Bone cavities and deficits of oral cavity’s tissues occuring after tooth extractions and due to long-term pathological processes count among major dental problems. Repeatedly, they prevent optimal prosthetic rehabilitation of the stomatognathic system. Moreover, they cause diseases of the periodontium. Bone structure atrophy has a negative influence on shaping prosthetic base and inhibits subsequent impalntology treatment. Often, the amount of residual bone, despite the atrophy, is sufficient to place a dental implant. In most cases, the angle of placing the implant makes screwing the prosthetic work on impossible – what should be an implant treatment of choice according to current literature.
In implant treatment, one of the factors conditioning procedure’s success and long-term preservation of the treatment results is proper amount and quality of osseous tissue at the site of placing a post. Availability of sufficient amount of surrounding and supporting tissues is a pre-requisite for successful and aesthetic implantation. Often due to considerable transverse or vertical loss of the alveolar, it may be recommended to perform hard tissue augmentation to increase their width or height.
The main method used in implantology to supplement amount of bone necessary to place an implant is the use of autogenic bone or pure xenogeneic/synthetic material. The method is chosen on the basis of osseous tissue deficits.
A review of substitutionary methods for osseous tissue regeneration used in implantology:
1) AUTOGENOUS BONE GRAFT
In case of bone deficits that prevent classic implant procedures, there exists a method for osseous tissue restoration with the use of patient’s bone grafts. Autografts may be used in various forms and come from various sources. Using autogenous materials limits chances of graft rejection and is a treatment of choice for patients that do not give their consent to use biologically foreign materials.
Autogenous grafts, depending on the extent of bone loss, may be sampled in the form of chips (with small bone defects) or bone blocks (when an extensive bone augmentation is anticipated in order to obtain sufficient base volume for the planned implantation).
Autografts used in dental implantology are divided in the following way:
- grafts from the oral cavity – areas of the chin, maxillary tuberosity, mandibular molar, and mandibular ramus;
- extraoral bone grafts – taken from the iliac crest, cranial vault, and shank.
Depending on the loss size, in which grafts will be used, either bone blocks or bone chips can be used. Bone blocks are used for grafts when there is a significant loss of the alveolar bone, or when the bone is not thick enough to place an implant. Bone chips are mainly used in cases of small bone defects, post denudation, or when it is necessary to lift the maxillary sinus; bone chips are most often mixed with bone substitute materials.
Autografts constitute a perfect material for restoring bone loss – healing time equals about 3-4 months. Thanks to biocompatibility, this material is best tolerated by an organism, and as the only one has osteogenic, osteoconductive and osteoinductive features at the same time. However, these types of grafts are associated with introducing additional surgical procedures (additional cuts in order to collect a bone block), what is a barrier for some patients.
2) XENOGENEIC IMPLANTS
Xenogeneic implants are animal bone materials, thus the donor and the recipient are different in terms of species. They are collected from a compact bone or cancellated bone, which are then properly prepared and introduced into recipient’s tissue; they constitute a hydroxyapatite matrix for the future bone. Currently, a lot of manufacturers are offering such biomaterials in sterile vials.
3) ALLOPLASTIC IMPLANTS
Alloplastic implants are products fabricated synthetically or coming from natural organic sources (e.g. corals, alga), and sometimes non-organic (hydroxyapatite, tricalcium orthophosphate, bioactive glass). Alloplastic materials are used in a regular form (plate, cone, sphere), porous form with various sizes and shapes of pores, various size of granules, and in a powder form.
Both xenogeneic and alloplastic materials have only osteoconductive features (an implanted preparation is a matrix upon which a new bone forms and into which blood vessels from a neighbouring bed grow). Despite the fact that they do not cause resorption, creation of new osseous tissue requires a lot of time – from 9 to 12 months. An implant may be placed only after that period. Often complications are observed – they are associated with insufficient penetration of blood vessels and blood supply disorders, which contribute to irregular osseous tissue.
Biologically speaking, the most important aspects are precision and the highest standards of conducting a surgical procedure. Implantology experts at Perfect Dental Clinic have broad experience in dental implantology. Moreover, we have authored an innovative technique of osseous tissue augmentation that combines the best features of the above-mentioned methods and utilizes stem cells in augmentation materials. Learn more