Table 1.

Interdental brushes selected for use with the FD and the PE model. CSs were provided with funnel-shaped openings with triangular cross-sections. Opening size (diameter of the incircle to the triangular cross-section) at the narrowest part was either 1.5 mm or 2.5 mm depending on the IDB size. For the PE model, guide surfaces with an offset distance of either 1.0 mm or 2.0 mm from the respective tooth surfaces were added to the CSs.

Model	Interdental Space or Tooth Surface *	IDB Type	IDB Wire Diameter/Brush Diameter	CS Opening Size/Guide Surface Offset
FD	17 d, 17/16, 26/27, 27 d	CPS 07	0.7 mm/2.5 mm	1.5 mm/-
	16/15, 24/25, 25/26	CPS 08	0.8 mm/3.2 mm	1.5 mm/-
	15/14, 14/13, 23/24	CPS 11	1.1 mm/5.0 mm	1.5 mm/-
	13/12, 12/11, 21/22	CPS 405	1.3 mm/5.0 mm	1.5 mm/-
	11/21	CPS 406	1.7 mm/6.5 mm	2.5 mm/-
	22/23	CPS 408	2.2 mm/8.0 mm	2.5 mm/-
PE	17 d, 26 d	CPS 07	0.7 mm/2.5 mm	1.5 mm/1.0 mm
	17 m, 15 m/d, 13 m/d, 11 m/d, 22 m/d, 24 m/d, 26 m	CPS 406	1.7 mm/6.5 mm	2.5 mm/2.0 mm

* m: mesial tooth surface/d: distal tooth surface.