| Abstract|| | Background: The aim of this study was to
investigate whether the smear layer influences the removal of
calcium hydroxide from the root canal with manual or rotary
instruments. Materials and Methods: The root canals of 48
freshly extracted single-rooted maxillary incisors were prepared
to apical size 40 (n=40) and finally irrigated with sodium
hypochlorite (group A), or ethylene diamine tetra acetic acid
(EDTA) followed by sodium hypo chlorite (group B). 20 teeth were
assigned to each group, while the remaining eight teeth served
as positive and negative controls. Each group was divided into
two subgroups of 10 teeth (subgroup I - calcium hydroxide was
removed with master apical file; subgroup II - with profile
file); and, in all removal procedures, citric acid was used for
irrigation. The percentage of calcium hydroxide-[Ca(OH) [Ca(OH)
2 ] coated surface area was calculated by image processing
analysis. Results: Considering the root canal as a whole, the
removal of Ca(OH) 2 from the dentinal wa