The dimensions of keratinized mucosa around implants affect clinical and immunological parameters

Abstract

Objectives: To investigate the association between keratinized mucosa (KM) width and mucosal thickness (MTh) with clinical and immunological parameters around dental implants. Methods: Sixty‐three functioning dental implants (3I osseotite) were examined. Clinical examinations included plaque index (PI), probing depth (PD), bleeding on probing (BOP), KM width, MTh and buccal mucosal recession (MR). Peri‐implant crevicular fluid (PICF) samples were collected for PgE2 assay. Results: KM width ranged from 0 to 7 mm (mean 2.5±2), MTh ranged from 0.38 to 2.46 mm (mean 1.11±0.4) and the mean MR was 0.62 mm, ranging from 0 to 3 mm. A negative correlation was found between MTh and MR (r=−0.32, P=0.01); Likewise, KM width showed a negative correlation with MR, periodontal attachment level (PAL) and PgE2 levels (r=−0.41, P<0.001; r=−0.26, P=0.04; r=−0.26, P=0.04, respectively). In contrast, a positive correlation was found between KM width and PD (r=0.27, P=0.03). When data were dichotomized by KM width, a wider mucosal band (>1 mm) was associated with less MR compared with narrow (≤1 mm) band (0.27 and 0.9 mm, respectively, P=0.001). A wider KM band was also associated with a greater PD (3.13 mm) compared with a narrow band (2.66 mm, P=0.04). Similarly, a thick mucosa (≥1 mm) was associated with lesser recession compared with a thin (<1 mm) mucosa (0.45 and 0.9 mm, respectively, P=0.04). Conclusion: The KM around dental implants affects both the clinical and the immunological parameters at these sites. These findings are of special importance in the esthetic zone, where thin and narrow KM may lead to a greater MR.