RESUMO
OBJECTIVES: This study aimed to evaluate the clinical effects of xenogeneic collagen matrix (XCM) in augmenting keratinized mucosa width (KMW) around dental implants. MATERIALS AND METHODS: Articles that were published before or during April 2020 were electronically searched in four databases without any date or language restrictions and manually searched in regular journals and grey literature. The eligibility criteria comprised randomized controlled trials (RCTs) or prospective studies that analysed the clinical efficacy of XCM for augmenting KMW around dental implants. This systematic review (SR) was registered in PROSPERO under number CRD42018115399. RESULTS: Eleven studies published between 2009 and 2019 were included in this SR. There was no significant difference in KMW increase (p = 0.14), probing depth (PD) decrease (p = 0.17) or participants' aesthetic satisfaction (PAS) (p = 0.32) when XCM was compared to connective tissue graft (CTG). However, the increase in gingival thickness (GT) was significantly higher (p = 0.001) with the use of CTG. CONCLUSIONS: The use of XCM improved KMW and PD with rates comparable to those for CTG. XCM showed lower results for GT when compared to CTG. XCM presented similar results in terms of PAS when compared to CTG. CLINICAL RELEVANCE: The presence of a KMW around dental implants is associated with better peri-implant tissue health.