The association between shallow vestibular depth and peri-implant parameters: a retrospective 6 years longitudinal study.

Abstract

The aim of this study was to retrospectively evaluate the association between shallow vestibular depth (VD) and peri-implant parameters. Peri-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. Sites with shallow VD (≤ 4 mm) were associated with higher MR (0.91 mm versus 0.47 mm, p ≤ 0.009), higher RAL (4.23 mm versus 3.59 mm, p ≤ 0.0001) and higher RBL (2.18 mm versus 1.7 mm, p = 0.05) when compared with adequate vestibular depth sites (VD > 4 mm). Moreover, sites with shallow VD presented lower KMW compared with sites with adequate VD (1.24 mm versus 2.38 mm, respectively, p ≤ 0.0001). 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. Based 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.