The removable partial denture is the most common method that dentists use to replace a missing tooth or teeth. Many millions of removable partial dentures are made for patients in Europe every single year.
The other two methods of replacing a missing tooth or missing teeth are dental Bridges and dental implants but they both have disadvantages.
The construction of fixed dental bridge work requires extensive tooth preparation to be carried out to the teeth adjacent to the gap and we know from long-term studies that 20 to 30% of all abutment teeth will become non-vital and need future root canal treatment which is not an ideal situation.
On the other hand, dental implants are much more costly and complications can also arise such as implant failure due to non-osseointegration.
The main types of removable partial dentures are as follows:
1. The acrylic removable partial denture.
2. The Cobalt -Chrome based removable partial denture.
3. Removable partial dentures using thermoplastic resin and these are termed “flexible dentures.”
The Removable Acrylic Partial Denture
This is by far the most common out of the three different types of removable partial dentures that dentists can use. One of the main reasons for their popularity is that they have the least cost associated with them. They are therefore ideal for patients who can only afford the minimum.
Another advantage of the acrylic denture is that you can be added further teeth onto it. This is especially useful because many patients will have periodontal disease or dental caries and will require further extractions in the future. In this respect, immediate additions can be utilised without making a brand new denture each time for the patient.
Acrylic dentures are also good at replacing lost alveolar bone tissue loss which is important for aesthetics.
However acrylic dentures do have several significant disadvantages.
Personally, not all patients are able to tolerate wearing acrylic dentures. With the lower denture, this may encroach on the tongue and on upper dentures, it may activate the patient’s gag reflex. Acrylic dentures also reduce the pleasure of eating as a large amount of oral mucosa is covered.
Acrylic dentures may also need stainless steel wire clasps for increased retention and this may be in the aesthetic zone when the patient smiles, causing problems.
Probably the biggest disadvantage of acrylic partial denture is that they are entirely tissue-borne. This means that the oral mucosa takes all of the loading which may increase alveolar bone resorption and also cause trauma to the gingival tissues of teeth especially if patients do not have good oral hygiene which will increase periodontal disease and further tooth loss.
The Cobalt Chrome Based Partial Denture
This is the next most often used removable partial denture but only about 5% of dentures are this type.
The main reason being due to the cost of a Cobalt Chrome based denture as compared to the acrylic denture. An acrylic denture may cost €200 but a cobalt chrome denture will easily cost more than €1,500.
However, the cobalt Chrome-based denture has a very significant advantage compared to the acrylic denture in that it is both tissue borne and tooth borne. Occlusal rest seats are used on the patient’s remaining teeth which helps to distribute the loading away from the oral mucosa and gingival tissues. Less bone resorption will occur.
The other big advantage is that a cobalt chrome denture is much stronger and therefore ideal for patients who are always breaking their acrylic dentures. As a result of being stronger, less oral mucosa needs to be covered which makes them more easy for patients to tolerate. In fact on an upper denture, most of the palate does not even need to be covered.
But one of the reasons why cobalt chrome dentures are not used that often apart from the cost is that they are nearly impossible to add further teeth onto without making a new denture altogether. The acrylic denture is fairly easy to add-on but not with a chrome denture.
Because the cobalt chrome denture also uses clasps for retention, this is generally an advantage as long as it does not encroach in the patients aesthetic zone on those especially who have a high lip line.
The Flexible Resin Removable Partial Denture
These are the least common types of partial denture but are increasing in popularity.
The main advantages are that they are flexible and therefore they can engage small undercuts to increase retention without using clasps.
In addition, due to their flexible nature they are more resistant to fracture and deformation so can be used in thinner sections. This makes it easier for patients to wear and tolerate.
However they have several disadvantages with one of them being the cost. They cost much more than the acrylic denture and will cost at least €1,000 each.
The other big disadvantage is that they cannot be used to “add-onto” if the patient loses further teeth. This means that if the patient loses a tooth later on down the line, they will have to have a brand-new denture at further cost.
Flexible resin dentures also are difficult to adjust and pick up a lot of stains which patients may not like.
In conclusion, the removable partial denture is the most common method of replacing missing teeth and there are different designs and types available.