D3346 Dental Code: Anterior Root Canal Retreatment

What D3346 covers

D3346 reports nonsurgical retreatment of a permanent anterior tooth, meaning an incisor or canine. Carriers typically validate it against teeth 6 through 11 and 22 through 27. The tooth had a completed root canal, it failed, and the dentist reopens it through the crown, removes the existing filling material, re-cleans and reshapes the canals, and refills them.

Three things ride inside the code and are not separate lines:

• The old fill, and whatever is on top of it. Getting to the canal usually means removing a post, pins, and the existing obturation. Carriers commonly treat that removal as part of the retreatment. HDS says so directly in its endodontic guidelines: those component procedures are not separately billable to the patient.
• Every visit it takes. Anterior retreatments often run two appointments, with an interim medicament between them. The code reports the whole course of treatment once, on the date the canals are obturated.
• Intraoperative films. Working-length images taken during the procedure are part of it, and HDS says plainly that interim working films should not be submitted for payment. The diagnostic radiographs taken to evaluate the tooth bill on their own date of service. The final post-op periapical is a different matter: send it as the attachment the claim needs, but expect most carriers to treat it as part of the endodontic procedure rather than a separately payable film.

The final restoration is not included. An anterior tooth coming out of retreatment may need only a composite in the access, or a buildup (D2950) and a crown if the tooth was already heavily restored. Those bill on their own dates.

Retreatment or initial therapy: what the film has to show

The distinguishing axis is treatment history on that specific tooth, read off the pre-op radiograph. Tooth type sets which retreatment code you use; history sets whether you are in the retreatment family at all.

Obturation material visible in the canal means the tooth was treated before, and the redo is D3346. Canals with nothing in them mean the tooth is getting its first root canal, and that is D3310.

The trap on anterior teeth is the middle case. A traumatized incisor is frequently opened somewhere else years earlier, medicated, temporized, and never finished. There is an access opening, there is a temporary, and there is no fill. That tooth has no previous root canal therapy to retreat. Completing it now is initial therapy, D3310, even though the patient will tell you they already had a root canal on it.

An anterior tooth treated years ago with apexification (D3351 through D3353) on an immature root did receive a completed root canal filling, so redoing that case reads as retreatment. Carriers holding the apexification history sometimes ask for the narrative anyway, so send it with the claim.

Which code: the family around D3346

Retreatment splits by tooth position exactly the way initial therapy does:

• D3346 anterior, incisors and canines.
• D3347 premolar.
• D3348 molar.

That is the same split as D3310, D3320, and D3330 for first-time therapy. Position drives the code, not canal count and not difficulty. A mandibular incisor with two canals and a calcified apex is still D3346.

Two neighboring procedures get mixed up with anterior retreatment more often than the molar version, because anterior roots are the easiest ones to reach surgically:

• D3410, apicoectomy on an anterior tooth. This is a surgical root-end procedure through the gum and bone. D3346 is nonsurgical, through the crown. A case can involve both, at separate visits, and they are separate codes. Retrograde filling material placed during the surgery is D3430, per root, and is not part of the apicoectomy code.
• D3331, treatment of root canal obstruction by nonsurgical access. This one reports opening a pathway through a canal that cannot be negotiated, blocked by a separated file, a broken post, or heavy calcification, as the alternative to going in surgically. If the dentist retreated the canal and refilled it, the procedure is D3346. D3331 is for the obstruction case where establishing a pathway is the procedure.

When to bill D3346

1. Confirm the tooth position. Incisor or canine. A premolar retreatment is D3347 and a molar is D3348, regardless of how the case behaved clinically.
2. Confirm existing fill on the pre-op film. No obturation material, no retreatment code.
3. Find the date of the original root canal, and who did it. This is the detail that determines whether the claim pays at all. Pull it from the ledger if your office treated the tooth, and ask the patient if another practice did.
4. Check the plan’s elapsed-time rule before submitting. If the original is inside the window, decide up front whether the claim goes out, gets predetermined, or gets adjusted off.
5. Bill on the obturation date. One line, one date of service, not one per visit and not on the access appointment.
6. Schedule the restoration separately. Buildup and crown, if the tooth needs them, go on their own dates.

