Finishing braces or clear-aligner treatment is a milestone. Retention is what comes next.
Editor’s Note
This article was updated on September 2, 2026 to serve as Sentinel’s central dental retainer guide, with updated guidance on retainer types, long-term wear, cleaning, replacement, fit changes, and qualifying STL and PLY digital scan options.
A dental retainer is an appliance used after active orthodontic treatment to help maintain the tooth position created during treatment. Unlike braces or active clear aligners, a passive retainer is not intended to continue straightening the teeth.
This guide covers the essentials: why retainers matter, the main types, how long they are worn, how to care for them, when they need replacement and what to do when something changes.
What Is a Dental Retainer?
A dental retainer is a removable or fixed appliance designed primarily to maintain tooth position after orthodontic treatment.
That distinction matters because a retainer and an active orthodontic appliance do different jobs.
Braces and clear aligners move teeth.
Passive retainers help maintain the position reached after that movement is complete.
If you are still in active treatment, have unfinished aligner therapy or want noticeably shifted teeth moved back toward a previous position, that is an orthodontic question rather than simply a replacement-retainer question.
For the difference between retention and active movement, see Can Retainers Move Teeth Back? .
Do You Really Need a Retainer After Braces or Aligners?
Yes. Retention is a standard part of orthodontic treatment.
Teeth and the surrounding tissues continue changing after active treatment ends, and tooth position can continue changing throughout life.
Retainers are prescribed to help preserve the orthodontic result rather than assuming the teeth will remain permanently fixed in their new positions on their own.
The American Association of Orthodontists describes retainers as a long-term—and typically lifelong—part of maintaining orthodontic results. The frequency of wear may decrease over time, but the individual schedule should come from the orthodontist responsible for treatment.
What Are the Main Types of Dental Retainers?
Retainers generally fall into two categories: removable and fixed.
| Type | What it looks like | How it works |
|---|---|---|
| Clear removable retainer | A thin, transparent shell molded closely over the teeth | Removed and reinserted by the wearer according to the prescribed retention schedule |
| Hawley retainer | An acrylic or plastic base with a metal wire across the teeth | A removable orthodontic retainer that may be professionally adjusted |
| Bonded retainer | A thin wire attached behind selected teeth | Remains in place continuously unless repaired or removed professionally |
The right design depends on the orthodontic treatment, tooth position, bite, anatomy and the recommendation of the treating professional.
What Does a Clear Retainer Look Like?
A clear removable retainer looks like a thin transparent shell with an individual contour for each tooth.
It can look very similar to a clear treatment aligner, which is why the two are often confused.
Invisalign's branded post-treatment retainer is called Vivera™, although other clear retainers may also be provided after Invisalign treatment.
For the visual differences between an aligner, Vivera-style retainer and another clear retainer, see What Does an Invisalign Retainer Look Like? .
How Long Do You Have to Wear a Retainer?
There is no universal calendar that applies to every orthodontic patient.
Many patients begin with more frequent retainer wear after active treatment and later transition to nighttime maintenance. Long-term retention is commonly recommended.
What we do not recommend is replacing the orthodontist's instructions with a generic internet schedule such as “exactly six months full-time, then every other night.”
Treatment history and stability vary.
For the full discussion, see How Long Should You Wear a Retainer After Braces or Aligners? .
How Long Does a Retainer Last?
Retainers do not have one universal expiration date.
Their service life depends on the appliance type, material, wear pattern, care, grinding or clenching forces and changes in dental anatomy.
With a clear retainer, pay more attention to its condition and fit than its birthday.
Cracks, holes, warping, substantial thinning, looseness or a meaningful change in fit can all be reasons to consider replacement or evaluation.
Read How Long Do Retainers Last? Signs It's Time to Replace Yours .
How Should You Clean a Clear Retainer?
Consistent gentle cleaning is easier than trying to rescue an appliance after heavy buildup or odor has developed.
At Sentinel, our preferred routine is an ultrasonic cleaner for easy regular cleaning, with a retainer-compatible denture cleaning tablet periodically when you want a deeper, fresher clean.
Avoid excessive heat and aggressive cleaning methods that can scratch or distort clear thermoplastic.
For our complete routine, see How to Clean Clear Retainers: The Easiest Daily Routine .
You can also see the Sentinel Ultrasonic Cleaner .
What Should You Do If Your Retainer No Longer Fits?
First, do not force it.
A fit change can happen because the appliance has warped or worn, because dental work altered the shape of a tooth, or because the teeth themselves changed position.
Those situations do not all have the same solution.
For troubleshooting, see Retainer Doesn't Fit Anymore? What to Do Next .
Can a Retainer Move Shifted Teeth Back?
A passive retainer should not be treated as a substitute for active orthodontic treatment.
A retainer may feel snug, but that does not mean it should be used to predictably correct visible orthodontic relapse.
If the teeth have noticeably shifted or your bite has changed, consult an orthodontist before having a new passive retainer made from that new position.
See Can Retainers Move Teeth Back? .
What If You Lose Your Retainer?
Do not wait for visible tooth movement before figuring out your replacement path.
If your tooth position remains appropriate to maintain, first check whether a usable digital dental record already exists.
For the urgent step-by-step process, see I Lost My Retainer: What Should I Do Next? .
What If the Retainer Cracks, Splits or Warps?
Physical damage is different from ordinary cosmetic wear.
