Purpose: To evaluate transportation and its effect of leakage
N= 47 curved, single roots mandibular premolars, and 27 single, and straight mandibular premolars
•Access, WL measured 1 mm from apex, RG was taken with #15 file
•Canals were divided into 5 groups:
–G1: hand filing/straight (step-back) 17 teeth,
G2: hand filing/curved (step-back)
–G3: Lightspeed/ curved 23 teeth,
G4,5:negative and positive control group
-Apical transportation index was measured (Fig 1).
-Teeth were obturated using lateral condensation (spreader 2mm from WL).
-Then GP was removed with gates to keep 3 mm for leakage study and packed
Most highlighted Results:
•Apical transportation in hand filing/curved (87%) ≥ 0.4mm, Light speed (19%)
•The hand filing/curved group leaked significantly more than the hand filing/straight and Lightspeed
•AT index was ⦤ 0.3 mm, only (3%) tooth showed leakage, and the AT index was > 0.3 mm, the leakage was 42%
•Apical transportation is a factor that negatively influences the apical seal when curved canals are obturated by lateral condensation of gutta-percha