Clinical, Microbiological, Mechanical and Optical Behaviour Of Zirconium Oxide Nanoparticle coated Orthodontic Thermoformed Retainers - A Randomized Controlled Trial

Title: Clinical, Microbiological, Mechanical, and Optical Behaviour of Zirconium Oxide Nanoparticle-coated Orthodontic Thermoformed Retainers - A Randomized Controlled Trial

Aim: To compare and evaluate the Clinical, Microbiological, Mechanical, and Optical performance of Uncoated orthodontic thermoformed retainers and Zirconium Oxide nanoparticle-coated orthodontic thermoformed retainers.

Objectives:

1. To evaluate the clinical effectiveness including retention characteristics
2. To examine biological properties such as plaque biofilm formation and microbial adhesion.
3. To determine mechanical properties, including water sorption, dimensional stability, and coating wear.
4. To analyze optical properties, including transparency and staining over time.

Rationale: Thermoformed retainers are widely used for orthodontic retention, but they are prone to discoloration, biofilm accumulation, and mechanical wear, affecting their clinical performance and esthetics. This study aims to evaluate whether material modifications can improve the biological safety, mechanical durability, and optical stability of retainers compared to conventional ones.

Sample Size: 22 participants (11 per group).

Group 1: Uncoated thermoformed retainers

Group 2: Zirconium Oxide nanoparticle-coated thermoformed retainers

Methodology: This is a randomized controlled, parallel-arm clinical trial. Participants who have completed orthodontic treatment will be randomly assigned to Group 1 and Group 2.

Randomization will be done using a computer-generated sequence with allocation concealment through sealed envelopes. Outcome assessment will be double-blinded. Clinical, microbiological, mechanical, and optical parameters will be recorded at baseline (T0) and after 6 months (T1). Data collection will include standardized measurements along with photographic documentation.

Ethical Considerations: The study has been applied for Institutional Ethics Committee approval. Written informed consent will be obtained from all participants (and from parents/guardians in case of minors) before inclusion in the trial.