The advancement of digital dentistry continues to improve the disconnected communication between dental teams and achieve excellent clinical outcomes for patients. Digital analysis and planning of complex cases requiring the involvement of dental professionals from different specialties can be accomplished with a high degree of predictability and accuracy. 3D printed surgical and preparatory guide templates produced using precision digital smile design technology are invaluable tools for improving the accuracy of clinical interventions, helping to limit human error and increase predictability. Additionally, advanced CAD/CAM ceramic materials can be combined with the use of appropriate adhesion protocols to promote long-term functional and esthetic success.
This is a clinical case report that contributes to long-term functional and aesthetic success. This clinical report describes and illustrates digital treatment planning and the application of an integrated approach in the surgical and restorative treatment of a complex clinical case that required aesthetic rehabilitation.
Digital dentistry and its analytical capabilities have expanded the boundaries of what clinicians can do with the biological capabilities of human tissues. Digital dentistry has expanded the clinician's capabilities to confidently and predictably handle complex multidisciplinary cases, working in coordination with the patient, with the final treatment direction clearly defined at the beginning of treatment.
Facial feature analysis, radiographic examination, and tissue architecture examination, combined with Digital Smile Design (DSD) concepts, enable the dentist to iterate on the patient's optimal treatment plan and minimize the uncertainty and unpredictability often associated with complex treatments and the involvement of multiple specialists. These “blueprints” are essential communication tools – from inception to cementation – between the treatment team, whose members may be located in different locations around the world.
The possibilities of digital dentistry provide precise guidance to clinicians through thoughtful efforts to achieve the most ideal biological, structural, functional and esthetic result. In addition, this result can significantly improve the patient's self-confidence and quality of life. The following clinical case description presents an example of the possibilities of digital dentistry in the interdisciplinary interaction of clinicians.
Case Presentation
A 45 year old male patient who was an actor/director presented to the authors' clinic primarily with a cosmetic problem. He was unhappy with the width of his anterior teeth and was very unhappy with their tilt and the way they showed when he smiled. Four maxillary incisors were restored with laminated veneers. Following a thorough clinical examination, photographic documentation, intraoral scanning and video analysis (Figure 1), a number of initial clinical findings were made and recommendations for the upcoming treatment were made.
Figure 1. A portrait photo of the patient before treatment is presented.
The patient had a very symmetrical face with well-positioned and proportioned features and appropriate soft tissue framing of the facial cranium. However, the maxillary teeth were angled and displaced to the right, which was his main complaint. It was explained to the patient that rather than limiting treatment to comprehensive orthodontic therapy to correct this problem, smile design protocols in digital dentistry could be used to surgically recontour the soft tissue and bone of the upper right jaw to achieve a harmonious gingival contour in ideal facial planes. The upper anterior teeth could be restored with porcelain laminate veneers to create a natural and symmetrical smile. The patient was motivated by the fact that the proposed treatment would allow him to visualise the final outcome before committing to any surgical procedure. He therefore chose this option over very extensive orthodontic treatment.
Planning Phase
Cosmically complex multidisciplinary cases such as this require careful planning from the outset to achieve a successful outcome. The authors suggest that the following general principles of patient management generally apply:
- The clinical outcome will be as good as the management of the clinical history.
- Careful planning helps to determine the optimal course of treatment tailored to the patient's unique situation, taking into account biological conditions such as the type and quality of the patient's hard and soft tissues.
- The first two principles can be enhanced by the use of digitally guided surgical templates to ensure a predictable aesthetic and functional outcome for the patient.
Data Collection and File Format
For this case, a significant amount of data was collected for transmission to the Digital Smile Design (DSD) planning center, including intraoral, portrait, 12 o’clock dental photos, digital intraoral scans, functional phonetic videos of the patient’s speech with and without retractors for phonetic analysis, and a Cone Beam Computed Tomography (CBCT). These were sent to the Digital Smile Design (DSD) planning center in JPEG, MP4, STL, and digital image files for communication between specialists (DICOM). In order to obtain high-quality clinical photographs, lighting and the patient’s position and angle are of paramount importance. Especially when taking extraoral facial photographs in asymmetric cases, it is important that the patient has excellent posture and equal head projection, and that the ears on both sides of the head are unobstructed if possible.
