Summary:
Purpose: to evaluate and compare the seal created by cold burnishing gutta-percha after resection and with no further manipulation of the gutta-percha after resection
N= 60 single rooted teeth (4 groups of 15)
Materials/Methods:
•Teeth were cleaned and shaped to a minimal apical size of 45
•The apical 2 mm of the root were sectioned at right angle
•Group I: well obturated (spreader placed 1 mm short of WL), no further manipulation of GP
•Group II: as group I except that the exposed GP was cold burnished with a small-ball burnisher
•Group III: poor obturation (spreader placed 5 mm short of WL), no further manipulation of GP
•Group IV: as group III except that the exposed GP was cold burnished with a small-ball burnisher
•The apical seal was investigated using a linear dye penetration technique and stereomicroscope.
Most highlighted Results:
•In well obturated canals: cold burnishing the apical GP resulted in significantly more dye penetration ( Group 2 > Group 1)
•In poorly obturated canals: cold burnishing the apical GP resulted in significantly less dye penetration (Group 3 > Group 4)
Clinical significance: a well obturated GP has an better apical seal than poorly obturated



