Dental Biofilm Control During Orthodontic Treatment

The aim is: * to determine the clinical characteristics of gingiva of subjects not exposed to metals of dental alloys and exposed to metals * characterization of microbiome of dental biofilm in subjects not exposed to metals of dental alloys and exposed to metals and to determine changes in the structure of dental biofilm due to exposure to metals * examine the extent to which environmental influences modify the effectiveness of treatment of gingivitis by mechanical removal of biofilm and chemical control (chlorhexidine digluconate mouthwash (CHX)) * to examine the behavior of bacteria of early and late colonizers of dental biofilm after chemical control * to analyze biofilm on metal and non-metal appliance * to explore patient reported outcome measures Study design is a randomized controlled trial with 4 parallel groups: (I) fixed metal orthodontic appliance with regular oral hygiene, (II) fixed metal orthodontic appliance with CHX, (III) non-metal fixed orthodontic appliance with regular oral hygiene, and (IV) non-metal orthodontic appliance with CHX.