Abstract:

Objective This study aimed to establish a SD rat model of chronic periodontitis (CP) merged with hyperlipidemia (HL), perform periodontal treatment, detect the expression of partial C-reactive protein (CRP) and Porphyromonas gingivalis (P. gingivalis) in the rat carotid artery, and explore the relationship between periodontitis and atherosclerosis. Methods SD rats were randomly divided into three groups: control group (A), HL group (B), and CP+HL group (C). Group C rats were divided into natural process group (C1), scaling and root planning group (C2), and tooth extraction group (C3). Group C2 rats were randomly divided into C2-1 (scaling and root planning group) and C2-2 (scaling and root planning+minocyline+systemic antibiotics group). Group C3 rats were randomly divided into C3-1 (tooth extraction group) and C3-2 (tooth extraction+systemic antibiotic group). One rat from group B was randomly selected and sacrificed after 15 weeks. Subsequently, the carotid vas-cular tissue was collected for oil red O staining. Modeling was successful when foam cell formation was observed. Periodontal treatments were conducted twice, and euthanasia was performed after the experiment. Moreover, double-carotid artery bifurcation was carried out to detect the expression of CRP and P. gingivalis. Immunohistochemical and 16sRNA semiquantitative methods were used to detect the CRP expression and the relative contents of P. gingivalis, respectively. Results Immunohistochemical results showed that the CRP-positive expression in groups B and C was significantly higher than that in group A (P<0.05). The CRP-positive expression in other group C rats were significantly lower than that in group C1 (P<0.05). The CRP-positive expression in group C2-2 was the lowest among the groups (P<0.05). The relative quantity of P. gingivalis in group C1 was the highest and significantly higher than that in groups A and B (P<0.05). The relative quantities of P. gingivalis in groups C2-1, C2-2, C3-1, and C3-2 were sig-nificantly lower than that in group C1 (P<0.05), and the quantity in group C3-2 was the lowest (P<0.05). Conclusion Rats with CP associated with HL will increase the CRP expression and oral bacteria quantity on carotid artery, and lesions will gradually aggravate. Interventions, such as periodontal basic treatment and tooth extraction, could improve carotid artery lesions. The basic treatment with local and systemic anti-inflammatory drugs exerts the most satisfactory effect on local CRP expression. Tooth extraction with antibiotics is an effective method on reducing oral bacteria in carotid artery. Periodontal basic treatment associated with local and systemic antiflammatory drugs can obviously improve the effect.

Key words: hyperlipidemia, periodontitis, Porphyromonas gingivalis, C-reactive protein, periodontal basic treatment