Peri-implant mucosal recessions are a common complication in implant dentistry and usually occur at later stages following implant placement thus negatively affecting oral hygiene measures, esthetics and subsequently patient satisfaction. Despite its increasing prevalence, the scientific evidence for the treatment possibilities for peri-implant mucosal recessions is still extremely limited. The aim of the present paper is, therefore, to review the potential etiological factors, the rationale for treatment and possible treatment options for facial peri-implant mucosal recessions.The limited available data suggest that only shallow peri-implant mucosal recessions (e.g. up to 2 mm) may be successfuly covered by using a coronally advanced flap (CAF) combined with either a subepithelial connective tissue graft (SGCT) or GBR. At present no data are available on successful coverage of deep and large peri-implant mucosal recessions.
The anatomical features of the peri-implant mucosa surrounding implants differ from those of the gingiva surrounding teeth. The periodontal ligament fibers surrounding teeth feed into the root cementum via collagen fibers, while the peri-implant connective tissue fibers run parallel to the implant or abutment surface and do not feed into or attach to the implant (Sculean 2014). The peri-implant connective tissue contains a lower number of fibroblasts and a higher amount of collagen fibers than that at teeth, thus resembling scar tissue. Dental implants present a longer and more permeable junctional epithelium than around teeth, while the number of blood vessels in the peri-implant mucosa is lower than in the gingiva (Sculean 2014). In cases when the peri-implant soft tissue is densely located, the peri-implant mucosa is frequently not attached to the underlying bone despite its keratinization. In such situations, the junction between the keratinized and the lining mucosa is located more coronally in relation to the peri-implant bone margin (Sculean 2014).