D3351 is the CDT code for apexification or recalcification, initial visit. It covers the first appointment in treating a tooth with an open apex, where the canal is opened and an apical medicament or barrier is placed to encourage the root tip to close. The starting visit of a multi-step process.
Last updated June 2026 · Reviewed by the PracticeAlpha billing team
Use D3351 for the first apexification visit on a tooth with an open or immature apex. The defining features are the open apical foramen and the fact that this is the initial appointment in the apexification sequence. The canal is accessed, debrided, and the initial apical medicament or barrier is placed to induce closure or a calcified barrier.
Common clinical scenarios: A young permanent tooth with an incompletely formed root that has lost pulp vitality due to trauma or caries. A tooth with a blunderbuss or open apex where a normal apical seal cannot be achieved. The first step in inducing apical barrier formation before the canal can be obturated.
Do NOT use D3351 for: Interim medicament changes during apexification (use D3352). The final completion visit (use D3353). Conventional root canal treatment on a tooth with a closed apex (use the standard endodontic therapy codes by tooth type). A tooth where the apex is already mature and closed.
Click any code to see the difference.
The first appointment. The canal is opened, debrided, and the first apical medicament or barrier is placed to begin inducing apical closure. Billed once at the start of the sequence.
A follow-up visit during apexification where the existing medicament is removed and replaced while the apex continues to develop a barrier. Used between the initial and final visits, often more than once.
Billing tip: Bill D3351 once for the first visit. Each subsequent medicament change is D3352. Repeating D3351 on the same tooth for a follow-up dressing is a coding error. The visit type in the note must match the initial or interim code.
D3351 requires a tooth with an open or immature apex. If the radiograph and notes do not show an incompletely formed root or open apical foramen, the payer cannot confirm that apexification was the correct procedure. Include the pre-operative image that demonstrates the open apex.
D3351 is the initial visit and is billed a single time for each tooth. If it appears again for a follow-up appointment on the same tooth, the duplicate is denied. Subsequent medicament changes belong under D3352 and completion under D3353. Match the visit to the correct stage code.
Billing apexification for a tooth with a mature, closed apex is a coding error. A closed apex calls for standard endodontic therapy, not apexification. If the apex was already closed, the payer will deny D3351 and expect a conventional root canal code instead.
A pre-operative radiograph is the baseline justification. It shows the tooth, the open apex, the pulpal status, and any periapical pathology. Without it, the claim lacks the evidence that the tooth met the criteria for apexification. Include the image with the claim or have it available for review.
Periapical image showing the tooth, the open or immature apex, and any periapical pathology. This is the primary evidence that apexification, not a conventional root canal, was indicated.
Document that the apex is open or immature and the reason, such as trauma or caries that interrupted root development. Establishing the open apex supports the choice of apexification.
Describe the canal access, debridement, and placement of the initial apical medicament or barrier material. Make clear this is the first visit of the apexification sequence, matching D3351.
Note the planned sequence of interim medicament changes and the eventual completion visit. This supports the later D3352 and D3353 claims and shows the staged nature of the treatment.
Record the tooth number so the initial visit can be tracked across the sequence. Tying every visit to the same tooth prevents duplicate or mismatched apexification claims.
Endodontic claims getting denied? We fix the coding, documentation, and follow-up patterns that cause it.
Learn about our billing servicesD3351 is the CDT code for apexification or recalcification, initial visit. It covers the first appointment in treating a tooth with an open apex, where a medicament is placed to encourage the root tip to close or a barrier to form.
D3351 is the initial apexification visit. D3352 is the interim medication replacement visit during the apexification process. D3353 is the final visit that completes the treatment. They form a sequence for the same tooth across multiple appointments.
Bill D3351 for the first apexification visit, when the canal is opened, debrided, and the initial apical medicament such as calcium hydroxide or a barrier material is placed in a tooth with an open or immature apex.
Common reasons: missing radiographs showing the open apex, the tooth not meeting the open-apex criterion, billing D3351 more than once for the same tooth, and notes that do not document an immature or open apical foramen.
No. D3351 is the initial visit and is billed once per tooth at the start of apexification. Subsequent medicament changes are billed as D3352 interim visits, and completion is billed as D3353. Repeating D3351 on the same tooth triggers a denial.
No. Apexification treats a tooth with an open or immature apex by inducing a barrier or apical closure before the canal can be sealed. A conventional root canal is performed on a tooth with a closed, mature apex. The open apex is what makes apexification a distinct procedure.
Search all 206 CDT codes in our dental coding guide.