Digital smile design in the dental lab: photos to mock-up
How a dental lab runs digital smile design: the photos and scans it needs, natural tooth proportions, the 3D wax-up, the mock-up and gingival changes.
Digital smile design is often sold as software. In the lab it works as a sequence: collect the right records, design teeth that fit the patient’s face and let the patient try the proposal in the mouth before anything irreversible happens. The software makes each step faster and easier to show and the order of the steps is what makes the result predictable. This post describes that sequence as I run it for clinics.
Records the lab needs
The design starts from intraoral scans of both arches with a reliable bite. Standardized photos come next: full face smiling, full face at rest, a retracted frontal view and lateral views. When the clinic has a face scan, it gives the most reliable 3D reference (see face scanning with an iPhone).
The clinician’s notes matter as much as the images. They should say what the patient wants to change, what must stay as it is, which treatments are planned and which constraints apply, such as existing restorations, periodontal condition, occlusion and the intended materials. When any of this is missing the lab has to assume and in aesthetic work assumptions are a common cause of remakes.
Natural proportions instead of a template
Very white, perfectly uniform teeth are still requested. On a real face they often look artificial and they age badly. The designs that patients accept and keep liking follow their own features: proportions that suit the face, individual tooth shapes with some characterization and a shade and brightness in line with skin, eyes and age.
The least invasive route matters as well. Where it is clinically possible, a design based on additive or minimal-preparation solutions preserves tooth structure. The clinician decides whether no-prep or minimal-prep is indicated and the design should show what each option would look like so that decision can be made.
From 2D analysis to 3D wax-up
- Analyze the photos in 2D: facial midline, horizontal references, smile line and tooth proportions.
- Align the photos or the face scan with the intraoral scans.
- Build the 3D wax-up in CAD, guided by the 2D references.
- Check occlusion and guidance on the wax-up (see virtual articulator and jaw motion).
- Present the proposal to the clinician, who discusses it with the patient.
In exocad this sequence runs in the Smile Creator module, described step by step in the exocad Smile Creator guide. Other CAD platforms have comparable tools.
The mock-up
The mock-up moves the design from the screen into the mouth in a reversible way. The usual route is to print a model of the wax-up, make a silicone key on it and fill the key with provisional material chairside. A thin printed shell that the patient tries in is another option.
The patient sees and feels the new shape, speaks with it and can show it at home. The clinician checks lip support, phonetics and function. Adjusting the design at this stage takes minutes, while the same change after delivery means new restorations.
When the gingival line has to change
Teeth that look short or asymmetric are sometimes a gingival problem. Lengthening them over an unchanged gingival line produces teeth that look out of proportion.
In the design the new gingival contour can be drawn first and the tooth shapes built on it. If the clinician decides that a gingival correction is indicated, a guide can be designed from the planned contour so the procedure follows the plan. The gingivectomy attachments I use for this are free on the download page.
The timing has to be agreed with the clinic: gingival correction first, then healing, then final preparations and scans.
Why smile design cases disappoint
Most disappointments trace back to a few causes. The design was made on scans without facial references. The patient approved a render that the mouth could not reproduce, something a mock-up would have shown. Function was sacrificed for appearance. The gingival line was changed on screen without planning the clinical step. Or the teeth were simply too white and too uniform for that face.
Frequently asked questions
What does a lab need for digital smile design?
Intraoral scans with a reliable bite, standardized photos (full face smiling and at rest, plus a retracted frontal view), a face scan when available and the clinician's notes on what the patient wants to change.
What is a mock-up?
A temporary transfer of the planned tooth shapes into the patient's mouth, usually with a silicone key and provisional material or with a printed shell. Patient and clinician evaluate the proposal before any irreversible step.
Can the lab plan a gingivectomy?
The lab can show the new gingival contour in the design and produce a guide from it. The indication and the procedure are clinical decisions.
Why do many patients now prefer natural-looking smiles?
Very white, uniform teeth often look artificial on a real face. Designs that follow the patient's proportions, age and character are accepted more easily and keep looking right over time.