Production Meets Boutique

Dentistry has always had conventional laboratory methods and chairside manufacturing techniques. For the last 8 years, the author has been lecturing on behalf of Sirona and Patterson on the theories of CAD/CAM and digital dentistry. He has visited more than 300 laboratories and dental offices, learning from these experiences. In summer 2012, the author and his business partners launched Smile Design Inc. Their business strategy was to provide same-day dentistry at a quality and esthetic level most dentists would expect in a 5- to 10-day turnaround from a traditional laboratory.

Smile Design’s laboratory absorbed the capital expense of the technology and created strategically located milling centers for its dentist clients. Dentists pay a slightly higher fee for Smile Design’s service, but no longer have to buy the chairside equipment in order to deliver same-day restorations. Smile Design has 4 franchises, or partnerships, in the Midwest and continues to grow. The company’s first CBCT scan center and pilot program launched in October 2014. The dental industry is quickly evolving, and dental professionals need to find a way to set themselves apart. Smile Design provides its clients with the most esthetic, best-fitting restorations done the same day. These are not chairside crowns with mediocre esthetics. The restorations fabricated same day take into account form, function, and beauty. Future technicians will be required to have excellent understanding of CAD/CAM technology and workflow combined with the talent of a seasoned ceramist. With that being said, here is how production meets boutique.

The patient is a young and successful sales territory manager for a large company. He was dissatisfied with the esthetics of previously placed anterior laminate veneers. Because he is in front of customers every day, he had increasingly become self-conscious about his smile. The patient arrived in Farmington, Missouri on a Sunday night. The Smile Design imaging technician, Chadwick Rogers, CDT, from Elkhart, Indiana, and the restorative team met at Functional Esthestics Dental Lab. Douglas Frye, CDT, and Benjamin Bassett, DDS, of Bassett Family Dentistry were also on the team restoring the patient’s smile. Dr. Bassett, who had never been involved in a digital dentistry case firsthand, examined the patient and determined the patient’s existing veneers provided no cuspid rise or group function. In consultation with Frye, the team decided that the best approach was to replace the veneers on teeth Nos. 6 through 11 with crowns. It was critical the case be fabricated and seated in 1 day in order for the patient to meet work obligations on that Tuesday. A pre-operative photo was taken just after the patient’s consultation with Dr. Bassett at the laboratory (Figure 1). A custom shade then was taken at the laboratory to optimize the results; this is most critical, and proper lighting is a necessity. The photographs, along with notes of determining internal colorization, should be done at the same time. Note the translucency of the mandibular anteriors (Figure 2).

The process began at 9:30 AM Monday. The clinician removed the old laminates and refined the preparations for all-ceramic full-contour crowns, taking into account the necessary material thicknesses that would be needed to provide the patient with ultimate esthetics (Figure 3).

With the laboratory, the clinician, and the Smile Design imaging technician together, communication was seamless. The Smile Design technician had brought the digital impression unit and all necessary equipment to transfer digital impression files from the practice to Frye’s milling unit at the laboratory.

After tooth preparation, the imaging technician from Smile Design checked for interocclusal clearance and proper tissue management (Figure 4). The Smile Design technician then transitioned into imaging and capturing the data that would be needed to create a predictable as well as ultimately esthetic and functional outcome (Figure 5). On the computer, the Smile Design technician marked margins, confirmed them with the clinician, and uploaded the data file to the laboratory for milling and completion hours later (Figure 6). The clinician also took an alginate impression for creation of an analog model for the ceramist (a step not usually taken in the normal digital workflow). By completing the case same day, the team was not only able to create beautiful tissue emergence profile but was also able to eliminate any chance of super eruption and periodontal ligament shift

Once the digital impression data was uploaded to the laboratory from the dental office, the design technician downloaded the case and confirmed the digital bite. He quickly created the design proposal and refined the design to ensure perfect proximal contact and occlusion.

The analog modeling was simultaneously completed at the laboratory so that the ceramist and designer could collaborate on the result. The designer digitally cut back the restorations to allow for internal staining and layered ceramics.

The milling process for the six lithium disilicate crowns was soon finished, and de-spruing was completed. Some minor adjustments in the green state were done at this time (Figure 7). Idealizing the length and adjusting for ideal reduction for all internal colorization was quickly finished (Figure 8). At this point, they had approximately 20 minutes in adjustments post-milling. The finished green-state restorations were tried on the model prior to pre-crystallization staining techniques (Figure 9).

