What D6740 means

D6740 covers a retainer crown, porcelain/ceramic, for a fixed bridge. "D" is dental, "67" is the fixed prosthodontic retainer group, and "40" is this porcelain/ceramic retainer crown. In a fixed bridge, the 'retainer' is a crown placed on a supporting tooth (abutment) next to the gap; it anchors the bridge in place. The retainer crowns on each side are connected to the pontic (the replacement tooth) in the middle, forming the bridge. A porcelain/ceramic retainer crown is made entirely of tooth-colored ceramic, matching an all-ceramic bridge for a natural appearance.

A bridge is coded from its components: the retainer crowns (like D6740) and the pontic(s). A typical three-unit bridge replacing one tooth is two retainer crowns (D6740 each, for ceramic) plus one pontic (D6245 for ceramic). So this code represents the supporting-crown portion of an all-ceramic bridge.

The retainer crown codes parallel the regular crown and pontic codes by material — porcelain/ceramic (D6740), porcelain-fused-to-metal (D6750 series), and cast metal (D6790 series). The ceramic retainer is chosen for all-ceramic bridges where a natural, metal-free result is wanted. It's essentially a crown that's part of a bridge rather than standalone. Coverage is under major prosthodontic benefits with the rest of the bridge.

When it's typically used

D6740 is reported for the porcelain/ceramic crown placed on a supporting tooth as part of a fixed bridge — the all-ceramic retainer that anchors the bridge to the natural abutment tooth, holding the pontic in place, chosen for a natural appearance.

How much does D6740 cost?

A porcelain/ceramic retainer crown is a significant fee as one unit of a bridge, often roughly 900 to 1,600 USD per retainer crown depending on region. Since a typical bridge has two retainer crowns plus a pontic, the full bridge totals more — often roughly 2,500 to 4,500+ USD for a three-unit ceramic bridge.

Is D6740 covered by insurance?

Covered under major prosthodontic benefits, often around 50 percent after the deductible, with the bridge components (retainer crowns plus pontic) billed and evaluated together. Frequency limits (e.g., once every 5–7 years) apply, and all-ceramic may be alternate-benefited to a PFM rate by some plans. Documentation of the missing tooth and the need for the bridge supports the claim.

What a retainer crown does in a bridge

The retainer crown is a key structural part of a bridge, and understanding its role clarifies how a bridge stays anchored in the mouth.

In a fixed bridge, the replacement tooth (pontic) needs to be held in place, since it's not anchored to the bone itself. This is the job of the retainer crowns: crowns placed over the prepared supporting teeth (abutments) on each side of the gap. The retainer crowns are firmly cemented onto these supporting teeth, and because they're connected to the pontic between them, the whole bridge is held securely in place — the supporting teeth bear the load and anchor the bridge. So the retainer crown is what attaches the bridge to the natural teeth, making the bridge a stable, fixed restoration.

This is why creating a bridge involves preparing (reducing) the supporting teeth to receive these retainer crowns — even if those teeth were otherwise healthy, they must be shaped to hold the crowns that anchor the bridge. A porcelain/ceramic retainer crown (D6740) is the all-ceramic version of this anchoring crown, matching a ceramic bridge for a natural look. Understanding that the retainer crowns are the anchors — and that they require crowning the supporting teeth — explains both how a bridge works structurally and why a bridge involves the adjacent teeth, which is a key consideration when choosing between a bridge and an implant (which doesn't involve the neighboring teeth).

Retainer crown materials and matching the bridge

The retainer crowns are typically made of the same material as the rest of the bridge, and understanding the material options clarifies the choices for an all-ceramic versus other bridges.

For a cohesive, matching bridge, the retainer crowns and the pontic are usually the same material. A porcelain/ceramic retainer crown (D6740) pairs with a ceramic pontic (D6245) to form an all-ceramic bridge — metal-free and most natural-looking. A porcelain-fused-to-metal retainer crown (D6750 series) pairs with a PFM pontic for a PFM bridge — strong with a tooth-colored surface. A cast metal retainer crown (D6790 series) is used for metal bridges where strength is prioritized. So the retainer crown code matches the bridge type, and a complete bridge is coded as the appropriate retainer crowns plus the matching pontic(s).

