Introduction
Teeth are very rarely lost in this day and age, because every effort is made to save them. There are a number of reasons why teeth may need to be removed:
- Structural reasons: When there has previously been a lot of decay and very little of the tooth remains. For example root filled teeth with post crowns or broken teeth.
- Gum disease: The supporting bone around the tooth is lost due to pocketing and infection.
- Unsuccessful root canal therapy: Teeth that have been root canal treated can be prone to persistent infection resulting in a poor prognosis and are often better removed.
- Incorrect positioning: Such as when a tooth is buried under the gum or has come through in the wrong place.
Whatever the cause of the problem, the end result is the root of the tooth is removed. Dental implant therapy is the replacement of the root with an artificial root that is made from titanium. This procedure can be used to replace one tooth, several teeth, or all the teeth.
How Implants Work
Dental implants are metal posts or frames that are surgically positioned into the jawbone beneath your gums. Once in place, they allow your dentist to mount replacement teeth onto them.
Because implants fuse to your jawbone, they provide stable support for artificial teeth. Dentures and bridges mounted to implants won’t slip or shift in your mouth — an especially important benefit when eating and speaking. This secure fit helps the dentures and bridges — as well as individual crowns placed over implants — feel more natural than conventional bridges or dentures.
For some people, ordinary bridges and dentures are simply not comfortable or even possible, due to sore spots, poor ridges or gagging. In addition, ordinary bridges must be attached to teeth on either side of the space left by the missing tooth. An advantage of implants is that no adjacent teeth need to be prepared or ground down to hold your new replacement tooth/teeth in place.
Implants generally last 10-20 years, depending on the location of the implant and patient compliance with oral hygiene and dental visits. Because molars receive more stress and wear and tear, these implants typically do not last as long as implants located at the front of your mouth.
Why replace missing teeth
The effects of missing teeth can be detrimental to your long term oral and medical health. Missing teeth are also recognized associated with old age and can make you look older than you are.
Replacing missing teeth can dramatically improve your smile and the shape of your face. This greatly enhances both your dental health and self-esteem. As soon as a tooth is lost, either from gum disease or an extraction, the supporting bone in the jaw begins to dissolve. This process is called resorption. The longer a tooth is missing, the greater the bone loss.
Over time, resorption of the jawbone has a considerable effect on quality of life and on the possibility of replacing the missing teeth. As teeth are lost it becomes more difficult to eat and chew food.
A tooth should be replaced as soon as it is lost. This will retain your oral health by preventing bone loss, reducing movement of surrounding teeth and avoiding excess decay.
Teeth provide more functions than just the ability to chew. They are necessary for the health of the gum and jaw tissues as well, and a prolonged absence of a tooth will severely limit the possibilities for restorations. Missing teeth may also affect your confidence and well-being.
Single Tooth Implant
Dental implants placed next to natural teeth gives the best result in terms of aesthetics.
The single-tooth implant between two natural teeth is an almost perfect dental restoration; the appearance is almost undetectable and the success rates are close to 100%.
A single tooth implant does not affect your other teeth, looks better and is easy to keep clean. It is kept clean in exactly the same way as your other teeth. An implant replaces a missing tooth and is an independent restoration. It has the advantage that it stimulates bone to stay and get stronger. This is something that will not happen with any other option.
Larger Gaps / Multiple Teeth
When more than one tooth is missing implants may be used in the same way as when a single tooth is replaced. Sometimes a gap may be too large for a conventional bridge or there are no back teeth to bridge onto. There can be many variations on the number of implants used.
Upper Jaw
As a general rule the bone in the upper jaw is a little softer. If a patient is wants to have fixed teeth instead of dentures 8 – 10 implants would generally be used. If a patient wants to stabilize a denture 2 – 4 implants would be adequate.
Implants can be used to replace missing front teeth – this may be as the patient’s own teeth require extraction or because they are already wearing a partial denture and do not like it.
Implants can similarly be used to replace missing back teeth which makes chewing much easier.
Lower Jaw
In the lower jaw between 4 – 8 implants are normally sufficient to enable fixed teeth to be constructed. This is because the quality of bone in the lower jaw is better. If stabilizing a denture was being considered 2 implants would be sufficient.
Bridges
Bridgework constructed on implants is kept in place using cement. Soft cement is always used so that the bridge can be removed at any time in order to check that the implants are sound and to make any adjustments.
These bridges fit accurately and have a very natural appearance. The only disadvantage is that they can sometimes come off. This can be countered by small lateral screws that fit through the inside of the bridge into posts.
Overdenture
Implants can be used to support dentures so that the dentures do not move around. The treatment that is required is very simple and provides tremendous benefit.
In the lower jaw where the problem of a moving denture can be quite serious due to very little bone. Two implants can be placed in the front of the mouth and studs are used to hold the denture in place.
In the upper jaw four implants are often needed because of the softer bone. Ideally they should be splinted together for greater stability.
The three images on the right show teeth that are failing, the four implants joined together by a gold bar and finally the end result with the dentures be supported by implants.
Sometimes the old denture can be used as long as it is otherwise satisfactory. This however, does not give you an opportunity to design a smile or make any changes for the better.
Bone Graft
The best source of bone for your graft is your own bone tissue from elsewhere in your body.
Bone can be grafted from the chin, the back of the lower jaw, the hip and the tibia. Bone taken from your own body is the most viable and has faster healing times when compared to alternatives. In many cases, a combination of artificial bone substitutes and your natural bone is used. In any bone grafting procedure, the grafted bone provides an anchor and stimulus for the existing bone to grow onto, eventually providing an environment suitable for the placement of implants.
Bone grafts take in the region of 2-4 months to heal. Following the healing period implants can then be placed into the grafted site in the normal way.
Sinus Lift
In the back of the upper jaw the sinuses often occupy a large amount of space. Often very little bone remains and is not enough for implants.
Sinuses are large spaces in the bone and they have a thin lining. To create bone the sinus lining can be lifted and a bone graft can be placed in the floor under the sinus lining and allowed to heal.
The bone graft may be obtained from some other part of the body or it may be synthetic or obtained from a bone bank. This method of creating bone prior to implant placement is very predictable.