Significance of the width of keratinized mucosa on peri-implant health.

In implant therapy, the adequate state of peri-implant tissue health and soft-tissue aesthetics is the essential criterion of restorative success. The need for keratinized mucosa for the maintenance of peri-implant health and soft-tissue integration remains a debated issue. The aim of this paper is to provide a narrative review of the current literature concerning the significance of keratinized mucosa with respect to the clinical parameters of monitoring oral hygiene practice and tissue status. The published studies revealed that there were conflicting results with regard to the influence of keratinized mucosa on plaque score and soft-tissue inflammation. Most studies showed that the amount of soft-tissue recession was significantly increased at implant sites with narrow keratinized mucosa, but the amount of keratinized mucosa had little effect on deepening of peri-implant pockets. The evidence related to the effect of keratinized mucosa on the changes of attachment or bone levels is limited, and conclusions could not be drawn at present. Further, this review found that a band of keratinized mucosa was not absolutely necessary for the maintenance of peri-implant tissue, whereas lack of adequate keratinized mucosa around the implant might impede proper oral hygiene performance and compromise the aesthetic results. In conclusion, because there is a wide variety of clinical features in patients pursuing implant therapy, individual consideration of treatment strategies for the patient with minimal keratinized mucosa is recommended.