A small cavity caught early is one of the simplest problems in dentistry to fix — a filling, done in one visit, and you move on. Ignored, that same cavity rarely stays small.
How untreated decay progresses
- Small cavity in enamel: typically treated with a simple filling
- Decay reaching the dentin: may need a larger filling or a crown
- Decay reaching the nerve: often requires root canal therapy
- Severe or spreading infection: extraction may become the only option
Why it doesn't stay small
Tooth decay is a bacterial process that continues to spread through the tooth structure over time — it doesn't heal on its own the way some minor injuries can. What starts as a surface-level issue can gradually work its way deeper toward the nerve.
The cost curve
This is where waiting actually costs more, not less. A filling is a fraction of the cost of a crown, and a crown is a fraction of the cost of a root canal plus a crown, and an extraction brings its own replacement costs — an implant, bridge, or denture — down the line.
If your dentist has flagged a small cavity, treating it now is almost always the simpler and less expensive path compared to waiting for it to become unavoidable.