Which term describes tooth demineralization that occurred in the past and has stopped, biologically inactive?

• A. Inactive/arrested caries
• B. Active cavitated caries
• C. Active non-cavitated caries
• D. Rampant caries

Answer: (A)

Understanding caries activity status helps explain why a lesion isn’t progressing anymore. When demineralization has already occurred in the past and there is no ongoing destruction, the lesion is considered arrested or inactive. Clinically it often looks hard and may be brown or pigmented, with an intact surface and no soft dentin exposure. The tooth isn’t losing structure at the moment, and radiographs typically don’t show progression over time. This situation reflects remineralization and the protective effects of saliva and fluoride keeping the lesion in check.

In contrast, active cavitated caries shows a soft, undermined area with a true cavity; active non-cavitated caries are demineralizing but haven’t yet formed a cavity, often appearing as a white-spot lesion; rampant caries refers to extensive decay occurring rapidly in a high-risk patient. Therefore, the term for past demineralization that has stopped and is biologically inactive is inactive/arrested caries.