Histological analysis of the Ankylos peri-implant soft tissues in a dog model.

PURPOSE: The importance of the soft tissue-implant interface is enhanced by the presence of a microgap between the implant and the abutment, which represents a contamination site for bacteria. The aim of this study was to investigate the interface between the Ankylos gap-free implant system and the surrounding soft tissues in a dog model.

MATERIALS AND

METHODS

Six Labrador dogs were included in the study and two Ankylos implants were inserted per dog. The dogs were killed 6 months after abutment placement without functional loading and without plaque control. The implants were analysed histologically by scanning electron microscopy, light microscopy, and histomorphometry.

RESULTS

Some sections exhibited histologic signs of a mild inflammation. The connective tissue between the most apical epithelial cells of the junctional epithelium and the alveolar crest was characterized by collagen fibers running from the periosteum and the alveolar crest toward the oral epithelium and, in front of the cone-shaped abutment, by a narrow zone of extracellular matrix with a few collagen fibers.

CONCLUSION

Compared with results obtained in other studies using different types of implant (Astra, Bränemark, ITI), the Ankylos implant showed a higher length and a larger width of connective tissue contact as well as a shorter epithelial downgrowth. The absence of a microgap in the Ankylos system could explain the histologic mild inflammation in the connective tissue.