engleski

Detection of HEMA in self-etching adhesive systems with high performance liquid chromatography

One of the factors that can decrease hydrolytic stability of self-etching adhesive systems (SEAS) is 2- hydroxymethylmethacrylate (HEMA). Due to hydrolytic instability of acidic methacrylate monomers in SEAS, HEMA can be present even if the manufacturer did not include it in original composition. The aim of the study was to determine the presence of HEMA because of decomposition by hydrolysis of methacrylates during storage, resulting with loss of adhesion strength to hard dental tissues of the tooth crown. Three most commonly used SEAS were tested: AdheSE ONE, G-Bond and iBond under different storage conditions. High performance liquid chromatography analysis was performed on a Nucleosil C18-100 5 mm (250x4.6 mm) column, Knauer K-501 pumps and Wellchrom DAD K-2700 detector at 215 nm. Data were collected and processed by EuroCrom 2000 HPLC software. Calibration curves were made related eluted peak area to known concentrations of HEMA (purchased from Fluka). The elution time for HEMA is 12.25 min at flow rate 1.0 ml/min. Obtained results indicate that no HEMA was present in AdheSE ONE because methacrylates are substituted with methacrylamides that seem to be more stable under acidic aqueous conditions. In all other adhesive systems HEMA was detected.

HEMA ; high performance liquid chromatography ; self-etching adhesives

MOLECULAR SPECTROSCOPY AND MOLECULAR STRUCTURE 2008 - A Collection of Papers Presented at the XXIX European Congress on Molecular Spectroscopy, Opatija, Croatia, August 31 - September 5, 2008