A cavity (dental caries) is permanent damage on a tooth’s hard surface. This damage occurs when bacteria in the mouth produce acids that erode the tooth’s enamel and underlying dentin. If left untreated, the decay progresses deeper, eventually leading to pain, infection, and potential tooth loss. A dental filling is a restorative procedure designed to halt this decay, remove the damaged material, and replace the missing tooth structure to restore the tooth’s original form and function.
Preparing the Tooth for Restoration
The filling process begins with the administration of a local anesthetic to the area surrounding the affected tooth. This numbing agent ensures the patient remains comfortable and free of pain throughout subsequent steps of the procedure. The dentist must isolate the tooth to maintain a dry and clean operating field, often using cotton rolls or a dental dam.
Once the area is numb and isolated, the dentist uses a high-speed dental hand-piece (drill) or sometimes a laser to remove the decayed and damaged tooth material. This removal is meticulous, as any remaining bacteria or soft, infected dentin could lead to decay recurring beneath the new restoration. The goal is to leave behind only healthy, structurally sound enamel and dentin.
After the decay is completely removed, the cavity must be cleaned and shaped to ensure the filling material can adhere and withstand the forces of biting and chewing. The dentist may apply an acid gel, known as an etchant, to the tooth surface to create microscopic roughness. These tiny surface irregularities allow the bonding agent, which is applied next, to penetrate and create a strong mechanical and chemical seal with the tooth structure. This preparation step is fundamental to the long-term success of the dental filling.
Choosing and Applying the Filling Material
The choice of filling material depends on the location of the cavity, the chewing forces in that area, and the patient’s aesthetic preferences. The two most common types are composite resin and dental amalgam. Composite resin is a tooth-colored material made from a mixture of plastic and fine glass particles that blends with the natural tooth.
Composite resin fillings are applied by chemically bonding the material to the tooth. After the bonding agent is applied, the resin is placed into the prepared cavity in small, thin layers. Each layer is then hardened, or cured, using a specialized high-intensity light, which causes the material to solidify. This layering and curing process is more time-intensive but results in a restoration that requires less removal of healthy tooth structure than amalgam.
Dental amalgam, often referred to as a silver filling, is a durable alloy made of metals including silver, tin, copper, and mercury. Amalgam is more cost-effective and is favored for large cavities in back teeth that sustain heavy chewing pressure. Placement involves packing the pliable material directly into the cavity preparation, where it hardens on its own without the need for a curing light.
The final step involves shaping and polishing the restoration. The dentist molds the material to recreate the tooth’s natural contours and then checks the patient’s bite using articulating paper. Adjustments are made until the bite feels smooth and balanced, preventing the filling from being too high, which could cause pain or fracture.
Immediate Aftercare and Recovery
Immediately following the procedure, the most noticeable effect is the lingering numbness from the local anesthetic, which typically lasts for several hours. Patients should avoid chewing or consuming hot liquids until full sensation returns to prevent accidentally biting the tongue, cheek, or lip, or sustaining a burn. Soft foods are recommended for the first 24 hours to minimize pressure on the newly restored tooth.
It is common to experience sensitivity to hot, cold, or pressure after the anesthetic wears off. This sensitivity is often more pronounced if the original cavity was deep, allowing the pulp tissue closer to the nerve to become irritated during the procedure. This discomfort should be temporary and resolves within a few days to a week as the tooth recovers.
Over-the-counter pain relievers, such as ibuprofen or acetaminophen, can be used to manage mild soreness. Patients can resume brushing and flossing, though they should be gentle around the filled tooth for the first day. If sensitivity persists beyond a week, if sharp pain develops when biting, or if the feeling of a high spot in the bite remains, the dentist should be contacted for an evaluation.