Complete Dentures
 

What are the Common Adjustments that Full Dentures Need?

Excluding mini adjustments that the dentist performs at the chairside whilst you wait eg. Smoothing a sharp area, the main adjustments that may be needed for complete dentures are:

  • Repairs
(i) Fractures- you may fracture the denture base from dropping them, or accidentally sitting on them (it happens!). Over time, a heavy bite or grinding, can fatigue the denture and cause it to crack. Sometimes it is a clean break, other times you see cracks starting to appear . If you notice this happening, a break is imminent, so see your dentist to get it sorted before it does.

(ii) Teeth- you can also fracture teeth by dropping the denture or occasionally by biting something hard at the wrong angle. Sometimes a tooth may come off the denture- this is more likely to be due to a failure of the attachment to the denture base. Teeth can also occasionally look fractured from excessive wear; the actual appearance depends on your bite and the way the teeth have been moving across each other. This is more difficult to repair, since it involves multiple teeth and your bite has become accustomed to the new worn shape.

  • Relining or rebasing. To get maximum suction, and the best fit and comfort, the denture needs to fit closely and evenly on your gums and ridges. Where this is no-longer the case (generally as a result of bone resorption over time) yet the teeth are still good and other aspects of the denture ok, a reline or rebasing can be done to improve the accuracy of the fit. Rebasing or relining- these two phrases have become somewhat interchangeable, for describing putting a new underside or fitting surface on your denture to make it fit more closely.

There are three basic types of reline:

(i) Standard- this uses the same hard acrylic material as the denture itself.

(ii) Soft reline- this is, as the name suggests a softer lining inside the denture which improves comfort in situations where a convential hard acrylic can be sore. Special cleaning is required for this type of reline and it is not as durable as the standard hard acrylic, picking up food and bacteria much more easily. For this reason, it tends to be reserved for:

- After surgery, during healing.

- Older patients, with very thin mucosa or gum overlying their ridges- the denture can be sore with pressure on chewing.

- Exposed mental nerve- sometimes the lower bony ridge can resorb so much that the mental nerve, comes to lie at the surface and this can be painful when anything touches it. A soft lining can really help in this situation.

- Other bony anatomy such as tori, that rubs and requires a little extra cushioning.

  • Temporary. During healing phases, whilst changes are still being seen to your gums e.g. after an immediate denture or in order to reduce inflammation e.g. from denture stomatitis- a temporary reline material (such as Viscogel) can be used to improve the fit. This short term soft lining material has a cushioning effect and helps distribute pressure more evenly to your gums. This promotes healing before a more durable, longer term lining, is put into your denture. This reline is done by the dentist in the chair, without the laboratory and as such, is the least durable (hence ‘temporary’). It wears and stains more quickly than the other types of reline and is more tricky to keep clean.

What is the Process for a Denture Reline?

The process is a fairly simple one, taking two appointments unless the dentist is doing a temporary reline.

Most dentists will do their best to have the denture ready for you, either later the same day or the next day. Either way, you will have to be without it for some period whilst the laboratory does the reline. If you need to plan time off work or away from social arrangements and activities, for the time it takes to get the denture back, then do so.

The general process for a standard reline is as follows:


  • The denture will be modified by the dentist to remove any undercuts and roughen the surface, ready for the impression material.
  • The correct extension of your denture up into your sulcus may be recorded/ modified using greenstick- a wax like material which is heated, softened and put on your denture and your cheeks moulded against it to create the record. (Not always necessary.)
  • An impression will then be taken with material inside your denture- this will show exactly how your mouth is now and how things have changed. The material flows into any gaps or spaces that have been left by resorbtion or healing that have been affecting the fit and suction of the denture.
  • Different dentists prefer different materials to do this.
The most common are:

(i) Zinc Oxide Eugenol – a strong tasting, rather messy impression material that has a long history of success in this situation. The taste is of oil of cloves, and it is important for the dentist to Vaseline around your lips and facial hair (if you have any) to stop it sticking.

(ii) Silicone based impression materials- as used for crown and bridge impressions.

  • A thin layer of material is put into the denture, the denture is then placed into your mouth in the correct position and you will be asked to gently bite together, applying some consistent pressure to the denture, to hold it in place. Depending on the material it can take 2-5 minutes to set.
  • The dentist will then examine the impression, to see if all the necessary detail and extension has been recorded.
  • Then a prescription is written to the lab telling them what to do;you are cleaned up and told when to come back to have the denture reline issued.

The process for a temporary lining differs a little. Instead of an impression material, the temporary lining material will be mixed and put inside the denture. Again you will be asked to close and the dentist will mould this to your cheeks, lips and tongue.

After a few minutes, the dentist will take it out, trim off any excess and polish it up. There is no need to send the denture away, and the material will continue to set hard over a number of hours, even days, adjusting to the way your mouth moves as you wear it.

Remember special denture care instructions should be followed for soft and temporary lining materials. Standard relines and rebasings can be cared for in the usual way.

What is the Process for Denture Repair?

Most simple repairs, such as a broken base, can be done with in a day, to minimize the time you have to go without your denture.

Sometimes, it may take a day or so, depending on the situation with your dentist and the location of the laboratory that they use. They will let you know how long it will take, but plan and prepare to be without it for this time so it doesn’t come as a shock. Do not glue the denture together if it breaks, unless you absolutely have to. Household glue is not meant for the mouth and it makes the repair more difficult. If a tooth comes off, be sure to bring it with you.

Two appointments are necessary.

The basic process for denture repairs is the same whether it is a fractured tooth or a broken base.

Appointment one:

The dentist will assess the denture and the break/issue that needs repairing.

  • They may not need to take any impressions if it is obvious how the denture pieces fit together. They can simply write a prescription for the dental laboratory and send it away.
  • If it is not clear how the denture fits together, or some of it is missing, the dentist will definitely need an impression. The denture will be put in your mouth and an impression taken over the top, if this is possible. Otherwise, they will simply take an impression of your mouth without the denture and have the lab pour it up and make the denture fit.
  • Sometimes an impression of your bottom teeth and your bite will also be needed- if so the dentist will record these details too.

Appointment two:

When you return, the dentist will try it in, check it fits and that it is not rubbing anywhere, make any necessary adjustments and that’s it- done !