Comparative study on icariin and Bu-Shen-Gu-Chi-Wan for alveolar reconstruction in chronic periodontitis in rats / 口腔疾病防治

Objective@#To observe the effects of icariin (ICA) and Bu-Shen-Gu-Chi-Wan on the alveolar bone absorption of chronic periodontitis in rats, and to explore the effect and possible mechanism of ICA in the treatment of chronic periodontitis. @*Methods@#After the establishment of the periodontitis model, the rats were divided into the periodontitis group (group P), ICA high dose group (group H), ICA low dose group (group L) and Bu-Shen-Gu-Chi-Wan treatment group (group B). Each group received treatment for one month and two months, separately, and the serum osteocalcin (OCN) level was measured. Three-dimensional reconstruction was performed after micro computed tomography (micro CT) scanning to measure the bone parameters of specific points, and the distance between the enamel cementum boundary and alveolar crest (CEJ-ABC) was recorded as alveolar bone resorption value. Tissue sections were generated to evaluate the effect of ICA on alveolar bone repair and reconstruction in rats with experimental periodontitis. @*Results@# Compared with the periodontitis group (group P), OCN levels in the serum in treatment groups (groups H, L and B) were decreased significantly (P < 0.05); the values of bone volume/tissue volume (BV/TV) and trabecular number (Tb.N) in treatment groups (groups H, L and B) were significantly higher than that in group P (P < 0.05). Compared with group P, trabecular thickness (Tb.Th) values of groups H and B significantly increased, and trabecular separation (Tb.Sp) of groups H and B significantly decreased (P < 0.05). The changing trend of parameters in group L was the same as that in group H but only after two months of administration. The difference between Tb.Sp values in groups L and P was statistically significant (P < 0.05). Compared with group P, the CEJ-ABC distance significantly reduced in group L (1 month and 2 months after administration), group H (1 month and 2 months after administration), and group B (only 2 months after administration) (P < 0.05).@*Conclusion@#ICA and Bu-Shen-Gu-Chi-Wan improve the alveolar bone resorption in an experimental model of chronic periodontitis in rats, and the mechanism may be related to the regulation of osteocalcin serum levels.

Effects of vitamin C local application on ligature-induced periodontitis in diabetic rats

Abstract Objective: This study evaluated the effects of local vitamin C treatment on tissue advanced glycation end products (AGE), interleukin (IL)-6, 8-hydroxy-2-deoxyguanosine (8-OHdG), and matrix metalloproteinases (MMP)-8 in tissues; serum C-terminal telopeptide fragments (CTX); and alveolar bone loss (ABL) in rats. Methodology: 35 male Sprague Dawley rats were divided equally into five groups: 1) control (C), 2) experimental periodontitis (P), 3) experimental diabetes (D), 4) experimental diabetes and experimental periodontitis (D + P), and 5) experimental diabetes-experimental periodontitis-locally applied vitamin C (D + P + LvitC). Diabetes was induced in rats with alloxan monohydrate, after which periodontitis was induced by ligature placement in the right mandibular first molar teeth for 11 days. In the treatment group, vitamin C was administered locally three times with two-days interval after ligature removal. The animals were sacrificed, and the samples were analyzed histometrically and immunohistochemically. Results: CTX, 8-OHdG, and AGE values significantly decreased in the treatment group compared to the D + P group. IL-6 and MMP-8 values decreased in the treatment group compared to the D + P group, but this is not significant. ABL was significantly reduced by the local delivery of vitamin C. Conclusion: This study reveals that vitamin C treatment may be beneficial to reduce serum CTX and gingival MMP-8 levels, oxidative stress, inflammation, and AGE accumulation in periodontal tissue. Vitamin C may be an immunomodulator and antioxidant locally applied in the treatment of periodontitis to reduce the adverse effects of diabetes in periodontal tissues.

