Transition to Digital: The Time Is Now

When I began my practice in the late 1980s, computers did not exist in dental offices. Soon, they began to appear at the front desk to perform basic accounting procedures, word processing, and other clerical tasks. By the early 1990s, practice management software that enabled scheduling started to become more common.

For a lot of us, trusting a computer with all of our appointments was unfathomable. So, for some of us, we had both. We had our front desk employees write down the appointment in an appointment book, and we had them put it in the computer schedule. We then wondered why they seemed to have less time than they did before computers. As we look back at this example, we might get a chuckle at such ludicrous behavior. However, anytime we make the transition from an analog to a digital workflow, we will likely have a number of fears: “It won’t work,” “It will take longer,” and/or “Our team will struggle with it.” These fears make us hold on to analog methods while we also delve into digital alternatives. This is particularly true for protocols that have been in place and working well for years. Therefore, it is imperative that when we change anything in our practice, it should be a move toward something with a known track record. We should have confidence that it will make what we are doing better and more efficient. While there will always be a learning curve with any new technology, we have numerous options today (with proper protocols in place) to choose from. With so many options, it’s important to review the technologies and digital workflows available and evaluate how they may be best utilized to improve the dental practice.

CASE REPORT
A 53-year-old female patient came into our office for help with her dental issues. She wanted to pursue a cosmetic/aesthetic solution to what she described as an “aging smile.” She had been previously diagnosed with a TMJ problem, but she never pursued any sort of treatment. While she did not have any pain in the joint region, she described intermittent popping in her right joint, a feeling that her bite was off, and headaches 2 to 3 times per week in her temporal regions. She had also noticed that her teeth were wearing and becoming more and more discolored. She had no history of periodontal disease but had been told that her gums were receding in a few areas of her mouth. Her previous dentistry didn’t seem to match anything, and, at the time of this initial appointment, her primary goals were to have everything look more youthful, for all of her teeth to match and be strong, and for her bite to be comfortable and stable for the long term. She also wanted to have minimal dentistry in the future once her reconstruction was completed.

When we are evaluating a new patient, we first need to consider which type of patient they are. At The Dawson Academy, we describe 2 distinct types of patients, with 2 distinctly different workflows.

1. The general patient is a person in whom the size, contour, and position of the teeth are working both aesthetically and functionally. These patients do not have signs or symptoms of occlusal disease, their temporomandibular joints are functioning properly, and they do not have any desire to change. They may have biological diseases (such as caries or periodontal disease) that will need to be treated. They may also have structural problems with individual teeth that will require restorative procedures, but the general patient will not need to have his or her bite corrected (or changed) as part of his or her overall treatment plan.
2. The specialty patient is a person in whom the size, contour, and position of the teeth are not working for the patient. This could be an aesthetic problem, a functional issue, or a combination thereof, manifesting itself through “signs of instability” in the dentition, including:

• wear
• mobility
• migration
• abfraction
• cracked tooth syndrome
• certain TMJ problems
• a desire to change the size and shape of his or her teeth through cosmetic/aesthetic procedures

Specialty patients may also have biological or structural problems with individual teeth, but the main differentiator between a specialty patient and a general patient is the need to correct or change the patient’s bite as part of the treatment plan. The specific goals of the bite correction go beyond the scope of this article (see The Dawson Academy’s 5 requirements of occlusal stability),¹ but some of the treatment options for bite correction include:

1. selective reshaping/occlusal equilibration
2. orthodontics
3. restorative dentistry
4. orthognathic surgery
5. a combination of the above

As we looked at the patient’s preoperative photos (Figures 1 to 5), we could clearly see signs of wear. This, combined with her history of TMJ problems and her desire to make an aesthetic change, placed her in the specialty patient category. Once her patient type was determined, we began to work through several protocols, and we utilized various technologies to be more efficient during the workflow from diagnosis through treatment planning, the treatment phase, communication with the lab team, and case finishing.

The Diagnostic Phase
When we begin a case with a specialty patient, we combine a traditional dental examination (an oral cancer check, full periodontal probing, charting of existing conditions, and a full-mouth series of radiographs [DEXIS digital X-ray system]) with specific additional data. We entered a comprehensive TMJ/occlusal examination into The Dawson Diagnostic Wizard treatment planning software.² Additionally, we took 21 digital photographs with a macro digital SLR camera and entered these photos into the appropriate templates inside the Wizard. This software would drive our 2-D and 3-D treatment planning processes.

