Sylvain Catros*1; Mathilde Fenelon1; Sandrine Auget2; Jean-Christophe Fricain1; Laurent Bidault2; Joëlle Amédée1; Didier Letourneur2,3

1Inserm U1026 BIOTIS University of Bordeaux, Bordeaux; 2SILTISS, Brive La Gaillarde; 3Inserm U1148 University of Paris, Paris, France

Background: Insufficient bone height in the posterior maxilla after teeth extraction is frequent in implant dentistry. Pre-implant surgery is thus indicated and specific biomaterials are needed. Current reference biomaterials are mostly particles of bovine origin, with several limitations and side effects.

A novel synthetic material was developed using pullulan-dextran and hydroxyapatite and it was designed to be injectable. It is also radiolucent and becomes radio-opaque when mineralization occurs

Aim/Hypothesis: The aim was to evaluate dental implant stability and osseointegration in the sinus lift model in the sheep, after filling the maxillary sinus defect by a novel bone substitute, using a delayed implantation procedure.

Material and Methods: The test material was a composite injectable material, made of pullulan-dextran and hydroxyapatite (Glycobone®, Siltiss, France). The control material was BioOss® (Geistlich). Anthogyr® dental implants were used.

We have used the sinus lift model in the sheep (lateral window). The surgeries were conducted under general anesthesia, using an extraoral approach. During the first surgery, six sheeps were submitted to a bilateral sinus lift augmentation, using the test or the control article; after filling the subantral space, no membrane was placed and the tissues were sutured in 2 layers. After 6 months healing, one dental implant (Anthogyr®) was inserted into each grafted area (Second surgical procedure). 3 months later, euthanasia of all animals was done and the samples were collected for subsequent analyses.

The characterization methods included implant torque of insertion, implant stability quotient (ISQ,Ostell®), microscanner and histomorphometric observations.

Results: All animals survived the different surgical procedures and no local or general surgical complications occurred.

During implant placement in the regenerated area, the insertion torque was 44 N/cm-1 in the test group and 46 N/cm-1 in the control group; the ISQ was 74 for the test group and 73 for control group after implant placement.

At the end of experiment, the ISQ reached 78 in the test group and 77 in the control group. Qualitative histological analyses revealed a slightly higher mucosa inflammation in test samples. Micro-scanner and histological analyses have shown that Total Mineralized Area (TMA) and Bone-to-implant contact (BIC) were similar in both groups.

Conclusion and Clinical implications: The novel composite injectable material Glycobone® is as least as efficient as the control material (BioOss®) in the sinus lift model in the sheep. The test material lead to a similar bone formation around dental implants using a delayed approach for sinus grafting and implant placement.

Further experiments include a clinical study where the Glycobone® will be used for sinus lift.

Disclosure of Interest: S. Catros: None Declared, M. Fenelon: None Declared, S. Auget Conflict with: Siltiss Employee, J.-C. Fricain: None Declared, L. Bidault Conflict with: Siltiss Employee, J. Amédée: None Declared, D. Letourneur Conflict with: Director of Siltiss.

Keywords: animal study, biomaterial, sinus elevation