Participants’ preparation
Intraoral photographs with the standard-setting of the Canon EOS 800D camera (exposure time 1\125 s, iso speed 100, and focal length 55 mm) and periapical radiographs were first taken for the selected participants. The treatment plan was then developed, and all participants received scaling and polishing using medium grit fluoride-free polishing paste (PSP prophy paste, UK) with Colorful Nylon Polishing Brush (Azdent, china) in a low-speed contra-angle hand-piece (E-type Contra Angle, NSK, Japan). An oral hygiene training program was provided to all participants before a treatment based on official ADA dental health recommendations (