There are several options one can take when replacing missing teeth. Often the decision on which is the best option depends on a number of factors:
1. The number of teeth missing
2. The location of the teeth missing
3. The aesthetic effect of the missing teeth
4. The effect of the missing teeth on function
5. The reasons for desiring to replace missing teeth
All of these factors need to be taken into consideration when selecting the option of choice for replacing missing teeth in the mouth. Additionally, the current state of the individual’s mouth needs to be assessed by a dentist to determine which options are possible or advisable.
When deciding what to do about missing teeth, there are generally four options available to an individual:
1. Do Nothing
Having missing teeth in the mouth doesn’t necessarily mean that one has to replace them with artificial teeth. The placement of any artificial appliance into the mouth complicates the cleaning process. If the appliance is not cleaned properly, the health of the remaining teeth can be compromised. Therefore if function is not affected and aesthetics is not a concern, there really is no reason to place artificial teeth in the mouth.
2. Removable Partial Denture
A removable partial denture is a prosthesis that can be inserted and removed by the individual. It can range from something as simple as a spoon denture which is a single tooth suspended on a piece of acrylic to a more complicated device replacing many teeth. It can be made entirely of acrylic or it may be constructed from a metal frame covered with tooth and gum-coloured acrylic.
After the option to do nothing, the removable partial denture is the most affordable choice for replacing teeth. There are several benefits when opting for a removable partial denture:
The main benefit of a removable partial denture is the ease of cleaning. Since the device can be removed from the mouth, it facilitates cleaning of the device and the remaining structures in the mouth. Removable partial dentures also make it easier to replace several missing teeth in the mouth that are not located adjacent to each other. For instance, if there are missing teeth on both sides of the upper jaw, the appliance can be fashioned to span across the palate to replace all the missing teeth with a single device.
Some of the disadvantages of removable partial dentures include aesthetics and comfort. Because removable partial dentures require the placement of clasps to help fix the device into the mouth, it may not be as aesthetic, especially if these clasps cannot be entirely concealed. However, with a well selected case, a skilled cosmetic dentist and technician, removable partial dentures can be made to look fairly aesthetic.
The other downsides to removable appliances are that they are not as comfortable because of the additional bulk in the mouth and they are not as stable as the other two options that will be discussed below.
3. Fixed Bridge
A fixed bridge replaces missing teeth by crowning the teeth adjacent to the space and by suspending false teeth over the gap. The false teeth are fastened together in a string and attached to two crowns (caps) on either end. The two crowns sit over real teeth that help to hold the false teeth in place.
Fixed bridges cost more than partial dentures, although they are more stable and usually more aesthetic. They are usually more complicated to clean, although one can still do so with the aid of special cleaning devices.
The main limitation of a fixed bridge is that it cannot be used to replace too many missing teeth. If the gap is too large and too many false teeth are required to be suspended between the two crowns, then the successful placement of a fixed bridge is doubtful. Dentists generally err on the side of caution and will be reluctant to place a fixed bridge where the success of treatment is compromised.
The other downside to a fixed bridge is the necessary removal of sound tooth structure when preparing the adjacent teeth to receive crowns. In a mouth where tooth decay has rendered a crown necessary on the teeth that will support the bridge, this is not an issue. However, if the supporting teeth are intact and undamaged, placing a crown over them may seem unnecessarily aggressive.
A more conservative approach for the fixed bridge is called a Maryland Bridge. Instead of crowning the adjacent teeth to suspend a false tooth in the gap of the missing tooth, two metal wings are adhered to the backs of the adjacent teeth. However, the Maryland Bridge can only be used to replace a single missing tooth. It is generally not as strong as a regular fixed bridge and may not be indicated for certain individuals due to the nature of their bite (the positioning of the teeth, how they come together and move against each other during function).
Implants involve the placement of a pin into the jaw bone and a false tooth is then placed over the pin. It is not unlike planting a tooth and root, albeit an artificial one, back into the jaw where the missing tooth lies. The end result will be like having a new tooth or teeth back in the mouth, depending on how many teeth are replaced.
The benefits of having implants:
They are the most aesthetic of the four options available. Aside from the superior aesthetics, implants are also beneficial in that they help to preserve jaw bone. In a normal jaw, the tooth roots help to maintain the jaw bone. If a tooth and its root fall out, the jaw bone will shrink. Over time, the loss of jaw bone makes it difficult to wear a removable appliance. The preservation of jaw bone can help to maintain facial aesthetics as there is an accompanying negative effect on facial aesthetics when jaw bone is lost. Without the supporting structure of jaw bone beneath the facial muscles, the face may appear sunken in. Implants can be used to replace any number of missing teeth in the mouth. Implants are conservative to the remaining teeth as no preparation or removal of tooth structure is necessary to the adjacent teeth.
The disadvantages of having implants:
Implants are the most costly option for replacing teeth and are often not covered by health insurance plans. Implants are time consuming. The process involves a surgical procedure where the implant (or pin) is inserted into the jaw bone, followed by the fabrication of the false tooth (which is a little like a crown) to be placed over the implant. There is usually a time lag between the time when the implant is placed and when the false tooth can be attached. This usually spans several months to allow for healing and the acceptance of the artificial root in the mouth. The surgical placement of implants and required post-operative healing can be uncomfortable. There are individual cases where implants cannot be used – such as when there is insufficient bone to receive the implant.
To decide the best option for replacing missing teeth in the mouth an individual first needs to see a dentist for an assessment of the oral condition. After the dental assessment, a dentist will explain all the options available and their accompanying benefits and disadvantages as it applies to the specific individual’s case. Without such an assessment, it is difficult to determine the best option or even if the option is possible (for instance, if there is insufficient bone available for the placement of an implant). One can only make a decision to replace teeth once a full dental check-up has been completed and the state of the oral condition determined.