Potential adverse events of endosseous dental implants penetrating the maxillary sinus: long-term clinical evaluation.

OBJECTIVES/HYPOTHESIS The aim of this study was to evaluate the nature and incidence of long-term maxillary sinus adverse events related to endosseous implant placement with protrusion into the maxillary sinus. STUDY DESIGN Retrospective cohort study. METHODS All patients who underwent placement of endosseous dental implants with clinical evidence of implant penetration into the maxillary sinus with membrane perforation were included in this study. Only patients with a minimum follow-up of 5 years after implant placement were included in this study. Maxillary sinus assessment was both clinical and radiological. RESULTS Eighty-three implants with sinus membrane perforation in 70 patients met the study's inclusion criteria. Mean age was 65.96 years ± 14.23. Twelve patients had more than one implant penetrating the maxillary sinus, and seven of them had bilateral sinus perforation. Estimated implant penetration was ≤ 3 mm in all cases. The average clinical and radiological follow-up was 9.98 years ± 3.74 (range 60-243 months). At the follow-up appointments, there were no clinical or radiological signs of sinusitis in any patient. CONCLUSION This long-term study, spreading over a period of up to 20 years, indicates that no sinus complication was observed following implant penetration into the maxillary sinus. Furthermore, absence of occurrence of such complications is related to the maintenance of successful osseointegration. A contrario, and in the presence of an acute or chronic maxillary sinusitis, the differential diagnosis must always consider other potential odontogenic and nonodontogenic etiologies.