Table of Contents
Denture Relines and Rebases
After a new denture has been inserted, it ought to retain in the mouth quite nicely due to the fact that the shape of the inside of the denture base conforms closely to the shape of the gums. (Please note that good retention (suction) of the denture does not necessarily mean that the same denture is stable. For a good explanation of the difference between these two characteristics please click here.)
Unfortunately, the longer you wear the denture, the more your gums change underneath it, and the looser it gets. In order to restore the retentive qualities of the denture, and to prevent the production of flabby gum tissue under it, you should have the denture professionally relined at least every two years.
There are actually three types of denture relines: Hard, Soft and Temporary.
This is the kind of reline that should be done on all full dentures every two years. The dentist removes some of the plastic from the inside of the denture, and then fills the denture with a soft material (think of soft putty) which, when replaced in the mouth, conforms to the contours of the tissues, and then hardens to a rubbery consistency. When the denture is removed, the denture now contains an accurate impression of the shape of the gums. The denture is sent to the lab, and the impression material is replaced with pink, hard acrylic in exactly the same shape as the original impression material. When returned, the denture now conforms to the contours of your mouth and should make maximum contact with the tissues producing maximum suction. In our office, the impression is scheduled for first thing in the morning. The patient goes home without the denture, but returns later the same day (usually early afternoon) for the insert (fitting appointment).
Rebasing the denture
Rebasing a denture (0ften called “jumping” the denture, or a “jump case”) is similar to a reline except the denture comes back not only relined, but with ALL the pink plastic replaced. The only parts of the old denture that remain after a rebase are the teeth.
A rebase is often done when the denture has multiple cracks or repairs and does not fit well, but the teeth themselves are still in good condition and fit correctly with the teeth in the opposite arch. You don’t get a new denture with a rebase, since a new denture would be built to replace lost facial dimension, but you will end up with a revitalized old denture.
Rebases are done the same way that relines are done. The dentist takes an impression inside the old denture, and sends it to the lab. One difference, however, is that jump cases generally take two days in-lab rather than the same day service you can expect with a reline.
Occasionally, a patient finds that he cannot wear the denture because his gums are too tender, and he keeps getting sore spots. In cases where the patient is unable to wear ordinary dentures because of tender gums, the denture can be relined with a material that remains somewhat pliable for a year or two before it needs replacement. The consistency of this material can range from waxy to hard rubber, and is generally less likely to give the patient sore spots than ordinary pink acrylic.
Unfortunately, by the time that a patient resorts to a soft reline material to make the denture wearable, it usually means that factors other than simple sore spots are partly to blame for the difficulties that the patient is experiencing wearing the dentures. These could include an overbuilt denture (the vertical dimension is too great) or a resorbed ridge which is so unstable that the patient must keep constant force on the teeth to keep them in place. Both of these conditions can be corrected, sometimes with less expensive simple surgery or sometimes with much more expensive implant retained dentures.
Temporary relines (Therapeutic relines)
Frequently, by the time a patient with an old denture finally shows up at the dentist’s office looking for a new denture, the dentures have not been serviced for such a long time that the gums are in terrible condition. They may be red, swollen and quite misshapen. Relining the old denture, or building a new one using impressions taken while the gums are in such poor condition would lead to a denture that would simply perpetuate the problem with the new appliance.
When faced with situations like this, a dentist will frequently resort to a temporary, or palliative (medicated) reline material to allow the inflammation to subside. This reline makes the denture fit much more tightly, and is usually soft and pliable. It will not last more than a few months, but the patient wears it for a few weeks until the gums return to a more normal state. After this happens, then the patient is ready for his new denture or hard reline.
As a denture gets older and older, it becomes more prone to breakage. The major reason for this is that as it ages, the fit becomes looser and looser. This often causes rocking of the denture while it is being worn. Repetitive flexing like this weakens the plastic causing it to break. Alternatively, this flexing can cause the teeth embedded in the denture base to loosen and break out. You can prevent this from happening by having the denture relined about every two years (by a dentist) when it gets loose.
If your denture should break, there are a number of things you should know.
