Can You Wear an Old Retainer to Straighten Teeth?

If your teeth have shifted after orthodontic treatment or if you’re afraid they’re beginning to, it may be tempting to try to straighten them with an old retainer.

If your orthodontic treatment was completed recently, and you’ve only just lapsed on retainer use, wearing your ignored retainer is likely safe. Just be sure that it’s not at all damaged, has been thoroughly cleaned and sanitized, and still fits easily over your teeth.

If a long time has passed since you’ve worn your retainer, the retainer has been damaged in any way, or it has to be forced into fitting your mouth, do not wear your old retainer. Doing so can result in a number of serious problems, including tooth and gum damage, pain, a stuck or broken retainer, or even infection.

The best (and safest) solution is to check in with your orthodontist. Bring your old retainer and show them how it fits in your mouth. They will be able to advise you whether you can wear your old retainer or whether you’ll need a new one or a new round of treatment.

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 clear aligners, the process of moving teeth is similar. It involves the following:

• 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 move back to the spots they once held. 

In most cases, dental experts tell their customers 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 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.

Can You Wear an Old Retainer?

If your retainer is not damaged and still fits into your mouth, even if it is a little tight, you can often still wear it. This means that your teeth have not moved so much that the retainer is no longer effective.

The retainer will likely be tight for a few days after putting it back in, but your teeth will shift slightly to accommodate this.

When your teeth have moved too much for your retainer to easily fit back in, you have experienced an injury or trauma to the teeth, or your retainer is damaged, you should not attempt to wear the old retainer.

Additionally, if it has been more than 10 years or so since you tried to wear your retainer, the odds are that it is either damaged or your teeth have shifted too much for it to work. If you have to force it back over your teeth, do not wear it.

Dangers of Wearing an Old Retainer

An old retainer can often do more harm than good, especially if it has been years since you have tried to use it.\ \ The following are risks of using an old retainer:

• Damage to teeth: Forcing a retainer into place when your teeth have shifted can chip, crack, or break your teeth.
• Gum tissue damage: Pushing a retainer onto your teeth when it does not fit properly can create pressure on your gum tissue. When you try to remove the retainer, it can even rip some gum tissue off, causing bleeding and sensitivity.
• Stuck retainer: Forcing a retainer onto your teeth when it no longer fits could cause it to become stuck, requiring a dental appointment to have it removed.
• Sickness: Retainers that have been sitting for a long period of time could collect bacteria that you are then putting back into your mouth with the old retainer.
• Pain: Putting an old retainer back on when your teeth have moved can be painful and hurt your teeth and gums.
• Broken retainer: Plastic retainers will become brittle over time and can snap in your mouth, cutting it or causing pain.

Generally, if you have not worn your retainer for several months or years, you will need to speak to your orthodontist about getting a new one or restarting a treatment plan. Before trying to use an old retainer, it can be a good idea to check with your orthodontist to make sure it will be safe to do so. They may be able to adjust your retainer to fit again.\ \ Remember that if you need a new retainer, it will not actually move your teeth back into alignment. Instead, it will just hold your teeth where they are now. Retainers are designed to keep teeth from shifting. They are not intended to actually move teeth.

Why Your Teeth Move After Treatment

Most dental experts tell their customers how to use retainers. 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 these issues:

• 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 customers never wear the devices they're given.

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.

With a small investment of time and money, you can fix your bite and smile. And you'll be guided by a dental professional rather than doing the work yourself and putting your health at risk.

References

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.