The long-term success of dental implants relies on the formation of a protective soft tissue barrier that limits pathogen infiltration into peri-implant tissues. However, our understanding of how this barrier develops under different implant placement protocols (i.e., immediate vs. delayed placement) and in response to varying implant surface characteristics remains limited.

This study systematically evaluates the formation and maturation of peri-implant soft tissues in two contexts: (1) immediate versus delayed implant placement and (2) anodized versus machined implant surfaces.

Part I: Miniaturized titanium implants were placed in either fresh extraction sockets or healed maxillary first molar sites in mice. Peri-implant soft tissues were assessed at multiple time points to investigate molecular attachment mechanisms and the barrier function of the soft tissue. A healthy junctional epithelium served as a positive control. Notably, no significant differences were observed in the rate of soft tissue integration between immediate and delayed implants. However, mucosal integration took at least twice as long as osseointegration in this model.

Part II: Scanning electron microscopy and surface chemistry characterization were performed on miniaturized anodized and machined implants. Following placement in fresh extraction sockets, peri-implant tissues were examined at four time points. The findings corroborated those from Part I and led to several key conclusions:

1. Maturation of the peri-implant epithelium (PIE) is a prolonged process, aligning with clinical observations.
2. Soft tissue integration occurs more slowly than bone integration.
3. Anodized implant surfaces offer a transient advantage in promoting soft tissue maturation.

Together, these findings highlight the extended timeline required for PIE maturation, underscoring the potential clinical benefits of strategies aimed at accelerating this process.