Clinical and volumetric analysis of peri-implant soft tissue augmentation using an acellular dermal matrix: a prospective cohort study

Background: The role of keratinized mucosa in promoting peri-implant health is controversial, however recent evidence support the use of soft tissue augmentation procedures around dental implants. Soft tissue substitutes have been proposed to replace autogenous connective tissue grafts, therefore the aims of this study are to report clinical and volumetric three-dimensional changes in mucosal thickness (MT) 1 year after treatment with an acellular dermal matrix (ADM). Methods: Soft tissue augmentation was performed at second-stage surgery in the premolar maxillary area with an ADM. MT was assessed prior to implant placement and 1, 6, and 12 months after treatment. Digital linear and volumetric measurements were recorded at baseline and after 1 and 12 months. Furthermore, clinical parameters (Probing Pocket Depths, Bleeding On Probing, Plaque Index) and marginal bone loss were also recorded. Esthetic outcomes of treatment were evaluated objectively using the Pink Esthetic Score and through patient reported outcomes. Results: Twelve patients were enrolled in this prospective study. Post-hoc analysis of the assessments with Tukey's honestly significant difference adjustment revealed that the MT had increased significantly from baseline to 1 month (P < 0.001), 6 months (P < 0.001) and 12 months (P < 0.001), and remained stable between 6 months and 12 months (P > 0.05). Based on the volumetric evaluation, a shrinkage of 23.31% occurred from 1 month to 12 months (P > 0.05). Conclusions: A significant increase in MT was reported after 1 year, with a mean gain of 1.25 mm. Soft tissues were stable, with no statistically significant differences between 6 months and 1 year.