Interproximal Reduction (IPR)

Will You Need It?

If you're considering clear aligners, you may have come across the term IPR and wondered what it actually means.

IPR stands for interproximal reduction. It is a dental technique used to create a small amount of additional space between selected teeth by carefully reducing a controlled amount of enamel from their sides.

The idea of removing enamel can sound concerning, particularly if you've never heard of IPR before. However, when it is appropriately planned and performed by a qualified dental professional, IPR is a well-established technique used as part of orthodontic treatment.

Importantly, not everyone who has clear aligner treatment needs IPR. Whether it forms part of your treatment depends on your teeth, your bite, the amount of space available and the movements your treatment plan requires.

What is IPR?

Interproximal reduction is the controlled removal of a small amount of enamel from between two adjacent teeth.

The purpose is usually to create space so that teeth can move into their planned positions.

Rather than creating one large space in a single location, your dentist may create very small amounts of space between several teeth. Collectively, these small spaces can provide enough room to achieve the required alignment.

IPR is sometimes described as "tooth slenderising" or enamel reduction. It should not be confused with casually filing teeth down. The amount and location of IPR are planned as part of the overall orthodontic treatment.

Your dentist will determine whether it is appropriate and how much enamel, if any, should be removed.

Why is IPR used with clear aligners?

The main reason IPR is used is to create space.

Teeth need enough room to move. If your teeth are crowded, there may not be sufficient space for them to reach their planned positions without creating additional room.

There are several ways orthodontic treatment can create space. Depending on your individual case, your dentist may consider techniques such as expansion, tooth movement, IPR or, in more complex situations, other treatment options.

IPR can be particularly useful when only a relatively small amount of additional space is required.

Treating crowding

Crowding occurs when there isn't enough room for teeth to align correctly.

Rather than simply pushing teeth further outward, carefully planned IPR can sometimes provide additional space while allowing your dentist to maintain better control over the overall tooth position.

The amount of space required varies from patient to patient.

Managing tooth proportions

Teeth aren't always perfectly proportional to one another.

In some cases, differences in the relative size of upper and lower teeth can affect how they come together following orthodontic treatment. IPR can sometimes be used to make small adjustments to tooth proportions as part of a broader treatment plan.

Improving tooth shape

Some teeth have a naturally more triangular shape.

When teeth are aligned, this shape can sometimes leave small spaces near the gumline. These are commonly referred to as black triangles.

Depending on the individual anatomy, carefully reshaping the contact between teeth may help improve their appearance.

IPR isn't a guaranteed solution for black triangles, however. Your dentist will assess the shape of your teeth, gums and bone before deciding whether it is appropriate.

Does IPR hurt?

For most patients, IPR is a relatively straightforward procedure.

Enamel itself does not contain nerves, which means the controlled removal of enamel between teeth is generally not painful.

You may feel pressure, vibration or some mild discomfort while your dentist performs the procedure. Your dentist will also take appropriate steps to ensure the procedure is comfortable for you.

If you have particularly sensitive teeth or another reason that may affect your comfort, discuss this with your dentist before treatment.

How is IPR performed?

The exact technique depends on the teeth being treated and the amount of reduction required.

Your dentist may use specialised abrasive strips, discs or other dental instruments designed for controlled enamel reduction.

The process generally involves:

1. Identifying the teeth included in the treatment plan.

2. Measuring or controlling the planned amount of reduction.

3. Carefully reducing the enamel between the selected teeth.

4. Smoothing and polishing the surfaces.

5. Checking the contacts before continuing treatment.

The procedure is usually completed as part of a normal dental appointment.

How much enamel is removed?

The amount varies depending on the individual treatment plan.

IPR should be conservative and limited to the amount clinically required to achieve the planned result.

There isn't one amount that applies to every tooth or every patient. Your dentist will consider factors such as tooth shape, enamel thickness, the amount of space required and the planned movements.

This is one of the reasons IPR should always be performed by an appropriately trained dental professional rather than as a generic step in every aligner treatment.

Is IPR permanent?

Yes.

Enamel does not grow back, so IPR is an irreversible procedure.

That doesn't mean it is inappropriate. It means it should be carefully planned and performed only where clinically indicated.

Your dentist should explain why IPR has been recommended and which teeth are involved before carrying it out.

Are there risks with IPR?

As with any dental procedure, there are considerations and potential risks.

Because IPR involves permanently removing a small amount of enamel, careful planning and technique are important.

Your dentist will consider your individual dental anatomy and oral health before recommending it.

After IPR, the treated surfaces should be appropriately smoothed and polished. Maintaining good oral hygiene and following your dentist's recommendations is also important.

If you experience unusual sensitivity, discomfort or another concern following treatment, contact your dental provider.

Does everyone need IPR with clear aligners?

No.

Some patients can achieve their planned result without IPR.

Others may benefit from it because the treatment requires additional space that cannot be created adequately through tooth movement alone.

The fact that one person's aligner treatment includes IPR doesn't mean yours will.

Your treatment plan should be based on your individual teeth rather than a standard process applied to every patient.

Can IPR replace tooth extraction?

In some orthodontic cases, IPR can provide an alternative way of creating limited amounts of space that might otherwise contribute to a more extensive treatment approach.

However, IPR cannot replace extractions in every case.

The amount of space required, the position of your teeth, your facial structure, your bite and other clinical factors all need to be considered.

Your dentist or orthodontist is the right person to determine which approach is appropriate for you.

IPR, attachments and other aligner techniques

IPR is only one of the techniques that may be used during clear aligner treatment.

Depending on your treatment plan, your dentist may also recommend:

• Attachments

• Elastics

• Tooth movement or expansion

• Refinement aligners

• Other dental procedures

These techniques aren't necessarily signs that treatment is more complicated or that something has gone wrong.

They're tools that can be used to help achieve specific tooth movements.

What should I ask my dentist about IPR?

If IPR has been recommended, don't be afraid to ask questions.

You can ask:

• Why do I need IPR?

• Which teeth will be treated?

• How much enamel will be removed?

• What is the IPR helping my treatment achieve?

• Are there alternative ways to create the required space?

• Will I need IPR again later in treatment?

Understanding your treatment is an important part of informed consent.

Frequently Asked Questions

Is IPR necessary for clear aligners?

No. Some patients need IPR and others don't. It depends on the individual's treatment plan and the amount and type of tooth movement required.

Does IPR damage your teeth?

IPR intentionally removes a small amount of enamel, so the procedure is permanent. When appropriately planned and performed by a dental professional, it is an established orthodontic technique.

Is IPR painful?

Most patients tolerate IPR well. You may experience pressure or vibration during the procedure, but enamel itself does not contain nerves.

How long does IPR take?

The time required depends on how many teeth are involved and the technique used. Your dentist can give you a more accurate estimate for your treatment.

Can teeth be straightened without IPR?

Sometimes. Depending on your anatomy and treatment requirements, your dentist may be able to achieve the planned result without IPR.

Will IPR make my teeth weaker?

Your dentist should only remove the amount of enamel considered appropriate for your treatment. If you have concerns about enamel thickness or sensitivity, discuss them with your dentist before treatment.

The bottom line

IPR can sound much more dramatic than it actually is.

It is a precise orthodontic technique designed to create small amounts of additional space when needed. For some patients, it can be an important part of achieving the planned result with clear aligners. For others, it may not be necessary at all.

The only way to know whether IPR is appropriate for you is through a proper clinical assessment and personalised treatment plan.

Your treatment should be designed around your teeth — not around a standard formula.