Induction Of Periodontitis Research Articles

Preventive effects of melatonin and amifostine on irradiated rats with experimental periodontitis

BackgroundThe aim of this study was to investigate the preventive effects of amifostine and melatonin oxidatively, biochemically and histomorphometrically in rats with radiotherapy-induced experimental periodontitis.Methods40 female Sprague-Dawley rats were divided into 5 groups: Control, experimental periodontitis (Ep), Ep + radiotherapy (Ep + Rt), Ep + Rt + amifostine (Ep + Rt + Ami), Ep + Rt + melatonin (Ep + Rt + Mel). The day after induction of periodontitis by ligature, a single dose of 5 Gy radiotherapy was administered. On the same day, treatments with amifostine (200 mg/kg) for 3 days and melatonin (10 mg/kg) for 15 days were started. By after 23 days of experiment, periodontal bone loss was measured by histomorphometry. RANKL, OPG and Caspase-3 activities were analyzed immunohistochemically and inflammatory cytokine (IL-1β, IL-10, IL-6, TNF-α) levels and oxidative stress (TOS/TAS) were analyzed biochemically in tissue homogenates.ResultsIt was observed that there was a significant difference in many biochemical parameters and oxidative stress levels between the control group and Ep + Rt (p < 0.05). Alveolar bone destruction in the melatonin prophylaxis group was observed to be close to control (p > 0.05). Melatonin significantly improved biochemical, histochemical, apoptotic and bone loss levels in irradiated experimental periodontitis rats (p < 0.05). When comparing the two drug groups (Ep + Rt + Ami and Ep + Rt + Mel), no statistically significant difference was found at any parameter level (p > 0.05).ConclusionBoth melatonin and amifostine can significantly limit RT-induced periodontal bone loss by suppressing inflammatory stress, apoptotic mechanisms, and RANKL-related osteoclastic activity. Given the limited side effects of melatonin, it may be an alternative to amifostine.

Regenerative endodontic therapy in immature teeth using photobiomodulation and photodynamic therapy; a histomorphological study in canine model

BackgroundRegenerative endodontic therapy (RET) is still coming up short to demonstrate histological evidence for true regeneration with clinically feasible protocol of cell homing in single visit approach.AimThe aim of the present study is to evaluate the regenerative potential of photobiomodulation (PBM) on RET in immature roots when photodynamic therapy (PDT) protocol is implemented for root canal disinfection in canine model.Materials and methodsSeventy-two root canals were recruited, with sixty assigned to experimental groups and twelve to positive and negative controls. Following the induction of pulp necrosis and apical periodontitis, the roots were divided into two experimental groups: Group I received RET followed by PBM (seven sessions with an 808 nm diode laser at 300 mW for 90 s), and Group II received RET without PBM. Follow-ups were conducted at 1, 2, and 3 months (subgroups A, B, and C respectively). Qualitative and quantitative assessment was carried out histologically. All data were statistically analyzed with the Mann-Whitney U test and Bonferroni’s adjustment, as well as Chi square test.ResultsThe newly formed hard tissue highly resembled true dentine where the dentinal tubules looked well organized lined by poly layers palisading pattern of rounded odontoblast-like cells with cytoplasmic processes extending through the predentine layer. GI exhibited statistically significantly higher scores of vital tissue infiltration and hard tissue deposition in subgroups A and B (P ≤ 0.05). The inflammatory cells scores were significantly lower in GI than in GII at all time intervals. However, no significance could be detected regarding apical closure.ConclusionThe disinfection protocol of PDT and subsequent irradiation with low power laser in PBM protocol pose a promising potential for regenerative endodontics in immature teeth.

