Case report: Digital tools in planning and implementing ... · creating restorations in the aesthetic area for contemporary dentists. ... restorative treatment, but declined. Moreover,

Nov 20, 2017 12:16 UTC

Case report: Digital tools in planning andimplementing aesthetic ceramicrestorations – the SKYN concept

Clinical case report by Dr. Kirill Kostin

Until recently, indirect dental restorations in the aesthetic area required a highdegree of cooperation between dentists and dental labs. The planning processspanned several stages and entailed, therefore, several appointments for thepatient. Yet, the final result was often significantly different from the originalplan. Fortunately, new digital tools have since changed the nature of aesthetictreatments and enabled improved levels of care.

The development of digital tools has greatly simplified planning and creating

restorations in the aesthetic area for contemporary dentists. Moreover, thesetools enable us to communicate efficiently with our patients, increasing thepredictability of treatment outcomes for everyone involved. Still anotheradvantage is that the new techniques allow for shorter treatment timescompared to conventional methods.

This article presents a clinical case where the SKYN concept was usedalongside various digital tools to plan and create full-ceramic CAD/CAMrestorations.

The article features a female patient presented with the main complaint ofincisal edge wear of the upper central incisors. The patient also expressed adesire to have her diastema closed as it made her feel her smile was notharmonious.

Fig. 1. The patient’s upper teeth before treatment.

Fig. 2. The initial smile view.

The patient was offered to undergo an orthodontic preparation prior to herrestorative treatment, but declined. Moreover, the patient requested to haveas minimal intervention as possible done without involving other teeth.

Treatment Plan

To improve the appearance of the smile according to the patient's wishes, thedecision was made to restore the upper central incisors with full-ceramicCAD/CAM restorations. Given that colour correction was necessary, weselected IPS Empress CAD Multi A1 (Ivoclar Vivadent) as the material. Todiscuss and determine the shape of the future teeth, we further suggestedpreliminary aesthetic diagnostics with the Planmeca Romexis Smile Designsoftware.

Treatment Protocol

At the preliminary stage, we performed an intraoral scan to obtain a virtualdiagnostic model for further evaluation. Then we converted the digitalmodels into physical ones by way of 3D printing.

Fig. 3. A 3D-printed model showing the initial situation, as obtained at theorthodontic diagnostic stage.

As the patient could not undergo a long-term orthodontic preparation, weneeded to model the outcome based on the patient’s wishes and restrictions.Working with portrait photographs of the patient, we used the PlanmecaRomexis Smile Design software to visualise the shape and proportions of thefuture teeth.

Fig. 4. Digital design: shaping the central incisors in Planmeca Romexis Smile

Design.

Fig. 5. A portrait photograph with a digital mock-up of the future smile. Aphotograph like this allows the patient to better visualise the potential outcomesof an aesthetic treatment and makes the final result more predictable foreveryone involved – from dentist to patient to dental technician.

A design like this takes no more than two to three minutes and allowscreating a virtual mock-up chairside. Seeing the result of the proposed smilemodification significantly improves dentist-patient communication andincreases the efficiency of consultations.

After the patient approved the computer-aided smile design, she participatedin selecting the shape of her future centrals from the Anteriores catalogue byJan Hajtó. Attention was paid to both the desired shape and actual size of the

planned restorations. This was achieved by measuring the width of tooth 11and then selecting a matching sample from the Anteriores models.

Fig. 6. Measuring the width of tooth 11 on the diagnostic model.

Fig. 7. Measuring the width of tooth 11 on the М1 model from the Anteriores setby Jan Hajtó.

Fig. 8. The М1 model used as a sample for the digital rendering of the shape andsize of the central incisors, as part of the SKYN concept.

This was the outcome of the first appointment, when the patient visited theclinic for diagnostics and planning. By the following visit, we preparedindividual anatomical composite skyns based on the 3D-printed diagnosticmodel. Composite skyns can also be prepared and adjusted intraorallywithout any models. First, we obtained a silicone impression of the buccalsurfaces of the Anteriores set model.

