Adolescents aged 12 to 20 years will be allocated to different groups based on treatment ( n = 16 per group ) : ( 1 ) placebo ; ( 2 ) 6.0 % hydrogen peroxide ( White Class with Calcium , FGM ) ; ( 3 ) 7.5 % hydrogen peroxide ( White Class with Calcium , FGM ) ; and ( 4 ) 7.5 % hydrogen peroxide ( Oral B 3D White , Oral-B ) .