Retainers get lost, cracked, worn, accidentally thrown away — and, surprisingly often, chewed by dogs. Needing a replacement is common. The important part is figuring out which dental record should be used to make the new one.
Editor’s Note: This article was updated on September 2, 2026 to reflect Sentinel’s current replacement retainer process, including the option to use qualifying STL or PLY digital dental scans.
If you already have a professional digital scan from your dentist or orthodontist, that may be the easiest place to start. Sentinel Mouthguards accepts qualifying STL and PLY digital dental scan files for clear retainer fabrication.
If you do not have a digital scan, an at-home dental impression remains available.
When Do You Need a Replacement Retainer?
A replacement may be appropriate when your existing clear retainer is no longer usable or no longer available.
Common reasons include:
- the retainer has been lost or misplaced,
- it has cracked or split,
- heat has visibly distorted its shape,
- the material is significantly worn,
- the retainer has been damaged by a pet,
- your orthodontist has advised you to replace it.
Discoloration alone does not necessarily tell you whether a retainer needs to be replaced, and there is no single replacement schedule that applies to every clear retainer. Material, wear habits, cleaning, storage and individual use all affect lifespan.
For a deeper discussion of replacement timing, see How Long Do Dental Retainers Last?
Option 1: Replace Your Retainer From a Digital Dental Scan
This is the pathway we recommend exploring first when a current professional scan already exists.
Many people who have completed Invisalign, clear-aligner treatment or other orthodontic treatment have had their teeth scanned with an intraoral scanner. Depending on the system and dental office, that scan may be exportable as an STL or PLY file.
When the scan adequately represents your current teeth and contains the dental anatomy our laboratory needs, Sentinel may be able to use it as the starting record for your replacement retainer.
If you already have a scan
- Choose your Sentinel clear retainer.
- Select the digital scan option during checkout.
- Complete your order.
- Watch for the secure scan-upload email.
- Upload your STL or PLY files through the link provided.
Our laboratory reviews submitted files before fabrication and will contact you if another export or additional information is needed.
Why Digital Scans Can Be Especially Useful for Retainers
A clear retainer follows the contours of the teeth closely. That means the dental record used to make it needs to show the required anatomy clearly.
With an at-home impression, the impression material has to capture those surfaces sufficiently for the laboratory workflow. Shallow areas, missing tooth anatomy or incomplete posterior coverage can mean the impression needs to be repeated.
If a professional digital scan already exists and still represents your current teeth, using that record avoids having to recreate the same anatomy with a new physical impression.
Option 2: Replace Your Retainer With an At-Home Impression
You do not need to obtain a professional digital scan solely to order a Sentinel retainer.
If you do not already have usable scan files, Sentinel can provide an at-home dental impression kit.
Retainer impressions deserve particular care because the appliance follows the tooth anatomy closely. The impression should clearly capture the required surfaces of the teeth and arch so our laboratory has enough information to fabricate from.
Our team reviews the impression before fabrication. If the dental anatomy is too shallow or incomplete, another impression may be needed.
What If My Teeth Have Shifted?
This is different from simply replacing a lost or damaged retainer.
A replacement retainer is generally intended to correspond to the tooth position represented by the dental record used for fabrication. If your teeth have noticeably moved and your old retainer no longer fits, do not assume that ordering another retainer from the old tooth position will move them safely back.
An orthodontist or dentist can evaluate tooth movement and advise whether orthodontic treatment or another approach is appropriate.
We cover that question separately in Can Retainers Move Teeth Back?
What If My Old Retainer Still Fits?
If you are replacing an appliance because it is worn, cracked or you simply want a backup, the current position of your teeth is still important.
A recent professional scan that reflects that position may provide a useful fabrication record. If you do not have one, a new impression can capture your current dental anatomy.
If your existing retainer has become difficult to seat or no longer fits the way it once did, see Why Doesn't My Retainer Fit Anymore? before assuming you simply need an identical replacement.
Can I Replace an Invisalign Retainer Somewhere Other Than My Orthodontist?
People often use the phrase “Invisalign retainer” to describe the clear retainer worn after aligner treatment.
If you need a replacement after orthodontic treatment, the key question for an independent laboratory is whether a current dental record is available from which a new appliance can be fabricated.
If your orthodontist has a digital scan, ask whether it can be exported as STL or PLY files. If not, you can consider creating a new current dental record.
For cost-specific information, see Invisalign Retainer Replacement Costs: What to Know .
What If I Lost My Retainer?
If your retainer is completely gone, first consider whether you already have access to a current digital scan or another recent dental record.
The longer question — including what to do when you cannot immediately replace it — belongs in our dedicated guide: I Lost My Retainer: What Should I Do?
What If My Retainer Broke?
A cracked or broken retainer may need replacement, but the appropriate next step can depend on the extent of the damage and whether the appliance can still be worn safely.
See What Should I Do If My Dental Retainer Breaks? for the damage-specific guidance.
Can Sentinel Make a Clear Retainer Around a Permanent Retainer?
A bonded or permanent retainer changes the anatomy that must be captured in the dental record.
Whether a removable clear retainer can be fabricated in that situation depends on the individual dental anatomy, the condition and position of the bonded wire, and the record supplied to the laboratory.
If you have a permanent retainer, make sure it is represented in the scan or impression and let us know before fabrication. If the bonded wire is loose or damaged, contact your dental professional first.
About Sentinel Clear Retainers
Sentinel clear retainers are custom fabricated from the dental record supplied for your order and made in our St. Petersburg, Florida laboratory.
You can order an upper retainer, lower retainer or set depending on your needs.
View the current options here: Sentinel Clear Dental Retainers .
The Bottom Line
If you need a replacement clear retainer, start by asking one question:
Do I already have a current digital scan of my teeth?
If the answer is yes, ask your dentist or orthodontist for the STL or PLY files and consider using that record for your Sentinel order.
If you do not have a usable scan, an at-home impression remains available — but the impression needs to clearly capture the dental anatomy required for retainer fabrication.
And if your teeth have noticeably shifted, the problem is no longer simply “replace the retainer.” That is the point to involve your dentist or orthodontist before recreating the old tooth position.