Quick reference
Dental hygiene codes at a glance: D1110, D4346, D4355, D4341/D4342, D4910
Six CDT codes cover almost every hygiene visit. Which one fits depends first on the patient’s periodontal history, then on today’s findings, and never on the length of the appointment or what a plan pays.
| Code | In plain words | When it fits | Type |
|---|---|---|---|
| D1110 | Adult prophylaxis | Healthy gums or localized gingivitis; also recession with no periodontitis history. | Preventive |
| D4346 | Scaling, generalized gingival inflammation | Generalized moderate or severe gingivitis (30%+ of teeth), no attachment or bone loss. | Therapeutic |
| D4355 | Full-mouth debridement | Heavy deposits prevent an evaluation; done before the diagnosis, which follows at a later visit. | Enabling |
| D4341 | Scaling and root planing, 4+ teeth per quadrant | Periodontitis with attachment and bone loss. | Therapeutic |
| D4342 | Scaling and root planing, 1 to 3 teeth per quadrant | Periodontitis with attachment and bone loss in fewer teeth. | Therapeutic |
| D4910 | Periodontal maintenance | After completed active therapy (root planing or surgery), for as long as the dentist sets. | Maintenance |
Plain-English summaries, not the official descriptors. CDT is © American Dental Association.
Perio maintenance vs prophy (D4910 vs D1110): the history decides
The most common mistake is choosing between D1110 and D4910 by how hard the cleaning was. The deciding fact is whether the patient has completed active periodontal therapy. A prophylaxis (D1110) is preventive care for a patient without periodontitis. Periodontal maintenance (D4910) follows scaling and root planing or periodontal surgery, and includes cleaning above and below the gumline, root planing at any site that needs it, and a check of every pocket.
The 2017 AAP/EFP classification explains why the visit stays therapeutic: a successfully treated periodontitis patient has periodontal health on a reduced periodontium but remains a periodontitis patient, at higher risk of recurrence than someone who never had the disease.
Can a patient go back to prophy after perio maintenance?
This is the question clinicians disagree on most, so both positions are here.
- The ADA’s coding guidance: nothing in the Code makes periodontal maintenance permanent. If the dentist determines the patient’s periodontal health can be kept with routine prophylaxis, that is reported as D1110. It is the treating dentist’s clinical judgment, and it should be documented.
- The other view: some authors hold that a treated periodontitis patient always stays on maintenance, and some payers will not pay D1110 once D4910 has started.
What both sides agree on: alternating D1110 and D4910 to fit a plan’s frequency limits is not appropriate. If the patient is not stable, it is periodontal maintenance.
Code by code
Each hygiene code in plain English
Dental code D1110: adult prophylaxis
D1110 is the preventive cleaning for adults: removing plaque, calculus and stain to control local irritants. It fits healthy gums, localized gingivitis, and a patient with recession but no pockets, inflammation or periodontitis history (ADA D4346 guide, Q7 and Q8). It does not become D4346 because the cleaning took longer; the ADA is explicit that a “hard prophy” is still D1110.
Dental code D4910: periodontal maintenance
D4910 is the periodontal maintenance code. It starts after active periodontal therapy (scaling and root planing or periodontal surgery) and continues at intervals the dentist sets. The visit includes supra- and subgingival cleaning, site-specific root planing where needed, and polishing. A patient who has never had active therapy is not a D4910 patient, however difficult the cleaning. If you are looking for the perio maintenance code, this is it: D4910.
Dental code D4346: scaling with generalized gingival inflammation
D4346 is for generalized moderate or severe gingival inflammation with no attachment or bone loss, after an oral evaluation. The ADA treats 30% or more of teeth as a reasonable reading of “generalized”. It is chosen by diagnosis, not time.
- D4346 vs D1110: generalized moderate to severe inflammation vs healthy gums or localized gingivitis.
- D4346 vs D4341/D4342: any attachment or bone loss from periodontitis means root planing, never D4346.
- D4346 vs D4355: D4346 follows the evaluation; debridement comes before it, when deposits prevent one.
