Why Do Dentures Break?

If you've ever experienced a broken denture, you're certainly not alone. One of the most common questions we hear at The Swissedent Denture Clinic in London is, "Why did my denture break?"

Many people assume dentures simply wear out with age or that they accidentally dropped them. While those are common reasons, the reality is far more complex.

Speaking from our experience of clinically treating and technically manufacturing over 800 denture cases every week, and having done so for more than 20 years, we have seen almost every possible reason a denture can fail. The causes often go far beyond simple accidents.

Understanding why dentures break can help you prevent future problems, protect your oral health, and save money on avoidable repairs and replacements.

Dentures Naturally Age and Become Brittle
Just like anything else, dentures do not last forever. Most dentures are made from high-quality acrylic materials designed to withstand years of daily use. However, over time, the chemical properties of the material begin to change.
Many patients are surprised to learn that excessive cleaning and bleaching can actually weaken a denture. We frequently see older dentures that have become dry, brittle, and fragile because they have been soaked in strong cleaning products for years.

While keeping dentures clean is essential, overusing harsh cleaners can gradually remove plasticisers from the acrylic, making it more prone to cracking and breaking.

A denture that may have survived a small drop ten years ago could shatter today because the material has simply reached the end of its lifespan.

Changes in the Jawbone After Tooth Extraction
One of the most overlooked reasons dentures break is jawbone shrinkage. When teeth are extracted, the bone that once supported those teeth begins to shrink naturally. This process, known as bone resorption, occurs throughout life but is most significant during the first few years after extraction.

When a denture was originally made, it fitted the shape of your gums and bone perfectly. However, as the bone changes shape, the denture gradually loses support. Many patients think a denture still fits because it stays in place most of the time. The reality is often very different.

When the denture no longer seats fully onto the gums, biting forces become concentrated on unsupported areas. This creates pressure points and stress within the denture base. Eventually, the acrylic weakens and cracks.

In many cases, the break is simply the symptom. The real problem is that the denture no longer fits the changing shape of the mouth.

Worn Denture Teeth Can Cause Denture Fractures
This is something we see regularly in long-term denture wearers. Over the years, denture teeth gradually wear down. This changes the way the upper and lower dentures meet together.

As the teeth become flatter, chewing forces no longer distribute evenly across the denture. Instead, stress begins to concentrate in the centre of the denture, particularly in upper dentures. The result is often a fracture running straight through the middle.

Many patients are surprised when their denture suddenly snaps while eating something relatively soft. However, the actual cause may have been years of gradual tooth wear creating excessive pressure in the wrong areas.

Regular denture assessments can identify these issues long before a crack develops.

Poorly Fitting Dentures Create a Dangerous Cycle
A loose denture is more than just an inconvenience. When a denture moves during eating, speaking, or chewing, it is no longer functioning as intended.

Instead of resting securely on the gums, it rocks, twists, and flexes. Every movement creates tiny stresses within the acrylic. Over time, those repeated stresses act like bending a paperclip backwards and forwards. Eventually, the material reaches its breaking point. The problem does not stop there.
Poorly fitting dentures can also accelerate bone loss by placing uneven pressure on the gums and supporting structures.

As the bone shrinks further, the denture becomes even looser.
This creates a vicious cycle:
• Loose denture
• Increased movement
• More bone loss
• Reduced support
• Higher risk of breakage
• Even poorer fit

Breaking that cycle early with relines, adjustments, or replacement dentures can often prevent much bigger problems later.

Dropping Dentures Is Still a Major Cause
Despite all the technical reasons, sometimes the answer is simple.
Dentures are often dropped while cleaning them.
We frequently hear stories such as:
• "It slipped out of my hand."
• "It fell into the sink."
• "The dog grabbed it."
• "I accidentally stood on it."

Acrylic dentures are surprisingly strong when used correctly inside the mouth. However, they can be vulnerable to impact when dropped onto hard surfaces such as tiles, sinks, or stone floors.

This is why we always recommend cleaning dentures over a folded towel or a sink partially filled with water.
One simple precaution can prevent an expensive repair.

Eating Habits Can Damage Dentures
Your dentures may look strong, but they are not designed to handle everything.

Over the years, we have repaired dentures damaged by some very unusual foods.
Common culprits include:
• Crackling
• Bones
• Hard boiled sweets
• Ice cubes
• Nuts
• Crusty bread
• Hard toffees
• Tough meat

Some patients develop habits of chewing on one side only, which creates uneven loading across the denture.
Others attempt to bite directly into foods that would challenge even natural teeth. Repeated exposure to excessive force can weaken the denture structure and eventually cause fractures.

Night-Time Grinding and Clenching
Many people grind or clench their teeth without even realising it. This condition, known as bruxism, places enormous pressure on dentures. While natural teeth have ligaments that help absorb forces, dentures do not.

Every clenching episode transfers force directly into the acrylic. Over time, small stress fractures can develop.
These tiny cracks often go unnoticed until one day the denture suddenly breaks during normal use.

If you suffer from jaw pain, headaches, or notice excessive wear on your denture teeth, grinding may be contributing to the problem.

Previous Repairs Can Create Weak Points
A repaired denture is often stronger than many people expect. However, every repair creates an area where old and new materials join together.

In some situations, repeated repairs in the same location can create a structural weak point. If a denture has fractured multiple times, it is often worth investigating why the break keeps occurring rather than simply repairing it again.

The underlying fit, bite, or bone support may need attention.

Poor Denture Design or Low-Quality Materials
Not all dentures are created equally. The quality of materials, manufacturing processes, and clinical planning can significantly affect durability.

A denture that lacks sufficient thickness, reinforcement, or proper support may be more prone to failure.
This is one reason why professional assessment, accurate impressions, and high-quality laboratory work are so important.

A well-designed denture should not only look natural but also withstand the demands of everyday life.

When Should You Have Your Dentures Checked?
Many denture wearers wait until something breaks before seeking professional advice. Unfortunately, by that stage, the damage has already occurred.

We recommend having dentures professionally assessed if:
• They feel loose
• They move during eating
• You notice visible cracks
• The teeth appear worn down
• You experience sore spots
• Your facial appearance has changed
• The dentures are more than five years old
Regular maintenance can often prevent fractures before they happen.

The Bottom Line
Dentures rarely break for no reason. In our experience of treating and manufacturing thousands of dentures every year, breakages are usually the result of underlying changes that have developed gradually over time.

Bone loss, worn teeth, poor fit, ageing materials, grinding, eating habits, and accidental damage can all contribute.
The good news is that most of these problems can be identified early and corrected before a major fracture occurs.
If your dentures feel loose, uncomfortable, or are showing signs of wear, it is worth having them assessed before a small issue becomes a costly repair or replacement.

At The Swissedent Denture Clinic in London, We offer trusted care and premium quality dentures, with fair and transparent pricing, to help you eat, speak, and smile with confidence.


📞: 0203 489 2055 or 0208 520 8528 

📧 : [email protected]

📍: 25a St James Street, London, Walthamstow,  E17 7PJ