Is the presence of keratinized mucosa associated with periimplant tissue health? A clinical cross-sectional analysis

Background: Long-term data concerning the impact of missing keratinized mucosa (KM) on periimplant tissue health are rare. The importance of KM for implant success remains unclear. Methods: Two hundred eleven patients with 967 dental implants were analyzed up to 15 years after implant placement. Implants were divided into two groups: no keratinized mucosa (NKM) and KM. Evaluated parameters were plaque index (mAPI), bleeding index (mSBI), bleeding on probing (BOP), probing depth (PD), width of KM, and radiographic vertical bone level. Results: mAPI, mSBI, and BOP were significantly higher for the NKM group. Implants of both groups showed no significant difference in PD and vertical bone level. Of the implants in the posterior regions (n = 261), 40.3% (regions 37 to 34, 44 to 47, 27 to 24, 17 to 14) showed NKM, whereas 30.4% of the implants in the anterior regions (regions 13 to 23; regions 33 to 43) presented NKM (n = 97). Conclusions: Results indicate that the presence of KM has a positive effect on periimplant tissue health, but does not seem to have an influence on the periimplant bone level.