GCF Inflammatory Mediators and Subgingival Species in Peri-implantitis

Objective: To examine the levels of 10 GCF biomarkers and 40 subgingival species in healthy and failing implants. Methods: 16 subjects with healthy implants and 26 subjects with failing implants due to peri-implantitis were recruited. After clinical examination, 30-second GCF samples were collected from the deepest site of each implant using periopaper. The volume of GCF was measured using a Periotron 8000 and samples were stored at -70^oC until assay. The GCF samples were analyzed for their content of GM-CSF, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IFN-γ and TNF-α using Luminex. Subgingival biofilm samples were collected from the same sites and examined for their content of 40 subgingival taxa using checkerboard DNA-DNA hybridization. Sites were further subdivided into healthy implants from healthy subjects (HH, n=59), healthy implants from peri-implantitis subjects (HP, n=51) and failing implants from peri-implantitis subjects (FP, n=54). Significance of differences between HH vs. HP and HH vs. FP sites was determined using the Mann-Whitney test and between HP vs. FP using the Wilcoxon rank test. Results: There were significant differences between HH and HP sites for all clinical parameters: PD, AL, %BOP and GCF volume (p<0.001). There were no significant differences among the 3 site-categories for any of the GCF biomarkers and any of the 40 subgingival species. However, there was a trend for increases in GCF levels of GM-CSF, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10 and IFN-α with a worsening of the peri-implant condition: HH < HP < FP. The microbiological data revealed a trend for increased levels of Actinomyces, Orange and Red complex species in FP compared to HH implants. Conclusions: Failing implants present increased levels of GCF cytokines and periodontopathogens compared to healthy implants. Supported by NIDCR grants DE016700 and T32DE07327 and by FAPESP and CNPq, Brazil.