Effects of diode laser application on inflammation and mpo in periodontal tissues in a rat model

Abstract Objective In this study, we aimed to histologically and immunologically evaluate the effect of diode laser treatment when applied adjunctive to scaling and root planing (SRP) in an experimental periodontitis model. Materials and methods We used Wistar-Albino rats (n=60) with average weight of 230 g. Experimental periodontitis was induced by ligature at the right and left first mandibular molar teeth in all rats. After 11 days, the ligature was removed and rats were divided into two groups. The control group (n=30) received only SRP treatment, while the laser group (n=30) received a diode laser (GaAlAs, 810 nm, 1 W, 10 J, 20 s) treatment adjunctive to SRP. Ten rats in each group were sacrificed after 7, 15, and 30 days. Histopathological examination was performed in the left mandible of rats. Myeloperoxidase (MPO) was evaluated by western blot in the gingival specimens from the right mandible. Results MPO levels in the laser group were statistically significantly lower compared with the control group (p≤0.05). There was no statistically significance at any time between MPO levels in the control group (p>0.05). MPO levels in the laser group at the 7th day were statistically significantly higher compared to the 15th (p≤0.05) and the 30th day (p≤0.05). Inflammatory cell infiltration decreased over time in both groups and was statistically significantly lower in the laser group than in the control group at all times (p≤0.01). Conclusions Within the limits of this study, we suggest that diode laser application is an adjunctive treatment because it reduced inflammation and MPO when applied in addition to SRP. On the other hand, more studies are needed for the assessment of the effects of diode laser application to periodontal tissues.

The effects of experimental periodontitis on serum C reactive protein and insulin resistance in obese rats / 实用口腔医学杂志

Objective:To investigate the effects of experimental periodontitis on serum C reactive protein(CRP) and insulin resistance in obese rats.Methods:4 week old SD rats (n=35)were fed with high fat diet for 16 weeks to establish the model of obesity.According to the obesity criteria,5 rats were screened out.According to the proportion of 1:2,10 rats were randomly selected as obese control group,20 obese rats were used for the establishment of the obesity with periodontitis model(combination group) by periodontal ligation using silk thread.4 rats died after ligation.Before periodontal ligation,1 and 4 weeks after periodontal ligation,orbital venous blood were collected for the detection of fasting blood glucose and fasting insulin.Homeostasis model assessments of insulin resistance index(HOMA-IR) and beta cell function index(HOMA-β) were calculated.The level of serum CRP was examined by ELISA.Results:The level of CRP in the combination group was increased 1 week after periodontal ligation,and then gradually decreased in the following 4 weeks(F=7.773,P=0.004).HOMA-IR in the combination group were higher than that in the obese group(F=-4.691,P=0.000),and beta cell function index was significantly lower(F=3.672,P=0.002) than that in the control group 4 weeks after periodontal ligation.Conclusion:The experimental periodontitis may affect the serum level of CRP in obese rats,aggravate insulin resistance and decrease the function of beta cells in obese rats.

Protective effect of proanthocyanidins on endotoxin induced experimental periodontitis in rats.

The pathogenesis of periodontitis involves anaerobic oral bacteria as well as the host response to infection and several drugs have been developed which can curtail these deleterious effects. Proanthocyanidin, a novel flavanoid extracted from grape seeds, has been shown to provide a significant therapeutic effect on endotoxin (Escherichia coli) induced experimental periodontitis in rats. In this study, protective action of different doses of proanthocyanidins was investigated in blood by assaying the reactive oxygen species such as hydrogen peroxide, superoxide anion, myeloperoxidase and lipid peroxides, lysosomal enzyme activities such as cathepsin B, cathepsin D, β-glucuronidase and acid phosphatase, nonenzymatic antioxidants such as ascorbic acid, -tocopherol, ceruloplasmin, reduced glutathione and antioxidant enzymes such as catalase, superoxide dismutase, glutathione peroxidase and glutathione-s-transferase. Experimental periodontitis rats showed a reduction in body weight and body weight gain could be noticed when they were administered proanthocyanidins. The levels of reactive oxygen species and lysosomal enzymes were found to increase whereas antioxidant levels were decreased significantly in experimental periodontitis. Proanthocyanidins at an effective dose of 30mg / kg body weight, sc, for 30 days effected a decrease in serum reactive oxygen species, lipid peroxides, lysosomal enzymes, acute phase proteins and an increase in antioxidant levels. Histopathological evidence of experimental periodontitis showed cellular infiltration of inflammatory cells while proanthocyanidin treated groups demonstrated only scattered inflammatory cells and blood vessels. Thus, the results showed that dietary supplementation of proanthocyanidin enhanced the host resistance as well as the inhibition of the biological and mechanical irritants involved in the onset of gingivitis and the progression of periodontal disease.