A unique set of important data and information can be extracted from video viewing, facilitating dynamic analysis of the smile and face that is not possible with static photography. Dynamic functional videos with retractors and natural phonetic footage contain a wealth of information that allows the creation of an ideal smile in three dimensions. It also gives the clinician a more complete understanding of the functional and expressive movements and boundaries of the face and mouth. CT scanning is an important part of the patient's medical history to allow accurate analysis of the periodontal soft tissues in cases such as this involving crown lengthening. The lips must be retracted away from the periodontal tissues to reduce interference with the measurement of periodontal hard and soft tissue thickness and alveoli. To achieve this, a useful clinical tip described by Gluckman and colleagues is to insert a device into the mouth to retract the lips and cheeks away from the teeth on the buccal side – a retractor – during the CBCT scan.
Data analysis and planning of digital smile design (DSD)
When evaluating a future Digital Smile Design (DSD), all smile parameters are taken into account, including ideal tooth size, texture, proportion and color, smile curve, gum harmony and the ratio of white (tooth) and black (buccal corridors) to pink (gingiva). Achieving natural results can be facilitated by using the large number of natural files available in the digital planning software. Although the results can still be improved by additional planning, “borrowing” from nature with the “copy-and-paste” method can provide a more predictable and natural-looking final aesthetic result (Photo 2).
Photo 2. An example of digital smile design planning is presented.
At this stage of digital smile design (DSD) planning, simulations can be created to develop a treatment plan with the lowest clinical risk. Based on the initial clinical presentation compared to the idealized final outcome, the clinician can design and test potential treatment sequences and combinations. These potential outcomes can be analyzed in great detail by virtually superimposing the planned design results on the patient’s hard and soft tissues. Any potential adverse outcomes and risks can be identified and the treatment adjusted accordingly. This capability significantly reduces the risk of inadequate treatment planning and misdiagnosis. Predictability and treatment success can be ensured before a single bur or blade touches the patient’s tissue, which is one of the major advantages of digital dentistry.
Treatment Process Protocols
Diagnostic Simulation
The patient came to the appointment with a mock-up to demonstrate the Digital Smile Design (DSD) and the desired outcome; a silicone key, bis-acrylic material and black ink for intraoral blocking were used to create the mock-up. Complex mock-ups such as this may require the creative use of visual illusions and skilled photography to create the appearance of the ideal smile in a realistic and believable way. The use of photography or videography allows patients to see the intended smile in the context of their face, rather than simply looking in the mirror and seeing their expected smile in tunnel vision. When using Digital Smile Design (DSD), each clinical step should be explained to the patient in a presentation format to facilitate understanding of the procedural steps required to achieve the ideal outcome. Patients are able to provide feedback and request any adjustments they may wish in collaboration with the clinician, which may prove beneficial to the patient (Figure 3). The physical layout and presentation provide visualization for the patient, as well as all other information the patient may need to give informed consent for treatment.
Photo 3. The ideal digital layout of the smile design in the patient's mouth is presented.
This stage of the diagnostic mock-up also allows for the evaluation of the surgical plan. The proposed design, existing teeth, and gingival and bone levels are analyzed by superimposing the current file, the proposed ideal design file, and the CBCT scan slices. This facilitates a detailed determination of the necessary gingival and bone removal. In this case, the extent of the surgical intervention was deemed appropriate and was approved by the patient.
Crown Lengthening and Revised Digital Smile Design (DSD)
The planned crown lengthening procedure involved the removal of bone and gingival tissue in the area of the maxillary lateral incisors, canines and premolars while maintaining the existing biologic width. As a result of crown lengthening, the gingival margins were advanced from 0.48 mm to 2.55 mm apically to achieve the desired leveling effect (Figure 4). The patient’s gingival biotype was quite thin, ranging from 0.49 mm to 1.14 mm, with a bone thickness of 0.73 mm to 1.18 mm. Great care was taken throughout the surgical procedure not to tear these delicate tissues. A Crown Lengthening (CL) surgical guide was designed and 3D printed, along with two additional copies to ensure accuracy and to serve as spares in case one was damaged (Figure 5).
Photo 4. A plan for lengthening the crown of tooth 2.3 (1.1.) is presented according to the numbering accepted in the USA.
Photo 5. The surgical guide template for lengthening the crowns of the teeth (CL) is placed on the dentition of the upper jaw.
