AimThe aim of this study was to retrospectively evaluate the association between shallow vestibular depth (VD) and peri-implant parameters. Material and MethodsPeri-implant parameters were evaluated in 61 periodontal patients under regular supportive periodontal therapy. Clinical parameters included gingival index (GI), plaque index (PI), bleeding on probing (BOP), peri-implant pocket depths (PPD), mucosal recession (MR), relative attachment level (RAL), width and thickness of keratinized mucosa (KMW, KMT) and VD. Radiographic bone level (RBL) was measured on peri-apical radiographs. ResultsSites with shallow VD (4mm) were associated with higher MR (0.91mm versus 0.47mm, p0.009), higher RAL (4.23mm versus 3.59mm, p0.0001) and higher RBL (2.18mm versus 1.7mm, p=0.05) when compared with adequate vestibular depth sites (VD >4mm). Moreover, sites with shallow VD presented lower KMW compared with sites with adequate VD (1.24mm versus 2.38mm, respectively, p0.0001). Slightly greater BOP, and GI were recorded for the shallow VD compared with adequate sites. According to multivariate analysis, factors that could predict RAL included: VD, GI, age, supporting periodontal therapy, implant type and design. ConclusionsBased on this study, inadequate vestibular depth around dental implants may be associated with increased peri-implant bone loss and mucosal recession. Further prospective and intervention studies will be required to fully understand this phenomenon.