Abstract
This study was conducted to estimate the bony tissue response to β-calcium sulphate hemihydrate (CSH) as a bone
substitute via radiographic assessment using ImageJ software. The extraction sockets in dog mandible were the regions of
interest (ROI). Twenty adult (12-24 months), local breed dogs were included in the experiment. All had a complete set of
permanent dentition. They were randomly allocated into four groups, each containing 5 animals. Bilateral lower third
premolars have been extracted. The right socket was filled with β-calcium sulphate hemihydrate, whereas no material was
placed to fill that in the left side to serve as a control. Tissue response in extraction sockets was evaluated using two postoperative
intra-oral periapical radiographs for each tooth socket, the first immediately after extraction and the second at the end
of each study interval (i.e., after 2 weeks, 4 weeks, 8 weeks, and 12 weeks period for group I, II, III, and IV, respectively). The
radiographs were converted from conventional to digital by X-ray scanner, then examined by ImageJ software. Radiographic
assessment included the evaluation of differences in extraction sockets densities, bone resorption %, bone formation %, and
density of the newly formed bone. The results showed significant differences between the left (control) and right
(experimental) sides in all study periods in relation to differences in extraction sockets densities. Meantime, significant
differences were noticed between right and left sides during a 12 week period in relation to bone resorption and bone
formation %. Concerning density of the newly formed bone, significant differences were noticed during 8 week and 12 week
period.In conclusion, the use of β-calcium sulphate hemihydrate as a bone substitute significantly reduced bone resorption and
increased the rate of new bone formation. In addition, the density of the newly formed bone in the right (experimental) side
was greater than that noticed in the left (control) side.