A typical dental treatment estimate lists procedures by CDT code — a five-character identifier starting with "D" that tells you exactly what procedure is being billed. Dentists use these codes for billing; insurance companies use them for claims processing. But patients rarely learn how to read them, which means they often don't notice when a treatment plan includes surprise line items, duplicate entries, or questionable procedures.
This guide walks through how CDT codes work, which codes are most commonly misused or upsold, and how to verify that your estimate is reasonable.
What the codes mean
CDT codes are maintained by the American Dental Association and published annually. They're divided into twelve categories, each starting with a specific letter-number prefix:
- D0100-D0999: Diagnostic. Exams, x-rays, consultations.
- D1000-D1999: Preventive. Cleanings, fluoride, sealants.
- D2000-D2999: Restorative. Fillings, inlays, onlays, crowns.
- D3000-D3999: Endodontics. Root canals.
- D4000-D4999: Periodontics. Gum disease treatment.
- D5000-D5999: Prosthodontics (removable). Dentures, partials.
- D6000-D6999: Implants and prosthodontics (fixed). Implants, bridges.
- D7000-D7999: Oral and maxillofacial surgery. Extractions, surgical procedures.
- D8000-D8999: Orthodontics. Braces, aligners.
- D9000-D9999: Adjunctive services. Anesthesia, emergencies, consultations.
When you get an estimate, every line item has a CDT code. Google the code to read the ADA's official description. This removes the mystery from what you're being charged for.
Common codes and typical prices
Prices vary by region, but these are rough national averages for cash-pay uninsured patients in 2026:
Diagnostic and preventive
- D0150 (comprehensive evaluation new patient): $75-150
- D0120 (periodic evaluation established patient): $50-85
- D0210 (full mouth x-rays): $100-200
- D0274 (bitewing x-rays, 4 films): $50-100
- D0330 (panoramic x-ray): $100-200
- D1110 (adult prophylaxis / cleaning): $85-150
- D1206 (fluoride varnish topical): $25-60
Restorative
- D2330 (anterior composite, 1 surface): $150-250
- D2331-D2335 (anterior composite, 2-4+ surfaces): $175-400
- D2391-D2394 (posterior composite, 1-4+ surfaces): $175-450
- D2740 (porcelain/ceramic crown): $900-1,500
- D2750 (porcelain fused to metal crown): $800-1,400
- D2950 (core buildup): $200-400
Endodontics
- D3310 (root canal, anterior): $600-1,000
- D3320 (root canal, bicuspid): $700-1,200
- D3330 (root canal, molar): $900-1,600
Periodontics
- D4341 (scaling and root planing, full quadrant): $200-400 per quadrant
- D4342 (scaling and root planing, 1-3 teeth per quadrant): $100-250 per quadrant
- D4910 (periodontal maintenance): $100-175 per visit
Oral surgery
- D7140 (simple extraction, erupted tooth): $150-400
- D7210 (surgical extraction, erupted tooth with sectioning): $300-500
- D7240 (surgical extraction, impacted tooth full bony impaction): $400-800
Line items to watch carefully
Deep cleanings (D4341, D4342) when you don't have periodontal disease
Scaling and root planing is a legitimate treatment for patients with documented periodontal disease (typically pocket depths of 4mm or more, with bleeding or bone loss). It is sometimes recommended for patients with healthy gums as an "enhanced cleaning" or "therapeutic cleaning." This is often inappropriate upcoding.
What to verify: Ask to see your periodontal chart. If pocket depths are 1-3mm with no bleeding, a standard prophylaxis (D1110) is the appropriate code, not scaling and root planing.
"Additional exam" codes on routine visits
Some offices bill a comprehensive evaluation (D0150) on visits where only a periodic evaluation (D0120) is appropriate. New-patient exams are legitimately more involved, but a routine check-up shouldn't generate a new D0150 every time.
Fluoride on adults without caries risk
D1206 (fluoride varnish) is often appropriate for high-caries-risk adults — those with active decay, dry mouth, or orthodontic appliances. It's less clearly indicated for low-risk adults with healthy teeth. If every visit includes a fluoride application, ask why.
Duplicate or layered restorative codes
Watch for a tooth listed with both a filling (D23XX) and a crown (D2740) in the same treatment plan. If the tooth needs a crown, it shouldn't also need a filling first. Sometimes this reflects a core buildup (D2950), which is legitimate — but the codes should match the actual sequence of work.
Crown buildups that aren't really needed
Core buildup (D2950) is legitimate when significant tooth structure is missing and needs to be replaced before the crown can be fabricated. It's sometimes added to crown estimates where a simpler bonded substructure would work. The distinction is clinical, but it adds $200-400 to the bill.
Questions to ask about any estimate
- Can I have a written itemized estimate with CDT codes?
- For each restorative line item, what's the clinical rationale — active decay, broken restoration, cracked tooth, something else?
- For each periodontal line item, can you show me the periodontal chart with pocket depths?
- Are there any alternative treatments that would be clinically acceptable?
- What's the priority ordering if I can't do all of this at once?
Most dentists will answer these questions thoughtfully. The questions alone signal that you're a patient who will notice when things don't add up.
Using a second opinion
For any estimate over $1,500, a second opinion is worth $149. Upload the written estimate with CDT codes and your x-rays; an independent licensed dentist can review each line item against the clinical evidence.
The second opinion will tell you which codes appear clinically supported, which codes are questionable, whether any important codes are missing, and whether the pricing is reasonable for your region. It's not a guarantee, but it's excellent information to have before committing thousands of dollars.
DentalPlanRx's Second Opinion is designed specifically for this. Join the waitlist to be first when we launch in your state.