MicroRNA expression profiling in the adult offspring of rats with periodontal disease

ObjectiveThe present study investigated the relationship between maternal periodontal disease, insulin resistance, activation of inflammatory pathways and epigenetic modifications in adult offspring. DesignTherefore, female Wistar rats were divided into control and experimental groups. Seven days after the induction of periodontal disease, female rats from both groups were mated with healthy male rats. After weaning, male offspring were divided into control offspring (CN-o) and periodontal disease offspring (PED-o) groups. Body weight was measured at 0–75 days of age. At day 75, the following were measured in the offspring: insulin resistance by the HOMA-IR index; global miRNAs by microtranscriptome array; validation of the selected miRNAs by quantitative real-time PCR expression; interleukin 1 receptor associated kinase 1 (IRAK1) and tumor necrosis factor receptor-associated factor 6 (TRAF6) content in the gastrocnemius muscle tissue (GSM) by western blotting. ResultsMaternal periodontal disease leads to low birth weight (LBW) in the offspring and insulin resistance in adulthood; changes in global miRNA expression (5 miRNAs upregulated and 6 downregulated); and increased protein expression of IRAK1 and TRAF6 in GSM. ConclusionsThese findings demonstrate that maternal periodontal disease causes LBW, insulin resistance, activation of inflammatory pathways, and changes in global miRNA expression.

Effect of chronic periodontitis on the endothelial glycocalyx of rat penile corpus cavernosum.

Chronic periodontitis may induce erectile dysfunction (ED), however, the specific mechanism involved is unclear. The endothelial glycocalyx (eGlx) is a structure that can regulate endothelial nitric oxide synthase (eNOS) phosphorylation on the cavity surface of vessels. To investigate whether chronic periodontitis leads to ED by affecting the eGlx. Twenty-four 4-week-old male Sprague‒Dawley rats were randomly divided into four groups (n=6): the control group, chronic periodontitis group, chronic periodontitis + heparin group (subcutaneous heparin 200 U/kg/day, 7 days), and control + heparin group. Four weeks after the induction of periodontitis in the rats, the maximum intra-cavernous pressure/mean arterial pressure (ICPmax/MAP), serum C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), nitric oxide (NO), heparin sulfate (HS), syndecan-1 (SDC-1), heparanase (HPSE), eNOS, and phosphor-eNOS (p-eNOS) concentration were measured, and the eGlx of the penile corpus cavernosum was observed by transmission electron microscopy (TEM). Chronic periodontitis can degrade eGlx on the rat penile corpus cavernosum by increasing serum CRP, TNF-α, and IL-6 levels, reducing the p-eNOS/eNOS ratio and the NO concentration in the penile corpus cavernosum, and resulting in the inhibition of the erectile function. Serum CRP, TNF-α, and IL-6 levels and HPSE expression in penile cavernous tissue were significantly greater in the chronic periodontitis group than in the control group and the chronic periodontitis + heparin group (P<0.05). The average thickness of the eGlx muscle in the penile corpus cavernosum in the chronic periodontitis group was significantly lower than those in the control group and chronic periodontitis + heparin group (P<0.05). The HS concentration, SDC-1 expression, p-eNOS/eNOS, NO concentration, and ICPmax/MAP in the chronic periodontitis group were significantly lower than those in the control group and chronic periodontitis+ heparin group (P<0.01). The eGlx on penile cavernosum vessels may be a new therapeutic target for the treatment of ED. This study revealed that chronic periodontitis promotes the decomposition of vascular eGlx in the rat penile corpus cavernosum, however, it is not clear whether chronic periodontitis inhibits the synthesis of eGlx. Chronic periodontitis can degrade eGlx on the rat penile corpus cavernosum by increasing serum CRP, TNF-α, and IL-6 levels, reducing the p-eNOS/eNOS ratio and the NO concentration in penile cavernous tissue, and resulting in the inhibition of the erectile function. Heparin inhibited eGlx decomposition and improved erectile function in rats with chronic periodontitis.

Experimental Periodontitis Worsens Dopaminergic Neuronal Degeneration.