Fig. 9. Taking a silicone impression of the central incisor buccal surfaces on the

Jan Hajtó anatomical model.

Then, using a light-cured composite, we created individual anatomical skyns,reproducing exactly the shape and micro-texture of natural teeth.

Fig. 10. Introducing the light-cured composite into the silicone index.

Fig. 11. The silicone index was lubricated with modelling resin (Bisco) prior toinjecting the composite in order to achieve a smoother surface on the anatomicalcomposite skyn.

Fig. 12. When creating skyns, the composite was spread in the silicone index intoa thin, homogenous layer.

Fig. 13. The individual anatomical skyns and the original model from theAnteriores set.

The skyns were then fitted and finished, with margins corrected, on thediagnostic model. The marginal correction was performed with rotaryinstruments.

Fig. 14. Try-in of the composite skyns and marginal adaptation on the diagnosticmodel. A similar try-in procedure can also be performed in the patient's mouth.

Fig. 15. The individualised composite skyns are ready for fitting and cementationin the mouth.

All of the work can be performed during the very first visit directly on thepatient's teeth. In our case, however, we created the skyns betweenappointments, so that during the second visit all that was left to do was to fitand adjust the individual anatomical composite skyns in the mouth.

Fig. 16. The initial situation intraorally prior to the adaptation of the compositeskyns on the patient's teeth.

Fig. 17. For best positioning and adaptation of the skyns, a preliminary occlusaladjustment was made on teeth 11 and 21.

Fig. 18. On the buccal, All-Bond 3 (Bisco) was applied without prior enameletching.

Fig. 19. The individual composite skyns adapted on the teeth with small amountsof a flowable light-cured composite.

Fig. 20. Composite cementation allows you to visually demonstrate to the patientthe potential final outcome.

Fig. 21. One of the advantages of the SKYN concept is the immediatevisualisation of the final outcome without the need for impressions or laboratorymanufacturing of a diagnostic wax-up.

As we fitted the individual composite skyns in the patient's mouth, wenoticed a small black triangle forming between the central incisors when theshapes were copied into future restorations. To avoid this effect, it wasnecessary to prepare the medial surfaces slightly taking the preparationslightly into the sulcus. Moreover, the contours of the restorations weremodified for a more rectangular shape. 

As the patient wished to preserve the shapes we tried in, it was important forus to prevent potential disappointment with the final aesthetic result.Visualising the final outcome helps to achieve mutual understanding with thepatient still at the planning stage, and helps the dentist choose the requiredpreparation design. Furthermore, at this stage the patient was also able toinform us that the macro-texture and the “uneven” incisal edge of theoriginal composite skyn were not desirable.

Thus, after discussing all the details with the patient, we were able totransfer all the details agreed upon into the final restoration. This wasachieved by way of preliminary intraoral scanning and obtaining a virtualmodel with “digitised” anatomical composite skyns.

Fig. 22. The composite skyns on the surfaces of teeth 11 and 21 scanned forfurther digital copying at the restoration modelling stage.

Next, teeth 11 and 21 were prepared for ceramic veneering. As is known,adhesion to enamel is highly superior to adhesion to dentin. Consequently, atthis stage it is crucial to preserve the healthy tissues within the enamel.

Fig. 23. Preparing teeth 21 and 11 through the composite skyn to control thethickness of the future restoration.

Fig. 24. The patient’s teeth after preparation before taking a digital impression.

Upon preparation, Ultrapak 00 cord (Ultradent) was inserted into the sulcusand an intraoral scan was performed with the Planmeca PlanScan intraoralscanner.

Fig. 25. The digital model obtained by intraoral scanning.

As an adjunct, we obtained a partial silicone impression of the upper teethfrom 13 to 23 in order to produce a control composite model. This is not anobligatory step in creating digital restorations, but can be useful when micro-contouring and dyeing ready veneers or crowns.

Fig. 26. Partial silicone impression: the upper segment from 13 to 23.

