Analysis of four gutta-percha techniques used to fill mesial root canals of mandibular molars

Marciano MA, Ordinola-Zapata R, Cunha TVRN, Duarte MAH, Cavenago BC, Garcia RB, Bramante CM, Bernardineli N, Moraes IG. Analysis of four gutta-percha techniques used to fill mesial root canals of mandibular molars. International Endodontic Journal. Aim To compare the percentage of gutta-percha, sealer and voids and the influence of isthmuses in mesial root canals of mandibular molars filled with different techniques. Methodology Canals in 60 mesial roots of mandibular first molars were prepared with ProTaper instruments to size F2 (size 25, 0.08 taper) and filled using a single-cone, lateral compaction, System B or Thermafil techniques. An epoxy resin sealer was labelled with Rhodamine-B dye to allow analysis under a confocal microscope. The percentage of gutta-percha, sealer and area of voids was calculated at 2, 4 and 6mm from the apex, using Image Tool 3.0 software. Statistical analysis was performed using nonparametric Kruskal-Wallis and Dunn tests (P<0.05). The influence of isthmuses on the presence or absence of voids was evaluated using the Fisher test. Results At the 2mm level, the percentage of gutta-percha, sealer and voids was similar amongst the System B, lateral compaction and single-cone techniques. The single-cone technique revealed significantly less gutta-percha, more sealer and voids in comparison with the Thermafil technique at the 2 and 4mm level (P<0.05). The analysis of all sections (2, 4 and 6mm) revealed that more gutta-percha and less sealer and voids were found in root canals filled with Thermafil and System B techniques (P<0.05). The Fisher test revealed that the presence of isthmuses increased the occurence of voids in the lateral compaction group only (P<0.05). Conclusion Gutta-percha, sealer filled area and voids were dependent on the canal-filling technique. The presence of isthmuses may influence the quality of root filling.