Histological analysis of the biocompatibility of calcium hydroxide associated with a new vehicle.

ABSTRACT

Background: Several substances have been researched to act as vehicles associated with calcium hydroxide. The specific type of vehicle is directly related to the effectiveness of the ionic dissociation, antimicrobial action, and biocompatibility of this medication. Aim: To make a histological evaluation of the biocompatibility of calcium hydroxide associated with a new vehicle (triethanolamine), compared with polyethylene glycol, saline solution, and olive oil. Materials and Methods: Fifty mice of guinea pig species were randomly divided into five groups (n = 10) according to each vehicle used – Group 1 calcium hydroxide, Group 2 triethanolamine, Group 3 polyethylene glycol, Group 4 saline solution, and Group 5 olive oil – and further divided into subgroups according to the two analysis periods – (a) 30 and (b) 90 days. Teflon carriers filled with the evaluated substances were placed in standardized bone cavities in the anterior mandible region. The animals were euthanized to perform a histological analysis after the time periods analyzed. Results: In 30 days, specimens from Groups 1, 3, and 5 showed a very pronounced inflammatory response. Specimens from Group 2 showed an inflammatory reaction ranging from mild to severe, with rapid resorption of the material and progressive advancement of osteoid tissue into the teflon carriers. Specimens from Group 4 showed a moderate inflammatory reaction. In 90 days, specimens from Group 1 showed a very pronounced fibrous replacement. In regard to Group 2 specimens, the tested material was solubilized and replaced by newly formed bone tissue. For Groups 3 and 5 specimens, the inflammatory reaction went from acute to moderate. In relation to Group 4 specimens, an organized bone formation process was observed. Conclusions: Specimens from Group 2 showed higher biocompatibility, especially as compared with the specimens from Groups 3 and 5.