A dental filling is a common procedure designed to restore a tooth damaged by decay, also known as a cavity. When bacteria produce acids that erode the tooth’s outer layers, a hole forms, compromising the tooth’s structure. The purpose of a filling is to remove this decayed material, clean the area, and fill the space with a durable material to seal it off. This restoration prevents further decay and returns the tooth to its proper shape and function for biting and chewing.
Preparing the Tooth and Patient
The initial steps focus on patient comfort and creating a controlled environment. To ensure the procedure is painless, the dentist administers a local anesthetic to numb the affected tooth and surrounding gum tissue. This often begins with a topical numbing gel applied before the injection, which reduces the sensation of the needle prick. The anesthetic, such as Lidocaine or Septocaine, blocks pain signals, allowing the dentist to work without causing discomfort.
Once the area is numb, the dentist isolates the tooth from the rest of the mouth. Saliva and moisture interfere with the bonding process of modern filling materials. To achieve isolation, the dentist uses tools like a dental dam or cotton rolls placed strategically around the tooth. This keeps the site clean and dry, ensuring a strong seal for the filling.
Removing the Decay
With the tooth numb and isolated, the next phase involves the precise removal of the compromised tooth structure. The dentist uses a specialized dental hand-piece, often called a high-speed drill, to carefully remove the soft, infected enamel and dentin. This tool removes only the decayed tissue while preserving as much healthy tooth material as possible.
In some cases, the dentist may use alternative, less invasive methods, such as a dental laser or air abrasion. After the bulk of the decay is removed, the dentist meticulously cleans the remaining cavity preparation to ensure all bacteria and infected debris are gone.
This cleaning is followed by the application of an acid gel, known as an etchant, which microscopically roughens the tooth surface. This etching prepares the surface for the bonding agent, creating a stronger grip for the filling material. The dentist also shapes the cavity during this phase, contouring the internal walls to ensure the final filling is securely retained and can withstand chewing forces.
Restoring the Tooth Structure
After the cavity is cleaned and prepared, the restorative material is placed into the space. If composite resin is used, the dentist first applies a liquid bonding agent to the etched surface. This agent is then cured, or hardened, with a specialized blue light, creating a durable chemical link between the tooth and the filling material.
The composite resin is placed in small, incremental layers to ensure it cures completely and uniformly. Each layer is shaped and hardened using the curing light, which chemically changes the soft resin into a hard, tooth-like structure. This layering technique minimizes shrinkage and achieves maximum strength in the final restoration.
Once the final layer is placed and cured, the dentist sculpts and refines the filling to match the tooth’s natural anatomy, including the grooves and cusps necessary for proper chewing. The final step is checking the patient’s bite, or occlusion, using thin articulating paper. The paper leaves marks on the filling indicating where adjustments are needed, ensuring the restoration does not interfere with the natural alignment of the teeth.
Filling Material Choices and Aftercare
Material Choices
Patients typically choose between composite resin and dental amalgam. Composite resin is a plastic and glass mixture that can be matched to the natural tooth color, making it the preferred aesthetic option for visible areas. Amalgam, a silver-colored mixture of metals, is known for its durability and lower cost, making it a practical choice for back teeth that endure heavy chewing forces.
Composite fillings bond chemically to the tooth and require less removal of healthy tooth structure, but they may be slightly less durable than amalgam. Amalgam fillings are more moisture-tolerant during placement and can last 10 to 15 years, though they lack the cosmetic benefit of resin. The choice balances aesthetic preference, cavity location, and the patient’s budget.
Aftercare
Immediately after the procedure, patients should be mindful of the lingering effects of the local anesthetic, which can keep the mouth numb for several hours. It is advised to avoid chewing until the numbness has completely worn off to prevent accidentally biting the cheek, lip, or tongue. A temporary, mild sensitivity to hot or cold temperatures and pressure is common following a filling as the tooth adjusts to the new material. This sensitivity usually diminishes within a few days to a couple of weeks, but patients should contact their dentist if the discomfort persists or worsens.