What should the D3347 chart note include?
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Retreatment of root canal - premolar. RMH: Medical history reviewed/updates Vitals: BP/pulse; other vitals if indicated Tooth: #Tooth number(s) Indication: Indication/diagnosis Previous RCT failure. Persistent periapical pathology. Symptomatic. Retreatment support: Approximate prior RCT date Failure description: What portion of prior RCT failed and how retreatment addresses it Consent: Consent/PARQ reviewed; signed/verbally obtained Diagnostic tests/radiographs: Diagnostic tests, pre-op/working/post-op radiographs and findings Pulpal/periapical diagnosis: Pulpal and periapical diagnosis Endo radiograph sequence: Diagnostic-quality pre-op, working length, post-op/final radiographs and findings Diagnostic tests/findings: Cold/EPT/percussion/palpation/probing/sinus tract findings Working lengths/file sizes: Canal working lengths and final file type/sizes Irrigation/obturation details: Irrigants, medicaments, sealer, obturation material Restoration recommendation/prognosis: Definitive restoration needed and prognosis Anesthesia: Anesthetic used Carps: Carpules/amount Procedure: Isolation with rubber dam. Access opened. Pulpal status upon entry: Pulpal status/condition Previous obturation material removed. Canals renegotiated to apex. Working lengths established. Radiograph confirmed. Canals reinstrumented to size: Final instrument sizes Copious irrigation with NaOCl. Canals dried with paper points. Reobturation with gutta percha and sealer. Radiograph confirmed adequate fill. Access sealed with: Access seal material Complications: None or describe. Patient tolerance: Tolerance/response. Post-op instructions: Instructions reviewed. Crown recommended. NV: Next visit
What documentation is required for D3347?
D3347 documentation must support a previously treated tooth, a defined failure mode, and a non-surgical retreatment performed today — three elements that the carrier and any auditor will look for. The defensible note includes:
- Tooth number — universal numbering, premolar (#4, #5, #12, #13, #20, #21, #28, #29). One tooth per D3347 line item.
- Indication / diagnosis — pulpal and periapical diagnosis specific to a previously treated tooth: previously treated, symptomatic apical periodontitis; previously treated, asymptomatic apical periodontitis; previously treated, acute apical abscess; or previously treated, chronic apical abscess per AAE diagnostic terminology. "Failed RCT" alone is not a diagnosis.
- Prior RCT history — approximate date of prior RCT, provider when known (in-office vs referred / outside office), tooth coronal restoration since (post-and-core, crown, direct buildup), and any interim endodontic interventions (re-access, palliative).
- Failure description — the specific reason retreatment is indicated. Be concrete: "missed buccal canal," "short obturation 3 mm from radiographic apex with persistent PARL," "leaking coronal seal under fractured crown with recurrent caries to canal orifice," "separated #25 K-file at apical third of buccal canal," "voids in mid-root obturation with sinus tract tracing to apex." Generic "failure" or "needs retreatment" is the most common audit defect.
- Diagnostic tests — cold (Endo-Ice / CO2), EPT, percussion, palpation, periodontal probing (rule out vertical root fracture), sinus tract (trace with gutta-percha cone if present), bite test if indicated. Document each test's response — positive, negative, lingering, exquisite — not "tests performed."
- Pre-op radiographs — diagnostic-quality pre-op PA showing prior obturation, post if present, and periapical findings; angled PAs (mesial/distal shift) for canal-count assessment; CBCT when missed canal anatomy or perforation/resorption is suspected (bill separately under D0364-D0368 if performed). Note diagnostic quality explicitly.
- Working-length radiographs — per canal, with file in place, working length confirmed (and corroborated with apex locator if used). The retreatment note should make canal count explicit by showing a working-length image for each canal.
- Post-op / final radiograph — diagnostic-quality final image showing complete obturation to working length per canal with no voids.
- Pulpal status upon entry — what was found when access was opened: prior gutta percha and sealer present, post visualized, missed canal located, separated instrument visualized at depth X. Patient-specific finding, not a default.
- Working lengths and final file sizes — per canal, in millimeters; final apical instrument size and taper; rotary system used (ProTaper Gold, WaveOne Gold, Vortex Blue, Reciproc, hand K-files) and any retreatment-specific files (ProTaper Universal Retreatment, R-Endo, Reciproc Retreatment).
- Irrigation and obturation details — irrigants and concentrations (5.25% or 6% NaOCl, 17% EDTA, 2% chlorhexidine if used), activation method (passive ultrasonic, EndoActivator, sonic), interappointment medicament if two-visit (Ca(OH)2), sealer (bioceramic / AH Plus / zinc oxide eugenol / Sealapex), obturation technique (warm vertical, single-cone, lateral condensation), and obturation material (gutta percha, bioceramic).
