About the author
Dr. P. Hartjen, Univ.-Prof. Dr. Dr. M. Gosau, Prof. Dr. Dr. RE. Friedrich, E. Madani, Dr. D. Duddeck, C. Fischer, F. Tebbel, Univ.-Prof. Dr. Dr. R. Sader, Univ.-Prof. Dr. Dr. R. Smeets
Influence of an ultrasonic cleaning and disinfection method for CAD/CAM abutment surfaces on cell viability and the inflammatory reaction in vitro
To evaluate the effect of an ultrasonic cleaning and disinfection method for CAD/CAM abutment surfaces on cell viability and inflammatory response in vitro.
Materials and methods
Untreated and manually polished surfaces of CAD/CAM generated titanium and zirconia disks were randomly assigned, either to a 3-step ultrasonic cleaning and disinfection process (test: TiUF, TiPF, ZrUF, ZrPF) or to 30 sec. steam cleaning (control: TiUS, TiPS, ZrUS, ZrPS). Pre-cleaning surface analyses using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and surface profilometry were performed. Human gingival fibroblasts (HGFs) were cultured on test and control specimens and subsequently examined for cell viability and inflammatory response. Expression of acute inflammatory cytokine interleukin (IL)-6 and vascular endothelial growth factor A (VEGF-A) were assessed by means of RT-qPCR.
Cells on all specimens exhibited a satisfactory viability, indicating firm attachment. Cells on polished zirconia samples, cleaned by means of sonication (ZrPF), exhibited significantly higher viability than cells on the same material cleaned by steam (ZrPS), p = 0.019. For all other three material/surface treatment combinations (TiU, TiP, ZrU), no such difference was observed between the cleaning methods. The messenger ribonucleic acid (mRNA) levels of IL-6 and VEGF-A were between 50 and 105 per cent of that of the control cells on the non-toxic control surface. mRNA levels of IL-6 and VEGF-A correlated well with each other.
Except for higher viability of cells cultured on polished zirconia specimens, no universally applicable advantage could be found for the ultrasonic cleaning procedure for zirconia and titanium abutment surfaces regarding cell viability, IL-6 expression or VEGF-A expression. The cleaning procedures did not have any negative effect either.