into place and a 2-second (“tack”) light-cure was done. Figure 14. Marginal and interproximal excess luting cement was removed using a No. 12 surgical blade.
Figure 15. Luting composites were then fully light-cured for 20 seconds each. Figure 16. Marginal finishing was done using a carbide-finishing bur (ET3 008 [Brasseler USA]).
Figure 17. Interproximal areas were flossed, then smoothed with aluminum oxide strips (Epitex [GC America]). Figure 18. Retracted facial view, finished case.
Figure 19. Incisal view, finished case. Figure 20. The patient’s new smile.

Next, light-cured luting com­posite (Choice 2 [Milky Bright shade] [BISCO Dental Products]) was applied to the intaglio surfaces of the veneers (Figure 12) and then put into place using cotton pliers. The curing light was used to tack the veneers in place, using a 2-second burst of light (Figure 13). Then, a No. 12 surgical blade was used to “peel” off the excess luting agent at the margins and in the interproximal areas (Figure 14). After most of the excess was removed, the curing light was used to finish the cure for 20 seconds per tooth (Figure 15).

A fine-tapered carbide-finishing bur (ET3 008 [Brasseler USA]) was used to remove any excess luting agent at the margins (Figure 16), and a football-shaped carbide-finishing bur (OS1 023 [Brasseler USA]) was used to remove excess on the lingual areas. Dental floss was then worked in between each contact, then thin aluminum oxide finishing strips (Epitex [GC America]) were used to smooth and polish interproximal surfaces (Figure 17). Next, a polishing cup (Enhance [Dentsply Sirona Restorative]) was used to polish all the margins. Last, but not least, the occlusion was checked and, in this case, no adjustments were needed. Treatment time for the veneer placement appointment was 90 minutes.

The retracted facial view of the finished case is shown in Figure 18. The incisal view in Figure 19 illustrates the increase in the arch form and incisal length, along with the whiter smile that had been requested by the patient. The patient’s new smile can be seen in Figure 20. The patient stated that exactly what she was looking for had been achieved, and that she absolutely loved her new smile.F

Acknowledgment
Dr. Nash would like to thank the team at daVinci Studios in West Hills, Calif, for their expertise and excellent technical work on this case.


Dr. Nash has a private practice in Huntersville, NC, focusing on aesthetic dentistry. He is an Accredited Fellow in the American Academy of Cosmetic Dentistry. He lectures internationally on aesthetic dentistry topics and has been published extensively. He is co-founder of the Nash Institute for Dental Learning in Huntersville and is a consultant for numerous dental products manufacturers. He is listed in Dentistry Today’s Leaders in Continuing Education. He can be reached at rosswnashdds@aol.com.

Disclosure: Dr. Nash reports no disclosures.

Also By Dr. Nash

Impression Techniques: Clinical Properties That Matter

A New Smile for Judy: A Multimaterial Approach

Marrying Clinical Techniques and Teamwork