To investigate the hypothesis supporting the link between periodontitis and dopaminergic neuron degeneration. Adult male Wistar rats were used to induce dopaminergic neuronal injury with 6-hydroxydopamine (6-OHDA) neurotoxin and experimental periodontitis via ligature placement. Motor function assessments were conducted before and after periodontitis induction in controls and 6-OHDA-injury-induced rats. Tissue samples from the striatum, jaw and blood were collected for molecular analyses, encompassing immunohistochemistry of tyrosine hydroxylase, microglia and astrocyte, as well as micro-computed tomography, to assess alveolar bone loss and for the analysis of striatal oxidative stress and plasma inflammatory markers. The results indicated motor impairment in 6-OHDA-injury-induced rats exacerbated by periodontitis, worsening dopaminergic striatal degeneration. Periodontitis alone or in combination with 6-OHDA-induced lesion was able to increase striatal microglia, while astrocytes were increased by the combination only. Periodontitis increased striatal reactive oxygen species levels and plasma tumour necrosis factor-alpha levels in rats with 6-OHDA-induced lesions and decreased the anti-inflammatory interleukin-10. This study provides original insights into the association between periodontitis and a neurodegenerative condition. The increased inflammatory pathway associated with both 6-OHDA-induced dopaminergic neuron lesion and periodontal inflammatory processes corroborates that the periodontitis-induced systemic inflammation may aggravate neuroinflammation in Parkinson's-like disease, potentially hastening disease progression.

Effect of photobiomodulation with different wavelengths on periodontal repair in non-hyperglycemic and hyperglycemicrats.

Hyperglycemic conditions is associated with more severe periodontitis and poorer outcomes after nonsurgical periodontal treatment (NPT). Then, these patients are candidates for adjunctive therapy associated with NPT. This study evaluates the effect of photobiomodulation (PBMT) at different wavelengths on periodontal repair in non-hyperglycemic/hyperglycemic animals. Sixty-four rats were submitted to induction of periodontitis by ligatures. Hyperglycemia was induced in half of these animals, whereas the other half remained non-hyperglycemic. The animals were subdivided into 4 groups according to the PBMT protocol applied at the time of ligature removal (n = 8): CTR: Without PBMT; IRL: PBMT with infrared laser (808 nm); RL: PBMT with red laser (660 nm); and RL-IRL: PBMT with red (660 nm) and infrared laser (808 nm). After a period of 7 days, the animals were euthanized. The parameters assessed by microtomography were the bone volume relative to total tissue volume (BV/TV%), distance from the cemento-enamel junction to the top of the bone crest (CEJ-CB), trabecular thickness, space between trabeculae, and number of trabeculae. Additionally, the percentage of inflammatory cells, blood vessels, and connective tissue matrix were assessed by histomorphometric analysis. PBMT reduced bone loss and increased trabecular density in hyperglycemic animals (p < .05), with RL being more effective in reducing linear bone loss (CEJ-CB), whereas RL-IRL was more effective in maintaining BV/TV%. PBMT reduced blood vessels and increased the connective tissue component in hyperglycemic animals (p < .05). RL-IRL reduced inflammatory cells regardless of the systemic condition of the animal (p < .05). PBMT (RL, RL-IRL) improves the repair of periodontal tissues in hyperglycemic animals.

Overexpression of the receptor for resolvin E1 (ERV1) prevents early alveolar bone loss in leptin receptor deficiency-induced diabetes.

