A small cavity might seem harmless—but tooth decay never stops on its own. The earlier it’s treated, the easier and more comfortable it is to fix. Here’s how to know when it’s time to fill a decayed tooth . 🪥 1. As Soon as You Notice a Cavity If you see a brown or black spot , rough surface, or small hole, the decay has already started damaging enamel . ➡️ Early filling prevents it from spreading deeper into the dentin and causing pain. 😬 2. When There’s Sensitivity or Mild Pain If you or your child feel discomfort while eating sweet, hot, or cold foods , it’s a warning sign. ➡️ Filling at this stage can save the tooth and avoid pulpal involvement (which would later need root canal or pulpectomy ). 🦷 3. Before the Decay Reaches the Nerve Once bacteria reach the pulp (nerve), pain becomes severe and constant. ➡️ At this stage, a simple filling will not work—you’ll need root canal or extraction. Regular dental check-ups can detect decay before it reaches this point. 👶 4. Eve...