Biomaterials for Bone Regeneration in Dentistry

The classification of bone grafts into autologous, allogenic, xenogenic and synthetic, and the role of membranes in guided bone regeneration (GBR).

Loss of bone volume — resulting from periodontal disease, extractions not followed by prompt rehabilitation, trauma or simple disuse atrophy — is one of the most common challenges in implant planning. Available graft biomaterials are classified into four main categories based on their origin: autologous bone, taken from the patient themselves (typically from intraoral sites or, for larger volumes, extraoral sites such as the iliac crest), which offers the best osteogenic properties overall thanks to the presence of viable cells able to directly form new bone, at the cost, however, of an additional surgical harvest site; allogenic bone, from a human donor and processed for clinical use; xenogenic bone, of animal origin (typically bovine), processed to ensure biological safety; and synthetic (alloplastic) biomaterials, such as hydroxyapatite, beta-tricalcium phosphate and bioglass.

An ideal graft material should be fully resorbable and progressively replaced by the patient's own vital bone. Synthetic and xenogenic grafts, while lacking the direct osteogenic properties of autologous bone, mainly act as an osteoconductive scaffold on which the patient's bone cells can progressively proliferate, offering the practical advantage of being available in unlimited quantity without needing a second surgical site.

Guided bone regeneration (GBR) is the surgical technique that pairs bone grafting with a barrier membrane, whose role is twofold: physically maintaining the space needed for regeneration (the so-called "tenting effect") and preventing gingival fibrous tissue, which grows faster than bone tissue, from invading the graft site before the bone has time to regenerate. Membranes are divided into resorbable, generally collagen-based or made of polylactic and polyglycolic acid copolymers, which are integrated by the body over the following months without needing surgical removal, and non-resorbable, typically expanded polytetrafluoroethylene (e-PTFE) sometimes reinforced with an internal titanium framework, fixed with mini-screws or pins and indicated for more pronounced horizontal and vertical bone augmentation cases.

The choice among the available options depends on the extent of the bone defect, the anatomical site involved and the patient's general clinical condition. Complications, while not frequent, include early membrane exposure through the mucosa, infection of the grafted site and partial resorption of the material, all preventable with careful surgical planning, use of certified-quality biomaterials and strict adherence to operative sterility.

On Oralzon you'll find synthetic and xenogenic bone graft biomaterials, resorbable and non-resorbable membranes, and all the instrumentation needed for guided bone regeneration procedures.