Melatonin improves periodontitis-induced kidney damage by decreasing inflammatory stress and apoptosis in rats.

BACKGROUND: Two main aims of this animal study were to inspect the possible effects of periodontitis on the structure and functions of the kidneys and the therapeutic effectiveness of melatonin. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into three groups: control, experimental periodontitis (Ep), and Ep-melatonin (Ep-Mel). Periodontitis was induced by placing 3.0-silk sutures sub-paramarginally around the cervix of right-left mandibular first molars and maintaining the sutures for 5 weeks. Then melatonin (10 mg/kg body weight/day, 14 days), and the vehicle was administered intraperitonally. Mandibular and kidney tissue samples were obtained following the euthanasia. Periodontal bone loss was measured via histological and microcomputed tomographic slices. On right kidney histopathological and immunohistochemical, and on the left kidney biochemical (malonyl-aldehyde [MDA], glutathione, oxidative stress [OSI], tumor necrosis factor [TNF]-α, interleukin [IL]-1ß, matrix metalloproteinase [MMP]-8, MMP-9, and cathepsin D levels) evaluations were performed. Renal functional status was analyzed by levels of serum creatinine, urea, cystatin-C, and urea creatinine. RESULTS: Melatonin significantly restricted ligature-induced periodontal bone loss (P <0 .01) and suppressed the levels of proinflammatory cytokines (TNF-α and IL-1ß), oxidative stress (MDA and OSI), and proteases (MMP-8, MMP-9, and CtD) that was significantly higher in the kidneys of the rats with periodontitis (P <0.05). In addition, periodontitis-related histological damages and apoptotic activity were also significantly lower in the Ep-Mel group (P <0.05). However, the markers of renal function of the Ep group were detected slightly impaired in comparison with the control group (P >0.05); and the therapeutic activity of melatonin was limited (P >0.05). CONCLUSION: Melatonin restricts the periodontitis-induced inflammatory stress, apoptosis, and structural but not functional impairments.

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

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 Autogenous Tooth Bone Graft and Platelet-Rich Fibrin in Peri-Implant Defects: An Experimental Study in an Animal Model.

The aim of this study was to evaluate the effect of autogenous tooth bone graft (ATBG) combined with platelet-rich fibrin (PRF) on bone healing in rabbit peri-implant osseous defects. Eighteen New Zealand rabbits were divided into 3 groups. Bone defects were prepared in each rabbit, and then an implant cavity was created in the defects. Dental implants were placed, and the peri-implant bone defects were treated with the following 3 methods: no graft material was applied in the control group, bone defects were treated with ATBG in the ATBG group, and bone defects were treated with ATBG combined with PRF in the ATBG+PRF group. After 28 days, the rabbits were sacrificed, and the dental implants with surrounding bone were removed. New bone formation and the percentage of bone-to-implant contact (BIC) were determined with histomorphometric evaluations. New bone formation was significantly higher in the ATBG+PRF group than the control and ATBG groups (P < .05). In addition, BIC was significantly higher in the ATBG+PRF group than in the control and ATBG groups (P < .05). The combination of ATBG with PRF contributed to bone healing in rabbits with peri-implant bone defects.

Melatonin ameliorates periodontitis-related inflammatory stress at cardiac left ventricular tissues in rats.

BACKGROUND: The aim of this experimental rat study was to investigate the potential inflammatory effects of periodontitis on cardiac left ventricular tissue and the therapeutic activity of melatonin on these effects. METHODS: Twenty-four male Sprague-Dawley rats were randomly divided into three groups: control, experimental periodontitis (Ep), and Ep-melatonin (Ep-Mel). Experimental periodontitis was induced by placing and maintaining 3.0 silk ligatures at a peri marginal position on the left and right mandibular first molars for 5 weeks. Afterward, following the removal of ligatures, melatonin (10 mg/body weight) to Ep-Mel group, and vehicle (saline) to Ep and control groups were administered intraperitoneally for 14 days. On the first day of the eighth week, mandibular and cardiac left ventricular tissue samples were obtained following the euthanasia of the rats in all groups. Alveolar bone loss measurements were made on histological and microcomputed tomographic slices. Cardiac tissue levels of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), matrix metalloproteinase-9 (MMP-9), and cardiac Troponin-T (cTnT) were evaluated by appropriate biochemical methods. RESULTS: Measurements made on the histological and microcomputed tomographic slices showed that melatonin significantly limits the ligature-induced periodontal tissue destruction (P <0.01). In addition, melatonin was detected to cause a significant decrease of MDA, MMP-9, and cTnT levels which were found to be significantly higher on rats with Ep (P <0.05) while having no significant effect on antioxidant levels (GSH, SOD, and CAT) (P >0.05). CONCLUSION: Melatonin might be regarded as an important supportive therapeutic agent to reduce the early degenerative changes and possible hypertrophic remodeling at cardiac left ventricular tissues provoked by periodontitis-related bacteria and/or periodontal inflammation.

