Interproximal reduction (IPR) is a common orthodontic procedure involving the precise removal of a very small amount of outer tooth enamel from between two teeth. This technique is also known as interproximal stripping, teeth slenderizing, or enamel reduction. Performed by an orthodontic professional, it serves as a minimally invasive method to achieve various treatment goals.
The Purpose of Interproximal Reduction
One primary reason for IPR is to create space within the dental arch. This space allows for the proper alignment of crowded or crooked teeth, often providing an alternative to tooth extraction in cases of mild to moderate crowding. The procedure can generate several millimeters of space, enabling teeth to move into their desired positions.
Reshaping the contact points between teeth through IPR also enhances long-term stability after orthodontic treatment. By creating broader, more stable contact areas, the procedure helps prevent teeth from shifting back towards their original positions. This contributes to the overall durability of the orthodontic outcome.
Interproximal reduction also addresses “black triangles,” which are small, triangular-shaped gaps that can appear between teeth near the gumline. These spaces can result from tooth shape or gum recession. By subtly changing tooth shape, IPR allows teeth to be moved closer, minimizing or eliminating these aesthetic concerns.
The procedure can additionally correct tooth size discrepancies, sometimes referred to as a Bolton discrepancy. This condition occurs when there is a mismatch in the overall size ratio between the upper and lower teeth, preventing them from fitting together properly. IPR helps balance the width of the teeth, facilitating proper occlusion and a more harmonious bite.
The IPR Procedure
The interproximal reduction procedure involves the careful use of specialized tools to remove minute amounts of enamel. One method employs manual strips, which are flexible, diamond-coated abrasive strips. These strips are moved back and forth between the teeth, similar to flossing, and are reserved for very minor reductions. Different grits are available, with coarser options for initial reduction and finer ones for polishing.
Another common approach involves dental discs, which are thin, flexible, diamond-coated discs attached to a slow-speed dental handpiece. This mechanical method allows for precise and controlled enamel removal, making it suitable for larger-scale reduction while providing uniform results. The orthodontist can carefully navigate the disc to achieve the desired shaping between teeth.
Specific burs designed for IPR can also be utilized in a dental handpiece for shaping and more targeted enamel removal. Regardless of the tool chosen, the orthodontist measures the space created incrementally throughout the procedure to ensure accuracy and prevent excessive reduction.
Safety and Sensation
The amount of enamel removed during interproximal reduction is minimal, typically ranging from 0.2 to 0.5 millimeters per tooth surface. This is a very thin layer, often less than the thickness of a business card. The outermost layer of a tooth, enamel, can be as thick as 2.5 millimeters, meaning IPR removes only a small fraction of its overall thickness, leaving teeth structurally sound.
Scientific studies show that when performed correctly by a skilled professional, IPR does not increase the long-term risk of cavities or gum disease. Maintaining good oral hygiene, including regular brushing and flossing, remains important for overall dental health.
The procedure is generally painless because the outer enamel layer of the tooth contains no nerves. For this reason, local anesthesia is typically not required. Patients may experience sensations such as mild pressure, vibration, or a light sanding or filing feeling during the process.
Post-Procedure Expectations and Care
Following interproximal reduction, patients might immediately notice the newly created space between their teeth. It is common to experience some temporary, mild sensitivity to cold air or liquids. This sensitivity typically resolves quickly, usually within a few days after the procedure.
Maintaining excellent oral hygiene is particularly important after IPR, as the newly shaped surfaces need to be kept clean while the teeth are moved into their final positions. Regular brushing and diligent flossing are highly recommended to prevent plaque accumulation in the adjusted areas.
To support enamel health, an orthodontist may recommend or apply a topical fluoride treatment immediately after the procedure. This fluoride application, which can be in the form of a varnish, gel, or mouth rinse, helps strengthen and remineralize the enamel surfaces, providing a protective barrier against demineralization and potential cavities.