Soft vs Hard Mouth Guard Materials: What They’re Made Of & How to Choose

If you’re trying to figure out whether a soft or hard night guard is right for you, the decision really comes down to two things:

1. What the guard is made of, and

2. How severe your grinding or clenching is

Most people don’t realize that the material of your mouth guard plays the biggest role in comfort, durability, feel, and long-term protection. This guide breaks down everything you need to know — in simple, honest terms — so you can confidently choose the right type for your teeth, jaw, and lifestyle.

This article is part of the Sentinel Mouthguards Materials, Allergies & Safety Pillar, our educational series focused on what night guards are made of, how safe they are, and how to choose the best material for your needs.

What “Soft” and “Hard” Night Guards Actually Mean

There’s a lot of confusion about these terms, so let’s clear it up:

✅ Soft Guard = Flexible, Cushioned, Chewable

Made of: EVA (ethylene-vinyl acetate)

• Same family as athletic mouthguards

• Flexible and comfortable

• Cushions light grinding

• Most forgiving if you have sensitive front teeth

• Least durable (especially for heavy grinders)

✅ Hard Guard = Rigid, Strong, High-Protection

Made of: Medical-grade Copolyester

• Dental-lab standard for durability

• Helps prevent further tooth wear

• Resists flattening, cracking, and micro-shredding

• Best for moderate–severe grinders

• More structured fit on your teeth

⭐ Dual-Laminated (Hybrid) Guards

Made of: Soft inner EVA + hard outer copolyester

• Cushioned inside = comfort

• Rigid outside = durability

• Ideal for moderate grinders who want both comfort and strength
  

What Each Material Is Actually Made Of

Soft Guard Materials (EVA)

Soft guards are made from EVA, a flexible, rubber-like material.
Key properties:

• Heat-moldable

• Shock-absorbing

• BPA/BPS-free

• Not chemically reactive

• Very comfortable

However, EVA wears down faster because you can “chew through” it if you clench firmly or grind heavily at night.

Hard Guard Materials 

Hard guards are fabricated from copolyester, a rigid dental plastic used in:

• Dental retainers
• Invisalign-type aligners (PETG is a copolyester)
• Water bottles
• Medical devices
• Food packaging

Keystone’s dental-grade copolyesters are often PETG-based (polyethylene terephthalate glycol-modified), which makes them:

• Crystal clear

• Tough

• Biocompatible

• Easy to thermoform

• Free from BPA, latex, PVC

It’s essentially a durable, safe, clear plastic designed to flex without breaking.

This is what dentists prescribe when someone has severe grinding, flattened molars, or TMJ problems driven by clenching.

Dual-Laminated Materials (EVA + COPOLYESTER)

Dual-lam combines the best of both worlds:

• Inner layer (EVA) molds cushiony to the teeth

• Outer layer (copolyester) prevents wear

It’s the most advanced material option for people who want comfort and longevity.

Which Material Is Safest? (Allergies, Chemicals, Sensitivities)

EVA (soft)

• Non-latex

• Non-PVC

• Biocompatible

• Very low allergy risk

• No BPA/BPS

• Slightly more porous → must be cleaned well

Copolyester (hard)

• Copolyester is a type of thermoplastic polymer made by combining two different types of polyester molecules.
  Think of it like “polyester 2.0” — modified to be:

  • Stronger

  • Clearer

  • More flexible than standard polyester

  • More impact-resistant

  • Less brittle

  Dual-laminated

• EVA + copolyester combination

• Safe for most people

• Best choice for those sensitive to pressure on front teeth

Durability: How Long Each Material Lasts

Hard and dual-laminated guards almost always last longer.

Comfort: How Each Material Feels in the Mouth

⭐ Soft Guards Feel:

• Cushy

• Gentle

• Flexible

• Easy to adapt to

• Ideal if front teeth feel “pulled” by rigid guards

⭐ Hard Guards Feel:

• Firm

• Secure

• Structured around every tooth

• More like wearing a retainer (though thicker)

• Don’t distort over time

⭐ Dual-Lam Guards Feel:

• Soft on the inside

• Structured outside

• Great for people who want comfort and protection

Which Mouth Guard Should You Choose?

Here’s the simplest decision chart possible:

Choose a SOFT guard if:

✔ You’re a light grinder
✔ Your front teeth are sensitive
✔ You want the most comfortable feel
✔ You prefer a guard that’s easy to get used to

Choose a HARD guard if:

✔ You’re a heavy grinder or clencher
✔ Your molars are worn down
✔ You’ve broken guards before
✔ Your dentist says you need your bite “stabilized”
✔ You want comfort and protection

Choose a DUAL-LAM guard if:

✔ You want comfort + durability
✔ You grind moderately
✔ You hate the feel of full hard plastic
✔ You’ve chewed through soft guards in the past

Is One Material Better Than the Others?

Not universally.

Each one has a purpose:

• Soft → comfort & mild protection

• Hard → maximum protection & stability

• Dual-lam → best all-around option for most people

Most heavy grinders outgrow soft guards fast and benefit from switching to hard or dual-lam.

Final Recommendation (Based on 12+ Years of Sentinel Data)

If you are unsure what to choose:
👉 Pick the Dual-Laminated Guard.

It consistently has:

• the best fit feedback

• the longest lifespan

• high comfort scores

• the fewest returns

• excellent performance for light-to-severe grinders

It’s the “Goldilocks” choice.