Immune modulatory and antioxidant effects of locally administrated vitamin C in experimental periodontitis in rats.

Background: Vitamin C is an important water-soluble vitamin with antioxidant and immune-modulatory actions. The aim of this study was to investigate the effects of locally applied vitamin C on alveolar bone resorption in rats with experimental periodontitis.Methods: Twenty-one male Sprague-Dawley rats divided into three groups with seven animals in each group: (1) control, (2) experimental periodontitis and 3) experimental periodontitis-local vitamin C treatment group. After ligature was removed, 50 µL vitamin C was locally administered into the subperiosteum of the buccal gingiva of periodontitis vitamin C (PvitC) group rats for three times in intervals of 2 days. At the end of the study, the animals were scarified, and serum and gingival samples were collected for analysis of serum IL-1ß, oxidative stress index (OSI), CTX and malondialdehyde (MDA) levels and gingival MMP-8 immunostaining. Alveolar bone loss and attachment loss were determined based on measurements on histological sections obtained from rat mandibles.Results: Serum MDA and OSI levels which are related to the oxidative stress were significantly lower in the PvitC group as compared with those in the P group (p < .05). Serum CTX levels which are related to the bone resorption were significantly lower in the PvitC group as compared with those in the P group (p < .05). The numeric density of MMP-8-positive cells was significantly lower in the PvitC group compared to P group (p < .05). Alveolar bone loss and attachment loss were significantly lower in the PvitC group compared to P group (p < .05)Conclusions: The local vitamin C administration provided protection against inflammation-induced alveolar bone resorption by decreasing oxidative stress and inflammation-induced tissue breakdown vitamin C may be a therapeutic agent that can be used in periodontitis treatment.

A biochemical and immunohistochemical study of the effects of caffeic acid phenethyl ester on alveolar bone loss and oxidative stress in diabetic rats with experimental periodontitis.

Caffeic acid phenethyl ester (CAPE) is used as a therapeutic agent to prevent bone loss. We determined the effects of systemically administered CAPE on alveolar bone loss and oxidative stress in diabetic rats with experimental periodontitis. Forty male rats were divided into four equal groups: control, experimental periodontitis (EP), EP-diabetes mellitus (EP-DM) and EP-DM-CAPE. DM was induced by streptozotocin, then lipopolysaccharide was injected to induce periodontitis. CAPE was administered to the EP-DM-CAPE group daily for 15 days. Then, serum samples were taken and the rats were sacrificed for histological analyses. Serum interleukin (IL-1ß) and oxidative stress also were evaluated. Alveolar bone loss was assessed histomorphometrically. Alveolar bone loss and IL-1ß levels were significantly less in the EP-DM-CAPE and EP groups compared to the EP-DM group. Oxidative stress was significantly less in the EP-DM-CAPE group compared to the EP and EP-DM groups. Receptor activator of nuclear factor kappa-B ligand (RANKL) levels were significantly higher in the EP-DM group compared to the disease groups. CAPE significantly reduced RANKL levels in the EP-DM-CAPE group compared to the EP-DM group. We found that CAPE treatment significantly inhibited DM induced oxidative stress and RANKL induced osteoclastogenesis and alveolar bone loss in diabetic rats with periodontitis.

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.

Evaluation of New Bone Formation Using Autogenous Tooth Bone Graft Combined with Platelet-Rich Fibrin in Calvarial Defects.

The purpose of the present study was to evaluate the contributions of autogenous tooth bone graft (ATBG) combined with platelet-rich fibrin (PRF) on new bone formation and bone morphogenetic protein (BMP)-2 in rabbit calvarial defects. Twelve male New Zealand rabbits were used in this study. Three circular bone defects were prepared in each rabbit with a drill. These defects were divided into 3 groups: control, treated with ATBG, and treated with ATBG+PRF. The animals were sacrificed at 28 days. Samples were evaluated by histomorphometric analyses and total augmented area, new bone area and bone density were calculated. In addition, expression of BMP-2 was determined by immunohistochemical staining. The total augmented area, new bone area and bone density were significantly greater in the ATBG group than in the control group (P <0.05). Also, these values were significantly higher in the ATBG+PRF group than the ATBG group (P <0.05). Test groups demonstrated significantly increased BMP-2 levels compared with the control group (P <0.05). The present study suggested that ATBG combined with PRF significantly increased the new bone formation and enhanced bone healing in cranial defects.

