Objective:Intercanine fixed lingual retainers have been used frequently to prevent relapse in ortodontic treatment. The aim of this study was to observe the survival of a fixed retainer made of a glass-fiber reinforced composite.Materials and Methods:The post-orthodontic treatment for a 25-year-old male was achieved with a glass-fiber reinforced composite (FRC)material(Splint-it,Jeneric-Pentron,USA).The FRC was used as a fixed lingual retainer in both maxillary and mandibular arches. The intercanine teeth were acid-etched (%35 orthophosphoric acid, 30 s.)and a bonding agent was applied. Following this, an adhesive was applied on the lingual aspects of the teeth and the glass-fiber was embedded in a high-viscosity composite and each tooth was light-cured for 40s. The lingual splint was covered with a low-viscosity composite and light-cured for 20 s.The patient was followed-up for 1,5 years.Results: During the retention period no damage or debonding was observed and the intercanine distance remained stable.Conclusion: The use of a glass-fiber reinforced composite as a splint material could be an alternative to conventional post-orthodontic treatment retention.