A custom night guard starts with a record of your teeth. For Sentinel customers, that record can come from one of two places: an at-home dental impression or a qualifying digital scan created by a dentist or orthodontist.
Neither option is automatically the “better” choice for everyone. The more useful question is which method makes the most sense based on what you already have, how you prefer to complete the process, and whether your existing dental records are current.
What Is an At-Home Dental Impression?
A dental impression creates a physical negative of the teeth using impression material and a fitted tray.
With Sentinel’s at-home process, the impression kit is sent to you with the materials and instructions needed to capture your dental arch. Once the completed impression is returned to our laboratory and approved, it is used as the starting point for creating the dental model needed for fabrication.
You can see the full process in our at-home impression guide .
An impression kit may make sense if:
- you do not already have a digital dental scan,
- you prefer to complete the tooth-record process from home,
- you do not want to schedule a separate dental appointment solely to obtain a scan,
- your teeth have changed since an older scan was created.
The main tradeoff is that an impression requires you to follow the instructions carefully and return the completed impression to the laboratory before fabrication can move forward.
What Is a Digital Dental Scan?
A digital dental scan is created with an intraoral scanner, usually in a dental or orthodontic office. The scanner captures the surfaces of the teeth and creates a three-dimensional digital model.
Many dental scanning systems allow that model to be exported in an open file format such as STL or PLY.
Sentinel accepts qualifying STL and PLY dental scan files. If you already have a usable scan, it may allow you to bypass the at-home impression step.
If you are trying to determine whether your dentist’s scanner can export a compatible file, see our dental scanner compatibility guide .
A digital scan may make sense if:
- your dentist or orthodontist has already scanned your teeth,
- the scan still represents your current dental anatomy,
- the office can provide an STL or PLY export,
- you would prefer to use an existing digital record rather than take another impression.
If you do not already have a scan, obtaining one may require a dental appointment and could involve a separate fee from the dental office.
Impression vs. Digital Scan: Side-by-Side
| Consideration | At-Home Impression | Digital Dental Scan |
|---|---|---|
| Where it happens | Completed at home using a Sentinel impression kit | Usually completed in a dental or orthodontic office |
| Best fit for | Someone who does not already have a usable digital scan | Someone who already has a qualifying scan available |
| Physical material | Uses impression material and a tray | No impression putty is used during scanning |
| Dental appointment | Not required for the impression process itself | Usually required if a scan has not already been taken |
| File requirements | None for the customer | Sentinel accepts qualifying STL or PLY files |
| Return shipping | The completed impression must be returned to Sentinel | No physical impression needs to be mailed when the scan is usable |
| If your teeth have changed | A new impression can create a current record | An older scan may need to be replaced with a new scan or impression |
Is a Digital Scan More Accurate Than an Impression?
It is tempting to reduce the comparison to “digital is more accurate,” but that is not especially helpful for someone choosing how to order a night guard.
Both workflows are methods of capturing dental anatomy. The usefulness of either record depends on the quality and completeness of the information captured.
A carefully completed impression can provide the information needed for fabrication. A digital scan can also provide detailed dental information, but simply being digital does not make every scan automatically usable.
An incomplete impression may need to be retaken. An incomplete or improperly exported digital scan may need another export or, in some cases, an updated scan.
Which Option Is More Convenient?
That depends heavily on whether you already have a scan.
If your dentist or orthodontist has recently scanned your teeth and can provide the files, using that existing record may be the simplest route because there is no physical impression to complete or return.
If you do not already have a digital scan, the equation changes. Scheduling a dental appointment solely to create one may be less convenient than completing Sentinel’s impression process at home.
In other words, a digital scan is often most convenient when it already exists.
What If My Digital Scan Is Old?
The age of the file alone does not determine whether it can be reused.
The more important issue is whether your teeth have changed since the scan was created. Orthodontic treatment, restorations, extractions, tooth movement and other dental changes can make an older record less representative of your current anatomy.
We cover that question separately in Can I Reuse an Old Digital Scan for a New Night Guard?
How Do I Send Sentinel a Digital Scan?
If you decide to use an existing scan, select the digital scan option during checkout.
After checkout is complete, you will receive an email containing a secure link for uploading your scan files. Upload your STL or PLY files there and our laboratory will review them before fabrication.
For the complete process, see How to Send an STL or PLY Digital Dental Scan for a Custom Night Guard .
So, Which One Should You Choose?
If you already have a current, usable digital scan, there is usually little reason to create a second record simply for the sake of using an impression kit.
If you do not already have a digital scan, Sentinel’s at-home impression kit provides a straightforward way to create the dental record needed for your order without obtaining a separate professional scan first.
And if your existing scan may no longer represent your current teeth, creating a new record — whether by scan or impression — may be the more appropriate choice.
The Bottom Line
An at-home impression and a professional digital scan are simply two different ways of creating the dental record used in a custom night guard workflow.
Already have a qualifying, current STL or PLY scan? You may be able to use it.
Don't have one? You do not need to obtain a digital scan just to order from Sentinel. The at-home impression process remains an option.
Either way, the goal is the same: provide our laboratory with a usable representation of your current dental anatomy before fabrication begins.