This is a randomized open label trial that evaluates the efficacy of an autologous platelet concentrate (APC) in pre-implantation reconstruction of maxilla.

The sinus occlusion will be performed under general anaesthetic. On one side by the usual technique with hipbone transplant, the other side will be restored with APC mixed with autologous bone tissue removed from the surgery site.

The side selection will be determined by the randomization.

Rational

Maxillary Edentulous is one of the more frequent handicaps that cause many problems for dental prosthesis. Dental implants are currently the most convenient solution but require sufficient bone sinus height.

The filling of the sinus can be made by two ways :

• Either with autologous bone removed from hipbone or cranial bone. This method has several drawbacks such as the multiplicity of the surgery sites.
• Or with alloplasty materials that are subject to uncertain osseointegration and that are very expensive.

The aim of this study is to show the interest of an autologous platelet concentrate (APC) in this surgery. We will use the osteogenic property of platelets associated with a small quantity of spongy bone removed from the surgery site.

It has been previously demonstrated that platelets contain growth factors, in particular PDGF (platelet derivated growth factors), TGF-α1 and 2 (transforming growth factors) and IGF-1 (insulin like growth factor). These molecules have receptors on spongy bone, enhance mitosis, osteoblast differentiation, angiogenesis and induce the inhibition of osteoclats.

Method :

The sinus filling will be performed under general anaesthetic. On one side by the usual technique with hipbone transplant, the other side will be restored with APC mixed with autologous bone tissue removed from the surgery site.

The side selection will be determined by the randomization. For each patient a waiting period of 6 months is required before dental implants.

Twenty patients will be enrolled in this single-centre study with a follow-up of one year.

Main objective :

- To demonstrate that the osteogenesis with APC mixed with a small quantity (1 to 2 cm2) of autologous bone tissue removed from the surgery site, has a sufficient quality to allow the dental implants.

Secondary Objectives :

• To compare the osteogenesis with the current procedure (hipbone transplant)
• To estimate the kinetic of osteogenesis using successive radiography.

Inclusion Criteria:

• Age above 18 years
• ASA1 class of anesthetic risk
• SA3 or SA4 of the Misch classification

Exclusion Criteria:

• Smoker
• Progressive sinusal lesion or previous history of maxillary sinusitis
• Previous history of maxillary surgery
• Hemopathy
• Contraindication to cytapheresis
• Progressive cardiopathy
• Severe cerebellar arteriopathy
• Infectious state
• Thrombopenia < 150 g/l controlled by citrate
• Serology : antibody anti-HVC, anti-HIV 1 & 2, anti HTLV 1 & 2 positive