Multiple failing maxillary implants in full arch rehabilitation- results of retreatment

15701 POSTER WITH ORAL PRESENTATION CLINICAL RESEARCH – PROSTHETICS

Background

Current implant research is shifting from survival to success, but failure is still an important topic to consider. When implants fail, there is often no fixed prosthetic alternative and retreatment is proposed. Current research on retreatment is predominantly based on single, early failures with survival rates varying between 71.0 and 94.6%. Retreatment of late and multiple failure is rarely described, despite the increasing incidence of failure due to peri-implantitis.

Aim/Hypothesis

The aim of this study was to assess implant retreatment in a group of patients with multiple failing implants after full maxillary rehabilitation, by implant removal, maxillary augmentation and placement of an overdenture supported by four to six implants.

Material and Methods

All consecutive patients (n = 16) referred for multiple late implant failures in rehabilitated maxillae between 2008 and 2018 were included in the study. The study was approved by the Medical Ethical Committee of UMCG. All patients were treated by removal of the failing implants combined with vertical and horizontal augmentation of the maxilla using the iliac, calvarial or maxillary tuberosity bone grafts. After four months of healing, four to six implants were placed in the maxilla. Four months later, a bar-retained overdenture was made. At time of last evaluation implant survival, complications, clinical parameters, change in peri-implant bone and patient-related outcome measures were recorded.

Results

76 implants were placed in 16 patients. One patient with six implants was lost to follow-up due to severe illness. Therefore, 70 implants in 15 patients were evaluated at 3.3 ± 2.5 years (range 1.1–8.6 years) after loading. Common complications were antrum perforation after implant removal (n = 4; 26.6%) and wound dehiscence after augmentation (n = 4; 26.6%). Complications did not interfere with successive implant placement. In all cases, enough bone volume was present to insert the implants. Overall implant survival was 95.7%. Three implant failures occurred within the first year of function. Peri-implant bone loss was 0.32 ± 0.46 mm, pocket probing depth was 4.55 ± 1.59 mm. Plaque, calculus, inflammation and bleeding were hardly seen (median 0). Patients scored high on satisfaction of their overdentures (mean overall score 8.7 ± 1.2, max. 10). Chewing soft and tough foods were scored as ëgoodí, hard foods were scored as ëmoderateí. Oral Health Impact Profile Score was 29.5 ± 33.3.

Conclusion and Clinical Implications

Removing multiple failing implants and immediate reconstruction of the maxilla with bone grafts is a safe and predictable treatment procedure when applied for an implant supported overdenture. Complications did not interfere with retreatment.