Effect of intracanal diode laser application and low-level laser therapy on CGRP change.

The aim of this study was to investigate the effect of a placebo, intracanal diode laser application, and low-level laser therapy (LLLT) on the change of the total amount of calcitonin gene-related peptide (CGRP) in the gingival crevicular fluid (GCF) (split-mouth study design). GCF sampling was performed on a contralateral tooth and experimental tooth (root canal-treated tooth) of thirty-nine patients. The patients were divided into three groups (n = 13), as follows: placebo (mock laser application), intracanal laser application, and LLLT. GCF sampling was repeated at the same sites (experimental and control teeth) one week after root canal treatment. The data were analyzed using the Pearson's correlation analysis and the independent-samples t-tests (p=0.05). In the placebo group, the total CGRP level changes in the GCF before and after treatment was significantly higher for experimental teeth than for control teeth (p<0.05). However, there was no significant difference between experimental and control teeth in the intracanal laser application and LLLT groups (p > 0.05). Intracanal laser application and low-level laser therapy have immunomodulation effects linked to the modulation of the total amount of CGRP in the GCF.

Therapeutic effects of caffeic acid phenethyl ester on alveolar bone loss in rats with endotoxin-induced periodontitis.

BACKGROUND/PURPOSE: Caffeic acid phenethyl ester (CAPE) is an antioxidant which is decreases the bone resorption and enhances the bone healing. The aim of this study was to investigate the effects of administering systemic CAPE on alveolar bone loss in rats with experimental periodontitis. MATERIALS AND METHODS: Thirty male Sprague Dawley rats were divided into three groups: control, endotoxin-induced periodontitis (EP), and EP treated with CAPE (EP-CAPE). Endotoxin was injected into the gingiva of test rats on days 1, 3, and 5, whereas saline was injected into the control rats. The EP-CAPE group received 10 mmol/kg/day CAPE intraperitoneally for 28 consecutive days. Saline was given in the control and EP groups in the same manner. At the end of the study, intracardiac blood samples were obtained, and the rats were sacrificed. Alveolar bone loss was analyzed with histometric measurements. The oxidative stress index (OSI) was used to evaluate the oxidative stress. The receptor activator of the nuclear factor kappa B ligand (RANKL) level was analyzed stereologically. RESULTS: CAPE administration significantly decreased the serum OSI and interleukin-1ß levels. Alveolar bone loss was statistically higher in the EP group compared with the EP-CAPE group (P < 0.05). Immunohistochemical analyses of the RANKL were significantly lower in the EP-CAPE group than in the EP group (P < 0.05). CONCLUSION: This experimental study revealed that CAPE administration significantly prevented alveolar bone loss and stimulated periodontal tissue healing.

The effect of photobiomodulation on total amount of substance P in gingival crevicular fluid: placebo-controlled randomized clinical trial.

To investigate the effect of photobiomodulation (PBM) and placebo on total amount of substance P in gingival crevicular fluid (GCF) pre- and postoperatively. Twenty-six patients having tooth with symptomatic apical periodontitis were enrolled in this study. GCF was collected preoperatively. The patients were assigned into two groups (n = 13), as follows: placebo and PBM. Sampling was repeated 7 days after root canal treatment. Two independent samples T test was used for analyzing of the differences between preoperative and postoperative substance P levels in GCF (p = .05). The Pearson correlation analysis was used for determination of correlation among substance P levels and other variables. For placebo group, there is no significant difference between preoperative and postoperative total amounts of substance P level (p = 0.553). For PBM group, postoperative total amount of substance P level was significantly higher than those of preoperative level (p = 0.005). Within the limitation of the present study, PBM has immunomodulation effect linked to the modulation of the total amount of substance P in the gingival crevicular fluid. Thai Clinical Trials Registry: TCTR20161228002.

Titanium-prepared platelet-rich fibrin provides advantages on periodontal healing: A randomized split-mouth clinical study.

