What are the effects of killing the nerve?

Generally, root canal treatment primarily involves removing infected dental pulp tissue inside the tooth to eliminate pain and preserve the affected tooth. However, this procedure may lead to several side effects, including reduced tooth strength, short-term mild pain or discomfort, tooth discoloration, possible swelling after treatment, and avoiding excessive use of the treated tooth. Most of these issues can be improved with proper follow-up care or restorations. A detailed analysis is as follows:

1. Reduced tooth strength: The dental pulp provides nutrients to the tooth. After root canal treatment, the tooth loses its nutrient supply and gradually becomes more brittle and prone to cracking. The risk of fracture increases significantly when biting hard objects. Therefore, a dental crown is usually recommended afterward to protect the tooth and enhance its resistance to fracture.

2. Short-term mild pain or discomfort: During treatment, medications or instrument manipulation may cause minor irritation to the periodontal tissues. Mild soreness or slight pain upon biting may occur within 1–2 days after the procedure. This discomfort is typically temporary; avoiding chewing hard foods with the treated tooth usually allows symptoms to resolve on their own.

3. Tooth discoloration: Over time, without pulp nourishment, the tooth structure gradually dehydrates and may darken, turning dull grayish-yellow—especially noticeable in front teeth, potentially affecting aesthetics. For patients concerned about appearance, tooth color can be improved later through dental crowns or teeth whitening procedures.

4. Possible swelling after treatment: In rare cases, if inflammation was not fully controlled during treatment or local irritation occurred due to procedural factors, slight gum swelling may develop. Maintaining good oral hygiene and avoiding spicy or irritating foods typically helps the swelling subside within a few days.

5. Avoid overusing the treated tooth: Due to decreased structural strength after root canal treatment, it's important to avoid using the tooth for chewing hard items such as nuts or bones until full restoration is completed. This precaution helps prevent tooth fracture and extends the lifespan of the tooth.

After treatment, maintain good oral hygiene by brushing twice daily and using dental floss regularly, and schedule routine dental checkups. If a dental crown is recommended, complete the restoration promptly to avoid leaving the tooth unprotected for prolonged periods. Additionally, maintain a bland diet to minimize irritation to the treated tooth and support recovery of normal function.