Frye, the ceramist, started the internal staining process. There is often the misconception that technicians do not have color control in the beginning of the process. However, studying the photographs at this time in the production process is a must in achieving lifelike results. The ceramist will determine what the underlying hues are and use stains that will help achieve perfection in shade matching. The custom shade notes were critical in choosing which stains were to be applied. In this particular case, the shades used in the mamelon area were a mixture of IPS e.max® (Ivoclar Vivadent, ivoclarvivadent.us) essence rose (E 20) and IPS e.max essence copper (E 05) mixed at a 50% ratio. Interproximal characterization also should be applied prior to the crystallization process. The coauthor used IPS e.max essence copper and IPS e.max essence mahogany (E 11) with the mixture of 80% copper and the remaining with mahogany.

The restorations were now ready for crystallization. The coauthor suggested that a putty-type material be used in the intaglio of the restoration, and then the restoration placed onto a wire peg. The restorations were crystallized for 30 to 35 minutes in a conventional porcelain oven.

Once crystallization was accomplished, the co-author started the buildup technique with the pre-determined shades needed. The addition of signature staining is what sets average restorations apart from above-average results and gives the ceramist and laboratory the chance to strive for excellence. A wet tray was used, and the shades needed were written on a sticky note for a quick reference during the buildup procedure. The porcelains and modifiers used in this particular case are as follows: shade A3.5 for the interproximal colorization; IPS e.max impulse (MM y-o) was used in the lobe areas of the incisal edge; using a staggered effect with the internal modifiers, a hint of IPS e.max impulse (MM s) was also placed; and IPS e.max Ceram (OE-1) was placed at the gingival one-third to help with the shade matching. The most critical area in this case was the incisal edges of the restorations. The ceramist had to discern the true saturation of translucency at this time for the best results. The author determined that the patient’s natural dentition on the lower anteriors had a significant amount of translucency (Figure 10). IPS e.max Ceram Transpa Clear was the choice for this particular buildup.

The buildup process was then finished, and it was time for the bisque bake firing. Once the restorations cooled, the ceramist adjusted the contacts and occlusion. The co-author uses only rubber-type wheels (RedBerry and BlueBerry, Wagner Precision Rotary, wagnerrotary.com) in all adjustments on lithium disilicate restorations. These products are extremely rigid for long life and provide a chip-resistant reduction of the lithium disilicate (Figure 10). Once the proper adjustments were made, surface texture was placed. The co-author once again used specialty rubber wheels because they don’t have the tendency to chip the material. Ceramists and technicians owe it to their clients and patients to study the surface texture of a patient’s existing natural dentition. Too often, surface texture is overlooked and the results are unnatural. Figure 11 demonstrates the natural-looking restorations on the model just prior to the glazing process. The co-author prefers using a small amount of Fluo glaze paste for achieving optimal results. Once the glazing process is finished, the co-author uses diamond paste to create the ideal surface luster. Note the imperfections present on the incisal edges. To create natural results, the ceramist needs an understanding of true natural dentition. This cannot be learned from photographs or ceramists’ work or from scrutinizing denture teeth but from years of studying and photographing natural dentition. For the newer ceramist, the co-author would suggest studying working models that come through the laboratory. With all the different tools technicians have at their disposal, the use of digital photography can be a particularly beneficial advantage.

Once the case was at the office, Dr. Bassett checked the fit, esthetics, and function of the final restorations (Figure 12). He then used his conventional bonding protocol to deliver the case a mere 5 hours from the start of the appointment.

Figure 13 shows the final results of this particular case. Accomplished by four very determined individuals from three states, this same-day service could not be achieved without the team’s passion for dentistry. Their commitment was rewarded with the patient’s emotional response when he saw the final result in the mirror. Passion is a prerequisite; excitement is infectious. In this ever-evolving competitive price-driven market, how will your laboratory adapt?

The authors would like to compliment the beautiful preparations that were achieved by Dr. Bassett. Our thanks to the clinician, the patient Robert Boyd, and Richard Braddock for all the hard work and passion for our industry and where it is going.

Chadwick Rogers
Technical Director
Professional Dental
Laboratory Corp.
Founder
Smile Design Inc.
Elkhart, IN

Douglas J. Frye, CDT
Owner
Functional Esthetics Dental Lab Inc.
Farmington, MO