What Is IPR and Do You Need It for Clear Aligners?

If you have been researching clear aligner treatment, you may have come across the term IPR. It sounds clinical and slightly alarming, particularly when you find out it involves removing part of your tooth enamel. In reality, it is a routine, safe and painless procedure that is commonly used as part of orthodontic treatment. Here is everything you need to know about it.

What Is IPR?

IPR stands for interproximal reduction. It is a procedure where a small, precise amount of enamel is removed from the sides of specific teeth, the surfaces where adjacent teeth touch each other, to create space in the arch.

The amount of enamel removed is tiny. A typical IPR procedure removes between 0.1mm and 0.5mm per contact point, which is roughly the thickness of a fingernail or less. To put that in context, tooth enamel is typically 2 to 3mm thick at the contact point between teeth. IPR removes a fraction of that, leaving the structural integrity of the tooth fully intact.

IPR is sometimes called enamel stripping, tooth slenderising, or interproximal enamel reduction. These all refer to the same procedure.

Why Is IPR Used in Clear Aligner Treatment?

The most common reason IPR is used in aligner treatment is to create space for crowded teeth to move into alignment. When teeth are crowded, there is not enough room in the arch for them all to sit correctly. Before they can be guided into their correct positions, that space needs to come from somewhere.

There are generally two ways to create space in aligner treatment: expanding the arch outward, or reducing the width of individual teeth through IPR. In many cases, a combination of both is used. IPR is particularly useful for mild to moderate crowding where expansion alone would not create enough space, or where expansion would move teeth too far outside the supporting bone.

IPR is also sometimes used to improve the proportions of teeth relative to each other, particularly when slightly wider teeth are causing spacing or contact issues in the final alignment.

Is IPR Safe?

Yes. IPR is a well-established and widely used procedure in orthodontics with a long safety record. When performed correctly and within appropriate limits, it does not damage the tooth, increase decay risk, or cause sensitivity in the long term.

The enamel that is removed does not grow back, but the amounts removed in clinical IPR are so small that this is not a meaningful concern. The contact point between teeth is not a structural load-bearing area, and reducing it slightly does not affect the tooth's strength or longevity.

Research consistently shows that teeth that have had IPR performed as part of orthodontic treatment do not have higher rates of decay or sensitivity compared to teeth that have not, provided the procedure is performed correctly and within recommended limits.

Does IPR Hurt?

No, not in the way most people expect. IPR is performed using a thin dental disc, strip or bur that moves between the teeth at the contact point. There are no injections required and no drilling into the tooth body.

Most people feel mild pressure and vibration during the procedure but no pain. Some people with particularly sensitive teeth experience a brief moment of sensitivity, but this resolves quickly. The procedure itself is typically completed in minutes and causes no lingering discomfort afterward for the vast majority of patients.

If you have heard that IPR is painful, this is usually from outdated descriptions of older techniques or from confusion with other dental procedures. Modern IPR using current instruments is routinely described by patients as much less uncomfortable than they anticipated.

Will I Need IPR for My Treatment?

Not everyone needs IPR. Whether it is required for your treatment depends on the specifics of your case.

Factors That Increase the Likelihood of IPR

• Moderate to significant crowding where arch expansion alone cannot create sufficient space
• Cases where the teeth are proportionally wider relative to the arch size
• Cases where moving teeth outward would take them too far outside the supporting bone

Factors That Reduce the Likelihood of IPR

• Mild crowding where small amounts of arch expansion are sufficient
• Spacing cases where gaps already exist between teeth
• Cases where the primary movements needed are rotational or tipping rather than space creation

At Jawology, whether IPR is required is determined during the treatment planning process and confirmed before treatment begins. If IPR is needed, it is performed by a dental professional, either at a Jawology partner clinic or at a local dentist as directed by the clinical team. You will never be asked to perform IPR yourself.

Frequently Asked Questions