Comparative assessment of survival, stability and occlusal settling between full-time and part-time wear regime of two types of thermoplastic retainers: A randomised controlled clinical trial

Participants will be recruited from a private orthodontic practice located in Melbourne. Each patient will already have their retainer type (ie; Vivera® or Duran®) assigned in accordance with their preference. If they consent to be included in the study, they will then be randomly allocated in to either the full time (minimum 20hours of wear per day) or night time (Minimum 8hours and maximum 10hours) wear regime group for their respective retainer material and followed over a 6 month period. Adherence to the wear regime will be patient reported. The retainers and their care instructions will be delivered in person by specialist orthodontists with over 10years experience. In summary, Four patient groups: Vivera® - Full time and Night Time groups within this Duran® - Full time and Night Time groups within this Observation Period of 6 months - T0: Intra-oral scan for retainer manufacturing - T1: Insert retainers and begin observation period - T2: 8 week review including intra-oral scan - T3: 6 month review including intra-oral scan Primary Outcome: Survival rate compared between Vivera® and Duran®. This will be assessed for both a full time and night time only wear regime. Secondary Outcome/s: Occlusal stability and occlusal settling