Risk Factors Influencing the Success of Dental Implants: A Comprehensive Review

Abstract Several systemic and local factors influence the success of dental implants. Smoking impairs tissue healing, reduces osteoblast activity, and increases implant failure rates—roughly twice as high as in non-smokers. Diabetes, though not always a direct risk factor, contributes to post-surgical complications due to impaired bone metabolism and inflammatory responses. Long-term studies show similar survival rates in diabetic and non-diabetic patients, though increased bone resorption is observed. Osteoporosis leads to reduced bone density and quality, especially in older women. While implant failure rates are not significantly different in osteoporotic patients, marginal bone loss is often greater. Bone quality, measured using tools like CT and resonance frequency analysis, correlates strongly with implant stability and success. Bruxism, a parafunctional habit involving tooth grinding, causes excessive occlusal loading on implants, increasing the risk of complications like fractures and screw loosening. Studies show slightly lower survival rates in bruxers, particularly in men. Finally, implant surface characteristics play a critical role in osseointegration. Rough surfaces enhance initial bone contact but may lead to greater marginal bone loss over time compared to machined surfaces. Ongoing research is needed to optimize implant designs and treatment protocols for high-risk patients.