- D4346 vs D4910: D4346 is never followed by periodontal maintenance, because there was no periodontitis to treat.
Dental code D4355: full-mouth debridement
D4355 is an enabling step, not a cleaning for a diagnosed condition: heavy deposits are removed so that a comprehensive evaluation and diagnosis can happen at a later visit. Many payers will not pay it on the same day as a comprehensive evaluation.
D4341 and D4342: scaling and root planing
Scaling and root planing is active therapy for periodontitis with attachment and bone loss: D4341 for four or more teeth in a quadrant, D4342 for one to three. With bone loss in only some areas, the ADA’s table pairs root planing for those quadrants with D1110 for the rest of the mouth. After a re-evaluation, the patient moves to periodontal maintenance (D4910).
How often, and how long after root planing?
The CDT Code sets no waiting period between root planing and the first periodontal maintenance visit. A re-evaluation 4 to 6 weeks after root planing usually comes first, and many payers expect 8 to 12 weeks before they pay D4910. The interval after that is the dentist’s call, often every 3 months to start. Plans commonly cap D4910 at 2 to 4 visits a year, and some pay a prophylaxis amount instead (an “alternate benefit”). Submitting D4910 with a note asking for the alternate benefit is legitimate. Changing the code is not.
Documentation and narratives for D4910 and D4346
- Full-mouth periodontal charting: probing depths and bleeding on probing.
- Current radiographs, or the date of the last set.
- For D4910: the dates and type of prior active therapy.
- For D4346: (pseudo) pocket depths, bleeding, and images showing no bone loss.
- For a return to D1110: the dentist’s reason the periodontium is stable.
A narrative should only restate what is in the chart. The two examples below show the shape; replace every bracket with the patient’s real findings. The tool above builds a short note like these from your answers.
Perio maintenance narrative example (D4910)
Patient completed scaling and root planing ([D4341], [all four quadrants]) on [date] and has been on periodontal maintenance at a [3]-month interval since [date]. Today: probing depths [2 to 4] mm with [5] mm at [#3 and #14], bleeding on probing [12]% of sites. Full-mouth supra- and subgingival scaling with site-specific root planing at [#3 and #14]. Periodontal charting attached.
D4346 narrative example
[Comprehensive] oral evaluation on [date]: generalized moderate gingival inflammation, bleeding on probing at [46]% of sites on [22] of [28] teeth, pseudo-pockets of [4 to 5] mm, no clinical attachment loss, and radiographs show no bone loss. Full-mouth scaling for generalized gingival inflammation. Periodontal charting and radiographs attached.
For patients
Why was I billed for periodontal maintenance instead of a regular cleaning?
If you have been treated for gum disease (periodontitis), your cleanings are no longer the same procedure as a regular cleaning. Periodontal maintenance cleans below the gumline, treats any pockets that have become active again, and checks every measurement, because gum disease that has been treated can come back. That is also why it is often every 3 months instead of 6.
Insurance plans handle it differently: some count it as basic rather than preventive care, some limit how many visits a year they pay, and some pay only the amount of a regular cleaning. That is a plan rule, not a sign the visit was coded wrongly. If you are unsure, ask the office to show you your gum measurements and your plan’s periodontal maintenance benefit.
FAQ
Frequently asked questions
What is the dental code for periodontal maintenance?
D4910 is the periodontal maintenance code (the perio maintenance dental code). It is used after a patient has completed active periodontal therapy such as scaling and root planing (D4341/D4342) or periodontal surgery, at the interval the dentist sets. A regular adult cleaning is D1110, and generalized gingival inflammation without bone loss is D4346.
What is the difference between D4910 and D1110 (perio maintenance vs prophy)?
A prophylaxis (D1110) is a preventive cleaning for a patient without periodontitis. Periodontal maintenance (D4910) is a therapeutic visit for a patient who has completed active periodontal therapy such as scaling and root planing or periodontal surgery. It includes cleaning above and below the gumline, root planing at any sites that need it, and a check of every pocket. The difference is the patient’s history, not how long the appointment takes.