Figure 1. The preoperative smile (note wear).	Figure 2. The pre-op occlusal view of the maxilla.
Figure 3. The pre-op maximal intercuspation (MIC).	Figure 4. The pre-op teeth, apart (note cant and wear).
Figure 5. The pre-op lower occlusal view.	Figure 6. The digital diagnostic wax-up.
Figure 7. The provisional restorations.	Figure 8. An example of a digital scan of preps.
Figure 9. The postoperative smile.	Figure 10. The left lateral smile.
Figure 11. The post-op “E” position.	Figure 12. The post-op retracted (teeth apart) view of the completed case.

Figure 13. Close-up of the finished restorations.

Due to her history of TMJ problems, as well as issues that concerned us during the examination, we decided to take a cone beam computerized tomograph of the joints.³ We utilized a full-field view, using Galileos (Dentsply Sirona) to accomplish this, and the image was uploaded to a maxillofacial radiology service (beamreaders.com). We specifically wanted to assess the risk of degenerative joint disease and condylar position and any risk of sleep apnea due to the size of her airway. This information, along with the clinical data collected during the traditional dental examination, helped to determine the specific diagnosis of any TMJ issue and to drive the appropriate treatment.

Next, we utilized the CEREC OmniCam (Dentsply Sirona) to perform intraoral scans of both arches. We also did a face-bow transfer and centric jaw relation records. We sent these scans to a dental laboratory to be printed, and then the case was mounted on a Mark 320 Articulator (Whip Mix) for the diagnosis and treatment planning process. It is also possible to have these scans mounted onto a virtual articulator, which can be done inside CEREC OmniCam software or with something like 3Shape or Exocad.

As time moves forward, the ability to do virtual equilibrations, orthodontics, wax-ups, and orthognathic surgery (the 4 treatment options) will only get easier. Whether you decide to go analog or digital, properly mounted diagnostic casts in a stable and seated condylar position are imperative to have success in the diagnostic phase.

Lastly, we utilized the STOP-BANG sleep apnea questionnaire (stopbang.ca/osa/screening.php) to determine the patient’s risk for sleep apnea. While she had no history of sleep apnea problems and did not appear to be at risk, we wanted to make sure that the wear on her teeth was not due to an underlying problem related to her airways. She scored a 1 out of a possible 8 on this assessment, indicating a very low risk. Therefore, we determined no further diagnostic evaluations were necessary.

The Treatment Planning Phase
After we completed the diagnostic phase, we began to review her problems and determine the most effective plan of action. A complete treatment plan will solve all the biological issues (caries and periodontal problems), address structural problems with individual teeth, design a stable occlusal scheme for the patient, and allow the clinician to visualize the optimal size, shape, and position of the teeth for aesthetics. With all these factors to consider, a programmed approach to analysis is key.

Utilizing the photographs and information within The Dawson Diagnostic Wizard, as well as the mounted models and the data collected during the traditional dental exam (probings, the restorative chart, FMX), we can come up with a complete diagnosis (Figure 6). The diagnosis was:

• mild, localized gingivitis
• insufficient attached tissues on teeth Nos. 5, 6, 11, 12, and 20 to 29
• active caries around the margins of older crowns on teeth Nos. 3, 4, 13, 20, and 30
• TMJ not being an active degenerative joint disease—the diagnosis was a lateral pole click in right joint, left joint WNL
• bruxism/occlusal instability
• specific tooth shape issues that needed to be corrected to optimize the smile, as well as a canted lower incisal plane
• the position of the maxillary tissues needing to be optimized with grafting on the premolars and canines and crown lengthening on the maxillary central incisors

With the diagnosis completed, we created a comprehensive treatment plan that included a preliminary mouth preparation, which consisted of:

• prophy and home care instructions
• a referral for subepithelial grafting for teeth Nos. 5, 6, 11, 12, and 20 to 28
• a precision orthotic for TMJ stabilization (this was a mandibular full-arch appliance that was adjusted every 2 weeks to allow for condylar seating; the goal was to maintain a stable joint position, equal intensity contacts in this position, and anterior guidance)

The estimated treatment time for the preliminary mouth preparation was 3 to 6 months. After the precision orthotic treatment was completed, the models were then remounted in this position (adapted centric posture), and a full-contour wax-up for the treatment phase was completed.

Once these items were completed, we began the restorative phase, consisting of:

• maintaining and equilibrating the gold crowns on teeth Nos. 2, 15, 18, and 31 to the new condylar position
• placing IPS e.max (Ivoclar Vivadent) monolithic lithium disilicate crowns on teeth Nos. 3 to 5, 12 to 14, 19 to 21, and 28 to 30
• placing IPS e.max monolithic lithium disilicate crowns with micro layering on the facial side of teeth Nos. 6 to 11
• placing IPS e.max lithium disilicate veneers with microlayering on teeth Nos. 22 to 27

Treatment Phase
We prepared and provisionalized (Luxatemp [DMG America]) the upper and lower arches over 2 back-to-back morning appointments (Figure 7), and the final impression was only taken on the lower arch. Retraction was done from canine to canine with a 2-cord technique, and the posterior teeth were retracted using a YSGG (yttrium-scandium-gallium-garnet) laser (Waterlase MD [BIOLASE]). The impression was taken using the CEREC OmniCam to scan the lower arch and the opposing and lower provisionals. The bite registration was taken to mount the master casts in the seated joint position at the correct VDO.

