Comprehensive update on implants in patients with head and neck cancer (2021–2024): systematic review and meta-analysis of the impact of radiotherapy and chemotherapy on implant survival

Objectives: This study aimed to investigate implant outcomes in patients with head and neck cancer undergoing radiotherapy or chemotherapy by incorporating the latest research findings. Methods: The present review was conducted to update the focused question: What is the survival rate of implants placed in patients with head and neck cancer receiving radiotherapy or chemotherapy compared to non-irradiated patients? It built upon two previous systematic reviews (2014 and 2022) and provided an updated synthesis of the literature, focusing on clinical studies published between 2021 and 2024. The earlier reviews were included in the quantitative synthesis only to offer a broader longitudinal perspective. Results: Nine studies were identified, with seven included in the quantitative synthesis and meta-analysis. The implant survival rate was significantly lower in irradiated patients (85.6%) compared to non-irradiated patients (90.0%) (RR = 1.62, 95% CI: 1.33-1.98, p < 0.0001, I2 = 0.2%). Additionally, implant failure risk was higher in grafted bone (RR = 2.03, 95% CI: 1.39-2.96, p = 0.0018, I2 = 21.9%) than in native bone. Among irradiated patients, those receiving radiochemotherapy exhibited an even greater risk of implant failure (RR = 1.97, 95% CI: 1.09-3.56, p = 0.0331, I2 = 0%) compared to non-irradiated patients. Conclusions: Current evidence indicates that radiotherapy/chemotherapy significantly increases the risk of implant loss in patients with head and neck cancer, with higher radiation doses possibly being associated with increased peri-implant bone loss, while implants placed in native bone exhibit a lower risk of failure compared to those placed in grafted bone.