CTRI/2021/03/032110.

Study name	Comparison of effects of Essix and modified Essix retainer on final teeth positioning
Methods	Study design: double‐blinded (participant, outcome assessor), 2‐armed, parallel, randomised, active‐control trial Setting: conducted in a university and hospital setting Country: India Duration of follow‐up: debond, 3 months and 6 months Inclusion criteria  Male or female from 18‐40 years of age Patients who give consent for the proposed study Patients who have undergone fixed orthodontic treatment Patients who have completed their orthodontic treatment and are in retention phase of treatment Patients who are systemically healthy Exclusion criteria  Patients having craniofacial or dentofacial syndromes Patients treated for anterior open bite Patients suffering from diabetes Patients having habit of smoking Patients who are suffering from periodontal disorder Non‐compliant patients
Participants	The study aims to enrol and randomise 80 participants.
Interventions	Group 1: clear plastic (Essix) retainer. After completion of fixed orthodontic treatment, patients will be given Essix retainer to were in maxillary arch. Participant impression and bite registration will be taken at time of retainer delivery, 3 months and 6 months of retention; at 3 months and 6 months a questionnaire will also be given to participants to fill in. Group 2: modified clear plastic (Essix) retainer. After completion of fixed orthodontic treatment, participants will be given modified Essix retainer to wear in maxillary arch. Participant impression and bite registration will be taken at time of retainer delivery, 3 months and 6 months of retention; at 3 months and 6 months a questionnaire will also be given to patients to fill in. Participants will be instructed to wear the retainers 24 h/day for 6 months, excluding while eating and brushing their teeth.
Outcomes	Primary outcomes Change in occlusal contacts Change in patient compliance, assessed by questionnaires
Starting date	23 March 2021
Contact information	Principal Investigator: Dr Kalpesh Patel Institution: Department of orthodontics Manubhai Patel Dental College, India Email: dr_kalpeshp@yahoo.co.in
Notes	Contacted author, awaiting a response