Histopathological changes in dental pulp of rats following radiotherapy

Abstract

Background: Radiotherapy is one of the oral and pharyngeal cancer treatment methods that
can cause damage to the tissues in the radiation area; the purpose of this study is to evaluate the
effects of radiotherapy on dental pulp tissue in rats.
Materials and Methods: In this interventional, experimental double-blind study, 30 rats were
studied in three groups (n = 10 each). The fi rst group received 12 gray (Gy), the second group
received 18 Gy in one session, and the third group was not exposed to radiation (control group).
The 5 μm sections of mandibular molar tooth were prepared and stained with hematoxylin and
eosin. Samples were studied under optical microscope to evaluate and score infl ammation, necrosis,
hyalinization, and vascular congestion. The data were coded and analyzed by statistical tests of
χ² and Fisher’s exact tests. The signifi cant level of P = 0.05.
Results: In Group 1, necrosis in two cases, infl ammation in one case, hyalinization in one case, and
vascular congestion in four cases were observed. In Group 2, infl ammation in four cases, hyalinization
in two cases, and vascular congestion in fi ve cases were observed. In Group 3, infl ammation was
observed only in one case. In comparison between the groups, no signifi cant differences were
observed in infl ammation (P > 0.05), necrosis (P > 0.05), and hyalinization (P > 0.05). However, the
difference was signifi cant for vascular congestion (P < 0.05).
Conclusion: Radiotherapy with doses of 12 and 18 Gy had no signifi cant effect on infl ammation,
necrosis, and hyalinization in all groups; however, the difference was signifi cant for vascular congestion.
Key Words: Dental pulp, histology,Cancer, Radiotherapy