The steps of the crown lengthening procedure were as follows: first, a gingivectomy was performed to the planned gingival level using electrosurgery, as well as a curette and chlorhexidine (CHX) tablets to clean the surgical field (Figure 6). Then, a full-thickness gingival flap was elevated using a 15c scalpel, after which the bone level was marked to the ideal biologic width using a sterile surgical pencil and a surgical guide template. Then, the bone was debrided at the level of the bony septa of the target teeth using a round diamond bur, and the bone margins were debrided to the marked levels using an ultrasonic tip, hand instruments, and a limited rotation (lowering) tip (Figure 7). Finally, the soft tissue flaps were adapted to the wound margins using polypropylene sutures and a reverse cutting needle, and the area was closed with a vertical mattress suture.
Photo 6. Shows the stage of gingivectomy during crown lengthening using a CL-guided surgical template.
Photo 7. Shows the stage of processing the bone partitions of the procedure for lengthening the crowns of teeth using a CL surgical guide template.
To ensure a rapid healing process postoperatively, the patient was given 0.12% chlorhexidine (CHX) mouth rinse and 0.5% chlorhexidine digluconate (CHX) gel with a surgical toothbrush to apply to the gingival area. Augmentin® Duo 500 mg twice daily for 5 days (repeatable) plus naproxen 550 mg four times daily for 3 days was prescribed. The patient was followed up at 7-day intervals and the sutures were removed after 3 weeks. The patient was instructed to continue massaging chlorhexidine (CHX) gel with a surgical toothbrush for 10 days (Photo 8).
Photo 8. Showing the condition of the soft tissues after the surgical crown lengthening procedure.
A revised and refined Digital Smile Design (DSD) was fully simulated 8 weeks later to confirm the final veneer design with the new gum contours. A second mock-up of the dental crown appearance was made before the preparation of 12 teeth (Photo 9 and Photo 10).
Photo 9. Showing the new mock-up (mock-up) of the dental crowns after the patient's crown lengthening procedure, portrait photo.
Photo 10. New model of dental crowns (Mock-up) after the procedure for lengthening dental crowns, photo inside the oral cavity with retractors.
A procedure was performed to clean all the teeth in the mouth from the existing biofilm (using a lighter coating on the healing areas of the upper jaw) and complete the preparation of the soft tissues and teeth for the manufacture of veneers. The patient was given a mouthwash with hyaluronic acid to reduce inflammation.
Tooth preparation
Before the veneers were made, the teeth were bleached using phthalimidoperoxycaproic acid (PAP), which is intended for professional bleaching. This preparation is useful because, unlike solutions containing peroxide, it does not emit free radicals and, therefore, eliminates the need for a pause before fixing the structures to the teeth. As a rule, when using solutions containing peroxide, it is recommended to wait from 8 to 11 days for the color of the tooth tissue to stabilize, which is less true for the use of PAP preparations.
Preparation for the installation of digitally designed veneers was carried out using a series of special 3D-printed preparatory templates based on the final design of the restorations. The templates included a master template and preparatory templates for quality control of the main templates. The planned procedure for tooth preparation included the following stages:
- tooth preparation using the first template for tissue reduction on the vestibular side of the maxillary incisors (photo 11 and photo 12);
- application of a technical mock-up (mock-up) to the teeth and subsequent processing of the mock-up using a bur for deep preparation of veneers;
- checking the correctness of the preparation performed using templates that allow you to evaluate the quality of the manipulations performed;
- finishing and polishing the structures;
- evaluation of the technical model (Mock-up);
- evaluation of the template itself to control the quality of the work done (photo 13 and photo 14);
- evaluation of the template to control the quality of tooth preparation from the cheek side (photo 15 and photo 16);
- assessment of the template for quality control of interproximal tooth preparation (photo 17 and photo 18) and verification of the preparation of tooth tissue using templates for quality control of work performed in the dentist's chair (photo 19 – photo 21);
- small separation of contact points of teeth with a metal finishing strip;
- finishing and polishing of finished restorations on teeth.
Photo 11. Instructions and a plan for tissue reduction of incisors and lateral teeth are presented.
Photo 12. The first stage of teeth processing with a guide template in the oral cavity is shown.
Photo 13. The plan for implementing quality control of the preparation performed is shown.
Photo 14. Shown is a guide template for quality control of incisor preparation.
Photo 15. Shown is a plan for quality control of teeth preparation from the cheek side.
Photo 16. Shows a guide template for quality control of tooth preparation from the cheek side.
Photo 17. A plan for quality control of the preparation of contact points of teeth is presented.
Photo 18. A guide template for quality control of the preparation of contact points of teeth is shown.
