Authors' Contributions
orthodontic
DHA conceptualized and designed the study, interpreted the results, contributed to critical revision, and finally approved the manuscript. SIK collected data, analysed the study, performed statistics, and wrote the manuscript. All authors have approved the final version of the manuscript.Acrylic tiles made from polished and unpolished acrylic sheets.Construction of a modified acrylic-based orthodontic appliance. (a) Study model with metal discs; (b) fitting surface of the removable acrylic appliance with a chimney-like structure.Each appliance contained eight wells to house: four (5.5 mm) diameter polished tiles (yellow) and four similar diameter unpolished tiles (purple). The allocation of the polished tiles to the left or right sides, anterior or posterior of the removable appliance, was decided by a randomized number sheet; the unpolished tiles were subsequently inserted into the wells on the contralateral side.CONSORT flow diagram of subject randomization and selection criteria.Bar chart of streptococci and total anaerobic bacteria among groups on polished and unpolished tiles. Error bars represent the standard error of measurements for 13 patients in three separate sample runs (Bar chart of staphylococci among groups on polished and unpolished acrylic tiles. Error bars represent the standard error of measurements for 13 patients in three separate sample runs (SEM micrographs of retrieved acrylic tiles. (a–c) The unpolished acrylic tiles cleaned with the Lacalut cleaning tablet, brushing with CHX toothpaste, and a combination of methods, respectively. (d–f) The polished acrylic tiles cleaned with the Lacalut cleaning tablet, brushing with CHX toothpaste, and a combination of methods, respectively, using conventional laboratory polishing procedures.Comparison of bacterial biofilm on polished tiles among the three cleaning methods using the ANOVA test.Comparison of bacterial biofilm on unpolished tiles among the three cleaning methods using the ANOVA test.Comparisons of bacterial biofilm on polished and unpolished acrylic tiles of three cleaning methods using the independent 
