The purpose of this study was to compare the outcomes of a modified gingival graft technique, in which the released flap is positioned and sutured over the graft, with the conventional free gingival graft (FGG) procedure, when both are used for gingival augmentation. A 12-month, multicenter parallel randomized controlled trial was conducted. Subjects with buccal RT2 gingival recessions and keratinized tissue width (KTW) < 2 mm in at least one mandibular incisor were randomized to control group (n = 20; conventional FGG) or test group (n = 20; modified FGG; flap sutured over FGG using sling sutures). The primary outcome (KTW) was measured at baseline and after 3, 6 and 12 months, as was keratinized tissue thickness (KTT). Postoperative pain (POP) and analgesic intake were also recorded. Both techniques promoted a significant increase in KTW and KTT when compared to baseline (p < 0.05) with no significant differences between groups (KTW change of 6.1±1.5 mm and 5.4±1.6 mm, for control and test, respectively; p=0.16). However, test group patients reported less POP after 7 days and used less analgesic medication than control group patients (p < 0.05). We concluded that the modified FGG was comparable to conventional FGG in augmenting keratinized tissue width and thickness at mandibular incisors, but resulted in less patient morbidity.