D3346Retreatment of Previous Root Canal Therapy, Anterior

What This Code Covers

D3346 is the CDT code for retreatment of a previously completed root canal on an anterior tooth (incisor or canine). This procedure is required when the original root canal fails due to persistent infection, a missed canal, broken instrument, recontamination from a leaking restoration, or recurrent decay. Retreatment is more involved than the initial root canal because the dentist must first remove the existing fill material (gutta-percha, sealer, and sometimes a post) before re-cleaning, reshaping, and re-filling the canal. The final restoration is billed separately, just like the initial treatment.

Billing Guide

Bill this code when:

• The patient has a previously completed root canal on an anterior tooth that has failed or shows signs of persistent pathology
• The dentist removes the existing obturation material, re-instruments the canal, and re-fills it
• The retreatment is fully completed, whether done in one visit or across multiple appointments
• The original root canal was performed at your office or at a different practice

Do not bill this code when:

• This is the initial root canal on the tooth with no prior endodontic treatment, so use D3310
• The retreatment is on a premolar (use D3347) or a molar (use D3348)
• Only an apicoectomy or surgical retreatment is being performed, which uses D3410
• The retreatment was started but not completed. Document it as incomplete endodontic therapy

Insurance and Denial Prevention

Key Payer Rules:

• Most PPO plans cover retreatment at the same percentage as initial root canals (typically 80% under major services), but the allowed fee for D3346 is usually higher than D3310
• Some payers require a minimum time gap between the original root canal and the retreatment, often 12 to 24 months. If retreatment is needed sooner, a narrative explaining the clinical circumstances is critical
• Preauthorization is almost always required for retreatment. Submit the request with radiographs and a narrative before beginning the procedure
• If a different provider performed the original root canal, include that information in the claim. Some payers process retreatment claims differently when the original treatment was done elsewhere

Common Denials and How to Respond:

• Retreatment too soon after initial treatment --> Submit a narrative explaining why early retreatment is necessary. Common reasons include a missed canal discovered on CBCT, a fractured instrument, or recontamination from a failed temporary restoration. Include before-and-after radiographs.
• No evidence of failed treatment --> Provide a periapical radiograph showing radiolucency, a short or separated fill, or voids in the obturation. Add clinical notes documenting the patient's symptoms such as pain, swelling, or a draining sinus tract.
• Billed as D3310 instead of D3346 --> If the payer reprocesses the claim as an initial root canal, appeal with documentation showing the tooth had a prior root canal. Include the original treatment date, a radiograph showing existing fill material, and a note that retreatment, not initial treatment, was performed.