1. Obturation is the process of filling and sealing the cleaned and shaped root canal using a root canal sealer and core material to eliminate pathways between the periodontium and root canal. 2. Ideal root canal filling materials are easily manipulated, seal completely and laterally, have adequate physical properties, set slowly with no shrinkage, are impervious to moisture, sterile or easily sterilized, radiopaque, and do not stain or encourage bacterial growth. 3. Common core filling materials include gutta-percha, Resilon, and mineral trioxide aggregate (MTA), while common sealers include zinc oxide-eugenol, calcium hydroxide, glass ionomer, and resin