D2391 — Composite filling — one surface, posterior
A posterior composite is a bonded tooth-coloured filling in a back tooth. D2391 is the single-surface version.
One of four composite restoration, posterior tooth codes. If you are trying to understand the treatment, start with the composite restoration, posterior tooth guide; if you are trying to understand this line on your estimate, you are in the right place.
What the number specifies, what it costs, what your plan is likely to do with it, and the named differences between it and the codes around it — in that order.
The conditions built into D2391
Extent — a single surface. A single surface means the decay has not yet reached the side of the tooth. That keeps the preparation shallow and the appointment short — often under half an hour.
Material — tooth-coloured composite resin. Composite is a resin filled with glass particles, placed soft and hardened with a blue curing light in layers. It bonds chemically to enamel and dentine, so the preparation can follow the decay instead of being cut to a retentive shape, and less sound tooth is lost. The trade-offs are technique sensitivity — the tooth has to be dry and isolated for the bond to work — and a shorter working life than amalgam under heavy chewing load, typically seven to twelve years on a back tooth. The material is part of the code rather than a choice made afterwards, so D2391 is only the right code if that is what was actually used.
Tooth — a back tooth, where sealing the margin matters more than appearance.
Counted — per site rather than per tooth. What counts as a single site is the detail that gets argued about on these claims.
Told apart from the codes it is confused with
D2392 — Composite filling — two surfaces, posterior: It covers two surfaces instead of a single surface.
D2393 — Composite filling — three surfaces, posterior: It covers three surfaces instead of a single surface.
D2394 — Composite filling — 4+ surfaces, posterior: It covers four or more surfaces instead of a single surface.
Those three codes and D2391 are the whole group — nothing else describes this procedure. A single word separates several of these codes, and a payer reads that word literally. If the record does not support D2391 specifically, the claim comes back — usually repriced to whichever neighbouring code the reviewer thinks was actually performed.
Every code in this group
These codes describe the same broad procedure and differ in one respect each. Each has its own page with its own fee range and coverage notes.
| Code | Procedure |
|---|---|
| D2391 | Composite filling — one surface, posterior — this page |
| D2392 | Composite filling — two surfaces, posterior |
| D2393 | Composite filling — three surfaces, posterior |
| D2394 | Composite filling — 4+ surfaces, posterior |
Questions about D2391
What is D2391 on my dental bill?
D2391 records composite filling, one surface, posterior — one of the restorative codes.
Is D2391 expensive?
Between $150–$350 in most practices — and that is the figure before any benefit is applied, not what you would pay at the desk.
How do dental plans handle D2391?
Expect basic handling — 70–80% of the amalgam allowance on many plans. Submitting an estimate first turns that percentage into a number you can rely on.
What is the difference between D2391 and D2392?
D2392 is composite filling, two surfaces, posterior: it covers two surfaces instead of a single surface. Everything else about the appointment is identical, so the record has to show that one detail for D2391 to be the defensible code.
Also known as: white filling, composite filling, posterior composite, molar filling, tooth-coloured filling.