Inlays and onlays—conservative, durable, and esthetic alternatives to full-coverage crowns—once stood proudly as a hallmark of biomimetic dentistry. Designed to restore moderate tooth structure loss while preserving healthy enamel, they are often regarded as the ideal treatment between a basic filling and a full crown. But despite their clinical merit, these restorations are slowly disappearing from treatment rooms across the country.

Why? The answer lies buried in insurance policies, reimbursement codes, and years of systemic downgrading—literally and figuratively.

What Are Inlays and Onlays?

An inlay fits within the confines of the tooth cusps, while an onlay extends over one or more cusps, offering greater coverage and protection for compromised teeth. Both are typically lab-fabricated or milled in-office from porcelain, composite resin, or gold.

Unlike large fillings that may undermine tooth structure or crowns that sacrifice healthy tooth tissue, inlays and onlays strike a balance—preserving what’s good, replacing what’s gone, and restoring function with minimal sacrifice.

Insurance Coverage: Do Plans Pay for Inlays and Onlays?

Here's the harsh reality: most dental insurance plans either don't cover inlays/onlays or severely downgrade them—commonly reimbursing at the rate of a basic amalgam filling.

This leads to two major financial consequences:

1. For the provider: Reimbursement is significantly lower than the lab fees and time required to seat an inlay/onlay.

2. For the patient: The insurance contribution is minimal, leaving them to pay the difference out-of-pocket, sometimes making it more costly than a crown.

And if the patient’s plan specifically excludes inlays/onlays as “not a covered benefit” or “cosmetic,” the entire burden shifts to the patient.

The Insurance Downgrade Game: Amalgam vs. Inlay

Most plans are structured around least costly alternative treatment (LCAT) clauses. That means if a filling could be used—even if it’s not the best clinical choice—the plan will pay as if a filling was used. This is particularly true for porcelain and composite inlays, which frequently get downgraded to amalgam.

This downgrade also introduces confusion for patients who are often presented with a bill higher than anticipated, not realizing that their insurance considered a more archaic treatment option.

Has Insurance Changed the Culture of Inlays and Onlays?

Absolutely.

In fact, a 2022 survey from the Academy of Operative Dentistry indicated that less than 10% of general dentists in the U.S. routinely perform inlays/onlays, with over 70% of respondents citing "insurance-related issues" as a major deterrent.

Many dentists acknowledge that they’re seating more crowns simply because they’re easier to bill and get reimbursed—even when an onlay would have sufficed.

The insurance reimbursement climate has thus shifted not only patient affordability but clinical decision-making. This has serious implications for long-term oral health, tooth preservation, and ethical dentistry.

The Unspoken Cost: Tooth Loss and Over-Treatment

While a crown may be more profitable in the short term, the long-term consequences include:

• Excessive removal of healthy tooth structure

• Increased risk of pulpal involvement

• More invasive treatment down the road (e.g., root canals or extractions)

This is the cost of letting reimbursement policies dictate care. It's not just about insurance anymore—it's about preserving teeth and restoring trust.

So What’s the Best Approach for Dentists?

If you believe in the value of inlays and onlays, don’t give up. Here’s how to ethically and strategically incorporate them into your practice despite insurance challenges:

1. Get Ahead with Pre-Treatment Estimates

Always send pre-authorizations and include:

• Intraoral images

• Radiographs

• Clinical notes documenting why a large filling would not suffice

Many plans will deny the claim or downgrade it, but providing documentation upfront helps reduce surprises for both you and the patient.

2. Use Non-Covered Service Waivers

When plans downgrade or exclude inlays/onlays, have patients sign financial acknowledgment forms. Use language that clearly states insurance is not likely to cover the procedure, and they are responsible for the full fee.

Be sure your form meets HITECH Act compliance for privacy and consent.

3. Code with Accuracy

Use the correct CDT codes:

• D2610–D2630: Inlays (metallic, porcelain/ceramic, composite)

• D2642–D2664: Onlays (same materials)

Don't code a crown (D2740) when it’s not clinically justified—doing so may be considered insurance fraud.

4. Educate Your Patients

Explain the long-term benefits of inlays/onlays:

• Tooth preservation

• Stronger bond

• Longer-lasting than large fillings

Patients will often pay out of pocket if they understand that it’s in their best interest—and trust you to recommend what’s right.

5. Create Tiered Options

If patients decline due to cost, offer a tiered plan:

• Tier 1: Inlay/Onlay with full out-of-pocket fee

• Tier 2: Crown with partial coverage

• Tier 3: Large composite filling with a disclaimer of limited longevity

Patients appreciate choices when they're clearly explained.

6. Document, Document, Document

When treatment planning inlays/onlays, always document:

• The extent of decay/fracture

• Why a filling would fail

• Why a crown is excessive

This becomes your legal and clinical protection in the event of an insurance dispute.

Final Thoughts: Do What’s Right, Not Just What Gets Paid

The erosion of inlays and onlays from everyday dentistry is a consequence of a system designed around cost-minimization, not optimal care. But that doesn’t mean you have to play along.

By standing firm in your clinical judgment, educating patients, and navigating the insurance landscape with clarity, you can bring back this underutilized restorative option—and do right by your patients.

Because at the end of the day, insurance companies don’t sit in your operatory. But your patient does.

Quick Recap

• Most insurance plans downgrade inlays/onlays to amalgam, reducing coverage and increasing patient costs.

• This has led many dentists to default to crowns—even when less invasive options would suffice.

• Use pre-authorizations, proper CDT coding, financial waivers, and strong documentation to protect your practice and your patients.

• Educate patients about the long-term value of conservative care, and empower them to choose wisely.

• Doing the right thing may not always be the easiest thing—but in the long run, it’s what builds trust, longevity, and healthier smiles.

Benjamin Tuinei

Founder - Veritas Dental Resources, LLC
Phone: 888-808-4513

Services:
PPO Fee Negotiators | PPO Fee Negotiating | Insurance Fee Negotiating
Insurance Credentialing | Insurance Verifications

Websites:
www.VeritasDentalResources.com | www.VerusDental.com