Labs do NOT glue the broken pieces together. If there is a nice sharp fracture line along which the pieces can be tightly reapplied, the lab tech uses super glue to temporarily reattach the broken pieces. Then he pours a plaster or silicone matrix inside the denture to capture the original internal anatomy. Finally he entirely removes all the plastic for about 1/8 inch on either side of the fracture line and replaces it with NEW acrylic. This makes the denture stronger than it was before. The same process applies when replacing one or more teeth on the denture. All the old pink plastic is removed and replaced with new pink plastic.
How can I fix a cracked denture?
Do not attempt to repair the denture with glue! Glues that contain volatile solvents (airplane glue) that will melt the plastic around the edges and cause the repair to distort. A distorted denture is impossible for a dental lab to repair. Once the edges are melted, there is no way to put the denture together the way it was before it was broken. It will always rock and cause miserable sore spots until you either get a new denture, or have it rebased.
Theoretically, you could use Super Glue, which won’t melt the edges of the plastic, but Super Glue has two major drawbacks. Super Glue is water soluble, and the repair is always temporary. Secondly, it is difficult to replace even sharp edges together the first time without some sort of dislocation. This means that your denture will suffer the same problems it would have if you used airplane glue.
If the denture broke due to an ill fit, It will eventually break again for the same reason unless you have it relined or rebased at the same time as the repair.
The best thing to do with a broken denture is to go to a dentist with the separate pieces and let him or her look at it to see if it can be sent to the lab without an impression. Even better, the dentist can super glue the pieces together before sending it to the lab and then take an impression inside the temporarily repaired denture so the lab can reline or rebase it. Most labs provide for one-day service on repairs, or repair/reline procedures, so you can make arrangements to come come to the dentist in the morning, and get the denture back by late afternoon.
You can send the denture to a lab yourself. Some labs have websites that give instructions on how to send the denture through priority mail for them to repair. You can do a web search for “Fix Broken Denture” and find a slew of them along with all sorts of kits for home repair. This option is generally less expensive than going to a local dentist, HOWEVER: The same rules apply when you send the denture out yourself. Don’t try to glue the pieces together yourself, or the lab will send you back a denture that will rock and cause sore spots. If the denture broke because it fits poorly and flexes in use, then it will simply break again after the repair (presuming it fits at all).
But, even if you send it to a lab to fix:
- It will fit no better than before you sent it out.
- If you send it out to a lab yourself, there is no dentist available to adjust it if you have sore spots (and the chances are that you WILL have sore spots).
- Sending it out to a lab yourself precludes the possibility of having it relined or rebased.
It is not wise not wear your dentures all day long without giving your gums at least two hours per day to recuperate. If you do, it causes rapid loss of the underlying bony support and its replacement with soft flabby tissue which causes your denture to become unstable. (This is a serious issue and you should read about it here.) Leaving them out overnight is the best plan.
You also need to clean and deodorize your dentures at least once a day to avoid serious denture breath (ask the grand kids). Leaving your dentures out overnight and getting into a routine of denture hygiene is the best plan. You can soak them in a commercial denture cleaner, but you can really do a better job and keep them fresher by following these directions:
Brush the dentures thoroughly with a soft brush and plain dish detergent. Never use toothpaste or an abrasive powder. Denture teeth are made out of multiple layers of different colored acrylic to make them look more natural, and scrubbing them with abrasive powders like Comet or Babbo or using hard abrasive brushes will remove layers of the plastic making them look dead and eventually turning them into flat blocks of plastic. Plain dish detergent will work as well as any other cleaner.
If the denture is all plastic, (with or without metal wire clasps), soak them overnight in a dilute solution of laundry bleach once a week. A tablespoon of bleach in 6-8 ounces of water is more than strong enough to remove stains, disinfect and thoroughly deodorize them. Just rinse them off in the morning with copious water before inserting them in your mouth. You will be quite surprised at how much better they smell.
It is best to avoid using bleach on partial dentures with cast metal frameworks since some labs use high nickel alloys which might react with the bleach causing them to turn black.
bleach may affect the color of the pink plastic in some of the less expensive denture acrylics.