Do not glue, heat, bend or reshape a broken clear retainer at home.
If the crack creates a sharp edge, changes how the appliance seats or allows it to flex unpredictably, stop treating it as a simple cleaning or cosmetic problem.
See Broken Retainer? What to Do If It Cracks, Splits or Warps .
How Do You Replace a Retainer?
If active orthodontic treatment is complete and your current tooth position is appropriate to maintain, a replacement passive retainer may be made from an accurate current dental record.
Already have a current professional digital scan?
Start there. Sentinel accepts qualifying STL and PLY digital dental scan files. Our laboratory reviews submitted files before fabrication.
No usable digital scan?
Sentinel also offers an at-home dental impression process. An accurate retainer requires the dental anatomy needed for fabrication to be captured clearly and completely.
Teeth visibly shifted?
Speak with an orthodontist before simply creating a new passive retainer from the shifted position.
For the complete replacement pathway, see Replacement Retainers: How to Replace a Lost, Broken or Worn Clear Retainer .
Why Check for a Digital Scan Before Taking Another Impression?
Many people who have completed braces or clear-aligner treatment have already had their teeth professionally scanned.
If you have access to a current scan that accurately represents the tooth position you want to maintain, that digital record may eliminate the need to recreate the same anatomy with another physical impression.
At-home impressions remain a useful option when no qualifying digital file is available.
This is particularly important for clear retainers because fabrication depends on obtaining complete, usable dental anatomy. In our laboratory experience, excellent retainer impressions require careful capture of the full areas needed for the appliance.
If you already have a professional scan, it makes sense to check that record first.
Does the Edge Design of a Clear Retainer Matter?
Clear-retainer margins may be scalloped around the gumline or finished with a straighter trim.
Trim style alone does not determine the overall quality of a retainer.
At Sentinel, we individually scallop, trim and polish our clear retainers because we prefer a closely contoured, low-profile finished margin around the customer's individual dental anatomy.
See Scalloped vs. Straight-Cut Clear Retainers: Does the Edge Matter? .
Is a Retainer the Same as a Night Guard?
No.
A retainer's primary purpose is maintaining orthodontic tooth position. A night guard's primary purpose is protecting teeth and dental work from the effects of grinding or clenching.
The appliances can look similar, but they should not automatically be treated as substitutes.
Read Retainer vs. Night Guard: What's the Difference? .
What If You Have a Permanent Retainer and Need a Night Guard?
This is a common situation.
Sentinel has fabricated thousands of custom night guards for customers with securely bonded permanent retainers.
As long as the bonded wire is stable and not loose, it can generally be represented in an appropriate impression or digital scan and accounted for during fabrication.
For that specific situation, see Can I Wear a Night Guard If I Have a Permanent Retainer? .
Replacing a Retainer After Invisalign
If Invisalign treatment is complete, there may be several replacement-retainer pathways.
Vivera™ is Invisalign's branded post-treatment retainer, but it is not the only type of passive clear retainer available after completed Invisalign treatment.
Sentinel is not Invisalign and does not manufacture Vivera retainers. Sentinel makes separate custom passive clear retainers for people who have completed orthodontic treatment and need to maintain their current tooth position.
If cost is part of your decision, see Invisalign Retainer Replacement Cost: Vivera & Clear Retainer Options .
What About Former SmileDirectClub Customers?
The same central distinction applies.
If treatment was completed and the teeth remain in a position appropriate to maintain, a passive replacement-retainer pathway may be available.
If treatment was unfinished or the teeth have visibly shifted, a passive retainer should not be used as a substitute for orthodontic assessment or additional active treatment.
Former customers can read: SmileDirectClub Replacement Retainers: What Former Customers Can Do Now .
What Makes a Good Replacement Retainer?
A replacement retainer begins with an accurate dental record.
From there, material selection, fabrication, trimming, polishing and final fit all matter.
At Sentinel, clear retainers are made in our in-house dental laboratory from an approved digital scan or dental impression. Each appliance is individually finished around the customer's dental anatomy.
Our role is passive retention. We do not diagnose orthodontic conditions or create active treatment plans intended to move teeth.
Sentinel Clear Replacement Retainers
Sentinel has made custom removable dental appliances since 2012.
Our clear retainers are intended for people who have completed orthodontic treatment and need to maintain an appropriate current tooth position.
You can order for the upper arch, lower arch or both.
Already have a qualifying professional STL or PLY digital scan? Select the digital-scan option when ordering. If you do not have a usable scan, choose the at-home impression pathway instead.
Explore Sentinel Clear Dental Retainers .
The Bottom Line
Orthodontic treatment moves teeth. Retention is what helps maintain the result.
A good retainer plan is long-term, individualized and built around the tooth position your orthodontic treatment created.
Follow the wear schedule prescribed for you, keep the appliance clean, watch its condition and replace it when damage or fit changes make that necessary.
If you need a replacement and your teeth remain in the position you want to maintain, check for an existing professional digital dental scan first. If no usable scan exists, an accurate dental impression remains a reliable path.
If the teeth themselves have visibly changed position, address that question before simply creating a new passive retainer.
This article provides general educational information and does not replace individualized care from a dentist or orthodontist. Retainer design and wear schedules vary by patient. Invisalign® and Vivera™ are trademarks of Align Technology, Inc. Sentinel Mouthguards is not affiliated with, sponsored by or endorsed by Align Technology.