Table 3.

EDS semi-quantitative chemical analysis on the deposits found in an orthodontic bracket slot used for 12 or 24 months

	12 months			24 months
Element	weight %	atomic %	Element	weight %	atomic %
C	62.7	78.3	C	53.4	63.4
O	13.8	13	O	37.5	33.5
Na	2.2	1.5	F	0.5	0.4
Mg	0.4	0.2	Na	0.5	0.3
Si	0.3	0.2	Al	0.4	0.2
P	2.5	1.2	Si	0.2	0.1
S	1.3	0.6	P	0.5	0.2
Cl	0.5	0.2	S	0.2	0.1
K	5.4	2.1	Cl	0.2	0.1
Ca	1.1	0.4	K	0.9	0.3
Cr	0.9	0.3	Cr	1.6	0.4
Fe	2.6	0.7	Fe	4.2	1.1
Cu	6.3	1.5
Total	100	100	Total	100	100