Digital Technologies in Dental Rehabilitation Planning.

The goal of this clinical trial is to evaluate the influence of Facial Scan (FS) and cone beam computed tomography (CBCT) in the prosthodontic treatment planning in patients who require rehabilitation with a single crown, with aims:

1. assessing patient's comfort and aesthetics self-perception; ii) evaluate the influence of a virtual articulator in a diagnostic waxing; iii) evaluate the influence of implementation of FS and CBCT to the current digital procedure with a virtual articulator; iv) evaluate the influence of programming the virtual articulator.

Data collection will be carried out in participants, including: an intraoral scan (digital impressions), intraoral and extraoral photographs (DPhotos), CBCT, and facial scan.

In a CAD/CAM software, we will integrate IOS, CBCT, and FS data into the virtual environment, and it will be possible the articulation of virtual models.

The digital wax-up for the preparation of the crown will be designed by the prosthodontist and then adjusted based on the occlusion obtained in each of the groups.

The design and occlusal adjustment of the crown will carry out in four different ways, separating them into the following groups:

• Group 1: IOS + DPhotos - Diagnostic waxing done only with static occlusion, without a virtual articulator (as the laboratories commonly do).
• Group 2: IOS + DPhotos - Set up the models in the virtual articulator arbitrarily (without CBCT and FS) - with the program's default and standard values.
• Group 3: IOS + DPhotos + CBCT + FS - Set up the models in the virtual articulator (with CBCT and FS) - with the program's default and standard values.
• Group 4: IOS + DPhotos + CBCT + FS - Set up the models in the virtual articulator (with CBCT and FS) - with the articulator programmed for the patient - through dynamic scans.

For the representation of the Group 4, we will program a virtual articulator by modifying the values of the condylar guidance angles, in order to realize the changes that could occur just by modifying them. During the study, we plan to program the articulator with dynamic scans of each patient. These dynamic scans will result in individually customised condylar guidance angles.

Four crown tests will be produced, one for each group, to enable them to be tried out on participants (like a mock-up).

Participants enrolled in this study will be randomly allocated in the 4 groups, with a computer-generated randomization list (https://www.randomizer.org/).

Allocation concealment will be performed using sealed and opaque numbered envelopes which were opened by the dentist immediately before the mock-up.

All the procedures will be performed by one experienced clinician.

The steps of clinical procedure are:

Step 1 - In the first appointment, the patients mention their smile concerns, and the dentist evaluate and diagnoses.

Step 2 - Digital impressions, and a model of the teeth will be done. Step 3 - Diagnostic wax-up, where dentist and dental laboratory plan the wax-up on the study models.

Step 4 - Diagnostic mock-up, where dentist transfers the diagnostic wax-up to the patient's mouth.

We will evaluate the volumetric difference (in micrometers) before and after occlusal adjustments, in each group; and the volumetric difference between the diagnostic wax-ups obtained in each group.

After each mock-up, a questionnaire will be delivered to the patients in order to assess patients's aesthetics and comfort self-perception, using a numeric scale.