Canal Space Occupied by Gutta-percha and Sealer after Instrumentation of Double Curved Canals

The aim was to examine the quality of obturation after canal preparation with five different rotary NiTi systems by clinicians of different experience. Half of the canals were prepared by an experienced endodontist and the other half by an undergraduate student. All instruments were used according to manufacturer's recommendations. After canal preparation all obturations were carried out by the endodontist. The behaviour of the plastic carrier and its contact with the canal wall may result in leakage. According to the company the carrier is a transport medium and only gutta percha or sealer should be in contact with the canal wall. Therefore the percentage of gutta-percha/sealer in contact with the canal wall was measured, as the remaining percentages indicate contact of the carrier. A total of 80 simulated s-shaped canals were prepared and obturated. The highest percentage of gutta-percha/sealer in contact with the canal wall was found in the canals being prepared by the student using the ProTaper and ProFile instruments. The other canals showed comparable results with except for canals prepared by the student with M-files. These showed significantly lower percentages of gutta-percha/sealer contact to the canal wall. The experienced clinician was able to achieve an average of 76 % gutta-percha/sealer percentage with all systems.