The sealing ability of RSA Roekoseal Automix root canal sealer using ThermaFil Plus and cold lateral condensation was compared to Roth\u27s 801 root canal sealer. Fifty-two single canaled roots of extracted teeth were divided into four groups of twelve and instrumented to size 6 with .06 taper series 29 ProFiles. Group A canals were obturated with ThermaFil and Roth\u27s 801 sealer. Group B canals were obturated with ThermaFil and RSA Roekoseal Automix. Group C canals were obturated with cold lateral condensation and Roth\u27s 801 sealer. Group D canals were obturated with cold lateral condensation and RSA Roekoseal Automix. The linear penetration of ink was measured by two observers. Group B leaked significantly more than all other groups. RSA RoekoSeal Automix root canal sealer appears to seal as well as Roth\u27s 801 when using cold lateral condensation of gutta percha but not with ThermaFil Plus
