Coronal leakage of calcium phosphate-based root canal sealers compared with usual sealers

The purpose of the present study was to compare two experimental calcium phosphate-based sealers with AH Plus, Sealapex, Ketac-Endo and Hermetic with regard to coronal seal. Two standardized artificial canals were prepared in each of 120 blocks of bovine root dentin. The blocks were divided into six groups. All of the 40 canals of each group were filled with gutta-percha and either AH Plus, Hermetic, Ketac-Endo, Sealapex or two different experimental sealers. One canal of one block was filled with gutta-percha and sealer using lateral condensation, whilst the other canal was obturated using Thermafil. The roots were immersed in black ink and thereafter cleared. Maximum linear dye penetration was measured coronally. Statistical analysis was performed by means of the Kruskal-Wallis test for the global null hypothesis and the closed test procedure for pairwise comparisons. With lateral condensation, experimental sealer I was comparable with AH Plus and Hermetic but showed significantly higher penetration depths than Ketac-Endo and Sealapex. Using Thermafil, more leakage was found for experimental sealer I than for AH Plus, Ketac-Endo and Sealapex. Using both techniques, leakage of experimental sealer II did not differ significantly from leakage of AH Plus, Ketac-Endo and Sealapex. Due to the low leakage of experimental sealer II in the present study, further evaluations such as bacterial penetration or fluid filtration should follow.