Peri-Implant Soft-Tissue Phenotype Modification for Refractory Peri-Implant Mucositis: A 12-Month Prospective...

This prospective observational study evaluated the clinical, ultrasonographic, and patient-reported (PROMs) outcomes following surgical treatment of refractory/recurrent peri-implant mucositis (PM) using implant decontamination combined with soft tissue phenotype modification via a free gingival graft (FGG).

Subjects presenting with PM unresponsive to two consecutive cycles of non-surgical therapy-and exhibiting both inadequate midbuccal mucosa width (KMW ≤ 1 mm) and absence of adherent/firm mucosa (AM)-were included. Treatment consisted of an apically positioned flap (APF) with thorough decontamination of implant surfaces and restorative components, combined by placement of a facial FGG. Clinical, high-frequency ultrasonographic, and PROMs data were assessed at 2 weeks, and at 3, 6, and 12 months post-operatively.

Twenty subjects with 27 implants were treated. At 12 months, 22 implants (81.5%) were classified as clinically healthy. Significant reductions were observed in bleeding on probing (-85.2%), suppuration (-18.5%), and probing pocket depth (PPD: -0.3 mm). In parallel, significant gains were noted in KMW (+4.42 mm), mucosal recession coverage (+45.7%), and mucosal thickness (MT: +0.87 and 1.04 mm at 1.5 and 3 mm apical to the mucosal margin, respectively). Ultrasonography revealed significantly decreased perfusion parameters and a marked increase in tissue "stiffness" in the coronal facial zone, with 100% of treated sites exhibiting a non-displaceable band of AM. PROMs showed marked improvements in overall discomfort, discomfort during probing, and overall satisfaction.

Within the limitations of this study, surgical treatment of refractory PM using APF + FGG was effective in disease resolution, achieving reductions in PPD and clinical inflammation, significant gains in MT and KMW, partial recession coverage, and the re-establishment of a non-mobile band of AM. Ultrasonographic data confirmed reduced inflammatory perfusion and enhanced soft tissue stiffness in the grafted area, particularly in the most coronal region.