Study Year of
publication 		Type of study Country Graft dimension groups
(n) 		Graft measurement Donor site treatment Outcome measurements Main findings
Thickness Height Width
Tavelli et al. [11] 2018 Randomized clinical trial Italy ≤ 1.5 mm;
> 1.5 mm 		≤ 4 mm;
> 4 mm 		< 14 mm;
≥ 14 mm 		Periodontal probe Haemostatic porcine absorbable sponge alone or associated with tissue adhesive Visual analog scale analysis on days 1, 2, 3, 4, 5, 6, 7, 10, and 14 postoperative Graft width minor than 14 mm was related to less visual analog scale pain (days 3, 4, 6, 7, 10, and 14, P < 0.05).
Height and thickness did not show significant difference for perceived pain
(P = 0.05)
Wyrębek et al. [17] 2018 Prospective non-randomized Poland ≤ 2 mm
(n = 30);
> 2 mm
(n = 30) 		Not evaluated ≤ 10 mm
(n = 20) 		Periodontal probe Haemostatic sponge Pain visual analog scale analysis on day 7 postoperative Graft length and thickness did not influence the VAS pain
10 to 20 mm
(n = 20)
≥ 20 mm
(n = 20)
Zucchelli et al. [23] 2014 Randomized clinical trial Italy ≥ 2 mm
(n = 30);
< 2 mm
( n = 30) 		Equal to bone dehiscence
(n = 30);
4 mm
(n = 30) 		Not evaluated Periodontal probe Equine-derived collagen and suture Postoperative pain indirectly evaluated, on day 7, based on the mean analgesic intake Pain killer consumption was higher for bigger grafts group (P < 0.01)
Burkhardt et al. [28] 2015 Prospective non-randomized Switzerland ≤ 1 mm
(n = 16);
1.01 to 2 mm
(n = 49);
> 2 mm
(n = 25) 		Not evaluated Not evaluated Ultrasonic device and periodontal probe Gauze soaked in saline and a 15% ferric sulphate solution in case of bleeding Visual analog scale analysis on days 1, 3, 7, 14, 21, and 28 postoperative From day 1 until day 7 the visual analog scale pain values were directly related to the increase of the graft thickness.
The reduction of the graft thickness to less than 2 mm reduced the visual analog scale pain values by more than a half at the postoperative days 1, 3, and 7 (P < 0.05)

N = number of group population, VAS = visual analog scale.