- Restoration recommendation and prognosis — definitive restoration plan (full-coverage crown is the standard recommendation for premolar retreatment) and the endodontic prognosis (favorable / questionable / unfavorable per AAE outcomes terminology). Premolar retreatment outcomes depend heavily on the apical seal achieved and the coronal restoration that follows.
- Pre-existing post and core handling — if a prior post-and-core was removed to access the canals, document the removal procedure, instrument used (ultrasonic, post-pulling system such as Ruddle Post Removal System or Anthogyr PRS), time, and any complications (root fracture risk, lateral wall thinning). Bill D2955 separately for the removal.
- Consent / PARQ — retreatment vs apical surgery vs extraction-and-implant, prognosis (lower than initial RCT — published outcomes range 70-85% favorable for non-surgical retreatment in well-selected cases), risks of perforation, file separation, root fracture, post-removal complications, the need for a definitive restoration after retreatment, and the cost of a new crown if the prior crown must be removed or sacrificed for access.
- Anesthesia — agent, concentration, vasoconstrictor, technique (block vs infiltration), carpules. Premolars often respond to infiltration alone; mandibular premolars may require IAN or buccal infiltration with articaine.
- Procedure block — rubber dam isolation (mandatory for endo per AAE standard of care), access opened (through prior crown / through prior access / through new orthograde access), prior obturation removal method (rotary retreatment file, hand file, solvent — chloroform / xylene / orange oil), canal renegotiation, working lengths re-established and confirmed, instrumentation to final apical size per canal, irrigation protocol, drying with paper points, re-obturation method and material, final fill verified radiographically, access seal material (Cavit / IRM / Fuji IX / composite over a bonded base) for the interim period before the definitive restoration.
- Complications — explicit "None" or describe (ledge formation, perforation repaired with MTA / bioceramic, file separation with bypass / leave-in-place decision, sodium hypochlorite extrusion event, missed canal). Silence is read as undocumented; complications must be disclosed for informed consent and for any future quality review.
- Patient tolerance / response — tolerated well, no signs of distress, post-op vitals if relevant.
- Post-op instructions — soft diet, avoid chewing on the tooth until definitive restoration is placed, analgesic plan (ibuprofen 600 mg q6h prn / acetaminophen 1000 mg q6h prn), warning signs (increasing pain, swelling, fever), and return-precaution language.
- Crown recommendation — explicit statement that a full-coverage restoration is recommended after retreatment, with a target timeframe (typically within 4-6 weeks of completed retreatment to minimize coronal microleakage). The crown is billed separately (D2740 / D2750 / D2752 etc.) and is a frequent carrier-required follow-up for D3347 benefits.
- Next visit — definitive restoration appointment, post-op PA timing (commonly 6-month and 12-month recall PAs to monitor periapical healing), and any specialist co-management (referral back to GP for restoration, endo follow-up).
Two recurring audit defects: (1) chart notes that read like an initial RCT with no mention of the prior treatment, prior obturation removal, or failure mode — carriers downgrade or deny D3347 and request the chart; and (2) default-template wording with no patient-specific failure description, no canal count for a tooth that anatomically should have two canals, and no working-length film per canal. Both are recoupment-grade defects in Medicaid MCO and Delta Dental quality reviews.
Why does D3347 get denied?
The most frequent reasons D3347 is denied, downgraded, or recouped:
- No documentation of prior RCT — chart and claim do not establish that a prior root canal exists on the tooth. Carriers deny D3347 and request claim history showing D3320 (or equivalent) on the same tooth, or a pre-op PA showing prior obturation. This is the single most common denial reason.
- Frequency / time-gap violation — retreatment performed within 12 months of the original RCT is regularly denied as a complication of the original procedure and bundled into the original D3320 fee. Some carriers extend the post-op window to 24 months for complex retreatments.
- Once-per-tooth-per-lifetime limit — second D3347 on the same premolar is denied as a frequency violation; subsequent retreatment is patient out-of-pocket or routed to apical surgery (D3410).
- Insufficient failure description — chart says "RCT failed" or "retreatment indicated" without specifying the failure mode (missed canal, short obturation, leaking coronal seal, separated instrument, recurrent caries to canal, persistent PARL with symptoms). Auditors downgrade or recoup when the narrative is generic.
- Wrong code for tooth class — D3347 billed on an anterior or molar. Anteriors are D3346, molars are D3348. This is a clean denial that the front desk can prevent at claim entry.
- D3320 billed alongside D3347 on the same tooth — mutually exclusive; describes initial vs retreatment. The carrier denies one and may flag the claim for review.
