What are Overdentures?

An overdenture is a special type of denture that sits on top (over) one or more teeth roots for extra support. It can be a partial or complete denture. Overdentures can also sit on top of, and connect into dental implants instead of roots. You may hear these referred to as ‘implant dentures’ and they are a very good option for helping to stabilise complete dentures particularly the tricky lower one.

Overdentures have the following advantages:

• Prevent resorbtion. It can help prevent resorbtion- maintaining your bone levels and ridge height for a more stable denture.

• Better chewing experience. The roots themselves are held in by ligaments so some feedback about pressure and how hard you are biting is sent to the brain making the chewing experience more real.

• Can use precision attachments. Sometimes the roots can be used with precision attachments such as magnets or ball joints for extra stability and grip.

• Increased grip. The teeth (roots) provide extra support increasing stability and retention.

• Helps get used to dentures. They can help the transition from wearing partial dentures to wearing full dentures.

The teeth should generally have had root canal treatment or problems with the nerve are likely.

Keeping them, also requires extra care and improved hygiene since the roots can still decay or get gum disease around them- being under the denture, there is also a tendancy to collect more plaque.

Are the Teeth/ Roots Suitable?

• Are the teeth/roots healthy? Any decay needs to be removed and filled; any gum disease treatment completed. At least half of the root should be in bone and there should be no mobility or looseness. Have the teeth had root canal therapy? If not- is it possible to do it?

• Is there space? There should be sufficient space for the denture to be made on top without being too thin or you risk fracturing the denture. If the teeth are too high a more traditional partial denture can be made.

• Which roots are they? The best teeth are those will the most solid roots i.e. canines, then molars, premolars and lastly incisors.

Where are Overdentures Particularly Useful?

• In a free-end saddle situation in the lower jaw – that is where you have no teeth at the back to help support a partial denture. This is where you seem to get most resorbtion.

• Severe wear -Where severe tooth wear has occurred, they can help to open the bite up.

• Hypodontia– a condition where the patient does not grow the normal number of teeth and those that do grow tend to be small.