The effect of varnish and pit and fissure sealants on the sealing capacity of retrofilling techniques.

Freshly extracted teeth with single canals were instrumented and filled with laterally condensed gutta-percha and sealer. After obturation, the tooth apices were treated with various retrograde techniques. The sealing ability of these techniques, namely laterally condensed gutta-percha, heat-sealed gutta-percha, and silver amalgam retrofilling, was compared on the basis of dye penetration. The apical foramen of the treated canals was then coated with different sealing materials--HelioSeal (light-activated sealant), Delton pit and fissure sealant (chemically activated sealant), and varnish--to examine their effect on the leakage resistance of these materials. Statistical analysis indicated that laterally condensed gutta-percha, as well as retrograde amalgam filling, produced a statistically significantly better seal than heat-sealed gutta-percha. Coating of the apical foramen with different sealing materials showed that HelioSeal had significantly improved the sealing capacity of all the materials tested at each time period. Delton pit and fissure sealant did not increase the sealing ability in the first week. However, this material has significantly improved the sealing ability after the first week. On the other hand, sealing of the apical foramen with varnish did not produce any significant change in the sealing capacity of the filling materials. Finally, dye penetration around all the filling and retrofilling materials, in the presence or absence of the apical seal, continued and increased with time. However, root canals sealed with Helioseal consistently showed the least amount of apical leakage of all the canals tested.