On The Use of a Sticky Bone Substitute in the Presence of a Ruptured Schneider Membrane During Sinus Lift Procedures - An Experimental Within-Rabbit Study

Purpose: To assess the efficacy and safety of a sticky dual-phase porcine-derived bone substitute, compared to a similar non-adhesive graft, in addressing induced perforations of the Schneider membrane during sinus lift using a within-subject design rabbit model. Materials and Methods: Bilateral sinus floor elevations were performed in 12 rabbits. The sinus mucosa was intentionally perforated using a blade on both sides and randomly filled with either a cortico-cancellous bone embedded in a 20% thermosensitive gel (GTO sticky bone test) or a cortical cancellous bone and 10% collagen (mp3 control). Healing progress was evaluated after 2 and 10 weeks in 6 animals at each time-point, with cone-beam computed tomography (CBCT), micro-computed tomography (microCT) and histological assessments. Results: One animal of the 2-week group died but was substituted. No other complications were observed. At 2-week, on CBCTs, biomaterials particles were observed in the vicinity of the Schneider membrane in two out of six sinuses of each group, but never dispersed into the sinus. MicroCT and histology consistently revealed few granules beyond the elevated region. Histologically, five sinuses in the mp3 group and two sinuses in the GTO group exhibited granules outside the elevated region but in the vicinity of the perforations. In the 10-week groups, the number of affected sinuses decreased to one in the mp3 group and two in the GTO group. Throughout all observations, the graft granules consistently resided proximate to the elevated region. Micro-CT demonstrated a reduction in the volume of the elevated region by approximately 12% after 2 weeks and 50-54% after 10 weeks. Conclusions: The use of both sticky and non-sticky bone substitutes seems to prevent a substantial amount of particles from extruding through an induced perforation of the Schneiderian membrane. This suggests that it could be possible to use a sticky bone as an alternative to a barrier membrane to avoid the extrusion of bone granules in the presence of accidental perforation of the sinus membrane in clinical practice. After 10 weeks of healing, the volume of the elevated region decreased by approximately 50%, possibly due to biomaterial resorption and loss through the surgically created perforation.