This study was designed to test the hypothesis that the leptin receptor (LepR) regulates changes in periodontal tissues and that the overexpression of the receptor for resolvin E1 (ERV1) prevents age- and diabetes-associated alveolar bone loss. LepR-deficient transgenic (TG) mice were cross-bred with those overexpressing ERV1 (TG) to generate double-TG mice. In total, 95 mice were divided into four experimental groups: wild type (WT), TG, LepR deficient (db/db), and double transgenic (db/db TG). The groups were followed from 4weeks up to 16weeks of age. The natural progression of periodontal disease without any additional method of periodontitis induction was assessed by macroscopic and histomorphometric analyses. Osteoclastic activity was measured by tartrate-resistant acid phosphatase (TRAP) staining. At 4weeks, ERV1 overexpression prevented weight gain. From Week 8 onward, there was a significant increase in the weight of db/db mice with or without ERV1 overexpression compared to the WT mice, accompanied by an increase in glucose levels. By 8weeks of age, the percentage of bone loss in the LepR deficiency groups was significantly greater compared to WT mice. ERV1 overexpression in the db/db TG mice prevented early alveolar bone loss; however, it did not impact the development of diabetic bone loss in aging mice after the onset of weight gain and diabetes. The findings suggest that the overexpression of ERV1 prevents LepR-associated alveolar bone loss during the early phases of periodontal disease by delaying weight gain, diabetes onset, and associated inflammation; however, LepR deficiency increases susceptibility to naturally occurring inflammatory alveolar bone loss as the animal ages, associated with excess weight gain, onset of diabetes, and excess inflammation.

Single-cell transcriptome analysis reveals periodontal ligament fibroblast heterogeneity with distinct IL-1β and RANKL expression in periodontitis

Periodontitis is an inflammatory disease with alveolar bone destruction by osteoclasts. In periodontitis, both inflammation and osteoclast activation are significantly influenced by periodontal ligament fibroblasts (PDL-Fib). Yet, whether PDL-Fib has heterogeneity and whether distinct PDL-Fib subsets have specific functions have not been investigated. In this study, we discovered the complexity of PDL-Fib in periodontitis, utilizing single-cell RNA sequencing (scRNA-seq) data from human periodontitis patients. We identified distinct subpopulations of PDL-Fib: one expressing IL-1β and another expressing RANKL, both crucial in osteoclast differentiation and bone resorption. In periodontal tissues of mice with periodontitis, active IL-1β, cleaved caspase 1, and NLRP3 proteins were significantly elevated, implicating the NLRP3 inflammasome in IL-1β production. Upon stimulation of PDL-Fib with LPS from Porphyromonas gingivalis (pg), the mostly well characterized periodontal bacteria, a more rapid increase in IL-1β, followed by RANKL induction, was observed. IL-1β and TNF-α, another LPS-responsive cytokine, effectively increased RANKL in PDL-Fib, suggesting an indirect effect of pgLPS through IL-1β and TNF-α on RANKL induction. Immunohistological analyses of mouse periodontal tissues also showed markedly elevated levels of IL-1β- and RANKL upon periodontitis induction and displayed separate locations of IL-1β-expressing PDL-Fib and RANKL-expressing PDL-Fib in periodontitis. The heterogenic feature of fibroblasts expressing IL-1β and RANKL was also mirrored in our combined cross-tissue scRNA-seq datasets analysis. In summary, our study elucidates the heterogeneity of PDL-Fib, highlighting distinct functional groups for producing RANKL and IL-1β, which collectively promote osteoclast generation and bone destruction in periodontitis.

Correlation between PD-1/PD-L1 and RANKL/OPG in chronic apical periodontitis model of Sprague-Dawley rats.

Chronic apical periodontitis (CAP) is characterized by inflammation and destruction of the apical periodontium that is of pulpal origin, appearing as an apical radiolucent area, and does not produce clinical symptoms. Little is known about whether the PD-1/PD-L1 ratio is associated with the balance between RANKL and OPG in CAP. The relationship between PD-1/PD-L1 and RANKL/OPG in CAP is investigated in this study. A CAP rat model was established using Sprague-Dawley rats. The pulp chambers were exposed to the oral cavity to allow bacterial contamination. The apical tissues of the bilateral mandibular first molars were analyzed for histological morphology using hematoxylin and eosin (H&E) staining. Immunohistochemistry and qRT-PCR were used to determine the expression of PD-1, PD-L1, OPG, and RANKL mRNA and proteins in periapical tissues and mandibular samples, respectively. The radiological images indicated a poorly defined low-density shadow and alveolar bone resorption after periodontitis induction. Histological analysis revealed an infiltration of inflammatory cells and alveolar bone resorption in the periapical tissues. Mandibular mRNA and periapical protein expression of PD-1, PD-L1, and RANKL was upregulated 7-28days after periodontitis induction, while the expression of OPG was downregulated. No significant relationship was observed between PD-1/PD-L1 and RANKL/OPG at either mRNA or protein levels in CAP. There is an increased expression of PD-1, PD-L1, and RANKL and a decreased expression of OPG, indicating progression of CAP.

