Microbial adherence on vacuum-formed retainers with different surface roughness as constructed from conventional stone models and 3D printed models: a randomized controlled clinical trial.

Objective: This single center parallel, randomized controlled trial aimed to determine the propensity of microbial adherence on vacuum-formed retainers (VFRs) with different surface roughness imprints.

Materials And Methods: Thirty-six patients debonded from fixed appliances at a teaching institution were allocated by block randomization stratified for gender to three groups [VFRs fabricated on conventional, fused deposition modeling (FDM) or stereolithography apparatus (SLA) working models]. Participants wore the VFRs for three months full-time followed by three months part-time.