A dental cavity is an area of tooth decay caused by bacteria in the mouth. These bacteria consume sugars and starches, producing acid that gradually erodes the hard outer enamel and underlying dentin. The purpose of a dental filling is to halt this decay by removing the damaged tooth structure and sealing the resulting void with a restorative material. This procedure restores the tooth’s form, strength, and function, preventing further bacterial progression.
Preparing the Area for Treatment
The process begins by ensuring the area around the tooth is free of sensation. A topical anesthetic gel is typically applied to the gum tissue first, temporarily desensitizing the injection site. This initial step makes the subsequent administration of the local anesthetic more comfortable.
The dentist then injects a local anesthetic, such as lidocaine, near the affected tooth. This solution acts as a nerve block, preventing pain signals from reaching the brain. The numbing effect takes hold within minutes, ensuring the patient feels only pressure and vibration, not pain. Once the anesthesia is effective, the dentist isolates the treatment area, often using a dental dam, to keep the tooth dry and ensure a strong bond for the restorative material.
Cleaning and Shaping the Tooth Structure
Once the patient is comfortable and the area is isolated, the dentist begins removing the decayed tissue. A high-speed dental handpiece, or drill, is used to precisely cut away the softened enamel and dentin compromised by the decay. As the dentist approaches the deeper, more sensitive dentin layer, a slower-speed drill may be employed for careful removal.
The objective is to eliminate all traces of infected material without harming the healthy underlying pulp. Specialized dyes may be used to highlight any remaining carious tissue, ensuring complete eradication of the decay. The remaining healthy tooth structure is then prepared. This involves shaping the inner walls to create a strong mechanical or adhesive retention form, allowing the filling material to securely anchor and withstand chewing forces.
Applying the Restorative Material
The next phase involves placing the chosen restorative material into the prepared cavity to seal the tooth. For a composite resin filling, the process starts with applying an acidic gel to micro-roughen the surface. This etching creates microscopic pores, followed by a liquid bonding agent that establishes a strong adhesive layer between the tooth and the filling material.
The composite resin, a mixture of plastic and glass compounds, is applied in small, incremental layers. Each layer is sculpted to match the tooth’s contours and immediately hardened using a specialized light, a process called curing. In contrast, a silver amalgam filling is packed directly into the prepared space. The dentist condenses the malleable amalgam firmly into the cavity, then carves and shapes it to recreate the tooth’s anatomy before it fully hardens over the next 24 hours. After placement, the dentist checks the patient’s bite using articulating paper, making fine adjustments until the occlusion feels correct.
Aftercare and Recovery Expectations
Following the procedure, the local anesthetic will typically keep the area numb for one to three hours. During this period, it is advisable to avoid chewing to prevent accidentally biting the tongue, cheek, or lip. Patients should also avoid consuming hot beverages until sensation returns, as the numbness prevents them from accurately gauging temperature.
Mild tooth sensitivity to hot, cold, or sweet stimuli is a common and temporary experience. This sensitivity may last from a few days up to two weeks as the tooth adjusts to the restoration. For composite fillings, normal chewing can resume immediately, but for amalgam fillings, it is recommended to chew on the opposite side for the first 24 hours to allow the material to fully set. If the filled tooth feels significantly high when biting, or if pain persists after a couple of weeks, the patient should contact their dentist for an adjustment.