Inside the Lab
Before a custom night guard is ever trimmed, polished, or placed in its case, it begins as a model of your teeth.
At Sentinel, 3D printing is one important part of that process—but it is not how we make the finished guard itself. We print a resin model of your teeth, use our Drufomat Scan to thermoform the selected guard material over that model, then cut, shape, smooth, polish, and inspect the finished guard by hand in our St. Petersburg lab.
“The resin model is printed. The guard is thermoformed over it, then finished by hand.”
That distinction is easy to miss online. “3D-printed night guard” can mean a guard printed directly from resin, or a guard made over a 3D-printed model. Sentinel’s standard night guards use the second approach: digital technology for the model, professional thermoforming and hands-on finishing for the guard.
It starts with a record of your teeth
Every custom guard begins with a record of your current dental anatomy. That can be an at-home impression made with a Sentinel kit or a recent digital scan from a dentist, orthodontist, or aligner provider.
If you already have a qualifying .STL or .PLY file, you can upload it with your order and skip the physical impression kit. Our guide to custom night guards from digital scans explains what to request and how the process works.
Once the record reaches our lab, it is reviewed before production begins. It needs to reflect your teeth as they are now. If you have had a new crown, filling, implant, extraction, orthodontic treatment, or noticeable tooth movement, you will need a new impression or scan.
First, we print the resin model
After an acceptable impression is digitized—or an uploaded scan is reviewed—we create a digital model of the teeth. That model is then printed in dental resin.
The resin model becomes the physical foundation for the rest of the lab process. It gives our technicians a durable replica of your teeth to work from, rather than asking them to form and finish the guard from a generic shape or a one-size-fits-all tray.
Printing the model also creates a consistent workflow inside the lab. The same model can be used to form the guard, check how it seats, and inspect the final finish before it leaves Sentinel.
Then the Drufomat Scan forms the guard
Once the resin model is ready, it goes into our Drufomat Scan thermoforming unit. The selected night-guard material is heated and formed over the model under controlled pressure, creating the custom shape of the guard.
This is the point where the flat material becomes an appliance designed around the contours of your teeth. The model guides the shape; the material determines the construction.
Sentinel offers several options depending on the feel and level of protection you prefer:
- Comfort Guard: soft 2 mm EVA for people who prefer more cushioning.
- Hard Guard: firm 2 mm copolyester with slight flexibility.
- Hybrid Guard: a 2 mm dual-layer guard with a soft inner surface and firmer outer layer.
- Durability Guard: a thicker 3 mm copolyester option for people who want more material.
You can compare each option in our custom night guard collection.
The work that still happens by hand
Thermoforming creates the shape, but it is not the final step.
After the material has formed over the resin model, our technicians cut away excess material and shape the guard’s edges. Each guard is then smoothed and polished so it has a clean finish and comfortable edges.
Next comes the fit check. The guard is seated on the same model used to make it so our team can inspect its coverage, retention, and overall finish. If an edge needs additional refinement, that work happens before the guard is packed.
Digital tools help us make the process more consistent. Skilled hands make sure the finished guard is ready to wear.
A custom guard should feel secure once seated, without sharp edges or painful pressure. A snug fit can be normal at first, but a guard should not be impossible to remove or cause persistent discomfort. Learn more in our guide to how a night guard should fit.
Why we use this hybrid process
Sentinel has made custom guards in its Florida lab since 2012. As digital dentistry has evolved, we have adopted tools that help us create dependable working models while preserving the careful finishing work that still matters.
For us, 3D printing is not a replacement for fabrication. It is a better way to create the model that supports fabrication. The guard is still thermoformed over that model, then individually cut, shaped, polished, and checked by our lab team.
That balance is what makes the process feel personal: technology where it helps, craftsmanship where it counts.
What happens when you reorder
Digital records can also make a future order simpler. If we have a usable digital record on file and your dental anatomy has not changed, we may be able to use that record for another guard without asking you to repeat the impression process.
That can be useful when you need a replacement, want a backup, or decide to try a different guard construction. Read more about using a saved digital scan for a new night guard.
Frequently asked questions
Is my Sentinel night guard fully 3D-printed?
No. Sentinel prints a resin model of your teeth, then uses the Drufomat Scan to thermoform the selected material over that model. The finished guard is cut, shaped, smoothed, polished, and inspected by hand.
Can I use a dental scan instead of an impression kit?
Yes. If you have a current, qualifying .STL or .PLY scan, you can upload it with your order. Our step-by-step scan upload guide explains how to order with an existing dental file.
Does a night guard stop teeth grinding?
A night guard creates a protective barrier between the teeth. It does not diagnose or treat the underlying cause of grinding or clenching. Speak with your dentist about persistent pain, broken teeth, bite changes, or other concerns.
From resin model to Drufomat-formed guard to hand-finished appliance, every Sentinel guard is made one at a time around your teeth.