A Clinical Study of the Use of Brushite as Primary Stabilizer in Immediate Dental Implantation

Bone fractures or bone loss in specific sites are cases where a bone graft is sometimes needed to provide bone augmentation. For bone fractures, these are typically metaphyseal or maxillofacial fractures with risk of malunion or non-union. Bone loss can happen under various circumstances: it can be a consequence of a systemic disease like osteoporosis or of a surgical intervention like the extraction of a tooth or the removal of a bone cyst or tumor.

When a bone graft is required the gold standard still widely used is autogenous cancellous bone. However, the graft harvesting procedure is invasive and increases patient morbidity (lengthened surgical procedure, increased risk of infection). Moreover, the availability of autologous grafts is limited, especially in elderly patients. This has been the rationale for studying alternative sources for bone grafts.

The first alternative is allografts: they are usually obtained from cadavers. The advantages include elimination of a patient donor site, hence reduced surgical time and decreased blood loss and risk of infection. The principal shortcomings are the availability, the possible rejection of the graft and the risk of disease transmission.

Grafts of animal origin (xenografts) are also an option, even though not totally risk-free when it comes to disease transmission.

A third alternative to autologous bone is to use synthetic materials. Extensive research has been performed to develop such materials since the 80's. The majority of them are based on calcium phosphate compounds, made up of the same ions as those of the natural mineral phase of bone. These products are readily available, eliminate the risk of disease transmission or immunogenic response (allografts) and bypass the need for an additional surgical procedure (autografts). These materials are presented under either of the three forms: granules, pre-formed blocks or cements.

Granules and pre-formed blocks are generally made up of β-TCP, Hydroxyapatite (HA), or a mix of both. Depending mainly on their chemical composition, their manufacturing process and their porosity, they degrade more or less rapidly.

Calcium phosphate cements consist generally of a liquid and a powder which harden upon mixing. The final product phase can be hydroxyapatite, or another calcium phosphate phase like dahllite or brushite. The advantage of cements over pre-formed blocks is that they can be injected, shaped and hardened in situ, ensuring optimum bone-implant contact and minimally invasive surgery. Once hardened, they exhibit cohesive properties that granules cannot provide. Most of the calcium phosphate cements available on the market are hydroxyapatite cements. However, for some applications like periodontitis or peri-implant gap filling, their resorption rate is too slow, hampering their clinical applicability for these indications. The advantage of the brushite phase in the hardened cement is that it degrades faster than hydroxyapatite, allowing a more rapid bone regeneration. The purpose of this study is to evaluate the efficacy of "PD" VitalOs Cement as a primary stabilizer and bone augmenting source in dental implantology.