Clinical and radiographic peri-implant changes in patients with a history of COVID-19 infection: A 6-year prospective observational cohort study

Introduction The COVID-19 pandemic has impacted dental practice. While some studies suggest a link between COVID-19 and early implant failure, others report no adverse effects. This prospective observational cohort study aimed to evaluate long-term peri-implant tissue health and implant survival in patients with and without a history of COVID-19 infection. Methods Following the STROBE Statement, 44 implants (16 patients) placed prior to the pandemic were assessed over a maximum six-year period. Patients were divided into two groups based on COVID-19 history: exposure (16 implants) and non-exposure (28 implants). Clinical parameters including implant's probing depth (PD), bleeding index (BI), crestal bone loss (CBL), pain, mobility, and radiographic signs of failure were evaluated at two follow-up visits (2022 and 2024). Statistical analyses were performed with significance set at p < 0.05. Results All implants remained functional. However, CBL was significantly higher in the exposure group at the second follow-up (p = 0.044) and increased significantly in the exposure group over the time (p = 0.003). PD and BI increased significantly over time in both groups (p < 0.05). Conclusions Within the limitations of this cohort, a history of COVID-19 was associated with greater crestal bone loss around dental implants but did not compromise implant survival over six years.