The choice of material for the whole bridge — and thus the retainer crowns — depends on the same factors discussed for pontics: appearance (all-ceramic for the most natural look, ideal for visible areas and metal-free preferences), strength and track record (PFM as a proven standard), the location and forces, and cost. For an all-ceramic bridge, the porcelain/ceramic retainer crowns (D6740) provide natural-looking anchors that match the ceramic pontic. The dentist recommends the bridge material based on the situation, and the retainer crowns follow that choice. Understanding that the retainer crown material matches the bridge helps explain how the components fit together into a unified restoration.

The trade-off of preparing healthy teeth for a bridge

A significant consideration with bridges is that they require preparing the supporting teeth for the retainer crowns, which is worth understanding when weighing a bridge against alternatives.

To place the retainer crowns that anchor a bridge, the supporting teeth (abutments) on each side of the gap must be prepared — reduced in size and shaped to receive the crowns. This means removing healthy tooth structure from those teeth, even if they had no problems of their own. For teeth that already needed crowns (due to large fillings, damage, or decay), this is no great loss — they were going to be crowned anyway, so using them to support a bridge is efficient. But for pristine, healthy adjacent teeth, preparing them solely to support a bridge means sacrificing healthy tooth structure, which is a real downside.

This trade-off is a key reason dental implants are often preferred when feasible — an implant replaces the missing tooth on its own (with a post in the bone) without touching the neighboring teeth, preserving them entirely. A bridge, by contrast, depends on and alters the adjacent teeth. So when choosing how to replace a missing tooth, the condition of the neighboring teeth matters: if they already need crowns, a bridge makes good use of them; if they're healthy, an implant's tooth-preserving advantage weighs in its favor. Understanding that the retainer crowns require preparing the supporting teeth helps patients appreciate this important consideration in deciding between a bridge and an implant for replacing a missing tooth.

Protecting the supporting teeth of a bridge

Since the retainer crowns sit on the supporting teeth that anchor the bridge, keeping those teeth healthy is essential to the bridge's longevity, and it's largely in the patient's hands.

The supporting teeth under the retainer crowns remain natural teeth, vulnerable to decay at the margins where the crowns meet them, especially at and below the gumline. Because decay on a supporting tooth is a leading cause of bridge failure — if a supporting tooth fails, the whole bridge can be compromised — protecting these teeth is critical. The key is meticulous oral hygiene, particularly cleaning under and around the bridge. Since the connected units prevent normal flossing, a floss threader is used to pass floss under the pontic and around the retainer crowns, or an interdental brush or water flosser cleans these areas, removing the plaque and food that collect under the bridge and at the crown margins.

Good gum health matters too, as gum recession can expose crown margins and increase decay risk. Avoiding hard and sticky foods, wearing a night guard if you grind, and keeping regular dental checkups (so the dentist can monitor the retainer crowns, the supporting teeth, and the gumline for any developing problems) all help. With diligent daily cleaning of the supporting teeth and regular professional care, a bridge can last many years. The longevity of the whole bridge ultimately depends on the health of the few supporting teeth that anchor it via the retainer crowns — so caring for those teeth is the most important thing a patient can do to protect their investment in the bridge.

Frequently asked questions

What is the D6740 dental code?

It's a porcelain/ceramic retainer crown — the all-ceramic crown placed on a supporting tooth as part of a fixed bridge, anchoring the bridge to the natural abutment tooth and holding the pontic in place.

What does a retainer crown do in a bridge?

It anchors the bridge — the retainer crowns are cemented onto the supporting teeth on each side of the gap and, being connected to the pontic, hold the whole bridge securely in place.

How is a ceramic bridge coded?

From its components — the porcelain/ceramic retainer crowns (D6740, one per supporting tooth) plus the ceramic pontic (D6245). A three-unit bridge is two D6740 retainer crowns plus one D6245 pontic.

How much does a ceramic retainer crown cost?

Often around 900 to 1,600 USD per retainer crown. A full three-unit ceramic bridge (two retainer crowns plus a pontic) often totals roughly 2,500 to 4,500+ USD.

Why does a bridge require crowning the adjacent teeth?

The retainer crowns that anchor the bridge are placed on the supporting teeth, which must be prepared (reduced) to receive them — removing healthy structure even if those teeth were fine. This is a key bridge-vs-implant consideration.

How do I protect a bridge's supporting teeth?

Clean under and around the bridge with a floss threader, interdental brush, or water flosser to prevent decay at the crown margins, maintain good gum health, and keep up with checkups, since the supporting teeth's health determines the bridge's longevity.

This page is an independent, plain-language explanation for general information only. It is not billing, coding, or clinical advice. For the official CDT descriptor and current-year wording, refer to the American Dental Association.