Introduction: In this study One Shape file (OS) which was already designed as a shaping file was compared to R-Endo file (RE) in retreatment of endodontically treated teeth in terms of time required for completion of retreatment procedure and amount of remaining gutta-percha on root canal dentin.

Methods: Sixty mandibular mesio-buccal canals with angles of curvature between 15 and 45 degrees were prepared using Protaper Universal rotary files then obturated using gutta-percha and AH-Plus sealer. Canals were then divided equally into 2 groups according to the retreatment system. Time required to reach the full working length (T1) and for complete removal of gutta-percha (T2) were measured during retreatment procedure using a digital stopwatch. Also the amount of remaining gutta-percha on the root canal dentin was measured using Stereomicroscopic images analyzed by Image J software.

Results: OS group recorded statistically significant less time required for retreatment and less amount of remaining gutta-percha than RE group. As for the effect of Retreatment system on the percentage of remaining filling material regardless of canal curvature and Canal third:

There was statistically significant differencebetween (R-Endo) (47.61 ± 7.27) and (One Shape) (35.01 ± 5.77) where (p<0.0001). The lowest mean percentage of remaining filling material was shown in (One Shape) (35.01 ± 5.77). As for the effect of retreatment system on time required for retreatment regardless of canal curvature and (T1 and T2):

There was statistically significant differencebetween (R-Endo) (46.41 ±2.86) and (One Shape) (35.12 ±6.57) where (p=0.007). The lowest mean time was shown in (One Shape) (35.12 ±6.57).

Conclusion: OS system showed less time required for retreatment and less amount of remaining gutta-percha on the root canal dentin when compared and analyzed by Image J software.

Key words: Retreatment, OneShape, R-Endo, Image J, Time, Stereomicroscope.

Biography:
Mostafa Anwar graduated from Faculty of Dentistry – Ain Shams University.
He is an Assistant Lecturer of Endodontics at Faculty of Dentistry, The British University in Egypt & Infection Control Officer at the British University Dental Hospital. He is a Certified Healthcare & Hospital Management Specialist – AUC.
He took a Master Degree of Endodontics from Ain Shams University in Egypt, June 2015.
His practice is limited to Micro-Endodontics. He is a Lecturer & Participant in many International Dental Conferences. He conducted many Lectures and Hands-on workshops on Endodontics all over Egypt. He is an Endodontics Specialist at Whity Dental Center, Cairo (Egypt).