[Short-term clinical efficacy of a collagen matrix and free gingival graft in augmenting keratinized mucosa around dental implants].

To compare the short-term outcomes of a collagen matrix (CM) and free gingival graft (FGG) in augmenting keratinized mucosa around dental implants. Nineteen partially edentulous patients who had undergone implant surgery or implant review from June 2017 to June 2018 at Department of Periodontology, Peking University School and Hospital of Stomatology with lack of keratinized mucosa at buccal aspect of implants (<2 mm) were recruited in this study. According to the width of keratinized mucosa (KW) pre-operation, 9 patients including 5 males and 4 females were assigned into control group (KW<0.5 mm) which performed free gingival graft (17 implants) and 10 patients including 3 males and 7 females were assigned into experimental group (KW≥0.5 mm) which used collagen matrix as the grafts (15 implants). The KW at buccal aspect of each implant were measured pre-operation and 2 weeks, 1 month, 2 months, 3 months after surgery respectively. Each of the patients was required to fill out a questionnaire using a visual analogue scale to assess the postoperative morbidity. The KWs around implants were increased significantly during the 3 months follow-up period in both groups (0.01). At 3 months after surgery, KW gain in control group was (3.44±1.64) mm, in experimental group was (2.30±0.82) mm, the difference between two groups was statistically significant (0.05). Meantime, the total shrinkage of KW in control group [(34±25)%] and experimental group [(51±11)%] also showed a statistically significant difference (0.01). However, by using collagen matrix as the grafts, augmented tissues had a much more comparable appearance with adjacent tissues than that in control group. And the patients of experimental group experienced much less postoperative bleeding than those of control group. Both collagen matrix and free gingival graft can significantly increase the KW around implants within the 3 months post-surgery follow-up period. There were more KW gain and less shrinkage in group FGG than that in group CM. However, surgery time were reduced and the postoperative bleeding were less in group CM than in group FGG as no harvesting procedure was needed.