IADR Abstract Archives

Contact angle measurement of vinylpolysiloxanes: What do we measure?

Objectives: Contact angle measurement is commonly used to assess the hydrophilicity of impression materials. It is not known what this measurement actually reflects. Hence, it was the aim of this study to test the following null-hypothesis: contact angles reflect a reduction of surface tension caused by surfactant released from hydrophilized vinylpolysiloxanes (VPS).

Methods: Four experimental VPS formulations were fabricated containing 0 (control), 1.5, 3 and 5 wt.% non-ionic surfactant. Samples were prepared (n=6) and contact angles determined 30 min after mixing. After 60 s, droplets were transferred onto the control. MALDI-TOF mass spectrometry was used to analyse the droplets. Non-parametric procedures were used for statistical analysis (p=0.05).

Results: Contact angles were inversely correlated with the surfactant concentration (p<0.05). Droplets transferred from hydrophilized specimens onto the control showed similar contact angles. Surfactant could be clearly identified inside the droplets placed on the hydrophilized samples, but not in the control.

Conclusion: Contact angles predominantly reflect a reduction of the droplet's surface tension caused by leaching of surfactants and are therefore unsuitable for describing the surface hydrophilicity of VPS.


Continental European, Israeli, Scandinavian Divisions Meeting
2009 Continental European, Israeli, Scandinavian Divisions Meeting (Munich, Germany)
Munich Germany
2009
1
Scientific Groups
  • Balkenhol, Markus  ( Justus Liebig University of Giessen - Dental Clinic, Giessen, N/A, Germany )
  • Haunschild, Sylvia  ( Justus Liebig University of Giessen - Dental Clinic, Giessen, N/A, Germany )
  • Lochnit, Günter  ( Justus Liebig University of Giessen - Institute of Biochemistry, Giessen, N/A, Germany )
  • Wöstmann, Bernd  ( Justus Liebig University of Giessen - Dental Clinic, Giessen, N/A, Germany )
    • Oral Session
    Dental Materials 3
    09/09/2009