Can a patient go from perio maintenance back to prophy?
The CDT Code itself does not make periodontal maintenance permanent, and the ADA’s coding guidance treats a return to routine prophylaxis as the treating dentist’s documented clinical judgment. Others disagree: some authors hold that a treated periodontitis patient always stays on maintenance, and some payers will not pay D1110 once D4910 has started. If the dentist decides the patient is stable enough for routine care, document why. Switching codes back and forth to fit a plan’s limits is not appropriate.
Can you do perio maintenance without SRP?
No. Periodontal maintenance follows active periodontal therapy (scaling and root planing, or periodontal surgery). A patient who has never been treated for periodontitis is not a periodontal maintenance patient, even if their cleaning is difficult. A healthy patient or one with localized gingivitis is D1110; generalized moderate or severe gingivitis without bone loss is D4346; periodontitis with bone loss needs root planing first.
What qualifies a patient for periodontal maintenance?
A history of completed active periodontal therapy. After root planing or surgery and a re-evaluation, the dentist sets a maintenance interval, often every 3 months to start. Under the 2017 AAP/EFP classification the patient remains a periodontitis patient even when the gums look healthy, which is why the visit stays therapeutic.
What is the difference between D4346 and D4355?
D4346 is a therapeutic scaling for generalized moderate or severe gingival inflammation with no attachment or bone loss, done after an oral evaluation. D4355, full-mouth debridement, is an enabling step done before the evaluation when heavy deposits make probing and diagnosis impossible; the full evaluation follows at a later visit.
What is the difference between D4910 and D4341?
D4341 (and D4342 for 1 to 3 teeth per quadrant) is scaling and root planing: active therapy for periodontitis with attachment and bone loss. D4910 is the maintenance that follows that therapy. Root planing treats the disease; maintenance keeps it from coming back, and includes root planing at individual sites when needed.
Is D4346 followed by periodontal maintenance?
No. D4346 treats gingivitis in a patient with no attachment loss, so there is no periodontal therapy for maintenance to follow. After D4346 the patient returns to routine prophylaxis when the dentist judges the gums healthy; the ADA sets no waiting period.
How long after scaling and root planing can you bill D4910?
The CDT Code sets no waiting period. Many payers expect 8 to 12 weeks after root planing, and some only pay maintenance within a set window after therapy or after two or more quadrants were treated. A re-evaluation 4 to 6 weeks after root planing usually comes first.
How often is periodontal maintenance done?
At the interval the dentist sets for the patient, often every 3 months, adjusted at each visit based on pocket depths and bleeding. Plans commonly limit how many D4910 visits they pay per year (often 2 to 4) and some pay a prophylaxis amount instead. That limits payment, not the care the patient needs.
What should be documented for D4910 or D4346?
Full-mouth periodontal charting with probing depths and bleeding on probing, current radiographs, and for D4910 the dates and type of prior active therapy. For D4346 the ADA recommends charting the (pseudo) pocket depths and bleeding, and images that show no bone loss. Payers ask for the same records.
References
- American Dental Association. Guide to Reporting D4346 (scaling in the presence of generalized moderate or severe gingival inflammation). 2024.
- American Dental Association. D4910 Coding for Periodontal Maintenance.
- Chapple ILC, Mealey BL, et al. Periodontal health and gingival diseases and conditions on an intact and a reduced periodontium. J Clin Periodontol. 2018;45(Suppl 20):S68–S77.
- The age-old question: dental CDT code D4910 versus code D1110. RDH Magazine, 2023.
- Busting the myth of “once perio, always perio”. DrBicuspid, 2023.
Checked against the ADA’s published coding guidance, October 2026. Educational only: not clinical, coding, billing or legal advice. The treating dentist decides the procedure, payer policies and contracts vary, and the code should describe what was performed and documented. Not affiliated with or endorsed by the ADA or the AAP. CDT is © American Dental Association, all rights reserved.