Deep tissue injury as possible pathogenesis of acute inflammatory swelling or cellulitis after connecting implant super-structures: a case series study [version 1; peer review: 1 approved with reservations]

Background: Acute swelling or cellulitis may develop within a few days after placing a definitive prosthesis or reconnecting a loose healing abutment/prosthesis, though its cause remains unclear. In this study, we propose a mechanism for the underlying pathogenesis. Methods: We retrospectively reviewed the symptoms and signs, onset of symptoms, recovery duration, and laboratory data of seven women and two men (55–84 years) who exhibited acute swelling and pain around dental implants within a month of connecting definitive prosthesis or reconnecting a loose healing abutment/prosthesis between 2013 and 2021. Results: The extent of the swelling varied from the gingiva and vestibule around the implant to the face and neck regions. The swelling persisted despite removal of the connected superstructure. All patients recovered within three weeks of symptom onset. Conclusions: Our findings suggest that the rapid onset of symptoms and signs, progress, duration, and etiology were consistent with the pathogenesis of deep tissue injury, which is characterized by acute inflammatory swelling that initiates from the interface between bone and subcutaneous tissue and progresses outward. Clinicians should be aware of the pathogenesis of pressure-induced injury and provide adequate treatment based on the underlying physiological process.