Tooth decay progresses through five stages, each with its own symptoms and treatments. Here's a breakdown: 1. **Demineralization**: The enamel, the outer layer of your teeth, starts to weaken due to plaque. White spots may appear. Using fluoride mouthwash or getting fluoride treatments can reverse this damage. 2. **Enamel Decay**: If demineralization continues, white spots turn brown, and cavities form. Fillings are needed to prevent further damage. 3. **Dentin Decay**: If cavities aren't treated, decay reaches the dentin, causing tooth sensitivity. Fillings or crowns may be required. 4. **Damaged Pulp**: Decay reaches the pulp, causing pain and swelling. A root canal is needed to remove the damaged pulp and save the tooth. 5. **Abscess Formation**: Infection can lead to an abscess, causing severe pain. A root canal or tooth extraction may be necessary, along with antibiotics. Prevent tooth decay by avoiding sugary and acidic foods, brushing regularly, and visiting your dentist for check-ups.