DETECTION OF LEACHED MOIETIES FROM DENTAL COMPOSITES IN FLUIDS SIMULATING FOOD AND SALIVA

Objectives. The purpose of this study was to analyze the IR spectra of a liquid simulating food and an artificial saliva following exposure to resin composites. Methods. Fourier transform infrared (FTIR) spectr oscopy was used to analyze two solutions in which three commercially a vailable dental composites (Marathon One, Den-Mat Co.; Z100, 3M Co.; H erculite XRV, Kerr Co.) were stored. The solutions used were: a food s imulating fluid, 75 vol% ethanol/water, and an artificial saliva, Moi- Stir (Kingwood Labs., Inc.). Specimens (4.3 mm diam, x 2 mm thick) of the three resin composites were stored at 37 degrees C in 60 mt of eit her Moi-Stir or the 75% ethanol solution for 7, 14, and 30 d. The FTIR spectra were obtained using a liquid sample ATR (attenuated total ref lection) cell. Results. No obvious leachable materials were seen from any of the composite specimens stored in artificial saliva up to 30 d of immersion. For the composites stored in ethanol, the observed spect ra revealed increases in the principal absorption bands for the compon ents of the three composite systems. Methacrylate skeletal vibrations (1015-815 cm(-1)) and -CH3 alkane, C-H asymmetrical deformation vibrat ions (1520-1460 cm(-1)) appeared after 14 d of storage. A very strong peak characteristic of the aliphatic C=C moiety (1640 cm(-1)) and carb onyl C=O (1730 cm(-1)) occurred after 14 d. The peak heights of these two functional bands increased as a function of time and after 30 d of storage were approximately 5-7 times those produced after 7 d. Irregu lar O-H bands (3500-3300 cm(-1)) were also observed after 30 d in etha nol. Significance. Irreversible processes such as the leaching of comp onents occurs in the presence of ethanol. This phenomenon may contribu te to irreversible material degradation.