IADR Abstract Archives
Influence of Implant-abutment Corrosion on Human-gingival-epithelial Cells’ Biological Responses
Objectives: To investigate the impacts of various types and concentrations of metal ions generated from different designs of implant-abutment couplings on human gingival epithelial cell viability and pro-inflammatory cytokine gene expression.
Methods: Primary human-gingival-epithelial cells (HGEPs, CELLnTEC®, Bern, Switzerland) were treated with four different conditions of culture media saturated with metal ion concentrations containing titanium, cobalt and chromium. These concentrations were obtained from accelerated corrosion tests of implants connected to titanium or cobalt chrome alloy abutments with the design of matching or switching platforms in dynamic-static immersion tests. AlarmarBlue (AB) assay was used to observe cell viability over 14 days of exposure. The gene expression of interlukin- 1beta (IL-1β), interlukin-6 (IL-6) and interlukin-8 (IL-8) pro-inflammatory cytokines after exposure to metal concentration for 24 hours was evaluated by real time-quantitative polymerase chain reaction (RT-qPCR). A fifth group including a metal ion-free medium served as the negative control. All tests were run in triplicates per group at three separate times (total n=9). The data were collected and statistically analysed (Multifactorial univariate test, Bonferrini, P<0.05).
Results: Metal ion solutions corresponding to the cobalt-chrome abutments affected cell viability more than the solutions corresponding to the titanium abutments after 7 days of exposure (P<0.001). Moreover, the lowest percentage of cell viability was associated with the solutions corresponding to the platform-matched cobalt-chrome abutment (P<0.001). There was no significant difference in expression of the IL-1β, IL-6 and IL-8 genes compared to the control group. However, there was a tendency towards down-regulation of the tested genes when cells were treated with metal ions.
Conclusions: The cytotoxicity of metal ions on human-gingival-epithelial cells was positively correlated with the types and concentrations of metal ions even in very dilute concentrations. No inflammatory signs were observed in gene expression.
Methods: Primary human-gingival-epithelial cells (HGEPs, CELLnTEC®, Bern, Switzerland) were treated with four different conditions of culture media saturated with metal ion concentrations containing titanium, cobalt and chromium. These concentrations were obtained from accelerated corrosion tests of implants connected to titanium or cobalt chrome alloy abutments with the design of matching or switching platforms in dynamic-static immersion tests. AlarmarBlue (AB) assay was used to observe cell viability over 14 days of exposure. The gene expression of interlukin- 1beta (IL-1β), interlukin-6 (IL-6) and interlukin-8 (IL-8) pro-inflammatory cytokines after exposure to metal concentration for 24 hours was evaluated by real time-quantitative polymerase chain reaction (RT-qPCR). A fifth group including a metal ion-free medium served as the negative control. All tests were run in triplicates per group at three separate times (total n=9). The data were collected and statistically analysed (Multifactorial univariate test, Bonferrini, P<0.05).
Results: Metal ion solutions corresponding to the cobalt-chrome abutments affected cell viability more than the solutions corresponding to the titanium abutments after 7 days of exposure (P<0.001). Moreover, the lowest percentage of cell viability was associated with the solutions corresponding to the platform-matched cobalt-chrome abutment (P<0.001). There was no significant difference in expression of the IL-1β, IL-6 and IL-8 genes compared to the control group. However, there was a tendency towards down-regulation of the tested genes when cells were treated with metal ions.
Conclusions: The cytotoxicity of metal ions on human-gingival-epithelial cells was positively correlated with the types and concentrations of metal ions even in very dilute concentrations. No inflammatory signs were observed in gene expression.