Recurrent caries

Recurrent caries, also called secondary caries, is decay that starts at the edge of an existing restoration, where the filling or crown meets the tooth. It is one of the main reasons restorations are eventually replaced.

The research Ryan reviewed corrects a common assumption. Recurrent caries is a genuine risk at bridge abutments, where it was one of the leading complications, but the classic complication data does not support the idea that decay is the number-one reason single crowns fail. In the bulk-fill composite trial he covers, the few restorations that failed at five years did so mostly from tooth fracture and secondary caries, not from the bulk-fill technique.

In front of a patient, the clinical phrase is the wrong one. "You have recurrent decay under the distal margin of number 30" means little to them; "that tooth is getting weak" is what they understand.