Morphogenesis of Peri-implant Mucosa Revisited: An Experimental Study in Humans

Aim: To apply a novel human model to evaluate the morphogenesis of the mucosal attachment to implants. Material and methods: Twenty one patients receiving implant-supported single-tooth replacement were enrolled in this study. After implant installation, a custom-designed experimental abutment was connected to the implant. Soft tissue biopsies representing 2, 4, 8 or 12 weeks of healing were collected by the use of a circular cutting device and prepared for histological analysis. Results: The soft tissue biopsies were retrieved, preserved and processed with a technique that was safe and reproducible. The results from the histological analysis in regards to dimensional and qualitative changes in the mucosa over time were consistent with those reported from animal experiments. At 8 weeks, the soft tissue dimension was about 3.6 mm and included a barrier epithelium of 1.9 mm and a connective tissue portion of 1.7 mm. Similar dimensions were found at 12 weeks. Conclusion: It is suggested that the new human model provides advantages in terms of cost-effectiveness in research as well as from ethical aspects and should be considered as an alternative to pre-clinical in vivo studies in animals.