Perbedaan indeks plak pada penggunaan sikat gigi ortodonti dan sikat gigi konvensional pada pasien perawatan ortodonti cekat penelitian klinis di RSKGM-P FKG UI = Plaque index differences in the use of orthodontic toothbrush and conventional toothbrush in patients with fixed orthodontic appliances clinical research in RSKGM-P FKG UI