Effects of IPR by mechanical oscillating strips system on biological structures: a quantitative and qualitative evaluation

Progress in Orthodontics

Table 1 Descriptive statistics and statistical comparisons (independent samples t-test) of the surface roughness and waviness measurements between enamel undergone the complete IPR oscillating system (Group 1) and enamel treated with single oscillating metallic strip (Group 2)

Variables	Enamel after IPR sequence		Enamel after single strip		Comparison		95% CI of the difference
	Mean	SD	Mean	SD	Diff.	P value	Lower	Upper
Ra (µm)	0.45	0.04	0.79	0.08	0.34	0.000	− 0.01	0.91
RSm (µm)	0.02	0.01	0.03	0.02	− 0.01	0.185	− 0.09	0.11
Rt (µm)	4.57	0.58	6.12	0.82	− 1.55	0.000	3.46	− 10.24
Wa (µm)	2.16	0.13	1.91	0.16	− 0.25	0.000	− 3.31	2.95
Wt (µm)	11.58	1.73	7.56	0.66	− 4.02	0.000	− 0.172	1.118

Ra arithmetic mean roughness value; RSm mean peak width; Rt total height of the roughness profile; Wa arithmetic mean waviness value; Wt total height of the waviness profile; µm micrometer; SD standard deviations; Diff. differences; CI confidence interval