Custom Night Guards From Digital Scans (.STL Files): The Complete Guide

Everything you need to know about using your digital dental scan to order a perfectly fitting night guard online.

📌 Introduction

Digital dentistry has changed everything — especially for people who grind or clench their teeth at night. If you’ve already had an intraoral scan at your dentist’s office, you may be wondering:

“Can I use my .STL file to order a custom night guard online?”

The answer is yes — and it’s one of the fastest, most accurate ways to get a custom-fit night guard without taking a new impression.

This guide explains:

• What .STL files are

• How they’re used to create ultra-precise night guards

• How to submit a scan

• The benefits of 3D digital workflows

• Which scanners are compatible

• Common mistakes to avoid

• What to expect from a digitally produced guard

Think of this as the master resource on the entire process.

This article is part of Sentinel Mouthguards' Comprehensive Guide to Custom Night Guards — a full resource designed to help you make confident, informed decisions about your oral health. 💚

🧩 What Is an .STL File? (And Why It’s Perfect for Night Guards)

An .STL file is a three-dimensional digital model of your teeth created by an intraoral scanner. It captures every groove, cusp, contour, and surface with extreme accuracy.

Dentists use iTero, Medit, Trios, Planmeca, 3Shape, and others to generate these files.

Why .STL files work so well for night guard fabrication:

• ✔ Highly accurate (far more than physical impressions)

• ✔ No distortions from impression material

• ✔ Easy to store and reuse

• ✔ Instant transfer to a dental lab

• ✔ Ideal for 3D-printing workflows

If you want a night guard that fits like a glove, starting with an .STL file is the gold standard.

🦷 Why Order a Custom Night Guard From a Digital Scan?

Here are the biggest reasons customers choose a scan-based guard:

1. No Messy Impressions

No putty, no trays, no gag reflex — your scan already did the work.

2. Maximum Fit Accuracy

Digital scans capture sub-millimeter detail, resulting in:

• Better retention

• Fewer adjustments

• More comfortable wear

• Improved longevity of the night guard

3. Fastest Turnaround

With no shipping delays for impressions, production begins immediately.

4. Digital Files Never “Expire”

Once your .STL file is stored, you can reorder a guard anytime — with no new impression needed.

5. Seamless 3D-Printing Integration

Digital files → CAD design → 3D printing = the most efficient, precise system in dentistry today.

This is the future — and you’re ahead of the curve.

💡 How Do I Use My .STL File to Order a Night Guard Online?

Here’s the simple, step-by-step process:

Step 1 — Place your order online

Choose the guard type you prefer: soft, hard, dual laminate, or daytime.

Step 2 — Notify the lab that you’ll be using a digital scan

This lets the lab prepare for a digital file instead of an impression kit.

Step 3 — Send your .STL file

Depending on the company, this may be via:

• Email

• Upload portal

• Dentist-to-lab transfer

• Secure link from your dental scanner system

(Each provider handles this differently — Sentinel can assist with file transfer.)

Step 4 — The lab designs your guard digitally

Your file is imported into CAD software where:

• occlusion is checked

• thickness and material are selected

• retention surfaces are designed

• bite relief is built in

Step 5 — Your guard is 3D printed or thermoformed

Digital → physical in one smooth workflow.

Step 6 — It ships directly to you

Most digital orders ship faster because the lab begins immediately — there’s no impression delay.

🖥️ Which Scanners Work for Ordering a Night Guard From an .STL File?

Nearly all major systems can export .STL files, including:

• iTero

• Medit

• 3Shape Trios

• Planmeca Emerald

• Carestream

• Primescan

• Straumann Virtuo Vivo

• Shining 3D

• Dental Wings

If your dentist used one of the above, you can request your .STL file.

Dentists are legally required (in most states) to provide your digital records upon request.

🎯 Best Candidates for a Scan-Based Night Guard

You’ll benefit most from using an .STL file if:

• You have a strong gag reflex

• You previously struggled with impressions

• You want the fastest turnaround

• You’ve already had a digital scan recently

• You value maximum accuracy and precision

• You want to reorder guards with zero extra effort

🔧 How Labs Use Your .STL File Behind the Scenes

Here’s a behind-the-curtain view of the digital workflow:

1. File import

Your scan is reviewed for clarity, margin capture, and alignment.

2. CAD design

Using software like Exocad’s Bite Splint Module, the designer digitally creates your appliance.

3. Occlusal alignment

The guard is balanced to your unique bite.

4. Retention mapping

Subtle contours are added for secure fit without tight pressure.

5. Thickness control

Designers adjust the guard for comfort, protection, and wear resistance.

6. Fabrication

Depending on the guard type, the design is either:

• 3D printed

• Milled

• Thermoformed over a printed model

7. Finishing & polishing

Edges are smoothed, trimmed, and polished for comfort.

This workflow produces a guard that’s precise down to fractions of a millimeter.

⚠️ Common Problems When Submitting .STL Files (And How to Avoid Them)

To ensure the perfect guard, avoid these pitfalls:

1. Partial scans

Missing molars, distorted margins, or incomplete arch data = remake.

2. Wrong file format

Only .STL (or .PLY/.OBJ for color) is accepted by most dental CAD systems.

3. Scan not taken in maximum intercuspation

Your bite should be fully seated when the bite scan is captured.

4. Scans older than 2–3 years

Teeth shift — older scans may no longer be accurate.

5. Sending composite scans

Upper and lower arches should be separate files if possible.

If you’re unsure if your scan is usable, most labs (including Sentinel) will check it for you.

🧠 Night Guards Made From .STL Files vs. Traditional Impressions: Key Differences

This is why many modern dental practices — and customers — prefer the digital route.

💬 Frequently Asked Questions About Using .STL Files for Night Guards

Can I reuse my scan for future guards?

Yes — that’s one of the biggest advantages.

Is a digital scan more accurate than an impression?

Absolutely. Digital scans eliminate distortion and capture finer detail.

Do I still need a bite registration?

Do all online night guard companies accept .STL files?

No. Only advanced labs with digital workflows accept and process them.

💚 Final Thoughts

Ordering a night guard from an .STL file is the fastest, most precise, and most modern way to get a custom-fit guard. It eliminates guesswork, improves comfort, and provides a digital record you can use for years.

If you already have a digital scan, you’re just a few steps away from getting an ultra-accurate guard — no impression kit necessary.