Dental implants have transformed oral rehabilitation, exhibiting high survival rates; however, biological complications such as peri-implant mucositis and peri-implantitis remain prevalent. Poor oral hygiene is a recognized risk factor for these conditions, yet region-specific evidence, particularly in Saudi Arabia, is limited. This retrospective study aimed to evaluate the association between patient oral hygiene status and dental implant failure rates at Riyadh Elm University (REU) clinics. Clinical records of patients aged 18 years and above who received one or more implants at REU and were followed for at least 12 months were reviewed. Data extracted included demographics, systemic health, smoking status, implant details, oral hygiene indicators (plaque index, gingival index, brushing frequency, use of interdental aids, and professional maintenance), and implant outcomes. Two trained data extractors independently collected data, with inter-examiner reliability assessed via Cohen’s kappa. Statistical analyses were performed using SPSS 22, including descriptive statistics, chi-square tests, and logistic regression to adjust for potential confounders such as smoking, diabetes, and history of periodontitis. Significance was set at p<0.05. Among 350 patients, 41.7% of implants failed, with failure significantly associated with higher plaque and gingival indices (p<0.01). Patients with mild plaque had 60% implant survival, compared to 15% in those with severe plaque. Marginal bone loss correlated with poor oral hygiene. Logistic regression indicated poor hygiene as an independent predictor of implant failure, even after adjusting for confounding factors. Gender, systemic disease, and implant site showed variable associations with outcomes. Poor oral hygiene is significantly associated with increased dental implant failure and marginal bone loss. Regular maintenance, effective plaque control, and patient education are essential to improve implant survival. These findings support the implementation of tailored preventive protocols within REU clinics to optimize long-term implant outcomes.