Histometric analysis of ligature-induced periodontitis in rats: a comparison of histological section planes

The purpose of this study was to analyze the histometry of ligature-induced periodontitis in rats at different histological section depths. Sixteen male adult Wistar rats were randomly assigned to two groups: ligature and control. In the ligature group, rats received a sterile 4/0 silk ligature around the maxillary right 2nd molar. Thirty serial sections containing the 1st and 2nd molars, in which the coronal and root pulp, cementoenamel junction (CEJ) in the mesial side of the 2nd molar, interproximal alveolar bone and connective fiber attachment were clearly visible, were selected for histometric analysis. The histological sections were clustered in groups of 10 sections corresponding the buccal (B), central (C) and lingual (L) regions of the of periodontal tissue samples. The distance between the CEJ in the mesial side of the 2nd molar and the attached periodontal ligament fibers (CEJ-PL) as well as the distance between the CEJ and the alveolar bone crest (CEJ-BC) were determined. From CEJ-PL and CEJ-BC distances measured for each specimen, the measurements obtained in the B, L and C regions were recorded individually and together. Data were submitted to statistical analysis. Significant differences (p<0.001) were observed between the control and ligature groups regarding CEJ-PL (0.05 mm and 0.26 mm, respectively) and CEJ-BC (0.47 mm and 0.77 mm, respectively) measurements. Regarding the depth of the buccal, central and lingual planes, the means of CEJ-PL and CEJ-BC of both groups showed no statistically significant differences (p>0.05). In conclusion, the selection of 10 serial sections of the central region of periodontal tissue samples at any depth can be considered as representative for the evaluation of periodontal ligament fiber attachment and bone loss in ligature-induced periodontitis in rats.

Effects of minocycline at subantimicrobial dosage in the treatment of experimental periodontitis in rats / 实用口腔医学杂志

Objective: To evaluate the effectiveness of minocycline at subantimicrobial dosage in the treatment of experimentally induced periodontitis in rats.Methods: Periodontitis was induced by silk ligature technique on 4 second molars in each of 16 adult male Sprague-Dawley rats and the animals were fed with 100 g/L sucrose drink. The rats were divided into 2 groups: (1)periodontitis group without treatment;(2)treatment group, the rats with periodontitis were treated by systemic administration of minocycline at 5 mg/(kg?d).Another 8 normal rats were used as the controls. Assessment was carried out at day 28 and 56 using a number of different visual, histological and ultrastructure approaches.Visual assessment included tooth mobility(TM), gingival index(GI), and alveolar bone loss. Histological examination included monocyte effusion,resorption lacunae with osteoclasts and percentage of the periodontal collagen.The collected data were statistically analyzed using variance test.Results: Systemic administration of minocycline at subantimicrobial dosage can significantly reduce GI, TM, resorption lacunae with osteoclasts and alveolar bone loss either at day 28 or at day 56; significantly inhibited monocyte effusion and the collagen degradation in the periodontium at day 56 in rats with periodontitis. Conclusion: Minocycline at subantimicrobial dosage may decrease alveolar bone loss and osteoclasts formation in periodontium with periodontitis.