Adhesive sealing of the pulp chamber

The purpose of this in vitro study was to evaluate quantitatively the abili ty of four different filling materials to seal the orifices of root canals as a secondary seal after root canal therapy. Forty extracted human molar t eeth were used. The top of pulp chambers and distal halves of the roots wer e removed using an Isomet saw. The canal orifices were temporarily sealed w ith a gutta-percha master cone without sealer. The pulp chambers were then treated with a self-etching primer adhesive system (Clearfil SE Bond), a we t bonding system (One-Step), a 4-methacryloyloxyethyl trimellitate anhydrid e adhesive system (C&B Metabond), or a reinforced zinc oxide-eugenol (IRM). The specimens were randomly divided into four groups of 10 each. A fluid f iltration method was used for quantitative evaluation of leakage. Measureme nts of fluid movement were made at 2-min intervals for 8 min. The quality o f the seal of each specimen was measured by fluid filtration immediately an d after I day, 1 wk, and 1 month. Even after I month the resins showed an e xcellent seal. Zinc oxide-eugenol had significantly more leakage when compa red with the resin systems (p < 0.05). Adhesive resins should be considered as a secondary seal to prevent intraorifice microleakage.