Effects of Coriander on the Repair Process of Experimentally-induced Periodontitis in Rats.

The aim of this study was to evaluate the effects of Coriandrum sativum L. (CSL) seed extract on gingival levels of antioxidant enzymes, pro-inflammatory cytokines and on alveolar bone and attachment levels after experimental periodontitis induction in rats and compare it with low-dose doxycycline (LDD). Forty adult male Wistar Albino rats were divided randomly into 5 groups as follows: 1 = periodontally healthy (control); 2 = periodontitis; 3 = periodontitis + CSL (32 mg/kg); 4 = periodontitis + CSL (200 mg/kg); and 5 = periodontitis + LDD (6 mg/kg). Gingival superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) levels were evaluated by enzyme-linked immunosorbent assay. The presence of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1βeta (IL-1β) immunoreactivity was detected immunohistochemically. Alveolar bone area in the furcation space (ABA), alveolar bone loss (ABL), and attachment loss (AL) were evaluated histomorphometrically. The SOD level was lower in group 5 than in groups 2, 3, and 4. The IL-1β level was highest in group 4. The TNF-α level was statistically higher in groups 2 and 4 than in groups 1, 3, and 5. The IL-6 level was highest in group 4. Its level was higher in groups 2 and 3 than in group 5. ABA was less in groups 2, 3, and 4 compared to groups 1 and 5. ABL was less in group 5 than in groups 2, 3, and 4. AL was greater in group 4 than in group 5. The use of 200 mg/kg CSL showed a pro-inflammatory effect and IL-1β and TNF-α levels decreased after 32 mg/kg CSL application in the treatment of periodontitis.

Quercetin in the Prevention of Induced Periodontal Disease in Animal Models: A Systematic Review and Meta-Analysis.

Periodontitis is an inflammatory condition initiated by oral bacteria and is associated with several systemic diseases. Quercetin is an anti-inflammatory and anti-bacterial poly-phenol present in various foods. The aim of this meta-analysis was the evaluation of the effects of quercetin administration in animal models of experimental periodontitis. A systematic search was performed in electronic databases using the following search terms: "periodontitis" or "periodontal disease" or "gingivitis" and "quercetin" or "cyanidanol" or "sophoretin" or "pentahydroxyflavone". In vivo preclinical animal models of experimental periodontal disease with a measurement of alveolar bone loss were included in the analysis. The risk of bias of the included studies was assessed using the SYRCLE tool. The systematic search yielded 335 results. Five studies were included, four of them qualified for a meta-analysis. The meta-analysis showed that quercetin administration decreased alveolar bone loss (τ2 = 0.31, 1.88 mm 95%CI: 1.09, 2.67) in experimental periodontal disease animal models. However, the risk of bias assessment indicated that four SYRCLE domains had a high risk of bias. Quercetin diminishes periodontal bone loss and prevents disease progression in animal models of experimental periodontal disease. Quercetin might facilitate periodontal tissue hemostasis by reducing senescent cells, decreasing oxidative stress via SIRT1-induced autophagy, limiting inflammation, and fostering an oral bacterial microenvironment of symbiotic microbiota associated with oral health. Future research will show whether and how the promising preclinical results can be translated into the clinical treatment of periodontal disease.

