Table 2.

Mean ± SE (mm) registered for the changes of gingival margin height; n = 32 (Max = 13 and Mand = 19)

				Pre-post operation (TP-T0)	Baseline − 1 month (TP-T1)	Baseline − 3 months (TP-T3)	Baseline – 6 months (TP-T6)	p-valuea
Buccal height (BH)	Total change	Maxillary		-0.57 ± 0.15*	-0.90 ± 0.27*	-0.79 ± 0.33*	-0.83 ± 0.31*	0.010*
		Mandibular		-0.42 ± 0.22	-0.73 ± 0.34	-0.79 ± 0.31	-0.86 ± 0.33	0.227
		All		-0.48 ± 0.14*	-0.79 ± 0.23*	-0.79 ± 0.22*	-0.85 ± 0.23*	0.017*
	Intra-period change			-0.48 ± 0.14*	-0.31 ± 0.16	0.01 ± 0.07	-0.06 ± 0.06	0.017*
Palatal/ Lingual height (LH)	Total change	Maxillary		-0.51 ± 0.12*	-0.93 ± 0.16*	-1.01 ± 0.16*	-1.09 ± 0.17*	0.005*
		Mandibular		-0.45 ± 0.17	-1.01 ± 0.17*	-1.08 ± 0.17*	-1.22 ± 0.16*	< 0.001*
		All		-0.47 ± 0.11*	-0.98 ± 0.12*	-1.05 ± 0.12*	-1.17 ± 0.11*	< 0.001*
	Intra-period change			-0.47 ± 0.11*	-0.50 ± 0.11*	-0.07 ± 0.05	-0.12 ± 0.03*	< 0.001*
				Pre-post operation (T P -T 0 )	Baseline − 1 month (T 0 -T 1 )	Baseline − 3 months (T 0 -T 3 )	Baseline – 6 months (T 0 -T 6 )	p -value a
Mesial height (MH)	Total change	Maxillary		NA	0.14 ± 0.20	0.02 ± 0.20	-0.11 ± 0.21	0.338
		Mandibular		NA	-0.23 ± 0.22	-0.38 ± 0.24	-0.45 ± 0.23	0.072
		All		NA	-0.08 ± 0.16	-0.22 ± 0.17	-0.31 ± 0.16	0.017*
	Intra-period change			NA	-0.08 ± 0.16	-0.14 ± 0.06	-0.10 ± 0.05	0.017*
Distal height (DH)	Total change		Maxillary	NA	-0.52 ± 0.21	-0.48 ± 0.17	-0.41 ± 0.14	0.122
			Mandibular	NA	-0.14 ± 0.20	-0.03 ± 0.19	-0.05 ± 0.19	0.447
			All	NA	-0.30 ± 0.15	-0.21 ± 0.14	-0.20 ± 0.13	0.216
	Intra-period change			NA	-0.30 ± 0.15	0.09 ± 0.06	0.01 ± 0.07	0.216

^a Multivariate test. *Statistically significant values (p-value < 0.05)

Positive and negative valves indicate gingival margins higher and lower, respectively

NA: nonapplicable. The proximal sides could not be identified for the pre-operation stage (T_P).