BACKGROUND: The aim of this study to evaluate the contributions of titanium-prepared platelet-rich fibrin (T-PRF) combined with open flap debridement (OFD) on biological markers in gingival crevicular fluid (GCF)and periodontal outcomes. METHODS: Twenty-nine participants with chronic periodontitis were treated either with autologous T-PRF+OFD or OFD alone. GCF growth factor levels and relative receptor activator nuclear factor kappa-B/osteoprotegerin (RANKL/OPG) ratio at baseline and 2, 4, and 6 weeks postoperatively were analyzed, and clinical parameters such as probing depth (PD), relative attachment level (RAL) and gingival margin level (GML) at baseline and 9 months after surgery were compared. RESULTS: The mean PD reduction, RAL gain, and GML change were significantly greater in the OFD+T-PRF sites than in the OFD sites (P = 0.033, P = 0.029, and P = 0.026, respectively). Both groups demonstrated increased growth factor levels at week 2 compared with baseline, followed by reductions at weeks 4 and 6. GCF growth factor levels in the test group were seen at higher concentrations with respect to control group until 6 weeks post-surgery. During this 6-week period, relative RANKL/OPG ratio was found significantly lower in the OFD+T-PRF group compared to the OFD group(P < 0.05). CONCLUSIONS: Using T-PRF membrane combined with OFD provided significantly higher concentrations of growth factors and lower RANKL/OPG ratio in GCF for approximately 4 to 6 weeks, and improved periodontal healing compared to conventional flap sites.

The effect of leukocyte-platelet-rich fibrin on bone morphogenetic protein-2 and insulin-like growth factor-1 levels in patients with chronic periodontitis: a randomized split mouth clinical trail.

The present study evaluates the effects of leukocyte-platelet-rich fibrin (L-PRF) combined with open flap debridement (OFD) on clinical parameters and growth factors levels (GFL) in chronic periodontitis (CP) patients. This trial was registered at clinicaltrials.gov as NCT02594605. 16 patients (32 sites) with chronic periodontitis who had at least two areas of horizontal bone loss, were treated with OFD alone or L-PRF with OFD (OFD + L-PRF). GFL in gingival crevicular fluid (GCF) were analyzed at baseline, 1 week, 2 weeks and 4 weeks after operation. Probing depth (PD) and clinical attachment level (CAL) were measured at baseline and 6 months postoperatively. PD reduction and CAL gain were significantly higher in the OFD + L-PRF sites than in OFD sites. OFD + L-PRF group showed significantly increased bone morphogenetic protein-2 and insulin-like growth factor-1 at 2 weeks compared with baseline. L-PRF combined with OFD significantly increases GFL and thus, it enhances the periodontal healing on CP patients.

Effect of intracanal diode laser application and low-level laser therapy on CGRP change

Abstract: The aim of this study was to investigate the effect of a placebo, intracanal diode laser application, and low-level laser therapy (LLLT) on the change of the total amount of calcitonin gene-related peptide (CGRP) in the gingival crevicular fluid (GCF) (split-mouth study design). GCF sampling was performed on a contralateral tooth and experimental tooth (root canal-treated tooth) of thirty-nine patients. The patients were divided into three groups (n = 13), as follows: placebo (mock laser application), intracanal laser application, and LLLT. GCF sampling was repeated at the same sites (experimental and control teeth) one week after root canal treatment. The data were analyzed using the Pearson's correlation analysis and the independent-samples t-tests (p=0.05). In the placebo group, the total CGRP level changes in the GCF before and after treatment was significantly higher for experimental teeth than for control teeth (p<0.05). However, there was no significant difference between experimental and control teeth in the intracanal laser application and LLLT groups (p > 0.05). Intracanal laser application and low-level laser therapy have immunomodulation effects linked to the modulation of the total amount of CGRP in the GCF.

Advantages of Autologous Platelet-Rich Fibrin Membrane on Gingival Crevicular Fluid Growth Factor Levels and Periodontal Healing: A Randomized Split-Mouth Clinical Study.

