Single-rooted human mandibular premolars with fully formed
apices were used in this study. The teeth were cleaned of superficial
debris, calculus, and tissue tags and stored in normal saline to prevent
dehydration before use. Each tooth was radiographed to confirm the
presence of a single patent canal. The tooth specimens were sectioned
below the cementoenamel junction with a diamond disc to obtain a standardized
tooth length of 8 mm for uniform specimen.