Obturating the Type IV Canal by System B

Objectives: The purpose of this study was to evaluate the effect of the apical sealing in the Type IV canal according to the System B tip depth when root canal was filled gutta-percha and sealer by Continuous Wave of Condensation technique. Methods: 50 simulated resin blocks with J-shaped curvature canals were instrumented by ProTaper (Dentsply Maillefer, Ballagiues, Switzerland) Ni-Ti files using the crown-down technique recommended by manufacturer. Type �W canals were made using a broken F3 ProTaper Ni-Ti file for making a ledge at 3mm short from the working length. And F1 ProTaper Ni-Ti file was used for perforating resin block. This perforating canal enlarged to MAF (#50) was considered as main canal and existing canal was considered as lingual canal. The prepared Type �W canals were randomly divided into one control group (cold lateral compaction) of 5 and three experimental groups (Continuous Wave of Condensation) of 15 each according to System B tip depth up to 3, 5, 7 mm from the working length. All of experimental groups were used non-standardized gutta-percha cone (MAF #50) and AH-26 (Dentsply DeTrey, Johnson, Germany) as a root canal sealer. The length of gutta-percha and sealer in lingual of the Type �W canals was measured with a measuring digital caliper under magnifying glass (x 2.3). The data were analyzed statistically using one-way ANOVA and Turkey HSD test. Results: There was no gutta-percha and sealer in lingual canal in control group. 3 mm group showed relatively more gutta-percha than 5, 7 mm group (p�q0.05). 7 mm group didn't showed gutta-percha and relatively more void were observed than 3, 5 mm group (p�q0.05). Conclusion: within the limits of the results of this experiment, the 3 mm System B tip depth was acceptable for obturating the Type �W canal.