- Missing canal-count documentation — premolar with one working-length film and one obturation film when typical anatomy suggests two canals. Reviewers cite "incomplete instrumentation" and may downgrade to D3221 (pulpal debridement) or deny for inadequate documentation.
- Definitive restoration not placed within the carrier's window — some carriers retroactively recoup D3347 when no crown or definitive restoration is placed within 60-180 days. Less common than initial-RCT recoupment but documented in several Medicaid MCO policies.
- D2955 unbundled when policy bundles it — a small number of carriers (some Medicaid MCOs) bundle post removal into D3347; billing both produces a denial of the D2955 line. Verify per plan and document the post removal regardless.
- Default-template wording — "previous RCT failure" / "persistent periapical pathology" appearing on every D3347 chart with no patient-specific failure description, no prior-RCT date, no canal-count narrative, and no per-canal working-length and obturation imagery. Pattern-recognizable and recoupment-grade.
- Pre-authorization not obtained when required — Medicaid MCOs that require pre-auth on D3347 will deny without an approved authorization on file.
- Pediatric primary tooth — D3347 on a primary tooth is essentially never appropriate; primary-tooth pulp therapy uses D3220 / D3230 / D3240.
What do practices ask about D3347?
What's the difference between D3320 and D3347?+
Initial vs retreatment. D3320 is the first root canal therapy performed on a premolar — no prior endodontic treatment exists on that tooth. D3347 is a second-time-around procedure that requires removing a prior obturation, renegotiating the canals, addressing the failure mode, and re-obturating. The two codes are mutually exclusive on the same tooth same date. If a pre-op PA shows prior obturation material in the canals, the correct code is D3347, not D3320. Billing D3320 for a retreatment is a common coding error and a frequent recoupment finding.
Does D3347 cover post removal?+
No. Post removal is reported separately under D2955 in addition to D3347 when a prior post or post-and-core must be removed to access the canals. Document the post-removal procedure in its own block — instrument used (ultrasonic, post-pulling system), time, and any complications (lateral wall thinning, perforation risk, root fracture). A chart that describes a post removal without a separate D2955 line is undercoding; a D3347 with no post-removal narrative when a post is visible on the pre-op PA is undocumented. A small number of Medicaid MCOs bundle D2955 into D3347 — verify per plan.
Can D3347 be billed within 12 months of the original RCT?+
Often no. Many carriers treat retreatment within 12 months of the original D3320 as a complication of the original procedure and bundle the retreatment into the original RCT fee. Some carriers extend the post-op window to 24 months. If the original RCT was billed by your office, retreatment within the carrier's post-op window is generally not separately reimbursed; if the original was billed by another office, the carrier may still apply the post-op rule based on claim history. Submit a narrative documenting the failure mode, prior-RCT date and provider, and the clinical necessity of retreatment.
How many times can D3347 be billed on the same premolar?+
Once per tooth per lifetime under most PPO and Medicaid policies. A second retreatment on the same premolar is essentially never reimbursed as D3347; the patient's options at that point are apical surgery (D3410 / D3421), extraction-and-implant, or out-of-pocket re-retreatment. Document the lifetime-benefit consumption clearly in the consent discussion so the patient understands the implications of a second failure.
Do I bill D3347 if I refer the patient to an endodontist?+
No. D3347 is billed by the provider who performs the retreatment. If you refer the patient to an endodontist, the endodontist bills D3347 in their office; your office bills only the codes for services rendered (e.g., D0140 / D0220 / D9110 if you saw the patient for a problem-focused visit before referral). Specialist-vs-GP fee differentials apply on most PPOs — endodontists may be reimbursed at a higher D3347 rate than GPs based on credentialing.
Is pre-authorization required for D3347?+
Pre-authorization is not universally mandated on commercial PPOs but is strongly recommended and is frequently required by Medicaid MCOs (DentaQuest, Liberty Dental, Envolve Dental, MCNA). Submit pre-op PA showing prior obturation and periapical findings, narrative describing failure mode and prior-RCT date and provider, planned definitive restoration code (typically D2740 / D2750), and any post-removal plan (D2955). Pre-authorization significantly reduces the rate of frequency / time-gap denials and surfaces non-coverage early.
What if I find a missed canal during retreatment?+
Document it specifically — pre-op suspicion (angled PAs or CBCT showing untreated canal anatomy), location of the missed canal under the microscope, instrumentation and obturation per canal, working-length and post-op PAs showing both canals obturated. Missed-canal anatomy is one of the strongest justifications for D3347 and a leading reason prior premolar RCTs fail. The chart should make canal count explicit and the pre-op vs post-op imaging should support that the missed canal was located and treated. Reviewers compare canal count to typical anatomy for the tooth number and may downgrade D3347 if the chart suggests incomplete instrumentation.