BACKGROUND: This study evaluates contributions of platelet-rich fibrin (PRF) combined with conventional flap surgery on growth factor levels in gingival crevicular fluid (GCF) and periodontal healing. METHODS: Twenty-six patients (52 sites) with chronic periodontitis were treated either with autologous PRF with open flap debridement (OFD+PRF) or OFD alone. Growth factor levels in GCF at baseline and 2, 4, and 6 weeks after surgery were analyzed, and clinical parameters such as probing depth (PD), relative clinical attachment level (rCAL), and gingival margin level (GML) at baseline and 9 months after surgery were measured. RESULTS: Mean PD reduction and rCAL gain were significantly greater in OFD+PRF sites than in OFD sites. Mean GML change was -0.38 + 0.10 mm in OFD sites and 0.11 + 0.08 mm in the test group; difference between the two groups was statistically significant (P <0.05). Both groups demonstrated increased expression levels of fibroblast growth factor-2, transforming growth factor-ß1, and platelet-derived growth factor-BB at 2 weeks compared with baseline, followed by reductions at 4 and 6 weeks. The OFD+PRF group showed significantly higher growth factor levels compared with the OFD group at 2 and 4 weeks. CONCLUSION: PRF membrane combined with OFD provides significantly higher GCF concentrations of angiogenic biomarkers for ≈2 to 4 weeks and better periodontal healing in terms of conventional flap sites.

Influences of Fucoxanthin on Alveolar Bone Resorption in Induced Periodontitis in Rat Molars.

The aim of this study was to evaluate the effects of systemic fucoxanthin treatment on alveolar bone resorption in rats with periodontitis. Thirty rats were divided into control, experimental periodontitis (EP), and experimental periodontitis-fucoxanthin (EP-FUCO) groups. Periodontitis was induced by ligature for four weeks. After removal of the ligature, the rats in the EP-FUCO group were treated with a single dose of fucoxanthin (200 mg/kg bw) per day for 28 consecutive days. At the end of the study, all of the rats were euthanized and intracardiac blood and mandible tissue samples were obtained for biochemical, immunohistochemical, and histometric analyses. Fucoxanthin treatment resulted in a slight decrease in tumor necrosis factor-α, interleukin-1ß, and interleukin-6 levels and a significant decrease in oxidative stress index. It was observed that fucoxanthin caused a significant reduction in receptor activator of nuclear factor kappa-ß ligand (RANKL) levels and a statistically non-significant elevation in osteoprotegerin and bone-alkaline phosphatase levels. There were no significant differences in alveolar bone loss levels between the EP and EP-FUCO groups. This experimental study revealed that fucoxanthin provides a limited reduction in alveolar bone resorption in rats with periodontitis. One of the mechanisms underlying the mentioned limited effect might be related to the ability of fucoxanthin to inhibit oxidative stress-related RANKL-mediated osteoclastogenesis.

Effects of Melatonin on Oxidative Stress Index and Alveolar Bone Loss in Diabetic Rats With Periodontitis.

BACKGROUND: The aim of this study is to evaluate the effects of systemic melatonin treatment on serum oxidative stress index (OSI) and alveolar bone loss (ABL) in rats with diabetes mellitus (DM) and periodontitis. METHODS: Seventy Sprague Dawley rats were divided into control, experimentally induced periodontitis (EP), DM, EP-DM, EP and melatonin treatment (EP-MEL), DM and melatonin treatment (DMMEL), and EP-DM-MEL groups. DM was induced by alloxan, after which periodontitis was induced by ligature for 4 weeks. After removal of the ligature, the rats in the melatonin groups (EP-MEL, DM-MEL, and EP-DM-MEL) were treated with a single dose of melatonin (10 mg/body weight) every day for 14 consecutive days. At the end of the study, all of the rats were euthanized, and intracardiac blood samples and mandible tissues were obtained for biochemical and histologic analyses. Serum levels of total oxidant status/total antioxidant status and OSI were measured. In addition, neutrophil and osteoclast densities and myeloperoxidase activities were determined in gingival tissue homogenates, and ABL was evaluated with histometric measurements. RESULTS: Melatonin treatment significantly reduced fasting plasma glucose levels in the rats with DM. In addition, reduced OSI and ABL levels were detected in the EP-MEL and DM-MEL groups; the reductions in the EP-DM-MEL group were found to be more prominent. Melatonin also significantly decreased the increased myeloperoxidase activities and osteoclast and neutrophil densities in the EP, DM, and EP-DM groups. CONCLUSION: It is revealed in this experimental study that melatonin significantly inhibited hyperglycemia-induced oxidative stress and ABL through antiDM and antioxidant effects in rats with DM and periodontitis.

Therapeutic Effects of Melatonin on Alveolar Bone Resorption After Experimental Periodontitis in Rats: A Biochemical and Immunohistochemical Study.