Fig. 27. The control model made of composite, as obtained from the siliconeimpression. A similar model can also be obtained digitally by milling or 3Dprinting.

After the digital impression was obtained, the restorations were designedwith the Planmeca PlanCAD Easy software which is part of the Planmeca FITopen CAD/CAM system. Using the capabilities of the system, we essentiallycopied the shapes of the anatomical composite skyns. During the designprocess, we also used the teeth silhouettes which were created at the initialdiagnostic stage with the Planmeca Romexis Smile Design software. All in all,creating the virtual restorations took about 30 minutes for two units.

Fig. 28. Digital design of the restorations by way of digitally transferring theshape and macro-texture of the anatomical composite skyns. In the digitalenvironment, the contours of the scanned anatomical composite skyns weresuperimposed on the restorations being created.

Fig. 29. When designing the restorations, we exported the silhouettes of teeth 11and 21 from the Planmeca Romexis Smile Design software to control the shapeand proportions of the restorations.

Fig. 30. Superimposing the exported silhouettes on the restorations allowscorrecting the proportions of the restorations according to what was agreed uponwith the patient at the planning stage. This is how digital planning with thePlanmeca Romexis Smile Design software enables efficient communication withthe patient as well as the predictable transformation of the planned outcome intothe final restoration.

The next stage was manufacturing the restorations with the PlanmecaPlanMill 40 milling unit. The material of choice in this case was IPS EmpressCAD Multi, shade А1. This material has a high translucency which allowstransmitting the colour of the stump.

Fig. 31. Checking the restoration before milling. Because IPS Empress CAD Multiblocks have a fluorescence transition, the operator can change the position of the

restoration in the block and thus control the degree of translucency/opacity in thefinal restoration.

Fig. 32. The compact Planmeca PlanMill 40 milling unit.

Fig. 33. The ceramic restorations immediately after milling. Milling one unit takesabout 15 to 20 minutes.

The milled veneers are separated from the block, with the macro- and micro-texture added later.

Fig. 34 (a), (b), (c), (d). Stages of micro-contouring, which aims to imitate thenatural texture of teeth.

Fig. 35. The final look of the restoration after macro- and micro-contouring.

Due to their thinness (between 0.5 and 0.8 mm), ceramic veneers made of IPSEmpress CAD Multi blocks transmit the colour of the underlying tissuesnicely. To make the restorations look even more natural, the cervical andincisal areas were also dyed. Finally, the ceramic surface was glazed andpolished.

Fig. 36. Dyeing and glazing the ceramic surfaces.

Finally, the restorations were adhesively fixed with a light-cured compositecement, Choice 2 (Bisco), shade А1, according to the manufacturer’sinstruction.

Fig. 37 (a), (b), (c). Final outcome 3 days after the completion of the treatment.

Fig. 38 (a), (b). Final outcome 2 months after cementing the veneers.

Conclusion

Contemporary digital tools facilitate communication between dentist andpatient, enabling the high predictability of aesthetic treatments. The abilityto visualise potential outcomes boosts the efficiency of consultations at theinitial stages as well as helps to avoid conflicts upon completion oftreatment. The SKYN concept, along with the capabilities of modernCAD/CAM systems, allows performing aesthetic treatments in the shortesttimes possible and creating highly aesthetic restorations immediately andchairside without the need to work with a third-party dental lab.

About the author

Dr. Kirill Kostin graduated from Saint Petersburg State Medical University (Russia)in 2004. He became the co-founder of the PerfectSmile dental clinic and dentalstudy center in 2014. At his clinic in Saint Petersburg, Dr. Kostin runs a privatepractice concentrating on the aesthetic and functional rehabilitation of naturaldentition and implants, applying various digital instruments as part of restorativeprocedures (digital smile design, intraoral scanning, CAD/CAM milling, 3Dprinting, and guided surgical procedures). Using a dental microscope on a dailybasis, Dr. Kostin focuses on minimally invasive restorative procedures with directand indirect restorations.