Case report: Full mouth rehabilitation utilising Digital Smile Design (DSD)

Written on 03/25/2018
Masoud Abu Zant

By Fadi Yassmin, BDS (Syd), MSc Ae Dent (Kings College London) MFGDP (UK)

with the recent surge of digital treatment planning being incorporated into a dentist’s armamentarium, the advent of Digital Smile Design (DSD) ushers in a more streamlined workflow. In many cases, traditional methods to incorporate a simulation of what a patient can expect treatment to involve have now become outdated thanks to this new system which effectively communicates all variables.

This case demonstrates the effectiveness of DSD and how it can be implemented throughout a complete digital workflow in a full mouth rehabilitation
involving major OVD changes.
Case report
A 57-year-old patient presented with major aesthetic concerns . Examination revealed severe wear and intrinsic discolouration due to antibiotics at a young age (Figure 1). The lack of desirable tooth display was one of the motivational factors

Figure 1. Initial situation showing severe wear and intrinsic discolouration.

Figure 2. Comprehensive photographic and video graphic records were taken.

Figure 3. SKYN templates are utilised to help determine the ideal anatomical characteristics for the patient’s smile.

in seeking treatment. The clinical examination also showed wear facets due to bruxing. Airway involvement was ruled out following a sleep study. Further, there was generalised abrasion in the cervical region and lower anterior crowding. After discussing the various options available from minimal treatment to full mouth rehabilitation with an increase in vertical dimension, the patient decided on the latter which we would complete with a fully digital workflow. Comprehensive photographic and video records were taken along with an intraoral scan (Figure 2). These records allow us to make a facially driven smile design (DSD) in 2D so that an accurate mock up is achievable.

Figure 4. Digital smile designing in progress.

Figure 5. Virtual wax-up of 3D design.

Figure 6. The design is 3D printed and used to create a mock-up in acrylic.

Figure 7. Try-in of acrylic “motivational” mock-up.

Figure 8. Scan of new open bite using leaf gauge.

It is important to note that the workflow enables not only effective communication to the patient, but is individualised to each patient’s dental characteristics based on their facial type, gender and age. As part of the smile design process, a natural tooth library (SKYN) selection was used (Figure 3). The use of natural tooth files is gaining popularity in digital dentistry. These files come with natural textures which are picked up in the final milling process. A digital smile design (2D Smile frame) was finalised to allow a 3D design of the restorations (Figure 4). This was achieved in Nemostudio via the overalying of the patient photos and STL models of the patients teeth .The first model to be generated and printed is to allow the mock up to be demonstrated. This simulates the additive wax up except “virtually” (Figure 5). The STL file of the mock-up is 3D printed and a silicone key is made to allow a mock up in acrylic for the patient to see the potential smile (Figures 6 and 7). The PVS key is designed in such a way that excess is easily removed at the time and minimal polishing is necessary. The “motivational” mock-up is purely that. It allows the patient to visualise the outcome before we move to a functional design. Once we are satisfied with this, we then proceed to virtually/digitally designing the rest of the occlusion (Figure 8). The software allows this once the new vertical has been established. The teeth are scanned in the new open bite using a leaf gauge to establish the height. This is then placed into the software where it is “functionally” built-up. Then the STL files generated allow the printing of the new functional models that are used as the template for the provisional restorations (in this case it was for 6 weeks) (Figure 11).

Figure 9. Digitally designing the occlusion

Figure 10. Digitally designing the occlusion

Figure 11. Final functional upper and lower occlusion on the 3D printed models used as the template for the provisional restorations.

Figure 12. Silicone preparation guides are made that allow assessment of the need for vertical and labial reduction.

Figure 13. The natural textures of the SKYN file allow for very natural restorations that only need to be milled and stained.

Figure 14. Final restorations are cemented under rubber dam.

Figure 15. The final occlusion is verified with the T-scan a digital occlusion analyser

Figure 16-19. Final restoration in situ and a very satisfied patient.

The restorations are prepared through the provisionals, allowing for accurate and conservative tooth reduction. There are also silicone preparation guides made for vertical and labial reduction assessment (Figure 12).
The preparations are scanned with an intra oral scanner and the original digital restoration design is married up in the scanning software. The natural textures of the SKYN file is captured and allow for such a natural restoration that only needs to be milled and stained (no layering is necessary) (Figure 13).
The final restorations are cemented under rubber dam for ideal moisture control and bond strength (Figure 14.)
The final occlusion is verified with the T-scan a digital occlusion analyser that is extremely accurate. This is ideal for such cases that involve significant occlusal changes (Figure 15).
The final results show the consistency and accuracy of a refined digital workflow from mock up to final restoration all based on a facially driven design using digital smile design (DSD) Figures 16 to 19).

About the author

Dr Yassmin first studied DSD with Christian Coachman and not only did he incorporate it into his daily practice workflow but has become a speaker and official instructor for DSD. This training along with his Masters in Aesthetic Dentistry from the Kings College of London has enabled him to further establish his cosmetic and implant practice in Sydney. He is currently running his DSD courses in Australia and Asia.