A Preparation Technique to Minimize Tooth Reduction in Porcelain Veneers

by Gary M. Radz, DDS

The increased popularity of cosmetic dentistry and “smile makeovers” has lead to significant increase in the number of porcelain veneers fabricated in recent years. There has also been an increased interest in minimally invasive preparations and porcelain veneers.1-5

The use of stacked porcelain veneers allows for dentists to fabricate porcelain veneers that can be .5mm in thickness.1,4,5 Stacked porcelain veneers allow dentists to remove the minimal amount of tooth structure needed to provide their patients with new smiles with minimal trauma to their natural tooth structure.

.5mm of porcelain has the ability to allow the dentist alter the size, shape, color, contour, and texture of the tooth to either match the existing dentition or create a new smile to give the patient the esthetic change the are looking to achieve.

It has been the challenge to the cosmetic dentists to learn to determine how much tooth structure is required to be removed to allow for the placement of these thin laminates of porcelain.

Recently Mange and Belser published a technique that provides a way for a dentist to visualize and accurately remove enough tooth structure to allow for .5 mm of porcelain, yet provide a guideline that minimizes the chance of over-preparation.6

Their technique creates a way for dentist to see the desired end result, then work backwards in their preparation. Thus, allowing for an end result of a preparation that does not remove .5mm of tooth structure, but rather creates .5mm of room for the placement of .5mm of porcelain.

The following case study demonstrates the ideas published by Mange and Belser in their textbook with some minor modifications to allow for practical use in private practice.

CASE STUDY

A 40-year-old male presented with concerns about the esthetic appearance of his smile. Of primary concern was the presence of multiple anterior diastemas as well as being displeased with the color of his teeth (Fig. 1).

The patient was provided with several treatment options. To create the smile he wanted to have it was agreed to have the patient complete an in office bleaching procedure followed by placement of eight conservative stacked porcelain veneers on #’s 5-12.

Upon completion of the bleaching procedure the patient returns for the preoperative records appointment, at which time highly accurate study models are made from polyvinyl siloxane impressions (Status Blue, Zenith/DMG).

The accuracy of the preoperative impressions is imperative with this technique because the ceramist will be using these impressions to create the wax up.

The impressions are sent to the lab along with photographs of the patient and detailed instructions as to the final esthetic goals of the case. The ceramist then takes the provided information and creates a wax up with will demonstrate the final esthetically improved dentition (Fig. 2).

This wax up not only demonstrates to the patient and dentist one potential esthetic result. It also is demonstrating the final position of where the porcelain veneers will be spatially located. So if we are to think in reverse. If .5mm is removed from this wax up, we have now created a preparation that will accept a .5mm porcelain veneer. In order to transfer this information back to the mouth, an impression is made of the wax up using a putty/wash technique to capture the detail of the wax up (Fig. 3).

Now the information and detail of the ceramists’ wax up can be transferred to the patient.

At the preparation appointment the impression/matrix of the wax up is loaded with an automix bisacryl temporary material (Luxatemp Fluorescence, Zenith/DMG).

The maxillary dentition is air dried and the matrix is fully seated to place and allow 4 minutes to completely set up. Upon removal of the matrix the wax up has now been successfully transferred into the patients mouth (Fig. 4).

Now we can see where the final desired position of the porcelain is to be, so all that is now necessary is to create .5mm of room for porcelain. Using a .5mm depth cutting diamond bur (Axis Dental), depth cuts are created in all teeth (#’s 5-12) to receive veneers (Fig. 5).

Then a medium grit chamfer diamond is used to uniformly remove .5mm of temporary material and/or tooth structure. Figure 6 shows the uniform reduction of the facial aspect of #9. Stacked porcelain veneers also will require 1mm of incisal reduction. Figure 7 shows the removal of 1mm off the incisal edge of #9.

The remaining 7 teeth are initially prepared in a similar manner. Figure 8 shows the initial preparation of #’s 5-12. Then using a sickle scaler the remaining temporary material is removed (Fig. 9).

Figure 10 shows the initial preparation upon removal of the temporary material.

The preparations must now be completed to allow for proper and successful fabrication of the final veneers. Margins will be placed at the height of tissue, undercuts are eliminated, and any sharp angles are smooth over. Figure 11 shows the final preparations for the stacked porcelain veneers

The final result is 8 stacked porcelain veneers (Avante, Pentron Ceramics) that are minimally invasive and yet proved the patient with the new smile he was hoping to achieve (Fig. 12)

CONCLUSION

Stacked porcelain veneers are a wonderful, conservative way to create dramatic changes to a patient’s smile. Using the ideas demonstrated by Mange and Belser it is possible to minimize the amount of reduction of tooth structure and still be able to provide our patients with highly esthetic results (Fig. 13).

Acknowledgements

The ceramic artistry displayed in this case was created by William “C.K.” Kim, Americus Dental Laboratory, Jamaica, New York.

Dr. Gary M. Radz maintains a cosmetically focused general practice in Denver, Colorado. He serves as an associate professor at the University of Colorado School of Dentistry. He can be contacted at www.garyradz.com.

Oral Health welcomes this original article.

REFERENCES

1.Nash, RW, “Thin yet Strong”, Dental Products Report, April 2006, pp.98-99.

2.Nash, RW, “The ‘Contact Lens’ Veneer”, Dental Products Report, August 2005, pp. 50-52.

3.Nash, RW, “An Integrated System for Esthetics and Function”, Contemporary Esthetics and Restorative Practice, Feb. 2000, pp.18-25.

4.Rosenthal, L, Rinaldi,P, “The Aesthetic Revolution: Minimum Invasive Dentistry”, Dentistry Today, June 1998, pp.42-46.

5.Lowe, RA, “Prep for Success-The stacked-porcelain veneer preparation”, Dental Products Report, February 2004, pp.50-52.

6.Bonded Porcelain Restorations in the Anterior Dentition – A Biomimetic Approach. Mange, P, Belser, U., Quintessence books. Copywrite 2002. pp.200-224.

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