In vitro evaluation of apical microleakage following canal filling with a coated carrier system compared with lateral and thermomechanical gutta-percha condensation techniques

Aim The apical sealing ability of a coated carrier system was evaluated in extracted human teeth and compared with lateral and thermomechanical condensation techniques using dye penetration. Methodology Sixty-four extracted single-rooted teeth were instrumented to an apical size 30 using 4% taper Hero642(TM) instruments (Micromega, Besancon, France). The sample was divided into three experimental groups. Twenty teeth were randomly obturated with lateral condensation, 20 with thermomechanical compaction and 20 teeth with the Herofill(TM) Soft-Core system. Four teeth were used as positive and negative controls. The teeth were covered with nail varnish up to 2 mm from the apical foramen and immersed in a 2% aqueous methylene blue dye solution for 1 week and then washed, dehydrated and embedded in resin. The apical 1 mm of each tooth was removed to reveal the apical limit of the preparation. Transverse sections of the teeth were taken at 500, 1000 and 1500 mum from this point and evaluated for apical leakage. Significant differences between the preparations were analysed with a semiautomatic analyser and the ratio of the dye-penetrated surface to the total dentinal surface was calculated. Results Statistical analysis of the results demonstrated significantly less leakage for the Herofill(TM) Soft-Core system compared to lateral condensation in terms of total mean dentinal surface and at the 500 mm level. No other differences were noted between Herofill(TM) Soft-Core and thermomechanical or lateral condensation, either for the total mean value or at each level. Conclusion TheHerofill(TM) Soft-Core system was a reliable obturation system in the apical portion and compared favourably with other gutta-percha filling techniques.