Influence of Implant Component Materials on Peri-Implant Soft Tissue Healing: A Comparative Histological and Immunohistochemical Study in Humans.

Background: Recently, the importance of peri-implant soft tissue integration quality has been recognised as an essential factor in the long-term success of dental implant rehabilitation.

Aim: The aim of this study was to explore the influence of three materials commonly used in implant dentistry, namely titanium (Ti), dental adhesive resin (Re) and polyetheretherketone (PEEK), on the peri-implant soft tissues.

Methods: In this clinical randomised comparative study, 37 bone-level implants were placed, and experimental transmucosal healing abutments made of different materials were randomly assigned to each implant. These abutments were removed together with the surrounding soft tissues after 8 weeks. Immunohistochemical analyses were performed to determine the presence and localisation of different immune cells. In addition, clinical and radiographic data were collected and peri-implant bone remodeling was assessed.

Results: Compared to the Ti and PEEK groups, Re abutments revealed a higher infiltration of macrophages in the connective tissue (p = 0.04) and neutrophils in the adjacent epithelium (p = 0.03). In the Re abutments, peri-implant bone remodeling was higher compared to the other groups (p = 0.01).

Conclusion: The use of resin material as a transmucosal healing abutment should be carefully considered as it was associated with a higher presence of inflammatory cells at 8 weeks post-implantation as well as superior bone remodeling compared to PEEK and Ti.