Combination in Two-Part Dental Implant Systems: An In Vitro Examination

Purpose: To test a newly introduced implant-abutment material combination against bacterial endotoxin leakage in a human whole blood assay. Materials and Methods: Two dental implant systems with internal connections and the following material combinations at the implant-abutment interface (IAI) were used (implant material/abutment material): yttrium-stabilized tetragonal zirconium dioxide (Y-TZP)/ polyetherketoneketone (PEKK), and titanium (Ti/Ti). Test implants were inoculated with lipopolysaccharide (LPS) and sealed and submerged in human whole blood. Untreated implants served as the control groups. Changes in gene expression levels of inflammatory markers indicating LPS leakage were assessed after 1, 8, and 24 hours using quantitative real-time polymerase chain reaction. Results: In the Y-TZP/PEKK test group, a significant influence of the implant system (P < .001) on increases in gene expression indicating leakage were detected after 8 hours for TLR-4 and after 24 hours for interleukin 1-i3 and nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-KB), indicating microleakage of LPS at the IAI. In the Ti/Ti test group, differences in gene expression were found only for NF-KB after 8 hours. Conclusion: The internal hexalobe IAI of two-piece dental implants fabricated from Y-TZP and PEKK do not prevent LPS molecular microleakage