Can You Wear an Old Retainer to Straighten Teeth?

Medically Reviewed by a
Licensed DDS

Table of Contents

  1. Retainers Process
  2. Teeth Movement
  3. Do Retainers Help?
  4. References

You've worn aligners or braces for months, and you finally have the smile you've been hoping for. Your dental professional gives you retainers to preserve the work you've done.

But as the months roll by, you stop wearing your retainer. It sits in a drawer, gathering dust. And meanwhile, your teeth start to move in ways you just don't like.

Can you use an old retainer to straighten your teeth? As with most medical questions, the answer is, "It depends."

How Do Retainers Work?

Retainers are made when your teeth have assumed an ideal position, and they're designed to keep your teeth from shifting back to their old spots.

Whether you wear braces or aligners, the process of moving teeth is similar and involves:

  • Pressure. The visible portion of your teeth is pushed by braces or aligner plastic.
  • Remodeling. Bone that supports the teeth wears away and rebuilds based on that pressure.
  • Stretching. Ligaments and soft tissues that support your teeth are lengthened and rebuilt in response to the movement.

When pressure from braces or aligners is removed, your teeth can be tempted to respond to the pull of ligaments. That means moving back to their old spots. The process is gradual, and you may not see a change when you look in the mirror. But every day, teeth slide back to the spots they once held.

In most cases, dental experts tell their patients to wear their retainers for a portion of each day in the months following dental treatment. Then, people are asked to wear their retainers at night for the rest of their lives.

Retainers hold your teeth in place, so they don't shift. Wear them right after treatment, around the clock, and your teeth will continue to be supported in their new spots. Wear your device at night for the rest of your life, and any tiny movements that happen during the day are fixed while you sleep.

Retainers aren't cheap, and most cost between $200 and $500 per set. Lose them during treatment, and you must pay to get new versions made. And if you commit to wearing them for the rest of your life, you'll probably need at least one replacement set.

For people with mild dental problems stemming from poor retainer compliance, putting in the old device could be the perfect solution; however if your teeth have shifted position dramatically, you may need more help than your old retainer can provide.

Why Your Teeth Move After Treatment

Most dental experts tell their patients how to use retainers, and the majority of these doctors check up on their patients within three years to make sure they're following instructions.

Wear your retainers properly, and your teeth should be secured in their new positions with healthy bone and springy ligaments. But plenty of forces could push your teeth out of place.

Your teeth could move due to:

  • Decay. If a neighboring tooth is compromised by cavities and removed, teeth can move to fill in the gap.
  • Injury. A blow to the face could move teeth forward or back. Sometimes, teeth are pushed out altogether.
  • Habits. Grinding your teeth together can wear away enamel and prompt your teeth to bow in or out.

Skipping your retainer could also prompt your teeth to move, and about 4 percent of orthodontic patients never wear the devices they're given. Your teeth are very tempted to move right after treatment ends, and if you don't support them, all of your hard work could be compromised.

Similarly, if you wore your retainer faithfully immediately after treatment, but you stopped wearing it as the months and years wore on, your teeth can move in ways you didn't predict.

Can Your Retainer Help?

Experts say the best way to keep your teeth straight for a lifetime is to continue to wear your retainer. But if you haven't worn the device for a while, it may not help you regain the smile you've been looking for.

Ask yourself these questions before you lean on your old retainer to straighten your teeth:

  1. Is the retainer in good condition? Most retainers are made of plastic. If you've stashed your trays in a hot, dry space, the materials can crack and warp. Broken retainers can't help to move your teeth.
  2. Can you use the retainer without causing damage? If you risk chipping or cracking your teeth because the device doesn't fit, do not use it.
  3. Has your mouth changed since you stopped treatment? Your retainer is a snapshot of your oral health at one point in time. If your teeth have moved because of an accident or injury that happened after your treatment, you probably need a new assessment and treatment plan.

Many people use old retainers because they're worried about the cost of braces. That's reasonable, as braces can cost thousands of dollars, and some insurance plans won't cover the cost.

Remember that aligners are a cost-conscious alternative to braces. With a small investment of time and money, you can help your teeth take up the proper positions in your mouth. And you'll be guided by a dental professional rather than doing the work yourself, so you're less likely to put your mouth's health at risk.


How Much Do Retainers Cost? CostHelper.

A Survey of Protocols and Trends in Orthodontic Retention. (October 2017). Progress in Orthodontics.

Post-Treatment. American Association of Orthodontists.

Orthodontic Researchers Ask: Where's Your Retainer. (May 2011). Science Daily.

A Protocol to Help Patients Keep Their Straight Teeth for Life Using Orthodontic Retainers. (February 2018). Dentistry IQ.

Disclaimer: This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to serve as dental or other professional health advice and is not intended to be used for diagnosis or treatment of any condition or symptom. You should consult a dentist or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment.