OBJECTIVE The aim of this study was to assess the feasibility of biodegradable polyurethane (PU) foam for closure of oroantral communications (OACs). METHODS Ten consecutive patients with OACs (existing <24 hours) were treated with PU foam. Standardized evaluations were performed at 2 weeks and 8 weeks after closure of the OAC. RESULTS In 5 patients, the OACs were closed successfully without complications. Three patients developed sinusitis, which was conservatively managed with antibiotics in 2 cases. In 1 case the sinus was reopened for irrigation, after which a buccal flap procedure was performed. In 2 patients the OAC recurred and was surgically closed with a buccal flap after thorough irrigation. CONCLUSIONS In this feasibility study, closure was achieved in 7 of the 10 patients without further surgical intervention. Complications of the procedure using PU foam may be related to the fit of the foam in the socket and the size of the perforation. In general, closure of OACs with biodegradable polyurethane foam is feasible and has the potential to spare a large number of patients with OACs a surgical procedure. Furthermore, in case the treatment with PU foam fails to close the OAC, the attending physician can always fall back on the standard surgical procedure.