Table 3.

Mean Ra values (μm) of the enamel before and after hygiene maintenance procedures, M (σ).

Substrate	USS		p Value	APPCC		p Value	APPSB		p Value
	Baseline	Post treatment		Baseline	Post treatment		Baseline	Post treatment
Enamel	1.01 (0.22)	1.18 (0.18)	0.058	1.11 (0.28)	1.32 (0.25)	0.083	1.13 (0.29)	1.40 (0.31)	0.047 *

*—significant differences between pre- and post-treatment values; USS—ultrasonic scaling; APPCC—air-powder polishing using calcium carbonate; APPSB—air-powder polishing using sodium bicarbonate.