Overview: This article provides instructions for capturing a CBCT scan for edentulous patients to support implant-supported overdenture workflows.
Prerequisites
Ensure the patient's denture fits securely.
Prepare PVS material if a reline is necessary for retention.
Obtain six 2mm x-ray markers (such as Suremark VF-20 Stickers).
Edentulous scanning best practices
Confirm denture fit: If the denture has poor retention, reline the denture with PVS material before scanning to ensure stability. Only use enough material to fill gaps.
Patient instructions: Instruct patients to breathe through the nose, close their eyes, and place the tongue at the back of the mouth during the scan.
Prevent movement: Use a bite registration or cotton rolls to provide separation, ensure a secure fit, and eliminate denture rocking.
Verify scan quality: Review the scan to ensure no black air space exists between the denture and the soft tissue of the patient.
Prepare the denture for scanning
Apply x-ray markers: Place six x-ray markers (2mm diameter) around the surface of a dry, relined, well-fitting denture. Ensure the denture has no metal substructure, as metal makes the scan unusable.
Distribute marker placement: Place three markers on the facial/buccal surface and three markers on the palatal surface.
Vary axial planes: Place markers on varying axial planes. For example, if a marker is on the buccal area of teeth #28-29, place the next marker on the lingual area of #26-27.
Avoid intaglio surface: Do not place X-ray markers on the intaglio surface of the denture.
Create the tissue-supported guide order
Open the Dandy portal and set up a new order for a tissue-supported guide.
Skip the initial CBCT upload step and submit the order.
View the submitted order and select Capture New Scans under the Quick Order Actions menu on the right-hand side.
Capture the 360-degree denture scan
Initiate Trios scan: Capture a 360-degree Trios scan of the denture with all x-ray markers attached.
Scan tissue side: Begin the scan on the tissue side to capture the entire intaglio surface and the borders of the denture.
Scan occlusal surface: Roll the scanner across the occlusal, moving the arch to capture the entire cameo (outer) surface.
Scan Bite: Capture the correct intercuspation.
Evaluate for errors: Check the 360-degree scan for gaps or voids along the borders that might indicate stitching errors.
Scan order: Intaglio → Border → Occlusal → Cameo → Bite
Capture the dual-arch CBCT scan
Verify marker placement: Capture a dual-arch CBCT while the patient wears the dentures with the x-ray markers still attached.
Establish stability: Have the patient bite on cotton rolls or a posterior bite registration to eliminate air gaps between the denture and the tissue.
Set CBCT parameters: Use a field of view between 6cm and 8cm with a voxel size of 0.3 to 0.4.
Capture the arch: Ensure the scan captures the entire working arch.
Upload the CBCT files
Export the completed scans in DICOM format.
Compress the DICOM files into a zipped folder.
Navigate to the case in the Dandy portal and drag the zipped folder into the CBCT upload box.