Table 2.

Mean PHD measurements by 13 dental professionals (both measurement timepoints)

1st round of assessment – initial interdental brush set analysis (Interprox Plus, Dentaid, Barcelona)
	Nano	Super micro	Micro	Mini-conical	Mini	Conical	Maxi	x-maxi	xx-maxi
Arithmetic mean	0.7	0.9	1.0	1.3	1.3	1.6	2.4	2.4	3.1
Standard deviation	0.1	0.1	0.2	0.2	0.2	0.2	0.4	0.5	0.7
Median	0.7	0.9	1.0	1.2	1.3	1.6	2.2	2.2	2.9
2nd round of assessment – first prototypes
	PT 0 / InterproxMaxi without handle	PT i3#1	PT i4#1	PT i5#1	PT i6#1	PT i6#2	PT i7#1	PT i7#2	PT i8#1
Arithmetic mean	2.35	1.0	1.3	1.6	2.4	1.7	2.6	2.7	3.0
Standard deviation	0.4	0.1	0.2	0.3	0.4	0.3	0.6	0.8	0.6
Median	2.25	1.1	1.3	1.6	2.2	1.6	2.4	2.4	2.8
3rd round of assessment – second prototypes
	PT i4#2	PT i4#3	PT i5#2	PT i5#3	PT i5#4	PT i5#5	PT i6#3	PT i6#4	PT i7#3	PT i8#2	PT i8#3
Arithmetic mean	1.4	1.4	2.2	1.8	1.9	2.2	2.7	2.3	2.4	3.1	2.8
Standard deviation	0.27	0.22	0.51	0.3	0.3	0.5	0.7	0.5	0.5	0.9	0.6
Median	1.3	1.4	2.1	1.7	1.7	2.2	2.5	2.0	2.3	2.7	2.6

PT = Prototype.