Abstract
Protrusion of the dental implant into the maxillary sinus is known to cause thickening of the sinus mucosa and bacterial sinusitis. However, there are many cases where protruded implants do not cause long-term complications clinically or radiologically. Questions arise as to whether the protruding implant was exposed or covered with sinus mucosa. In the present case, lateral sinus floor elevation was planned on the maxillary sinus adjacent to the deeply protruded (6.5 mm) implant #13. The protruding implant was scheduled for removal. During sinus floor elevation through a lateral sinus window, there was no damage or perforation of the elevated sinus mucosa around protruded implant, and the implant surface was visibly clean. This suggests that the protruding implant was actually covered with sinus mucosa and not exposed. Therefore, maxillary sinus augmentation can be performed without explantation or surface treatment of the protruding implant. Within the limitations of this case report, implants that are deeply protruded into the maxillary sinus can be covered with sinus mucosa.
