D5640 is the CDT code for replacing a broken tooth on a partial denture, billed once for each tooth replaced.
- When to use: A prosthetic tooth the partial already had broke or came off the saddle, and the framework, clasps, and base are sound.
- When not to use: Adding a tooth after an extraction is D5650, a broken clasp is D5630, and a tooth on a complete denture is D5520.
- Billing note: Many plans pool repair frequency across the repair codes, so check the partial's repair history and bill one unit per tooth replaced.
What D5640 covers
D5640 reports replacing broken teeth on a partial denture, one unit per tooth. In the typical case, a prosthetic tooth shears off or fractures on the resin saddle of a cast-framework or acrylic partial. The lab, or the office for a simple anterior repair, sets and processes a replacement onto the existing saddle. The framework, clasps, and base stay; only the failed tooth is replaced. The occlusion check at redelivery is part of the fee.
It does not cover:
- Adding a tooth the partial never had, after a natural-tooth extraction. That’s D5650 (see below).
- Clasp work: repairing or replacing broken clasping material is D5630 (per tooth), and adding a new clasp is D5660 (per tooth).
- Base or framework damage. A cracked resin partial base is D5611 (lower) or D5612 (upper); a fractured cast framework is D5621 (lower) or D5622 (upper).
- Replacing all the teeth and acrylic on a cast metal framework. That rebuild is D5670 (upper) or D5671 (lower), not a stack of D5640 units.
- Tooth replacement on a complete denture. That’s D5520.
- Making the partial itself: D5211/D5212 resin base, D5213/D5214 cast framework, D5225/D5226 flexible base.
Repair or alteration: the D5640 / D5650 line
The two codes describe similar lab work for very different clinical events.
D5640 (repair): the partial’s own tooth failed. The patient’s dentition is unchanged; the prosthesis broke. The documentation is the failure itself (which tooth, how it broke), and the claim draws on the plan’s repair benefit, usually with a repair-frequency limit.
D5650 (alteration): a natural tooth came out, and the partial is modified to replace it. The documentation is the extraction (date, tooth number). Carriers commonly match the added tooth against the extraction record, and the missing-tooth clause can apply if the extraction predates coverage.
Coding an added tooth as D5640 to avoid the extraction review misrepresents the service. Coding a repair as D5650 invites a records request for an extraction that never happened. The chart note should make the event clear either way.
Arch numbering in the partial repair codes
Two pairs in the D56xx block are numbered mandibular-first, like the complete-denture repairs: resin base D5611 lower / D5612 upper, and cast framework D5621 lower / D5622 upper. D5611/D5612 replaced D5610, which the ADA deleted in 2018 in the same change that split D5510 into D5511/D5512. D5610 rejects today.
The full-rebuild pair runs the other way: D5670 upper, D5671 lower. Read the arch words, not the digit pattern, anywhere in this block.
Top reasons D5640 gets denied
- Wrong code for the event. An added tooth billed as D5640, or the reverse. The carrier’s extraction and prosthetic history exposes the mismatch.
- Prosthesis mismatch. D5640 on an arch with a complete denture, where D5520 was the code.
- Repair frequency. Prior repairs on the same partial inside the plan’s window. Limits are plan-dependent and often pooled across the repair codes, so a D5630 clasp repair last spring can use up the benefit this claim needed.
- Under-counted units. A multi-tooth repair billed as one unit pays as one unit. It is an underpayment rather than a denial, and goes unnoticed unless someone checks.
- Repair-versus-remake review. Extensive damage priced tooth by tooth can exceed what the plan will pay against a replacement or a D5670/D5671 rebuild, and the reviewer does that math even if the office didn’t.
Documentation that supports the claim
- Which prosthesis: “cast framework partial, lower” or “resin base partial, upper,” matching the claim’s arch field.
- Each replaced tooth by position, supporting the unit count.
- How the failure happened (fracture in function, dropped prosthesis). This distinguishes a repair from an alteration and supports any repair-versus-remake narrative.
- Companion repairs (clasp, base, framework) charted as their own procedures.
- The partial’s delivery date when available, for frequency and replacement-clock math.
Example case
A patient drops a lower cast-framework partial, and the first-molar prosthetic tooth fractures off the distal saddle. The framework, clasps, and base are sound. The office sends the partial to the lab, which processes a replacement molar onto the existing saddle.
Billing steps:
- Verify repair benefits and any repair history on this partial.
- Chart the prosthesis type, arch, the failed tooth by position, and the cause.
- Submit one unit of D5640 with the mandibular arch designation on the redelivery date.
- Post payment and log the repair against the prosthesis record. The next repair claim on this partial will be judged against today’s date.
FAQs
- What's the difference between D5640 and D5650?
- Repair versus alteration. D5640 replaces a tooth the partial denture already had, a prosthetic tooth that broke or came off the saddle. D5650 adds a tooth the partial never carried, typically after a natural tooth is extracted and the partial is modified to fill the space. D5640 claims run through repair benefits; D5650 claims are often checked against the extraction date and the missing-tooth clause.
- What's the difference between D5640 and D5520?
- The prosthesis. D5640 replaces broken teeth on a partial denture; D5520 replaces missing or broken teeth on a complete denture. Both are per-tooth codes for the same kind of failure. Carriers can see which prosthesis exists on the arch, so a mismatch surfaces on history review even when the claim initially pays.
- What code covers a broken clasp on a partial?
- D5630, which repairs or replaces broken clasping material, per tooth. Adding a new clasp to a tooth that never had one is D5660, also per tooth. D5640 covers only the prosthetic teeth, so a partial with a fractured tooth and a bent clasp can carry both a D5640 line and a D5630 line.
- How is D5640 billed for more than one tooth?
- Per tooth, the same as D5520 on a complete denture: one unit for each replaced tooth, charted by position. Submit repeated lines or a quantity, depending on the clearinghouse. Billing one unit for a two-tooth repair leaves the second allowable unclaimed.
- Can a flexible-base partial get a D5640 tooth replacement?
- Often not. Flexible nylon bases (billed as D5225/D5226 when made) generally can't have teeth added or replaced chairside or at most labs, so a failure usually means a remake. That limitation is worth quoting when treatment planning the flexible option. Whether a given flexible partial is repairable is a lab question, so ask before promising a repair appointment.
Related codes
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CDT codes are maintained by the American Dental Association. This page is an editorial billing guide, not the official ADA code descriptor. Verify current coverage policies with each carrier before submitting claims.