Variable S group M group GM group S vs. M S vs. GM M vs. GM
Mean (SD) in mm P-value
Socket type 1
ΔHVC -1.08 (0.71) -0.52 (0.64) -0.49 (0.26) < 0.0001a < 0.0001a 0.0561b
ΔHLC -0.92 (0.48) -0.43 (0.28) -0.41 (0.59) < 0.0001a < 0.0001a 0.0542b
ΔRW -2.41 (0.58) -0.31 (0.35) -0.27 (0.47) < 0.0001a < 0.0001a 0.0748b
Socket type 2
ΔHVC -1.56 (0.39) -0.69 (0.27) -0.42 (0.73) < 0.0001a < 0.0001a < 0.0001a
ΔHLC -1.67 (0.72) -0.52 (0.69) -0.37 (0.81) < 0.0001a < 0.0001a < 0.0001a
ΔRW -2.97 (0.61) -1.16 (0.25) -0.88 (0.53) < 0.0001a < 0.0001a < 0.0001a
Socket type 3
ΔHVC -3.08 (0.71) -2.51 (0.19) -1.36 (0.27) 0.0179b < 0.0001a < 0.0001a
ΔHLC -2.92 (0.48) -2.39 (0.78) -1.18 (0.51) 0.0124b < 0.0001a < 0.0001a
ΔRW -4.41 (0.58) -3.94 (0.26) -2.73 (0.54) 0.0209b < 0.0001a < 0.0001a

aStatistically significant at P ≤ 0.05 (Kruskal-Wallis test).
bStatistically significant at P > 0.05 (Kruskal-Wallis test).
SD = standard deviation; ΔRW = changes in ridge width, ΔHVC = changes in height of the vestibular crest, ΔHLC = changes in height of the lingual crest; S = spontaneous healing; M = porcine-derived collagen membrane alone; GM = porcine-derived graft material associated with collagen membrane.