A dental crown is a custom-made cap placed over a natural tooth to restore its shape, strength, and function. Crowns are needed when a tooth is damaged by decay, fracture, wear, or after a root canal. To ensure the crown fits properly, the natural tooth structure must be precisely reduced in a process known as tooth preparation. This reshaping creates the necessary clearance for the permanent restoration. Since the procedure involves working with the tooth’s surface, many people wonder about pain.
Preventing Pain: Local Anesthesia
The primary method used to ensure comfort during the procedure is the administration of local anesthesia. This numbing agent works by temporarily blocking the nerve signals from the tooth and surrounding tissues to the brain. The goal is to eliminate the sensation of pain entirely during the preparation process.
Before the injection of the local anesthetic, a topical numbing gel is applied to the gum tissue. This gel helps to mitigate the sharp sensation of the needle, making the initial part of the process more comfortable. The local anesthetic is then injected slowly and steadily, which reduces the internal pressure and burning sensation that can occur with rapid injection.
Once the anesthesia takes full effect, the area around the tooth becomes numb. The dentist confirms the nerve is completely anesthetized, often using a cold test or a small instrument, before beginning preparation. When properly administered, local anesthesia ensures the mechanical work of reshaping the tooth proceeds without causing pain.
What Happens During Tooth Preparation
The process of tooth preparation involves meticulously shaping the tooth structure to make room for the crown. This is done by reducing the outer layers of the tooth, including the enamel and underlying dentin, using a high-speed dental handpiece. The amount of tooth structure removed is minimal but precise, creating a uniform reduction around the entire tooth.
While the local anesthetic prevents you from feeling pain, you will still experience other sensations, which is completely normal. The most common sensations are pressure, vibration, and noise from the dental handpiece. These mechanical forces are transmitted through the jawbone, and the anesthesia does not block these tactile and auditory signals.
It is important to communicate with your dentist if you feel any sharp pain, as this indicates the anesthetic may not be fully effective. A sensation of pressure is expected and is not a cause for concern, but sharp, hot, or cold feelings signal that more anesthetic is needed. The preparation process also generates a water spray to keep the tooth cool and rinse away debris, which you will feel as a coolness in the mouth.
After the Numbness Fades: Temporary Sensitivity
Once the local anesthesia wears off, three to five hours after the procedure, temporary sensitivity or mild discomfort is common. This occurs because the preparation process exposes the underlying dentin, which contains millions of microscopic channels called dentinal tubules. Since the temporary crown may not seal the tooth as effectively as the final restoration, the exposed dentin is vulnerable to external stimuli.
Changes in fluid movement within these exposed tubules, triggered by temperature changes or pressure, can cause a short, sharp pain known as dentin hypersensitivity. The temporary discomfort usually resolves within a few days to a few weeks as the nerve inside the tooth settles down.
Managing this temporary sensitivity involves a few simple steps. Over-the-counter pain relievers, such as ibuprofen or acetaminophen, can manage mild soreness or discomfort. To reduce sensitivity triggers, avoid consuming extremely hot or cold foods and drinks. Sticking to a soft diet and chewing on the opposite side of the mouth helps reduce pressure on the prepared tooth until the permanent crown is placed.