Loose dentures that move or will not stay in: causes and solutions

Dentures that move: why, and is it normal?

A removable denture that moves is a common problem, but not one you have to put up with. The main causes are gradual bone shrinkage under the gum, which makes an old denture too big, wear of the teeth or of the denture base, a dry mouth, and the less favourable shape of the lower jaw. Depending on the cause, the solution ranges from a simple adjustment to a reline, a new denture or stabilisation with implants.

A few signs show that a denture no longer fits:

• it was secure at first, then comes loose more and more often;
• food slips under the base during meals;
• sore spots or ulcers appear on the gum;
• you need more and more adhesive;
• your face looks more "collapsed", with the chin closer to the nose, a sign that the teeth have worn down.

A new denture that moves in the first days is a different matter: the tongue, cheeks and lips have to learn to hold it, and a few adjustments are normal.

Why does the lower denture hold less well than the upper one?

This is the most common complaint, and it has an anatomical explanation. In the upper jaw, a full denture covers the palate: this large surface creates a suction effect, with a peripheral seal that keeps it in place. In the lower jaw, the supporting area is much narrower and horseshoe-shaped, and the tongue sits in the middle. Each time the tongue moves to speak, swallow or push food around, the denture is disturbed.

Other factors often make things worse in the lower jaw:

• the lower bony ridge generally shrinks faster than the upper one after the teeth are lost;
• a very flat ridge offers almost no relief to stop the denture sliding;
• saliva acts as a natural "glue", and a dry mouth, linked to age or certain medicines, reduces retention;
• significant weight loss changes the gums and cheeks.

This is why stabilising the lower denture with two implants is often proposed as a standard solution when it will not stay in place.

Relining, adjustment or a new denture: working on the denture itself

Before considering surgery, the dentist checks whether your current denture can be improved.

• Adjustment: trimming an over-extended edge that tips the denture, or rebalancing how the upper and lower teeth meet. An unbalanced bite is enough to dislodge a denture with every mouthful.
• Relining: a new layer of resin is added to the inside of the denture so that it fits the gum again, whose shape has changed as the bone shrank. It can be done chairside with a temporary, sometimes soft, material, or in the laboratory with a harder, longer-lasting resin, based on an impression taken inside the denture.
• A new denture: when the resin teeth are badly worn, the base is cracked or the height between the jaws has collapsed, a reline is no longer enough. A new denture also allows the appearance and lip support to be improved.

Sore spots under a denture should not be ignored: an ulcer that has not healed within two weeks, even after adjustment, must be examined.

Denture adhesives and powders: a help, not a solution

Adhesive creams improve the hold of a well-fitting denture, especially at the beginning or in people with a dry mouth. They should not be used to make up for a denture that no longer fits the mouth.

To use them properly:

• apply a few small dots or thin strips to a clean, dry denture, not right up to the edge;
• if the cream oozes out, you are using too much;
• every evening, remove all residue from both the denture and the gum with a damp gauze or soft brush;
• choose zinc-free products: prolonged use of very large amounts of zinc-containing creams has been linked to neurological problems.

If you have to reapply adhesive several times a day, or the denture still moves despite it, that is a sign you should see a dentist: a reline or another solution is probably needed.

Gagging with the palate: what can be done?

Some people have a strong gag reflex when the upper denture covers the palate. The reflex often fades with practice, but a poorly designed denture can keep it going.

What the dentist checks:

• a back edge that is too long or too thick and touches the soft palate;
• an unstable denture that moves and triggers the reflex with every movement;
• excessive thickness of the resin.

A few tips help during the adaptation period: build up wearing time gradually, breathe through your nose, and avoid putting the denture in on an empty stomach if the reflex is strong on waking.

When the palate remains unbearable, there are ways to free it. An upper denture stabilised on several implants can be made horseshoe-shaped, without a palatal plate, and so can a telescopic denture supported on teeth or implants. These options require a bone assessment and, for implants, surgery.

Partial dentures: acrylic, flexible or cobalt-chrome?

When some teeth remain, a partial denture clips onto them. How well it holds depends largely on the material and design:

• Acrylic (resin) dentures: simple, quick to make and easy to modify if another tooth is lost. They are often thicker and rest more on the gum, which makes them less stable. They are often used as a transitional solution.
• Flexible dentures (nylon or thermoplastic): with no visible metal clasps, they are discreet and comfortable at first. However, their flexibility can let them move when chewing, they are hard to repair and reline, and they are generally suited to limited situations.
• Cobalt-chrome dentures (a metal framework known in French as "stellite"): thinner, rigid and precise, they rest on the remaining teeth through clasps and rests prepared on them. This is often the most stable removable partial denture, at the cost of clasps that may show.

To do away with clasps while gaining stability, a telescopic denture fits over crowns placed on the remaining teeth. Its advantages and constraints are explained in our article on the telescopic denture.

Stabilising with implants: the assessment in Agdal

When a denture still will not stay in after relining, dental implants often change everything. In the lower jaw, two implants with attachments that the denture clips onto are frequently enough to stop it lifting, and the existing denture can sometimes be adapted if it is in good condition. In the upper jaw, more implants are generally needed. The more complete options, up to a fixed full arch, are compared in our article implant-retained denture or telescopic denture.

At German Dental Clinic in Agdal, the assessment starts with an examination of your current denture and gums, followed by a panoramic X-ray to assess the bone. The practitioner will tell you whether an adjustment or reline may be enough, or whether stabilisation is more sensible. If you live in Rabat and your denture bothers you every day, you can book an appointment and bring the denture with you.