Effect of tooth extraction and antibiotics on carotid artery wall and serum interleukin 6 in chronic periodontitis rats with or without atherosclerosis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of tooth extraction with antibiotics on atherosclerosis, and to examine the expression of serum interleukin 6(IL-6) and the pathological changes of the carotid artery in chronic periodontitis(CP) rats with or without atherosclerosis(As).</p><p><b>METHODS</b>A total of 44 SD rats were randomly divided into four groups, group A(normal control), group B(As), group C(CP), group D(CP+As). After model establishment, group C and group D were randomly divided into group C1/D1 (tooth extraction) and group C2/D2(tooth extraction with antibiotics) according to random number table and received the corresponding oral intervention treatment respectively. Serum IL-6 levels were determined by enzyme linked immunosorbent assay(ELISA) respectively one week before the intervention, one week after the first intervention, one, three, five weeks after the second intervention. The pathological changes of the carotid artery were accessed under light microscope.</p><p><b>RESULTS</b>At all sampling time points, the levels of serum IL-6 in group B, C, D were higher than that of group A, with group D1 being increased most obviously, significantly higher than that of group A(P< 0.001). One week after the second intervention, the content of IL-6 in group C and group D peaked[C1(127.0 ± 29.9) ng/L, C2: (120.6 ± 23.1) ng/L, D1: (175.1 ± 50.8) ng/L, D2: (160.5 ± 37.7) ng/L], and was significantly higher than that of group B[B: (43.4 ± 7.5) ng/L,P<0.001]. Then they all had varying degrees of decline, 5 weeks after the second intervention, group C1 and D1 were still higher than that of group B, but group C2 and D2 were lower than that of group B. At all sampling time points, the levels of serum IL- 6 in group C2/D2 were lower than those in group C1/D1, 5 weeks after the second intervention the difference was most obvious and statistically significant(P<0.001). Pathology showed that the carotid artery wall in group A was normal. The carotid artery wall was thickened in group B, inflammatory cells and foam cells could be seen, and elastic fibers disordered. The carotid artery wall in group C1 was uneven, foam cells and a small amount of inflammatory cells were visible, and elastic fiber disordered. Obvious thickening was not seen in the carotid artery wall of group C2, a small amount of foam cells and inflammatory cells were found, and elastic fiber mildly disordered. The carotid artery wall in group D1 was obviously uneven, calcium salt deposits were visible in the artery wall, a large amount of inflammatory cells and foam cells could be found, and elastic fiber disordered. Obvious thickening was not seen in the carotid artery wall of group D2, a small amount of inflammatory cells and a large amount of foam cells could be seen, and elastic fiber disordered.</p><p><b>CONCLUSIONS</b>Periodontitis and hyperlipidemia could increase the level of serum IL- 6 and the risk of the As. In chronic periodontitis rats with or without atherosclerosis, when periodontal inflammation was not controlled, tooth extraction may increase the risk of the As. At the time of tooth extraction, giving the anti-inflammatory treatment can reduce the risk to a certain extent.</p>

Influence of periodontal therapy on serum interleukin-6 and carotid metalloproteinases in animals with chronic periodontitis associated with atherosclerosis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of periodontal mechanical treatment on serum interleukin-6 (IL-6) and carotid artery matrix metalloproteinase (MMP)-2 and MMP-9 expression in chronic periodontitis (CP) SD rats with atherosclerosis (As).</p><p><b>METHODS</b>Forty-four six-week-old male SD rats were randomly divided into three groups: control group (group A), As group (group B), As+CP group(group C). According to different periodontal interventions, group C was randomly subdivided into four groups: natural process group (C1), the periodontal mechanical treatment group (C2), the periodontal mechanical treatment+ local drugs group (C3), and the periodontal mechanical treatment+local and system drugs group (C4). Each group received the appropriate treatment and periodontal interventions. Serum IL-6 levels were determined by enzyme linked immunosorrbent assay (ELISA). MMP-2 and MMP-9 levels in the proximal aorta were examined by immunohistochemistry.</p><p><b>RESULTS</b>The gray value of MMP-2 and MMP-9 was basically the same in all groups. Compared with group A, the gray value of MMP-2 and MMP-9 of group B and C were decreased. C1 group showed the formation of atherosclerotic plaque and fibrous cap. Compared with group B (126.4 ± 2.0, 124.8 ± 2.8) , the gray value of group C1 (101.3 ± 2.4, 101.2 ± 4.1) was significantly weaker (P < 0.05). The staining depth of MMP-2 and MMP-9 of groups C1, C2, C3 and C4 were sequentially decreased, and the differences of gray value were statistically significant(P < 0.05). The levels of serum IL-6 in groups B and C1 increased gradually with time and became significantly higher than that of group A (P < 0.01). The levels of serum IL-6 in groups C2, C3, and C4 increased gradually and reached the peak 5 weeks after the establishment of model (P < 0.001). After that, the levels of serum IL-6 decreased gradually and was lower than baseline. The levels of serum IL-6 in groups C3 and C4 were significantly lower than that in group C2 7 weeks after the establishment of model(P < 0.01).</p><p><b>CONCLUSIONS</b>In rats with periodontitis and cardiovascular diseases, chronic periodontal inflammation may significantly increase the severity of As and promote the formation of atherosclerotic plaque. Mechanical periodontal therapy may cause short-term systemic inflammation and then reduce vascular inflammation in long term.With supplement use of local and systemic antibiotics, the mechanical periodontal therapy may get the vascular disease and systemic inflammation improved.</p>

