Evaluation of Rat Alveolar Bone Resorption During Chronic Apical Periodontitis Induced by Different Specific Pathogen and Hyperlipidemia

Objectives:
To evaluate alveolar bone resorption and the changes of the microarchitecture of alveolar bone by building two bacterias induced chronic apical periodontitis (CAP) model. And to estimate the significance of CAP for the atherosclerotic burden and to examine the potential effect of Hyperlipidemia.

Methods:
30 male Sprague-Dawley(SD) rats were fed either chow-diet (CD) or HFD for 12 weeks, and then five rats in each group were infected with Enterococus faecalis(Ef) or Porphyromonas gingivalis (Pg) respectively from the pulp chamber (CD, CD + Pg, CD + Ef, HFD, HFD + Pg, and HFD + Ef). At sacrifice after 12 weeks, maxillas were harvested and scanned by microcomputed tomography (μCT) to analyse periapical bone loss. Histopathological scoring was then performed on the samples to determine the amount of inflammatory infiltrate within the periapical microenvironment.
Results: The size of perioapical lesions in HFD + Ef group is larger than CD + Ef group. When compared with CD + Ef, BV/TV, Tb.N. and Tb.Th. of alveolar bone decreased in HFD + Ef at 12 weeks (P＜0.05＝. There were no significant differences between in HFD + Ef and CD + Pg (P > 0.05). The size of perioapical lesions, BV/TV, Tb.N. and Tb.Th. in CD + Pg group increased in compared with CD + Ef group.

Conclusions: Pg was more aggressive than Ef in rat apical periodontitis model. Hyperlipidemia might exacerbate alveolar bone resorption in rats infected by Ef.