Objective: The reliability of posttreatment canine-to-canine retention with resin composite retainers reinforced with plasma-treated woven polyethylene ribbons was compared to the reliability of directly bonded, multistranded wire retainers. Method and materials: This prospective study was based on an assessment of 20 consecutive patients (eight women and 12 men with a mean age of 22.4 years) who required a fixed canine-to-canine retainer after undergoing orthodontic treatment. The type of retainer used was randomized for each patient. A follow-up examination was carried out once every 3 months. The length of time the retainers stayed in place without resin fracture or loosening from the teeth at one or more points was evaluated. The study's endpoint was 24 months after the retainer had been bonded. Results: The ribbon-reinforced retainer remained in place for an average of 11.5 months, and the multistranded wire for a mean of 23.6 months. The difference was statistically significant. Conclusion: In terms of reliability for permanently fixed orthodontic retention from canine to canine, the direct-bonded multistranded wire is superior to the plasma-treated polyethylene woven ribbon and resin retainer.