Allergic reactions to traditional denture acrylics are rare, but for those who experience them, the discomfort is real and valid. At DigiDent, we understand how frustrating it can be to deal with irritation from something meant to improve your quality of life. Thankfully, modern dentistry offers safer, more biocompatible materials—especially through digital denture workflows.

What Is Dental Acrylic?

Traditional dentures are made from a pink acrylic resin that’s formed by chemically combining a powder and liquid monomer. This reaction creates a hardened baseplate—what most people know as the gum-coloured part of a denture. Denture teeth are set into the material during processing, and the result is a strong, lightweight appliance that’s easy to customise and adjust.

Before acrylics, materials like gold, carved wood, and even hardened rubber (Vulcanite) were used. Acrylic’s advantages—affordability, aesthetics, comfort, and durability—quickly made it the standard. But for a small number of patients, it can come with unintended side effects.

Signs You May Be Allergic to Denture Acrylic

Acrylic allergies are usually linked to residual unreacted monomer—leftover from incomplete polymerisation during manufacture. Symptoms are typically localised and may include:

• Redness or irritation in the gums

• Burning or itching sensations

• Tissue swelling or blistering

• Hives or ulcer-like spots

These symptoms can be easily mistaken for general denture adjustment issues, so careful evaluation is important.

Common Causes That Can Mimic Allergy Symptoms

Before concluding it’s an allergy, your clinician will likely rule out other common causes of irritation, such as:

• Poor fit – Uneven pressure can lead to friction, inflammation, or ulcers.

• Surface roughness – Even minor rough spots can cause irritation in sensitive mouths.

• Bacterial or fungal growth – Inadequate cleaning can result in infections that mimic allergic reactions.

• Reactions to cleaning products – Some soaking solutions can cause sensitivity if not rinsed thoroughly.

If the issue resolves when the denture is removed, or if you’ve ruled out these possibilities, a clinical re-evaluation is recommended.

What to Do if You Suspect a Dental Material Allergy

If symptoms persist despite proper fit and hygiene, we recommend:

• Reprocessing the denture to eliminate excess monomer

• Patch testing through an allergist to confirm specific sensitivities

• Exploring biocompatible alternative materials

DigiDent’s in-house lab and digital workflows allow us to offer personalised solutions quickly—without sending your case away.

Acrylic-Free Alternatives Available at DigiDent

Flexible Dentures

A metal-free, monomer-free option for partial dentures made from nylon-based thermoplastics. These are injection-moulded or 3D printed to snap securely into place using natural undercuts—ideal for patients who cannot tolerate acrylics.

Digital Dentures (Milled or 3D Printed)

Our milled and printed dentures use pre-polymerised or light-cured resins, eliminating the chemical reactions associated with traditional processing. Benefits include:

• Improved fit and comfort

• Elimination of residual monomer

• Faster turnaround times

• Longer-lasting, more durable appliances

Digital dentures represent the future of prosthetics - at DigiDent, they’re already standard practice.

Concerned About an Allergic Reaction?

At DigiDent, we specialise in premium digital dentures and are proud to offer materials and techniques that prioritise your health and comfort. From flexible partials to full-arch milled solutions, our team will work with you to identify the safest, most effective prosthetic for your needs.

What is MEHQ?

• MEHQ is a polymerisation inhibitor added to methacrylate monomers and oligomers to prevent premature curing during storage.

• It is not a structural component and typically does not remain in the final cured product in active or significant amounts.

• MEHQ may be present in uncured 3D printing resins (like NextDent) or light-cured dental composites — especially in methacrylate-based systems.

• The concentration is very low (often around 50–250 ppm, or 0.005–0.025%).

• After full polymerisation and post-curing, the MEHQ is no longer active, and often not detectable.

MEHQ in Final Products

Both CE and TGA require compliance with ISO 10993 for biocompatibility - These trace amounts are allowed by regulatory bodies.

If MEHQ is used as a processing aid or stabiliser and is not present above threshold levels in the final product, it does not have to be declared.

So: 

• Trace MEHQ in uncured resins = allowed.

• No MEHQ in cured products = aligns with CE and TGA expectations.

Safety Data Sheets (SDS) and Transparency

TGA often follows GHS (Globally Harmonised System) rules, which require SDSs to declare ingredients ≥0.1%.

CE-marked materials may provide additional disclosure, especially under MDR (EU Medical Device Regulation).

Material Registration

For PEEK, PMMA, and methacrylate resins:

• If the manufacturer declares CE compliance and the product is included in the Australian Register of Therapeutic Goods (ARTG), it's considered safe under TGA rules.

