A dental filling replacement is a common procedure that restores a tooth when the original restoration has worn down or failed. This process requires the dentist to first remove the existing filling material and any new decay that may have formed underneath it. The area is then thoroughly cleaned and prepared before the new material is placed and contoured to match the tooth’s natural shape. The time frame for a replacement is split between the long-term durability of the old filling and the actual duration of the appointment itself.
Lifespan of Different Filling Materials
The length of time a filling lasts before needing replacement depends primarily on the material used and the forces it withstands in the mouth. Composite resin fillings, which are popular because they match the natural tooth color, generally have a shorter average lifespan. These tooth-colored restorations typically endure for about five to seven years, though good oral hygiene and diet can extend that to ten years or more in some cases.
Amalgam fillings, often called silver fillings, are known for their strength and durability, especially in back teeth that bear heavy chewing pressure. These fillings tend to last much longer, with an expected lifespan ranging from ten to fifteen years, and sometimes significantly longer. Replacement becomes necessary not just due to age, but when issues like a fracture in the material, new decay forming around the edges (secondary caries), or excessive wear from grinding occur. The failure of composite fillings is most often due to secondary decay, while amalgam failures are more frequently related to material fracture.
The Actual Time in the Dentist’s Chair
The actual time spent replacing a filling in the dental chair can vary significantly, but most procedures fall within a 30 to 60-minute range. This duration is influenced by several factors, starting with the size and location of the filling being replaced; larger restorations or those on hard-to-reach molars naturally require more time. The appointment begins with the administration of local anesthesia, and the time spent waiting for the area to become fully numb is included in the overall estimate.
Once the area is numb, the dentist uses a drill to remove the old material and any damaged tooth structure. Removing old amalgam can sometimes be more involved than removing composite. A significant factor that prolongs the procedure is the discovery of deeper decay once the old filling is out, which requires additional time for careful removal to protect the tooth’s nerve.
After the preparation is complete, the new filling material is placed. For composite resin, this involves layering the material and curing each layer with a specialized light, which adds a few minutes compared to the placement of amalgam. The final steps include shaping the material to ensure proper alignment with your bite, followed by polishing the surface to prevent food or plaque accumulation. Simple replacements might take closer to 30 minutes, while complex cases involving multiple surfaces or deep decay can take an hour or more.
Caring for the Tooth Immediately After the Procedure
Immediate aftercare focuses on managing the sensations and protecting the new restoration in the hours following the appointment. It is important to avoid chewing on the side of the mouth where the procedure took place until the numbness from the local anesthetic has completely worn off, which usually takes a couple of hours. Chewing while numb increases the risk of accidentally biting the cheek, lip, or tongue.
Mild sensitivity to hot, cold, or pressure is a common sensation, particularly if the original decay was deep. This minor sensitivity subsides within a few days, but avoiding extremely hot or cold foods and beverages helps minimize discomfort during this period. If a composite filling was used, it is fully hardened upon leaving the office. If an amalgam filling was placed, you should avoid chewing hard foods on that side for up to 24 hours to allow for full setting. Contact your dental office if you experience severe pain, swelling, or if the new filling feels high when you bite down, as an adjustment may be necessary.