Changes of Keratinized Mucosa Width Around Posterior Implants: A Retrospective Cohort Study

To investigate the changes in keratinized mucosa width (KMW) at posterior implant sites through implant treatment procedures.

In this retrospective study, we measured the buccal KMW at three time points: immediately before implant placement (T0), before definitive prosthesis delivery (T1), and within 1 month after prosthesis delivery (T2). We analyzed changes in the KMW at the implant sites between these time points, using both submerged and non-submerged techniques.

A total of 72 patients and 98 implants were included. The KMW changed significantly from T0 to T1 (1.33 mm, 95% confidence interval [CI] [1.072, 1.561], p < 0.001) and from T0 to T2 (2.17 mm, 95% CI [1.929, 2.418], p < 0.001). No statistically significant differences were found in KMW changes between submerged and non-submerged implants from T0 to T1 (p = 0.556) or from T0 to T2 (p = 0.572). The height of the abutment was significantly related to the changes in KMW from T0 to T1 (-0.274 mm, 95% CI [-0.544, -0.004], p < 0.005), but implant technique, alveolar ridge preservation (ARP), and the diameter of the abutment were not (p > 0.05).

The KMW at posterior implant sites decreased significantly through implant treatment procedures, which were related to the height of abutment, but not to implant technique, history of ARP, or the diameter of abutment.