• No MEHQ in final polymer = no issue under either regulatory framework

Still, if you or a patient has extreme sensitivities or allergies, it may be worth confirming MEHQ content with the manufacturer - which is actually incredibly difficult to achieve!

Stage MEHQ Present? Why?

Uncured resin Yes (trace, stabiliser) Prevents premature polymerisation

Post-cure solid resin No (or undetectable) MEHQ is consumed or removed

Listed on SDS? Sometimes, if >0.1% Below that, may not be disclosed

PMMA-Based Dental Materials

PMMA Pucks (e.g., denture milling discs):

• PMMA pucks are pre-polymerised solids.

• If MEHQ is used during monomer manufacture, it is removed or rendered inactive during polymerisation.

• No active MEHQ remains in the final puck.

Methacrylic Oligomers

Methacrylic oligomers are short-chain methacrylate-based resins used in light-cured and 3D printable materials.

• They may contain MEHQ in uncured form as a stabiliser.

• Once fully polymerised, MEHQ is consumed or no longer present at detectable levels.

NextDent Base Shade 07

• A photopolymer resin used in 3D printing denture bases.

• Likely contains trace amounts of MEHQ for stability during storage.

• MEHQ is not listed in the SDS, likely due to low concentration.

• Once cured and post-processed, the material is biocompatible and safe.

Zirkonzahn Denture Gingiva Basic (Milling Disc)

• • Likely made from pre-polymerised PMMA or a PMMA composite.

  • Product is intended for milling and classified as biocompatible.

  • MEHQ is unlikely to be present in the final product.

PEEK (Polyether ether ketone)

• • PEEK is a fully polymerised thermoplastic used in dental and medical applications.

  • It does not contain MEHQ and does not require it for stability.

  • It is chemically inert and highly biocompatible.

  • Suitable for patients with acrylate sensitivity.

There are two main approaches to getting dentures for the first time.

Immediate Dentures

These are placed right after tooth extractions, allowing patients to leave the clinic with functional teeth. However, they may require multiple adjustments or relines as the gums and jawbone heal and reshape.

Conventional Dentures

Fabricated after the gums and bone have healed, typically a few months post-extraction. This option provides a more stable and precise fit but requires patients to go without teeth for a healing period.

How to Maximise Denture Longevity:

Clean dentures daily using non-abrasive cleaners and soft brushes to remove plaque and stains.

Soak dentures in a denture-specific solution to maintain their shape and hygiene.

Avoid exposing dentures to high temperatures or harsh chemicals that can warp or degrade the material.

Handle dentures carefully to prevent cracking or breaking.

Visit a Dental Prosthetist regularly for checkups to monitor fit and oral health.

While dentures are designed to last several years, they are not permanent. Regular care and prompt attention to issues like discomfort or wear can help maintain their function and aesthetics, extending their usable lifespan. Lack of care can reduce their lifespan.

Factors impacting the lifespan of dentures

Several factors can significantly reduce the lifespan of dentures, compromising their function, comfort, and appearance. These include:

1. Poor Oral Hygiene

Impact: Bacterial and fungal growth on dentures can lead to infections like denture stomatitis or odour, weakening the material and making the dentures unhygienic.

Solution: Regularly clean dentures with a soft brush and appropriate cleaner, avoiding abrasive materials like toothpaste.

2. Using Harsh Cleaning Methods

Impact: Scrubbing dentures with abrasive materials, using hot water, or soaking them in unsuitable solutions can cause:

Scratches on the surface, leading to bacterial build-up.

Warping or distortion of the denture material.

Solution: Use non-abrasive cleaning products, a soft-bristled brush, and lukewarm water. Avoid soaking in bleach unless recommended by a dental professional.

3. Not Removing Dentures at Night

Impact: Continuous wear can:

Prevent gum tissue from recovering overnight, causing irritation and sores.

Increase the risk of fungal infections, such as Candida albicans.

Solution: Remove dentures at night and soak them in a denture-safe cleaning solution.

4. Physical Trauma

Impact: Dropping dentures can lead to cracks, fractures, or breakage of the acrylic or metal components.

Solution: Handle dentures over a soft surface, like a folded towel or a sink filled with water, to prevent damage if dropped.

5. Ill-Fitting Dentures

Impact: Over time, bone resorption and gum changes can cause dentures to fit poorly, leading to:

Uneven stress distribution, causing fractures or wear.

