Expansion of the peri-implant attached gingiva with a three-dimensional collagen matrix in head and neck cancer patients-results from a prospective clinical and histological study.

OBJECTIVES: Attached peri-implant gingiva has proven to have an influence on the long-term stability of dental implants. In patients with head and neck cancer, a functional peri-implant gingiva is even more of critical importance. The aim of the presented prospective study was to investigate a three-dimensional xenogeneic collagen matrix for augmentation around dental implants in patients with former head and neck cancer. MATERIAL AND METHODS: Eight patients presenting with insufficient peri-implant gingiva underwent vestibuloplasty on 51 implants using a xenogeneic collagen matrix. The clinical performance and the shrinking tendency of the matrix were analyzed in a cohort study. Furthermore, eight biopsies from the augmented regions were examined histologically to determine the biomaterial-related tissue reaction. RESULTS: Initially after vestibuloplasty, a mean width of attached gingiva of 4.4 +/- 0.94 mm could be achieved. At clinical follow up investigation 6 months after vestibuloplasty, a mean width of 3.9 +/- 0.65 mm attached peri-implant gingiva with a mean shrinking tendency of 14 % could be detected. Histological analysis of the biopsies revealed a well integrated collagen22 matrix covered with epithelium. Within the compact layer, mononuclear cells were observed only, while the spongious layer was infiltrated with a cell-rich connective tissue. CONCLUSION: Within its limits, the presented study revealed that the investigated collagen matrix is suitable to enlarge the peri-implant attached gingiva in head and neck cancer patients without adverse reactions or a multinucleated giant cell-triggered tissue reaction. CLINICAL RELEVANCE: The application of the investigated three-dimensional collagen matrix in vestibuloplasty achieved a sufficient amount of peri-implant attached gingiva in head and neck cancer patients. The favorable tissue reaction and the low shrinking tendency make the collagen matrix a promising alternative to autologous tissue grafts.