Evaluation of the efficacy of keratinized mucosa augmentation techniques around dental implants: a systematic review.

STATEMENT OF PROBLEM: The absence of periimplant keratinized mucosa is considered risky in patients with a predisposition to periodontitis or recession. Although various soft tissue augmentation techniques exist, dentists are seeking for more efficient approaches to augment periimplant keratinized mucosa. PURPOSE: The purpose of this systematic review was to evaluate the efficacy of the various techniques and biomaterials adopted in periimplant keratinized mucosa augmentation and whether one technique or biomaterial is superior. MATERIAL AND METHODS: A search in Medline-PubMed and the Cochrane Central Register of controlled trials was conducted. Randomized clinical trials, prospective cohort studies, clinical control studies, and case series from January 1, 1980, to December 31, 2013, with a follow-up of at least 6 months reporting changes on keratinized mucosa width were included. Several journals were hand-searched for related articles. The bibliographies of all publications selected for inclusion were also scanned. RESULTS: The screening of titles and abstracts resulted in 60 relevant publications. Six of them were finally included. Free gingival graft, connective tissue graft, acellular dermal matrix, and collagen matrix were used for keratinized mucosa augmentation. Because of heterogeneity of the studies, only descriptive analysis was performed. Improvements in keratinized mucosa width were reported in all studies. CONCLUSIONS: A definitive conclusion could not be achieved owing to the lack of well-designed studies and appropriate methods of studying soft tissue. The establishment of universal surgical guidelines and measurement systems is imperative in the future.