Dental Procedure Codes: A Complete Lookup Guide

The CDT code categories every dental practice bills, what each one reports, and where the revenue leaks most often happen.

Dental procedure codes — the CDT (Current Dental Terminology) codes maintained by the American Dental Association — are the common language of dental billing. Every claim a practice submits uses one or more CDT codes to report what was done, and every PPO fee schedule negotiation revolves around the reimbursement tied to specific CDT codes.

For practice owners, office managers, and billing staff, a working map of the CDT code categories — and the specific codes within each that drive revenue — is foundational. This guide walks through the twelve major categories of CDT codes with the highest-frequency codes highlighted in each.

How CDT codes are organized

The CDT code set is organized into twelve categories, each prefixed with a letter and number:

Diagnostic: D0100–D0999

Diagnostic codes cover evaluations, radiographs, and diagnostic imaging. The most frequently billed diagnostic codes are the evaluations (D0120, D0150) and the radiograph codes (D0210 for FMX, D0274 for four bitewings, D0220/D0230 for periapicals).

Revenue leaks most often happen at the evaluation frequency boundaries: D0120 limited to twice per year, D0150 limited to every 3–5 years, and bitewings typically once per year.

Preventive: D1000–D1999

Preventive codes cover prophylaxis, fluoride, sealants, and oral hygiene. The highest-volume codes in this category are D1110 (adult prophylaxis) and D1120 (child prophylaxis), along with D1206 and D1208 (topical fluoride).

Because these codes are billed at nearly every recare visit, small fee schedule reductions compound dramatically. Tracking D1110 reimbursement across top PPOs is one of the highest-ROI revenue disciplines for a practice.

Restorative: D2000–D2999

Restorative codes cover fillings, crowns, and core buildups. High-frequency codes include:

• D2330–D2335 — Anterior composite fillings
• D2391–D2394 — Posterior composite fillings
• D2740 — Porcelain/ceramic crown
• D2750 — Porcelain-fused-to-high-noble metal crown
• D2950 — Core buildup

This category has the largest PPO write-offs of any practice category, driven primarily by alternate-benefit downcoding on posterior composites and by D2950 audit activity.

Endodontics: D3000–D3999

Endodontic codes cover pulpotomies, root canals, apicoectomies, and retreatment. The highest-volume codes are the root canal codes by tooth type:

• D3310 — Anterior root canal
• D3320 — Bicuspid root canal
• D3330 — Molar root canal
• D3346–D3348 — Retreatment of previous root canal

Endo codes generally have clearer reimbursement patterns than restorative codes, but frequency and retreatment documentation issues are common.

Periodontics: D4000–D4999

Periodontic codes cover scaling and root planing, periodontal maintenance, and surgical periodontal procedures:

• D4341 / D4342 — SRP per quadrant (4+ teeth / 1–3 teeth)
• D4346 — Full-mouth scaling in presence of gingivitis
• D4910 — Periodontal maintenance

This category has the highest audit risk of any in general dentistry. Documentation of periodontal diagnosis, charting, and imaging is essential for D4341 and D4342 claims.

Removable Prosthodontics: D5000–D5899

Dentures, partial dentures, and relines. Frequency limits on dentures (usually once every 5–10 years) and the distinction between immediate and conventional dentures generate most denials in this category.

Implant Services: D6000–D6199

• D6010 — Surgical placement of implant body
• D6056 / D6057 — Abutment (prefabricated / custom)
• D6058–D6065 — Implant crowns

Plan coverage for implants varies more than any other category. Pre-authorization is typically required, and benefit verification before surgery is essential.

Fixed Prosthodontics: D6200–D6999

Bridges, bridge abutments, and retainers. The core codes are D6240–D6245 (pontics) and D6750–D6783 (retainers), with reimbursement patterns similar to individual crown codes.

Oral & Maxillofacial Surgery: D7000–D7999

• D7140 — Routine extraction of erupted tooth
• D7210 — Surgical extraction of erupted tooth
• D7220–D7241 — Impacted tooth extractions
• D7953 — Bone replacement graft for ridge preservation

The D7140/D7210 distinction is the most common source of oral surgery denials. Documentation of flap elevation, bone removal, or tooth sectioning is required for D7210.

Orthodontics: D8000–D8999

Orthodontic codes cover limited, interceptive, and comprehensive orthodontic treatment, typically billed in banded or monthly installments. Orthodontic benefits are often structured as a separate lifetime maximum distinct from other dental benefits.

Adjunctive Services: D9000–D9999

Adjunctive codes cover anesthesia, nitrous, office visits after hours, and miscellaneous services. The highest-volume codes include D9230 (nitrous), D9222/D9223 (IV sedation), and D9630 (drugs dispensed in office).

How to look up a specific code

For authoritative and current CDT code definitions, the primary reference is the ADA’s annual CDT code book. The ADA also publishes code update summaries each year when codes are added, revised, or deleted.

Practice management software typically includes the current CDT set, but codes are often out of date when software is not current. Reviewing the CDT update each January ensures your practice is using the right codes — and avoiding deleted codes that generate automatic denials.

Where revenue leaks hide

For practice owners looking at CDT codes through the revenue lens, the consistent patterns are:

• D1110 fee schedule drift — small reductions that compound across thousands of cleanings per year
• D2391/D2392 alternate benefit — composite claims paid at amalgam rates
• D2950 downcoding to D2949 — core buildups paid as restorative foundations
• D4341 audit exposure — scaling and root planing claims scrutinized for periodontal documentation
• D7210 downcoded to D7140 — surgical extractions paid as routine extractions when documentation is thin
• Frequency boundary errors on D0120 and D1110 — patients arriving slightly early on the six-month cycle

Knowing where these leaks happen — and monitoring them systematically — is the difference between a practice that absorbs quiet fee schedule reductions and one that catches them in time to renegotiate or adjust.