Coverage and how carriers treat it

Retreatment is covered on most plans at the same tier as initial endodontics, often the major or basic percentage the plan applies to root canals. The rules that actually decide the claim are about timing and provider.

The elapsed-time window after the original root canal. Twenty-four months is the common number. A Delta Dental PPO plan document published for one employer group states the retreatment benefit as once per tooth after 24 months have elapsed from the initial treatment. The number is plan-dependent, and some plans run longer, so verify it against the contract rather than assuming.

Who performed the original treatment. This is where the endodontic rule diverges from most timing rules and where offices lose money by assuming. HDS treats a retreatment by the same dentist or dental office within 24 months as part of the original procedure, which also means the practice cannot bill the patient for it. Then it goes a step further: benefits are denied when the retreatment is performed by a different dentist inside the same 24 months, with exceptional circumstances reviewed case by case. Other carriers pay a different-office retreatment inside the window on the reasoning that the second practice was never paid for the first treatment. Two carriers, two opposite answers, both published. Verify the plan.

Lifetime limits on the tooth. Plans commonly cap both initial therapy and retreatment at once per tooth per lifetime. A DeltaCare USA copayment schedule published for State of Maryland employees lists D3346 that way, at an enrollee copay of $198 against $108 for initial anterior therapy under D3310. The lifetime cap is why a retreatment miscoded as D3310 tends to deny as a duplicate rather than just underpay: the carrier already has an anterior root canal on file for that tooth.

Prognosis review. Anterior retreatment on a tooth with a fracture, a perforation, or heavy resorption gets read as not restorable by some plans. Predetermination is worth it on borderline teeth, especially where the alternative treatment plan is extraction and an implant.

Documentation that supports the claim

Retreatment claims carry a heavier attachment requirement than initial therapy. HDS lists all three items as submission requirements on D3346 through D3348, and most carriers want the same set.

• Pre-op periapical showing the existing canal filling, plus whatever failed: an apical radiolucency, a short or voided fill, a missed canal, a post space, coronal leakage.
• Post-op periapical showing the completed retreatment. Label both films as pre-op and post-op so the reviewer is not guessing which is which.
• A narrative giving the diagnosis and the reason the first treatment failed. A pulpal and apical diagnosis stated in standard terms carries more weight than a description of symptoms alone.
• The date of the original root canal and the treating office. Say plainly on the claim when another practice performed the original. That fact is what pulls the case out of the same-office bundling rule on plans that apply it.

In the chart, record the material removed and any post or separated instrument taken out, the canals located and retreated including any the first treatment missed, working lengths, the obturation material, and the planned final restoration.

What to get right in your PMS

The menus differ across Open Dental, Dentrix, Eaglesoft, Curve, and Carestream, but the setup that prevents these denials is the same.

1. Keep the six endodontic codes labeled by position and by history. D3310, D3320, D3330 for first treatment; D3346, D3347, D3348 for retreatment. If the pick list reads only “root canal anterior” twice, somebody grabs the wrong one.
2. Surface the tooth’s prior endodontic history. Whatever your system offers for prior procedures on a tooth, use it before coding. The date of the original root canal is the field that decides the claim.
3. Post the retreatment on the obturation date only. Multi-visit retreatments tempt staff into posting at the access appointment. One line, one date.
4. Attach both films to the claim, not just to the patient chart. Many systems store images at the patient level, and the clearinghouse needs them linked to the specific claim.
5. Write the elapsed-time check into the endo workflow. Verification for a retreatment should ask two questions: how long since the original root canal on this tooth, and does the plan treat a same-office redo differently from a different-office one.

For how the tooth number, the date of service, and the remarks field are filled in on the claim itself, see the ADA dental claim form guide.