The amount of keratinized mucosa may not influence peri-implant health in compliant patients: A retrospective 5-year analysis.

AIM: (a) To investigate the influence of the keratinized mucosa (KM) on peri-implant health or disease and (b) to identify a threshold value for the width of KM for peri-implant health. MATERIALS AND METHODS: The total dataset was subsampled, that is one implant was randomly chosen per patient. In 87 patients, data were extracted at baseline (prosthesis insertion) and 5 years including the width of mid-buccal KM, bleeding on probing, probing depth, plaque index and marginal bone level (MB). Spearman correlations with Holm adjustment for multiple testing were used for potential associations. RESULTS: Depending on the definition of peri-implant diseases, the prevalence of peri-implantitis ranged from 9.2% (bleeding on probing threshold: <50% or >/=50%) to 24.1% (threshold: absence or the presence). The prevalence of peri-implant mucositis was similar, irrespective of the definition (54%-55.2%). The width of KM and parameters for peri-implant diseases demonstrated negligible (Spearman correlation coefficients: -0.2 < rho < 0.2). No threshold value was detected for the width of mid-buccal KM in relation to peri-implant health. CONCLUSION: The width of KM around dental implants correlated to a negligible extent with parameters for peri-implant diseases. No threshold value for the width of KM to maintain peri-implant health could be identified.