It deals with all jaw bone problems: the presence of cysts or neoformations, bone defects that do not allow implants to be placed or even simply to have adequate support for a removable prosthesis.
Bone regeneration
This is performed in cases where the patient’s bone is insufficient to allow the placement of implants, to reconstruct portions of bone destroyed by cysts, after very complex extractions, or in treatments for severe periodontal disease. If the bone has undergone significant resorption due to the absence of previously extracted teeth, for congenital reasons or as a result of other treatments that have caused damage, it becomes indispensable to intervene directly on the bone through a process known as regeneration or reconstruction.
There are many different materials that can be used to carry out bone regeneration.
A first possibility is to carry out a kind of autograft with the patient’s own bone (autologous bone grafting): bone is taken from another part of the mouth and grafted into the area to be regenerated; the process therefore requires two separate surgical operations.
Instead of one’s own bone, one can choose to use a human bone of external origin (homologous). This choice reduces the duration and invasiveness of the surgical session because it does not involve harvesting, but it does expose the patient to some additional risk of infection or immune reactions since it is material from a cadaver.
Another possibility is to use graft material of animal origin (heterologous). This material, supplied by the patient’s blood, fuses with the bone due to its osteoconductive characteristics. This type of operation does not expose the patient to the risk of rejection and is a simpler solution. The choice of heterologous bone (whether equine, bovine, porcine, etc.) does, however, expose the patient to the risk of developing immune or infectious reactions, albeit in a very low percentage. Moreover, this choice may be at odds with certain ethnic groups or religions.
A final option is to use synthetic (alloplastic) material, i.e. material made entirely in the laboratory. In return for a lower biological efficacy, it is guaranteed to be completely safe in terms of cross-infection or allergies.
Membranes are often then applied in the area of the bone defect in order to make healing and regrowth of the bone faster and more predictable.
It is therefore appropriate and essential that the practitioner explains very clearly to the patient what choice he/she intends to make and that the costs/benefits are properly understood and shared by the patient.
Finally, regeneration with the aid of platelet-rich plasma (PRP), which due to its high concentration of undifferentiated cells, is increasingly used today, greatly increasing the effectiveness of these techniques. PRP is obtained by taking a small amount of the patient’s venous blood in the surgery prior to the procedure. This blood will be placed in a specific centrifuge and after appropriate separation will be used to mix the bone to be grafted and to improve the quality and speed of wound healing with less bleeding and post-operative swelling.
Extensive bone reconstruction with harvesting from intra- or extra-oral sites
There are situations of bone deficiency in which the traditional regenerative techniques described above are not sufficient.
This can be the result of severe bone trauma, a long-standing loss of several dental elements, or even the fact that the patient has been wearing a full denture for many years. In fact, the latter can, over time, accentuate bone resorption due to rubbing against the underlying bone to the point where the denture is no longer wearable regardless of the use of adhesive pastes.
In these cases an excellent solution is the use of a block of bone fixed to the area to be corrected. Autologous bone represents the gold standard in regenerative surgery because it is immediately recognised as its own by the body and quickly takes on the same characteristics as the native bone.
This technique drastically increases the morbidity of the operation, since it is necessary to resort to bone harvesting, which may be intraoral (from the branch of the mandible or from the chin symphysis) or extraoral (the iliac crest or cranial calvaria), depending on the amount of bone needed to correct the atrophy.
