Radiographic analysis of the development of periapical lesions in normal rats, sialoadenectomized rats and sialoadenectomized‐immunosuppressed rats

Abstract

The purpose of this study was to investigate and to compare radiographically the development of periapical lesions in the lower left first molar of normal rats, sialoadenectomised rats and sialoadenectomised-immunosuppressed rats. Sixty male Wistar rats, weighing from 170 to 200 g were utilized. The animals were divided equally into three groups: group I--20 normal rats; group II--20 sialoadenectomised rats; and group III--20 sialoadenectomised-immunosuppressed rats. Groups II and III were sialoadenectomized using the modified Cheyne technique. After 2 weeks, group III was submitted to a immunosuppression regimen by daily subcutaneous cyclosporin A injection (10 mg/kg body weight). After 1 week of immunosuppression for this group, the pulps of all the animals (group I, II and III) were exposed to the oral cavity, to produce apical periodontitis. Five animals of each group were killed 7, 14, 21 and 28 days after pulpal exposure. Their mandibles were surgically removed and radiographically analysed. The lesions were measured using 'Global Lab Image' software. The results showed predictable growth of the lesions during the experimental period. No significant difference was observed between the groups. It was concluded that possible changes in the oral flora and in the host immune response due to xerostomia associated or not to the immunosuppression did not alter the development of the periapical lesions in rats.

Radiological aspects of apical periodontitis

“…In rats, periapical lesions develop rapidly after pulp exposure, with a maximum rate of bone loss occurring within the first 2 weeks. The bone loss becomes visible in radiographs after these 2 weeks (46–48). This period may represent the most active phase of periapical lesion pathogenesis, whereas the period of relative size stability after 2 weeks may be considered to be a more chronic phase in which expansion occurs at a much slower rate.…”

“…This period may represent the most active phase of periapical lesion pathogenesis, whereas the period of relative size stability after 2 weeks may be considered to be a more chronic phase in which expansion occurs at a much slower rate. At first, the periapical lesion extends mesio‐distally with the resorption of spongy bone and then vertically with the resorption of cortical bone and cementum (47).…”

An in vivo experimental model to assess furcal lesions as a result of perforation

“…Although morphometrical evaluation of alveolar bone loss was not documented, correlation between bone resorption and histological parameters has been described previously (Waterman et al. 1998, Teixeira et al. 2000, Xiong et al.…”

“…Alveolar bone mineral density was previously documented in mandibular radiographs and the film used was tested in rats previously (Xiong et al 2007, Mahl & Fontanella 2008. Although morphometrical evaluation of alveolar bone loss was not documented, correlation between bone resorption and histological parameters has been described previously (Waterman et al1998, Teixeira et al 2000, Xiong et al 2007).…”

Morphological Effect of Diode Laser Irradiation of Periapical Lesion in Rat

“…Therefore, rats were used in the present study as they are easy to use and only a short time is required for the development of periapical lesions. 29 The lesions became radiographically apparent after 14 days, achieving the maximum size after 28 days of pulpal exposure to the oral microflora. These results are in agreement with those of earlier studies.…”