Insufficient residual alveolar bone height is a common obstacle for the placement of dental implants in the posterior maxilla. Sinus lifting procedure involves the creation of a sub-sinus membrane pocket and the grafting with granular bone substitutes. Perforation of the sinus membrane is the most common complication with a large incidence rate (Testori et al. 2019). Graft material leak, through the perforation, results in a dental implant failure and/or postoperative sinusitis, requiring a complete reviewing of the maxillary sinus cavity and the removal of the remaining bone graft. The high perforation rate has led to develop new options involving 3 D biodegradable scaffolds instead of using granular bone substitutes. Case reports and case series have pointed out successful new bone formation after sinus membrane elevation using reoxidised cellulose (Gray et al. 2001), venous blood clot (Moon et al. 2011) and gelatin sponge (Sohn et al. 2010) as space maintainers. The main limitation of this promising technique was that the sub membrane space volume was limited and hardly predictable. The aim of this study was to evaluate the mechanical behaviour and volume kinematics of several haemostatic sponges to find out the best haemostatic medical device as space maintainers for new bone formation in sinus lift surgery. This study has been focused only on two devices: Gelita-spon® and Hemocollagene®. It aims to compare substitutes respectively made of porcine gelatine and bovine collagen.