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Would you like to have a dental implant treatment to replace a one or more missing teeth, but have been told you have a deficiency with not enough bone (i.e. a bony defect) or not enough gum to allow a successful result?
Fortunately, there are surgical techniques available to replace the bone and soft tissue that is missing. In many instances we can even place the implant(s) at the same time! We can either grow bone using ‘membrane technology’ or we can place bone obtained from somewhere else to fill the bony defect hence replacing the missing bone.
Often a combination of both techniques is used to provide an optimal result. If the bone is ‘bulked’ out then there may be insufficient gum (soft tissue) to cover it. In these instances gum can be taken from elsewhere in the mouth to replace it. In bone grafting is required; the best bone is your own bone taken from a donor site somewhere in your own mouth. Often this is collected from the wisdom teeth area however bone may be harvested from different locations, which often determines the volume and quality of the graft.
The best soft tissue is your own soft tissue which also requires a donor site. Usually soft tissue is harvested from the palate which again heals itself. Growing bone is often referred to as guided bone regeneration or GBR and is a procedure in which membrane is placed over the defect or grafted bone. This encourages new bone to grow and also prevents the ingrowth of scar tissue into the site.
The membrane is resorbed (dissolved) by the healing process (some non-resorpable type membranes have to be removed) and the grafted bone acts a scaffold for new bone to grow into, growing and remodelling until eventually the graft is completely replaced.
Often there is a need to augment the volume of a bone graft with ‘bone-in-a bottle’ which we can purchase, for example if the donor site does not provide sufficient quantity of bone for the defect. There are many types of ‘bone’ products, developed from different sources including animal sources; for instance Bio-Oss is a treated purified bovine bone sourced from Australian cows. It undergoes controlled processing and sterilisation procedures which remove all impurities and risk of disease, including CJD (Creutzfeld-Jacob disease). No allergic reactions have been observed following its use, in fact Bio-Oss is so similar to human bone that it is readily accepted by our immune defences and is not rejected by the body.
Likewise many types of membranes are also developed from animal sources for instance Bio-Guide is derived from purified and processed porcine (pig) collagen (like many replacement heart valves) and is deemed to be biocompatible and safe, however it is not indicated for patients who have demonstrated allergic responses to porcine derived products. Some of our patients object to the use of animal products in their treatment on religious or other grounds (e.g. vegetarians). Please let us know if this applies to you, in which case synthetic bone or membrane alternatives of non-animal origin can be used or if you prefer, we will use nothing that is foreign to the body - the advantages and disadvantages of which will be explained to you at your consultation.
Note: It is not always possible to place the dental implant(s) at the same time as grafting as there must be enough of your own non-grafted bone to ensure the implant does not move when it is placed. Larger grafts sometimes require taking a block of bone from the donor site which then needs to be screw attached and allowed to consolidate and heal in the recipient site before the implant(s) can be placed (of course the screws are removed).
Following a bone graft, healing usually takes 4-6 months. If an implant is placed at the same time as grafting it will need to be buried beneath the gum to ensure graft materials do not wash out or become contaminated. Once the implant has integrated with the bone, it can be easily accessed with a minor second surgical procedure and subsequently restored with prosthetic teeth. Very large grafts may require going to the hip as a donor site. This treatment requires referral to a specialist Maxillofacial Surgeon and cannot be carried out by us.
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