Table 2. Comparison of gelatinolytic activity of MMPs in irradiated and / or demineralized permanent teeth, performed by means of in situ zymography. The integrated density of fluorescent signal / mm2 (median and interquartile range) in the cervical region, at the cusp and at the groove was measured at the same depth and in the same area.

Variable	Cervical	Cusp	Groove

	arbitrary units (mm²)	arbitrary units (mm²)	arbitrary units (mm²)
Healthy	15.265 (12.594–17.170)^A	13.921 (13.056–15.703)^A	13.758 (13.234–16.315)^A
Demineralized	21.935 (20.992–26.714)^A.B	22.784 (21.562–23.482)^A.B	21.219 (20.407–21.815)^A.B
Irradiated	29.087 (28.446–29.591)^B	27.472 (25.870–29.013)^B	31.707 (28.654–35.317)^B
Irradiated + Demineralized	40.490 (39.426–42.080)^C	46.328 (43.097–50.409)^C	48.285 (46.511–51.093)^C

Different letters indicate statistically significant differences within the column.