The lower arch was fabricated first, allowing for additional time to fine-tune the maxillary incisal edge position and make any additional changes to the anterior guidance and the envelope of function. Once the lower arch was delivered (Figure 8), we followed the same protocols to fabricate the maxillary final restorations.

Laboratory Communication
Within The Dawson Academy’s philosophy, we do a “specialty” restorative case 4 times: first in our minds, second in wax, third in the provisional restorations, and the final time in glass. This protocol allows us to test our aesthetic and occlusal goals in the provisional phase. The concept cannot change as we move from the physical into the digital realm.

Previously, the dental laboratory team would cross-mount our provisional model with our master model and then fabricate a series of matrices from the mounted provisional model. This would allow the lab team to precisely duplicate all the key aesthetic and occlusal objectives. Today, the lab team duplicates these contours digitally by overlaying the scan of the provisional right over the die model (Figure 8).⁴

The lab team can then print or mill restorations to the precise contours that have worked so well in the provisional phase. They will have the ability to improve aesthetic contours and do the appropriate microlayering to functional, highly aesthetic surfaces to optimize the aesthetic result. This has proven to be an accurate method.

The final case can be seen in Figures 9 to 13. The lithium disilicate restorations were all bonded to place by utilizing a total-etch technique, a universal adhesive (ScotchBond Universal [3M]), a dual-cured resin cement (RelyX Luting [3M]) for the crowns, and a light-cured veneer cement (RelyX Veneer [3M]) that was cured using 2 curing lights (VALO Cordless [Ultradent Products]).

Case Finishing
The case was carefully finished using a combination of ET3 finishing burs (Brasseler USA) and GC Epitex strips (GC America). We completed the final equilibration using TrollFoil (Troll Dental USA) and Accufilm II articulating paper (Parkell). We adjusted until occlusal markings appeared to be ideal and then checked and fine-tuned the occlusal timing using the Dental T-Scan (Tekscan Dental).

It’s important to remember that when we look at occlusal marking paper, we are looking at the sum totality of time it takes for all the teeth to come together during closure, make the marks on the individual teeth, and then come apart again. Therefore, it is very difficult to know which tooth is actually hitting first. The T-Scan allows us to see this in a movie format in 0.01-second increments. Using the T-Scan in conjunction with quality articulating paper is the key to fine-tuning, according to the following 5 requirements of occlusal stability:

1. stable and equal intensity stops on all teeth in centric relation
2. anterior guidance is in harmony with the envelope of function
3. all posterior teeth disclude during mandibular protrusive movement
4. all posterior teeth disclude on the nonworking side during mandibular lateral movement
5. all posterior teeth disclude on the working side during mandibular lateral movement

CLOSING COMMENTS
The technologies that we use in our practice on a daily basis have allowed us to diagnose issues specifically; complete our dentistry more efficiently and accurately; and, in turn, finish our cases more precisely. This case report illustrates how the principles of good dentistry do not have to change as technology evolves.

For more than 30 years, we have been committed to teaching dental professionals how to implement the newest techniques, materials, and technologies into workflows that have been solving patients’ problems.

References

1. Dawson PE. Evaluation, Diagnosis, and Treatment of Occlusal Problems. 2nd ed. St. Louis, MO: Mosby; 1989.
2. Dawson PE, Cranham JC, eds. The Complete Dentist Manual. St. Petersburg, FL: Widiom Publishing; 2017.
3. Hatcher DC. Progressive condylar resorption: pathologic processes and imaging considerations. Semin Orthod. 2013;19:97-105.
4. Bae JC, Kim WH, Jeon YC, et al. Reconstruction of anterior guidance using duplication technique of CAD/CAM: a case report [in Korean]. Journal of Korean Academy of Prosthodontics. 2014;52:121-127.

Dr. Cranham is the clinical director of The Dawson Academy, where he teaches many lectures and hands-on courses, maintains the relevancy of courses, and leads its faculty members. He has published numerous articles on restorative dentistry and co-authored The Complete Dentist Manual with Dr. Peter Dawson. His private practice in Chesapeake, Va, focuses on aesthetic and restorative dentistry. He can be reached via email at smildoc@aol.com.

Disclosure: Dr. Cranham reports no disclosures.

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