Photo 19. Checking the quality of tooth preparation using 3D-printed quality control templates placed on the teeth: front view.
Photo 20. The quality of tooth preparation is checked using 3D-printed quality control templates placed on the teeth: side view.
Photo 21. The quality of tooth preparation is checked using 3D-printed quality control templates placed on the teeth: occlusal photo.
The gum contour was further outlined using an electrosurgical instrument. A #00 retraction cord was inserted into the gingival sulcus, and the retraction paste was squeezed out onto the gingival margins and left for 10 minutes. The preparation was then washed off, an intraoral scan was performed, and the files were sent to the DSD Digital Smile Design Planning Center. Photos of the selected sample of the tooth shade chart in the shade were taken to accurately transfer the desired shade of the future restorations to the laboratory. This allows the clinician to determine the desired staining result and select the correct transparency of the future veneer block, the thickness of the tooth tissue preparation, and select the desired shade of the fixing cement. The prepared teeth were pre-treated with bis-acrylic material, after which a silicone key of the new tooth shape was obtained, and then the restorations were fixed on the teeth using the point etching and point gluing technique. A temporary retainer (splint) was also made, covering approximately half of the teeth and protecting the temporary restorations. The patient removed it during meals. The patient was given a serum in the form of chewing gum for gums with hyaluronic acid and a 0.5% gel containing chlorhexidine (CHX) to use alternately.
Lithium disilicate veneers
DSD Digital Smile Design Lab milled 12 monolithic lithium disilicate veneers in BL4 shade based on the final design verified with a mock-up made after the crown lengthening procedure. The veneers were stained, glazed and toned using the make-up staining technique. High milling accuracy ensured excellent match of the designs at the gingival margin.
For final placement, the temporary veneers were removed and gently disinfected with a cotton swab soaked in 0.2% chlorhexidine (CHX) solution. The veneers were tried in with a clear try-in paste and photographed under studio lighting. Both the doctor and the patient were satisfied.
The maxillary teeth were isolated with a rubber dam to ensure control of the working area. The veneers were etched with hydrofluoric acid for 30 seconds and rinsed with water, then the structures were placed in a capsule with alcohol and immersed in an ultrasonic bath for 4 minutes. This step is designed to ensure the removal of all residual acids, crystalline deposits and remineralized salts for optimal bonding of the veneers to the enamel surface. A silane coupling agent was applied and the tooth surfaces were etched with 37% phosphoric acid for 20 seconds, rinsed and thoroughly dried. The primer (bonding agent) was applied using a microbrush applicator.
The veneers were cemented with resin cement using a “transparent” shade. Due to the ideal dentin shade and conservative preparation, there was no need for color masking with the luting cement shade itself. The cement was allowed to set and excess cement was removed with a #12 scalpel, dental floss and cotton balls. Final curing was completed under a liquid lens to ensure that all of the oxygen inhibition layer had been removed. Static and dynamic occlusion were checked and adjusted slightly to ensure balanced occlusion.
Sleep Guard Fabrication and Follow-up
An intraoral scan was performed and the file was sent to the lab for express fabrication of a digitally designed and 3D printed night guard. The patient was scheduled for a follow-up appointment three days later. During this appointment, an occlusal splint was applied and a digital occlusal analysis was performed with the patient sitting upright to analyze the uniform distribution of occlusal forces on the teeth. The lower teeth were re-bleached to match the final color of the maxillary veneers (Figure 22 and Figure 23). Since the patient would be traveling for several weeks for work, he was given a dental scanning and monitoring kit to allow re-scanning as needed to re-evaluate the post-operative outcome.
Figure 22. Portrait photo of the patient showing the oral condition after the procedures.
Photo 23. The final restorations in the mouth with retractors are shown.
Conclusion
Digital dentistry continues to empower clinicians by improving asynchronous communication between dental teams and enhancing clinical outcomes for patients. Digital analysis and planning of complex multidisciplinary cases can be performed with a high degree of predictability and accuracy. 3D printed surgical templates and preparatory guides produced using specific digital tools and programs such as Digital Smile Design (DSD) are invaluable tools used to improve the accuracy of clinical interventions by helping to limit human error and increase predictability. Finally, the use of advanced CAD/CAM ceramic materials coupled with proper cementation protocols contribute to long-term functional and esthetic success.
Authors:
Fadi Yassmin, BDS, MSc Ae Dent
Markus B. Blatz, DMD, PhD