HIGH-PRESSURE INFRARED AND FT-RAMAN INVESTIGATION OF A DENTAL COMPOSITE

Composite resins are often used as filling materials on load-bearing s urfaces of teeth. As masticatory stresses can be high, here, we study the effect of pressure on the behaviour of a dental composite. Using a polymerized wafer, the IR and FT-Raman spectra of a zirconia-containi ng proprietary composite (Z100, 3M, Minneapolis, MN, USA) were recorde d. The high-pressure IR spectra were also recorded. Band assignments w ere made for the main peaks of both organic and inorganic components. Breaks in the pressure dependences (d nu/dP) of the organic components were found at 22 kbar. Different pressure dependences for different v ibrational modes of inorganic components were also observed. These dat a suggest that the network structure of the composite is compacted und er high pressure and that both the atomic distance and bonding angles in the network are altered. (C) 1998 Elsevier Science Limited. All rig hts reserved.