Bone loss can occur in bones of a person leading to many orthopaedic diseases, prominent among them being osteo porosis where bone density decreases, making the bones brittle and porous which in turn make them susceptible for fractures.
What is bone loss?
When teeth are lost for whatever reasons, the bone which was supporting it gets absorbed in the body again, this process of bone being reabsorbed by the body is called resorption in dental and oral care parlance.
Causes of bone loss
There are numerous reasons for bone loss among which periodontist is the main reason and most common. Bone loss occurs because teeth are lost or missed. The main reason for losing teeth is periodontitis. When you do not take good care of your mouth and teeth, you end up having periodontitis which is a disease of the teeth and gums.
What is periodontitis?
Periodontitis is a disease caused by bacteria in the mouth. Lack of dental hygiene causes these bacteria to grow and multiply in the mouth feeding on the sugar left behind in the mouth. These bacteria eat away at the roots of the teeth and the jawbone, and then eats the ligaments that connects the tooth to the bone. This causes the teeth to fall out, creating gaps in the line of teeth. When the teeth are lost, the bone underneath the teeth have no pressure of chewing, which makes them get reabsorbed in the body, because chewing pressure is the motivation for the bone to grow and stay put. Slowly major portion of the supporting bone gets reabsorbed and bone from the jaw gets lost. The bone loss occurs very fast after the tooth is lost. About 25% of bone loss occurs in the first year itself after a tooth is lost.
The most common reason for bone loss is when this place, created by tooth loss is left alone, without taking any steps to keep the bone in place. When multiple teeth are lost, the bone loss is greater through resorption process.
The loss of bone occurs in alveolar bone which is surrounding and supporting the teeth. Alveolar bone is responsible for the ridges that imbeds the teeth in them. When teeth are lost, these ridges waste away from all sides leaving the surface flat.
Dentures as a replacement of the natural teeth do not help in getting back the lost bone because they do not exert pressure on the bone with chewing. Compared to natural teeth, the pressure applied on jawbone by dentures is less than 10%.
Sinus cavity that lies above the jawbone of upper molars is another reason for the resorption of the jawbone when upper molars are lost. With no teeth, the air pressure in the sinus cavity induces the resorption of the bone that lines the sinuses. Infection in bones is another cause of bone loss.
Dental implants and bone loss
Dental implants can prevent bone loss after teeth loss if the procedure can be done in time. Dental implants are a procedure where a metal (Titanium) screw is implanted in the jawbone and allowed to remain there till bone tissues grow around it making it secure in the bone. Then a crown is placed on it with the help of abutment which holds it in place. The implants can prevent further bone loss because the tooth exerts enough pressure on the jawbone to stimulate it and let it grow. When many teeth are lost, the implants can support a bridge built on them. Since implants are inserted in the jawbone, they take the pressure of chewing and help getting the bone remain in place and grow. When two implants support a bridge of 4 teeth, the pressure provided by the implants can equal of about 70 to 90 % of natural teeth. This helps prevent bone loss to quite an extent.
When bone loss severe in some individuals, the option of bone grafting is still open. Bone grafting is needed to provide enough bone to get ridges on the jawbone so that crowns can be fitted snugly on them after dental implants have been inserted. When bone loss has occurred for missing molars, the dentist will require enough width to place them on. Bone grafting can be useful in such cases.
In cases with severe gum disease, the bone loss is acute. Bone grafting can come to the rescue for dental implants in restoring the lost bone and repair the damaged surrounding bone around the teeth.
When bone grafting technique is used for dental implant, in severe bone loss incidents, the grafting not only helps replace the lost bone, but also provides motivation and stimulation to the jawbone to regrow and develop so that eventually it replaces the bone graft with the individuals own replenished bone.
The material used for bone graft is varied depending upon the need of the patient. The new technology used for bone grafting is dynamic and make uses of cutting age materials that requires minimum period of healing.
In many dentistry practices, the technology used is minimally invasive which is explained in detail to the satisfaction of the patient.
Many times, if the bone loss is not extensive, then the bone graft and implant can be placed during one surgery procedure without having to go through the procedure twice. In severe bone loss, the dentist prefers to call the patients twice for the surgery, once for bone graft and the other for placing the implant, depending on how well the bone graft is healing and new bone is surfacing.
When sinuses have slid down quite a bit, the surgeon has to lift the membrane separating the jawbone and sinuses.
There are instances when there is no need for bone graft even in a severe bone loss case. The 3D CT scanner gives a 360degree view which allows the dental team to see and measure the exact amount of bone needed for the place where implants are going to be placed, and in many cases the enough bone can be found for use. In this technology, with 4 implants, the surgeons can make the bridge for the entire mouth with enough bone available without separate surgery in another area of the body.