CHEMICAL CHARACTERIZATION OF THE RESIN-DENTIN INTERFACE BY MICRO-RAMAN SPECTROSCOPY

The chemical nature of the interface between dentin and adhesive resin materials was characterized by micro-Raman spectroscopy. The resultin g chemical profiles were correlated with photomicrographs obtained by SEM after an argon-ion-beam etching treatment of the sample surface. T wo commercially available dentin adhesive systems, of which one was al so applied with a different conditioning agent, were investigated. Ram an spectra, which were recorded along line scans across the interface with a step increment of 1 mum, revealed that resin effectively penetr ated 4 to 6 mum deep into the superficially decalcified dentin zone. A cross the interface, a gradual transition from resin to dentin over th e interdiffusion zone with a mixed contribution of both substances was noticed. Finally, resin appeared to penetrate to the entire decalcifi cation depth of dentin regardless of the aggressiveness of the conditi oning procedure.