Peri-Implant Soft-Tissue Phenotype Modification for Refractory Peri-Implant Mucositis: A 12-Month Prospective Clinical Study With Ultrasonographic Analysis.

AIM: 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).

METHODS

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.

RESULTS

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.

CONCLUSION

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.