D2393Resin-Based Composite - Four or More Surfaces, Posterior - Permanent

What This Code Covers

D2393 covers a large resin-based composite (tooth-colored) filling involving four or more surfaces on a permanent posterior tooth (premolar or molar). This is a significant restoration where decay or damage extends across most of the tooth. Common configurations include MODB, MODL, or MODBL. At this level of involvement, the dentist should also evaluate whether a crown would provide better long-term durability.

Billing Guide

Bill this code when:

• A composite filling involving four or more surfaces is placed on a permanent premolar or molar
• All surfaces are clearly identified and documented
• The tooth is permanent (not primary)

Do not bill this code when:

• Fewer than four surfaces are involved. Use D2391 (one or two surfaces) or D2392 (three surfaces)
• The tooth is primary. Use D2394
• An amalgam filling is placed. Use D2161
• A crown is more appropriate for the level of damage

Insurance and Denial Prevention

Key Payer Rules:

• Many plans apply an alternate benefit (downgrade) for posterior composites, paying at the amalgam rate (D2161)
• Large posterior composites may trigger a payer review or request for pre-authorization
• Some payers may recommend a crown for four-surface restorations
• The patient is responsible for the cost difference between composite and amalgam rates if downgraded

Common Denials and How to Respond:

• Downgraded to amalgam → This is an alternate benefit, not a denial. Inform the patient of the cost difference. This is common for posterior composites.
• Crown recommended → Document why a composite filling is appropriate (sufficient structure, patient preference, conservative approach).
• Surface count questioned → Submit radiographs and clinical documentation supporting the four-surface diagnosis.