Methods: We performed a genome-wide DNA microarray analysis and compared the gene expression rates of inflamed periimplant tissue, healthy and inflamed periodontal tissues in vivo. We selected differentially expressed ECM components and validated these results with the help of real-time RT-PCR. Furthermore, immunohistochemical staining of paraffin embedded teeth including their surrounding tissues was performed using antibodies against numerous ECM components.
Results: The comparison of inflamed periimplant and inflamed periodontal tissues showed an up-regulation of the laminin chains alpha1, alpha2, alpha3 and beta1 as well as the collagens type IV, VI, VII and XVII, whereas the collagens type III and XI were decreased. In inflamed periodontal tissue, compared with healthy periodontal tissue, the laminin chains alpha2, alpha4 and gamma3 were significantly down-regulated and the laminin beta3 chain as well as the integrins alpha6 and beta4 were up-regulated. Interestingly, the laminin alpha2 chain, aggrecan-2 and COMP are located solely in the interradicular epithelial cell rests of Malassez, but not in the middle part and the apical part of the roots.
Conclusion: Our results show, that periimplant and periodontal inflammation are two disease entities at least at the mRNA level. Moreover, the informations gained will help to further characterize the role of cell-matrix-interactions during inflammation of periimplant and periodontal tissue in vivo.