An interproximal cavity is decay that develops on the side of a tooth where it touches an adjacent tooth. This common procedure is technically demanding, and the total time in the dental chair typically falls between 45 and 90 minutes. This appointment time includes distinct phases, from ensuring patient comfort to the final polishing of the restoration. Recreating the natural contour of the tooth’s side wall, or proximal surface, makes this procedure longer than a simple filling on the chewing surface.
Essential Preparation Steps Before Restoration
The initial phase focuses on patient comfort and establishing a clean, dry field for the dentist. This begins with administering a local anesthetic, often applying a topical gel before the injection. The injected anesthetic needs 5 to 15 minutes to fully take effect. This ensures the patient feels no pain during the subsequent removal of the decayed tissue.
After numbness sets in, the dentist performs isolation, which is necessary for the success of modern composite fillings. Isolation involves placing a rubber dam or using cotton rolls and suction to separate the working area from saliva and the tongue. Saliva contamination significantly weakens the bond between the filling material and the tooth structure. This isolation step is crucial and can typically be completed in under five minutes.
The Technical Process of Interproximal Restoration
Once the area is prepared, the active restorative phase begins with removing all decayed tooth structure using a dental drill. This is followed by placing a matrix system, a specialized tool composed of a thin metal band and a wedge inserted between the teeth. The matrix band acts as a temporary wall, replacing the missing side of the tooth so the filling material can be correctly packed against it.
The challenge of this procedure is recreating a tight contact point with the neighboring tooth to prevent food trapping. After cleaning and shaping the cavity, the surface is treated with an etching gel for 15 to 20 seconds, followed by applying a bonding agent cured with a blue light for about 10 seconds. The composite resin is then placed in thin increments, typically no more than two millimeters thick. Each layer is cured for 10 to 20 seconds before the next is added to minimize shrinkage and ensure complete hardening. This layering technique adds considerable time compared to placing a single, large filling.
Key Variables Determining Total Procedure Duration
The total time spent actively working on the tooth is highly dependent on several factors. Cavity size is a primary factor, as a small, shallow interproximal lesion may take 15 to 20 minutes less than a deep cavity extending close to the nerve chamber. The number of surfaces involved also dramatically increases complexity. For example, a two-surface restoration is far quicker than a three-surface filling that involves both side walls and the chewing surface.
The location of the tooth in the mouth also plays a role in duration, as working on a back molar is more difficult due to reduced visibility and limited patient opening. This can extend the time needed for isolation and matrix placement. Composite resin, the tooth-colored material, inherently takes longer than traditional silver amalgam because of the meticulous layering, light-curing, and bonding steps required. However, advanced techniques like bulk-fill composite, which can be placed in thicker layers, can reduce the time spent on layering and curing.
Immediate Post-Procedure Time and Recovery
The final minutes of the appointment are dedicated to perfecting the newly placed filling. After the matrix band is removed, the dentist meticulously checks the contact point with the adjacent tooth. Specialized burs and polishing cups are then used to adjust the filling’s shape and smooth its surfaces. This step, which often takes about five minutes, ensures a smooth surface that does not catch floss or irritate the gum tissue.
The patient is asked to bite down so the dentist can make final adjustments, confirming the filling does not interfere with the natural bite. Although the composite material is fully hardened and ready for immediate use, the lingering effects of the local anesthetic are the main constraint. Patients are advised to avoid eating or drinking anything that requires chewing for one to three hours. This prevents accidental biting of the cheek or tongue while the numbness wears off.