OBJECTIVEThe aim of this study is to investigate the effects of serum high-sensitivity C-reactive protein (hsCRP) and the pathological changes in the carotid artery after periodontal mechanical therapy with local and systemic drugs in SD rats with chronic periodontitis (CP) associated with atherosclerosis (As).

METHODSThirty-five SD rats were randomly divided into two groups: control group (group A) and CP+As group (group B). Group B was further divided into the natural process group (B1), the periodontal mechanical treatment group (B2), the periodontal mechanical treatment plus local drugs group (B3), and the periodontal mechanical treatment plus local and systemic drugs group (B4). Each group comprised seven rats. Serum hsCRP levels were evaluated at baseline 1 week after the first periodontal therapy and 1, 3, and 5 weeks after the second periodontal therapy by enzyme linked immunosorbent assay (ELISA). The pathological lesion in the carotid artery plaque was stained with hematine and eosin.

RESULTSThe levels of serum hsCRP in group B1 increased gradually as time passed and became significantly higher than that of the other groups five weeks after periodontal therapy (P < 0.001). The levels of serum hsCRP in groups B2, B3, and B4 increased gradually and reached the peak 1 week after the second periodontal therapy. After that, the levels of serum hsCRP decreased gradually but were still higher than that of group A (P < 0.05). The levels of serum hsCRP in groups B3 and B4 were significantly lower than that in group B2 3 and 5 weeks after the second periodontal therapy (P < 0.001). Histologic sections revealed increased foam cell infiltration and disordered and destructed elastic fibers in groups B1 and B2. The thickness of the blood vessels in groups B3 and B4 was more uniform than that in groups B1 and B2. The elastic fibers in groups B3 and B4 were lined up in order.

CONCLUSIONDirect periodontal mechanical treatment results in acute, short-term, systemic inflammation and might increase the risk of atherosclerosis in SD rats. However, the levels of serum hsCRP decreased gradually 3 to 5 weeks after therapy. With periodontal mechanical treatment, the benefits of local and systemic drugs are associated with improvement in atherosclerotic lesion progression.