A pilot study was performed to investigate whether the Göttingen minipig is a suitable animal model for creating and closing oroantral communications (OACs) and to test whether these defects can be closed with a biodegradable polyurethane (PU) foam. In three adult minipigs, an OAC was created on both sides of the maxilla. The left side was closed by a standard surgical buccal flap procedure, the right side by applying a PU foam. The pigs were killed after two weeks, one month and three months, respectively. Postmortem and histological examination showed that an OAC was created in only one of six cases. In the remaining cases, the infraorbital canal was perforated instead of the floor of the maxillary sinus. It was concluded that the Göttingen minipig is not a suitable animal model for OAC investigations. As a result, the closure of OACs with a biodegradable PU could not be evaluated.