Distribusi elemen gigi yang mengalami periodontitis kronis pada penderita diabetes melitus tipe-2 studi retrospektif di klinik periodonsia rskgm fkg ui periode 2006-2016 = Distribution of teeth affected by chronic periodontitis in type 2 diabetic subjects a retrospective study in klinik periodonsia rskgm fkg ui periode of 2006 2016