Increased Peri-implant Keratinized Mucosal Thickness at Different Operative Times

Keratinized mucosa, which is composed of free gingiva and attached gingiva, is a barrier against bacterial invasion in oral cavity and provides good tissue sealing for periodontal environment. When the keratinized mucosa is insufficient, it is difficult to maintain the long-term stability of the implant, which is not conducive to the peri-implant health. It is generally believed that enough keratinized mucosa width is beneficial to reduce plaque accumulation and reduce the incidence rate of peri-implant diseases. In recent years, clinicians have gradually recognized that the thickness of keratinized mucosa plays an important role in maintaining the peri-implant health. Some researchers found that the thickness of mucosa is very important to maintain the aesthetic effect of implant restoration, and when the thickness of mucosa around the implant is less than 2mm, alveolar bone absorption will occur to maintain a stable biological width. A meta-analysis showed that when the thickness of the keratinized mucosa around the implant was greater than 2mm, the amount of marginal bone loss was significantly reduced (- 0.8mm, P \< 0.0001). It is considered that autogenous soft tissue graft is the most reliable technology to augment keratinized mucosa. Subepithelial connective tissue graft (SCTG) is a mucogingival surgery that transplant autologous free connective tissue under the pedicled semi thick flap to augment keratinized mucosa. It can effectively increase the thickness of soft tissue, cover the exposed implant, and reconstruct the interdental papilla. It is the gold standard for peri-implant soft tissue agumentation. Keratinized mucosal thickening surgery may be done prior to the surgical phase, after the surgical phase, before loading, or even after loading. It is believed that keratinized mucosal thickening at the same time of implantation can effectively reduce the possibility of mucosal recession after implantation, reduce the amount of marginal bone absorption in