/ Dental Implants / Bone Grafting
Bone Grafting & Regeneration
Occasionally because of infection, shrinkage of bone following extractions or simply from the wearing of a denture, there is insufficient volume of bone into which an implant can be placed in the ideal position. In such cases, the options are to either widen the bone using special techniques at the time of implant placement or re build the bone using a bone graft.
For smaller amounts of bone it is possible to take bone from the wisdom tooth area of the lower jaw or from under the lower incisor teeth. This is carried out in much the same way as a tooth extraction under local anaesthetic in the practice.
For larger amounts of bone, for example when there has been complete collapse from gum disease or long term denture wearing, it can be necessary to take the bone from outside the mouth. This would require a general anaesthetic and an overnight stay in hospital. We try to avoid these situations if at all possible by using Zygomatic implants.
The reason for using bone grafts in many of these situations is so that the natural contours of the original teeth and gums can be reproduced. However if it is felt that bone grafting is inappropriate then the options are to either accept longer teeth or use gum coloured acrylic or porcelain to mimic the missing gum. The ideal option however is natural, healthy, regenerated bone. It is usually necessary to leave bone grafts for up to four months to heal before implants are inserted in the normal way.
Photo 1: Canine to be extracted.
Photo 2: Shrinkage of Ridge before graft.
Photo 3: Expanded Ridge.
Photo 4: Porcelain crown two years after treatment.
Photo 1: Infected canine tooth.
Photo 2: Defect following extraction.
Photo 3: Grafted bone.
Photo 4: Implant, post and crown two years after treatment.
In many cases rather than using natural bone grafts it is possible to use a range of biomaterials to plump out or fill in around an already inserted implant. These materials come from a variety of sources including bovine, human bone and synthetic materials. Careful consideration is given to the use of such materials and discussed on an individual basis, but are a key asset in the treatment of these cases. Their use is termed Guided Bone or Guided Tissue Regeneration.
Towards the back of the upper jaws are the sinus spaces which are positioned above the remaining residual jaw bone. Following tooth removal the sinus spaces frequently increase in size and on some occasions in order to place implants in this area it is necessary to reposition the sinus lining to a higher level. This is done under local anaesthetic in the surgery and involves a procedure called sinus augmentation. The sinus lining is raised by a bone graft or biomaterial being introduced into the void and allowed to form new bone. The implants can either be placed at the same time as the augmentation or after healing has taken place. This technique is an extremely predictable way of creating new bone.
It is sometimes necessary to know the precise location and volume of bone nerves and sinus spaces. This is possible with a Cone Beam CT scan. Cone Beam CT scans are an invaluable diagnostic aid, particularly where multiple implants are considered. They are so accurate that it is possible to have 3D guides constructed that can help determine exact implant positioning.
Bath Spa Dentistry is delighted to have one of the most advanced CBCT machines on the market. This enables us to plan and treat every case with the greatest accuracy possible.