So you and your dentist have looked at all the alternatives for missing teeth
, discussed them and decided that a partial denture
is the way to go.
As we have seen, this leaves you with three basic choices:
More advanced variations are discussed in the section - 'Other denture options' below.
Having examined your mouth the dentist will advise you which they feel would be the best for your situation.
There are a number of factors that go into making the decision, which we will now look at:
The acrylic denture is the most basic, easiest to make and therefore the cheapest option. It will cost a few hundred dollars less than the generally superior valplast or chrome denture. See Denture costs
for specific details.
Is your mouth likely to change? What is the prognosis of the remaining teeth? Generally it is easier to add teeth and make changes to acrylic dentures than chrome dentures. Valplast dentures cannot be added to, so these should only be made where changes are not expected.
Both acrylic and chrome dentures can be relined if you gums shrink (from bone resorption) to make sure they are sitting down appropriately.
Difficulties may come when a tooth, or teeth need to be added to the chrome denture in a place away from the metal framework. If the metal framework of your denture lies near to the tooth to be added, it is generally not a problem. If it doesn't, this is technically more difficult, expensive and depending on the design, may or may not be possible. For example, if you have had a denture made to replace two missing back teeth then a front tooth needs extracting and adding, then the modification to your plate is so extreme that it may be simply better to make a new one.
- If the prognosis of your remaining teeth is very poor
If you have severe gum disease
and are likely to have to add teeth to your denture
on a number of separate occasions, then an acrylic denture will make life easier and more cost effective. It will also help with developing muscle control in preparation for perhaps a full denture down the track.
The best appearance is likely to come from the valplast denture since it contains no metal at all and blends very naturally with your existing gums.
Cobalt chrome dentures tend to be the next best, as the framework provides more grip to allow the denture to be made thinner than its acrylic rival. Because it is supported by your teeth and grips better, your mouth is able to move more naturally and confidentally during eating and speaking.
Acrylic dentures are often significantly more bulky (unless just replacing one or two teeth), requiring different muscle control- which can lead to a slightly less natural appearance. They do however have less visible metal than a cobalt chrome denture, with just the metal clasp arms to help with retention.
Obviously a balance between grip and looks is important and talking to your dentist about any concerns over visible metal is a must. Often there is a pay off and a comprise is needed.
Some patients want optimum aesthetics and some don’t care how it looks, as long as they can chew- most patients lie somewhere in between and in each case their smile is different. The nearer the front and the more gum you show when you smile, the more that metal tends to be a problem. In some cases, patients have clasps on their front teeth that are never seen because their smile is so low showing very little teeth.
Appearance will of course, not only be effected by the type of denture, but the quality and design of the denture and dentist and technicians ability to get the teeth's shape, colour, size, and position right.
- Support (tooth or mucosal borne)
Acrylic dentures and valplast dentures are both types of 'mucosal borne denture
'- that is they sit on your mucosa. Cobalt chrome dentures are different, in that they are generally supported by teeth; i.e. tooth bourne dentures
Note- if there isn’t a back tooth for support, (a situation known as a free end saddle), then the chrome denture will get some support from the gum and some from the teeth; in which case it is actually a tooth and mucosal borne denture
The number and position of the teeth affect the decision, but where suitable, dentists would be pretty unanimous in recommending a' tooth- borne denture' every time.
The main reason for preferring a tooth- borne (cobalt chrome) denture is that chewing and biting forces are transmitted down the teeth, (the purpose for which teeth were designed) and not to your ridges and jawbone which are more susceptible to resorbtion.
As a general rule chrome dentures are the most comfortable and best tolerated. Followed by valplast and finally acrylic dentures. Because of the strength of the metal framework and the great grip they achieve from teeth, chrome dentures can be made thinner and more streamlined, therefore they cover less of the mouth- especially in the palate where they can be cut away to leave the roof of your mouth exposed. This is much more comfortable and feels nicer to the tongue; it helps with taste and telling the temperature of your food and doesn’t affect your speech as much.
A thinner cobalt chrome lower denture can be kept away from the gums to improve hygiene and is much better tolerated by the curious tongue.
Acrylic dentures need to be made to cover a larger area since this is how they get their support, retention and stability and as such they naturally tend to be bigger and more bulky.
Because they need to be larger, it takes a bit more for your tongue, cheeks and lips to get used to them and for you to develop the necessary muscle control to use them. They are more likely to move around, drop, affect your speech and give problems, than the other two options. That's not to say they will, just that they are more likely to.
The flexi-denture grips the teeth tightly around the margins. Getting it in and out can sometimes be difficult but this comes with the added confidence of knowing it's not going to fall out. Where teeth on both sides of your upper jaw are missing, it will need to cover your palate in the same way as an acrylic denture. However if you are missing teeth only on one side, the flexi- denture can be a great small, simple and comfortable solution to fill the space effectively.
We have mentioned repeatedly that the grip (retention) and stability of an acrylic denture is less than the cobalt chrome denture and the flexi- denture.
They are much more prone to movement, dropping and require greater muscle control to be successful. The grip will depend on many factors See- Retention
such as the number and position of the missing teeth but with all things being equal, the best grip probably goes to the cobalt chrome, closely followed by the valplast.
The cobalt chrome has the advantage of being able to modify and use the teeth to improve retention, stability and bracing,via clasps, rest seats, guide planes and its path of insertion.
Valplast relys on its slightly flexible gum clasps, (that are an extension of the main base) to grip around the teeth and it’s very tight fit to hold it in place. It is a much more secure option than the acylic denture.
Some patients can have difficulty putting in and taking out their dentures if they have for example, arthritic conditions or neuromuscular conditions such as Parkinson’s.
It is crucial that dentures can be removed for cleaning or the remaining teeth will suffer. The denture must be made and designed with this in mind.
Acrylic dentures generally have the least grip and so are easiest to get in and out. Cobalt chrome dentures need to have their clasps around the teeth appropriately tightened - not too tight so they cannot be removed and not so loose that the dentures jump around.
Flexi-dentures can have so much grip that even very capable adults can sometimes struggle to remove them. Therefore, if dexterity is an issue, they may be best avoided.
Any conditions affecting muscle control, such as paralysis from a stroke, Bell’s palsy, muscular dystrophy, even advanced old age etc. may reduce a patients ability to control or learn to control dentures. This makes the inherent grip and stability of the dentures much more important but must be balanced with dexterity problems and the difficuties of getting the teeth in and out.
When it comes to oral health, the most important factor by far is how well you look after and clean your dentures
. The design and type of dentures does have some effect on health, but this is secondary to your hygiene. The risks associated with dentures
are discussed in the next article.
The most healthy dentures cover the least amount of gum and gingival margin. For this reason, appropriately designed cobalt chrome tooth- borne
dentures, tend to trap the least plaque and are most conducive to healthy teeth and gums. Small, single sided flexi-dentures are also very healthy.
Acrylic dentures, which require more gum and tooth contact to be effective, are thus the most prone to problems if proper oral hygiene is not being done.
My final thoughts… All things being equal and where sufficient good teeth are available, it is best if your denture is supported by your remaining natural teeth- that means having a chrome denture. Acrylic dentures are best if lots of changes to the teeth and mouth are expected.
These two dentures are still the staples of the denture world.
Flexi-dentures (the newcomer) can be a good metal free alternative in certain situations where the mouth is unlikely to change.