BACKGROUND: The present study aims to investigate the effects of systemic melatonin administration on alveolar bone resorption in experimental periodontitis in rats. METHODS: Twenty-four male Sprague-Dawley rats were divided into three groups (control, experimental periodontitis [Ped], and experimental periodontitis treated with melatonin [Mel-Ped]). For periodontitis induction, first molars were ligatured submarginally for 4 weeks. After ligature removal, rats in the Mel-Ped group were treated with a daily single dose of 10 mg/kg body weight melatonin for 15 consecutive days. At the end of the study, intracardiac blood samples and mandible tissues were obtained for histologic, biochemical, and radiographic analysis. Serum markers related to bone turnover, calcium, phosphorus, bone alkaline phosphatase (b-ALP), and terminal C telopeptide of collagen Type I (CTX) were analyzed. Myeloperoxidase levels were determined in gingival tissue homogenates, and receptor activator of nuclear factor-kappa B ligand (RANKL) activation was analyzed in the mandible samples stereologically. Alveolar bone loss was also evaluated radiographically in the mandible samples of each group. RESULTS: Melatonin treatment decreased serum CTX levels and increased b-ALP levels. Serum calcium and phosphorus levels were not statistically different among groups (P >0.05). Alveolar bone resorption and myeloperoxidase activity were statistically higher in the Ped group compared to the Mel-Ped group (P <0.05). Immunohistochemical staining of RANKL and osteoclast activity were significantly lower in the Mel-Ped group compared to the Ped group (P <0.05). CONCLUSION: This study reveals that melatonin treatment significantly inhibits regional alveolar bone resorption and contributes to periodontal healing in an experimental periodontitis rat model.

Assessment of cytogenetic and cytotoxic effects of chlorhexidine digluconate on cultured human lymphocytes.

OBJECTIVE: The aim of this study was to assess the genetic and cellular toxicity of Chlorhexidine digluconate (CHX) on peripheral human lymphocytes in vitro. MATERIALS AND METHODS: Micronucleus assay was used to investigate the genotoxicity, while the cell viability and proliferation were evaluated by Trypan blue exclusion test and Nuclear Division Index in control and CHX-treated (0.05, 0.1, 0.2, 0.4, 0.5 mg/ml) human blood cultures. RESULTS: A dose-dependent toxic effect was found depending on CHX incubation on the genetic and cell viability of the lymphocytes. Micronucleus frequency was found to be statistically higher at 0.5 mg/ml concentration compared to lower doses and the control group (p < 0.05). A significant reduction was shown in the cell viability and cell proliferation of the exposed lymphocytes at the concentrations of 0.4 and 0.5 mg/ml (p < 0.05), while no significant toxicity was found at lower concentrations compared to control (p > 0.05). CONCLUSION: This study showed dose-dependent genotoxic and cytotoxic effects of CHX on human lymphocytes in vitro. It should be considered during periodontal irrigation or novel CHX products at lower concentrations should be manufactured for clinical usage.

Therapeutic effects of alpha lipoic acid and vitamin C on alveolar bone resorption after experimental periodontitis in rats: a biochemical, histochemical, and stereologic study.

BACKGROUND: Alpha lipoic acid (ALA) and vitamin C (Vit-C) are very important and powerful antioxidants that have been used for the treatment of many diseases. The present study aims to investigate the role of ALA and Vit-C substances in the treatment of alveolar bone resorption in periodontal diseases. METHODS: Thirty-six male Wistar albino rats were randomly divided into four groups as follows: 1) control rats; 2) rats with experimental periodontitis (PED); 3) rats with PED treated with ALA (ALA); and 4) rats with PED treated with ALA+Vit-C (ALA+Vit-C). PED was simulated by placing ligatures around the neck of teeth for 5 weeks. After ligature removal, the PED group was given a single intragastric dose of 1 mL saline, and the ALA and ALA+Vit-C groups were treated with an intragastric dose of 50 mg/kg ALA and ALA+Vit-C for 15 days, respectively. Levels of serum bone alkaline phosphatase (B-ALP) and myeloperoxidase (MPO) activity in gingival tissues were analyzed. To evaluate the osteoclast activation, expression of activated receptor activator nuclear factor-kappa B ligand (RANKL) and bone density index (BDI) were determined stereologically in the bone sections obtained from the mandibles of the rats. RESULTS: The results showed statistically significant differences between the PED group and groups treated with antioxidant according to B-ALP, MPO, RANKL, and BDI values (P <0.05). ALA and ALA+Vit-C treatments showed beneficial effects on the mesial/distal periodontal bone support at the ligature-induced periodontitis tooth areas. CONCLUSION: This study shows that ALA and Vit-C treatment provides therapeutic effects on inhibition of alveolar bone resorption and periodontal tissue destruction.