Patient discomfort, leading to neglect or improper use.

Solution: Regular checkups for adjustments, relines, or replacements as necessary.

6. Excessive Wear and Tear

Impact: Chewing on hard or sticky foods, using dentures as tools, or grinding teeth (bruxism) can cause:

Premature wear of denture teeth.

Microfractures in the base material.

Solution: Avoid hard or sticky foods, and consult a dentist if bruxism is an issue.

7. Ignoring Repairs or Maintenance

Impact: Small chips, cracks, or looseness, if ignored, can worsen over time and render dentures unusable.

Solution: Seek professional repairs promptly if issues arise. Avoid DIY fixes or over-the-counter adhesives, which can damage the material further.

8. Poor Nutrition and Bone Health

Impact: A lack of vitamins and minerals, particularly calcium and vitamin D, accelerates bone resorption, leading to changes in the fit of the dentures.

Solution: Maintain a balanced diet and consult your dentist about nutritional supplementation if necessary.

9. Smoking and Tobacco Use

Impact: Smoking stains dentures, weakens acrylic materials, and increases the risk of fungal infections like oral thrush.

Solution: Avoid tobacco use and follow a rigorous cleaning routine if smoking cannot be eliminated.

10. Prolonged Use Without Replacement

Impact: Dentures are not designed to last indefinitely; over time, materials weaken, teeth wear down, and the underlying oral structures change, leading to:

Poor function.

Increased risk of breakage.

Solution: Replace dentures approximately every 5–10 years, or as recommended by a Dental Prosthetist.

11. Dry Mouth (Xerostomia)

Impact: Saliva acts as a lubricant and cushion, aiding in the stability and comfort of dentures. A lack of saliva can cause:

Friction between the denture and gum, leading to sores.

Reduced suction, causing instability.

Solution: Address dry mouth with hydration, saliva substitutes, or medications as advised by a healthcare professional.

12. Manhandling Dentures

Impact:

Rough handling when cleaning or inserting/removing dentures can cause cracks, bending of metal components, or even fractures in the acrylic base or teeth.

Improper storage, such as leaving them out of water or a suitable solution, can cause the material to dry out, warp, or become brittle.

Solution:

Handle dentures gently with both hands, and clean them over a soft surface or a sink filled with water to cushion accidental drops.

Store dentures in water or a recommended soaking solution when not in use to maintain their shape.

13. Dropping Dentures

Impact:

Dropping dentures can cause immediate physical damage, such as:

Cracks in the acrylic base.

Broken or dislodged teeth.

Distortion of metal components in partial dentures.

Repeated minor impacts can create microfractures, which weaken the denture over time.

Solution:

Always clean or handle dentures over a towel or a basin filled with water to prevent breakage if they slip.

Use a denture case for storage and transport to protect them from accidental drops.

14. Neglecting Proper Care

Impact:

Failing to clean dentures regularly or using improper techniques can lead to:

Plaque and tartar build-up.

Material degradation.

Aesthetic issues like staining or discolouration.

Prolonged neglect may lead to irreparable damage.

Solution:

Clean dentures daily using appropriate methods and products.

Avoid using abrasive toothpaste or harsh cleaning agents that can scratch or damage the surface.

15. Lack of Regular Checkups

Impact:

Minor damage or wear might go unnoticed and worsen over time if not addressed by a professional.

Misalignment due to bone resorption can stress the denture material, increasing the risk of breakage.

Solution:

Schedule regular dental checkups for adjustments, repairs, or relines to keep dentures in good condition.

Treating your dentures with care and respect is essential, as they represent both a significant investment and a critical component of oral health and daily function. By avoiding factors such as rough handling, neglect, and improper maintenance, you can maximise their lifespan and ensure they remain functional, comfortable, and aesthetically pleasing for many years.

It is recommended that you have your dentures assessed every 12 months, or sooner if you experience discomfort, looseness, or visible wear. Presenting for regular checkups allows for the early detection of issues such as poor fit, gum irritation, or material degradation. You should also seek dental advice if:

Your dentures feel loose or unstable, as this could indicate bone resorption or gum changes.

There is discomfort, soreness, or red spots in the mouth.

Cracks, chips, or visible damage to the dentures are observed.

The dentures have become difficult to clean or show persistent staining or odour.

You have difficulty chewing or speaking, suggesting a misalignment or wear of the denture teeth.

By adhering to these recommendations and ensuring timely professional assessments, you can maintain the function, comfort, and appearance of your dentures, extending their lifespan and supporting overall oral health.