Effect of oral intervention on matrix metalloproteinase-2, 9 expression in carotid arteries and serum interleukin-6 in rats with chronic periodontitis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To establish chronic periodontitis model in SD rats, and to investigate the effect of oral intervention on atherosclerosis.</p><p><b>METHODS</b>Fifty male SD rats were randomly divided into three groups, group A (normal control), group B (atherosclerosis,As) and group C (chronic periodontitis, CP). Group C was further divided into group C1 (natural process), group C2 (simple mechanical treatment), group C3 (systemic antibiotics), group C4-1 (teeth extraction) and group C4-2 (teeth extraction+systemic antibiotics), each group consisted of 7 rats. Every group received oral intervention. Serum interleukin (IL)- 6 levels were detected in five different time points (1, 3, 5, 7, 9 weeks after a successful modeling) by enzyme linked immunosorbent assay. All animals were killed after 24 weeks. Matrix metalloproteinase (MMP)- 2, 9 in the proximal aorta was detected by immuno histochemistry.</p><p><b>RESULTS</b>The levels of serum IL-6 in groups B and C1 increased gradually with time and became significantly higher than that in group A (P < 0.01). Levels of serum IL-6 were increased gradually in each intervention group (C2, C3, C4-1, C4-2) and reached its peak at 5 weeks after modeling [C2:(62.3 ± 14.3) ng/L, C3:(58.2 ± 8.7) ng/L, C4-1:(127.0 ± 29.9) ng/L, C4-2:(120.6 ± 23.1) ng/L]. Compared with group B, group C4- 1 and C4- 2 increased most significantly (P < 0.01). Levels of serum IL- 6 decreased gradually. Eventually, group C2 [(28.6 ± 8.1) ng/L], C3 [(40.8 ± 15.1) ng/L] and C4-2 [(32.7 ± 11.1) ng/L] were significantly lower than group B (P < 0.05), and in group C2 IL- 6 was the lowest. Although levels of serum of IL-6 significantly decreased in group C4-1 [(72.8 ± 16.4) ng/L], but remained the highest. Immunohistochemistry showed that MMP-2, 9 were expressed in group B, C1 and C4-1, and significantly higher than in group A (183.0 ± 2.0, 181.3 ± 2.0), the gray value differences were statistically significant (P < 0.01). Group C4-1 (123.1 ± 2.9, 121.0 ± 3.2) was the strongest, group B (126.4 ± 2.0, 124.8 ± 2.8) and C1 (140.0 ± 2.2, 139.7 ± 3.2) were decreased (P < 0.01). While group C2(169.3 ± 3.4, 169.7 ± 2.3), C3 (149.0 ± 1.7, 145.1 ± 2.5) and C4-2 (157.7 ± 1.2, 155.8 ± 2.7) were significantly lower than group C1 (P < 0.01), and group C2 was close to normal.</p><p><b>CONCLUSIONS</b>Periodontitis could increase the risk of atherosclerosis in rats with chronic periodontitis. Periodontal mechanical treatment and teeth extraction may increase the risk of As in the short time. However, the risk would gradually reduce in a long time.</p>

Effects of periodontal mechanical therapy with local and systemic drugs on carotid artery and serum high-sensitivity C-reactive protein in rats with chronic periodontitis associated with atherosclerosis / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The 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).</p><p><b>METHODS</b>Thirty-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.</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSION</b>Direct 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.</p>