Implant loss and sinusitis after sinus lift ‐ an underestimated complication

Background: Sinus lift is designed to enable the placement of maxillary implants in situations with vertically reduced alveolar bone. It has become a more frequently performed procedure. Possible complications comprise sinusitis, failing grafts and failing of the dental implant. More severe problems and chronic sinusitis have been reported. Aim/Hypothesis: To report on 76 patients with implant loss after sinuslift. To report the reasons, the possibilities for repair in routine cases and in more severe situations of sinusitis with multiple implant loss and damage to surrounding structures. To report the long‐term outcome. Materials and Methods: Between 2000 and 2020 76 patients with failing implants after sinuslift were referred to four Oral Surgery and ENT services in Switzerland. Of 169 implants originally placed 71 implants were already lost before the first consultation. 14 patients had no complaints other than implant loss. The other 62 patients complained about varying degrees of pain, swollen midface, pussy exudates, paresthesia etc. In 3 patients implants had been failing repeatedly. CBCT showed in 58 patients maxillary sinusitis, in 4 patients half‐sided pan‐sinusitis. In 11 patients, nasal fiberoptic endoscopy was carried out. Further investigations consisted of bacteriology, mycology and histology. Reasons for sinusitis were attributable to postoperative blowing of the nose, infection of the graft, antiresorptive drugs, peri‐implantitis reaching the floor of the sinus and allergic reaction to sinus grafting material mixed with collagen. Another reason for implant loss was a failing graft without signs of sinusitis. Results: 53 implants had to be removed under Local Anaesthesia (LA), 9 implants could be left in situ. 8 patients did not need surgical intervention for sinusitis but only antibiotic treatment. 41 patients needed surgical intervention under LA for cleaning the sinus of infected graft material and closing of fistula. 27 patients needed surgical intervention under General Anaesthesia (GA) because of more extensive disease, removal of debris, fungi, dislocated dental implants and nasal endoscopy. 51 patients became pain free. In 11 patients some chronic pain remained. In 18 patients the sinus did not heal to a degree that re‐sinuslift was deemed appropriate. Whilst 29 patients were subsequently treated with dentures, 47 patients underwent a second surgery for new grafting procedures with autologous bone, followed by implant insertion. This was possible in 28 patients under LA, whilst 19 patients needed GA for reconstruction of lost maxillary structures with large mandibular or with hip bone graft. Conclusions and Clinical Implications: Whilst many complications after sinus lift are not severe and can be treated locally, some patients exhibit more severe problems with e.g. pan‐sinusitis and chronic sinusitis. Multidisciplinary cooperation between dentists, oral surgeons, and ear, nose and throat specialists can be very helpful in diagnosing and treating these cases. To estimate the chance for success of redo of sinus lift is rather difficult, especially when bone substitutes were used beforehand which may not have integrated