Chenopodium Ambrosioides Linn Mitigates Bone Loss in Rats with Periodontitis.

Periodontitis is an inflammatory disease that causes bone loss. Some patients do not respond well to the classic treatment and need therapies that minimize bone loss, the main sequel of the disease. Chenopodium ambrosioides L. has stood out due to its anti-inflammatory and anti-oxidative activities. However, no study has yet investigated its effect on periodontitis. This study aimed to evaluate the bone protective effect of Chenopodium ambrosioides L. (CAL) extract on ligature-induced periodontitis model in rats. For this, a pre-clinical assay was performed, using male Wistar rats divided into 3 groups: Naive (N) (n=6), not submitted to any procedure; Saline (SAL) (n=6), submitted to ligature-induced periodontitis and receiving 2 ml/kg of 0.9% saline solution; and CAL extract, which was subdivided into 3 subgroups (n=6/subgroup) receiving the CAL at 3 (CAL3), 10 (CAL10) or 30 mg/kg (CAL30). All agents were given, by oral gavage, 30 min before periodontitis induction and daily until euthanasia (11th day). By then, maxillae were removed for macroscopic, histological, and histometric analyses. Kidneys, liver, and stomach were collected to evaluate the safety of CAL extract. High-performance liquid chromatography (HPLC) assay was used to investigate the flavonoid content in the extract. Chenopodium ambrosioides L. extract at 30mg/kg showed a reduction by 58% in bone loss marked by an increase (+35%) in the number of osteoblasts and a reduction (-51%) on the number of osteoclasts (p< 0.05). No significant alteration in the liver, kidney, or stomach was seen. Rutin was the main flavonoid found. In summary, it was observed that Chenopodium ambrosioides L. extract has shown important anti-inflammatory and bone anabolic and anti-resorptive properties without causing toxicity in the main organs. Rutin, as the main flavonoid of the extract, seems to be responsible for the beneficial effect of this agent.

Effect of experimental periodontitis on cardiac functions: a comprehensive study using echocardiography, hemodynamic analysis, and histopathological evaluation in a rat model.

Periodontitis is a prevalent and severe dental condition characterized by the gradual degradation of the bone surrounding the teeth. Over the past two decades, numerous epidemiological investigations have suggested a potential link between periodontitis and cardiovascular disease. However, the complex mechanistic relationship between oral health issues and cardiovascular disorders remains unclear. This study aimed to explore comprehensively the cardiac function through various methods, including conventional echocardiography, intraventricular pressure gradient (IVPG) analysis, speckle tracking echocardiography (STE), and hemodynamics analysis. Ligature-induced periodontitis was established in a group of rats while the second group served as sham. The successful establishment of the periodontitis model was confirmed through staining and radiographic examination of the affected mandibles. X-ray films and methylene blue staining revealed alveolar bone resorption in the affected first molar in the model rats, confirming the successful induction of periodontitis. The rats with periodontitis displayed a decrease in ejection fraction compared to the sham group, accompanied by a decrease in mid-to-apical IVPG and mid IVPG. Lower values of strain rate were recorded in the apical segment of the septum, the middle segment of the septum, and the basal segment of the lateral free wall in the periodontitis group, which was associated with histopathological examination showing some degree of myocardial tissue damage. Conversely, rats with periodontitis showed an increase in heart rate, end-systolic volume, and arterial elastance when compared to the sham rats. However, they also exhibited a decrease in stroke work, stroke volume, cardiac output, and end-systolic pressure. This study suggests that experimental periodontitis may lead to cardiac dysfunction especially compromised systolic function and myocardial relaxation, potentially indicating an increased risk of cardiovascular events in clinical periodontitis cases. The comprehensive assessment of cardiac function, hemodynamics, and histopathological evaluation underscores the profound impact of periodontitis on heart functions within this specific experimental model.

Osteoclastogenesis Inhibitor and Antioxidant Properties of Konjac Glucomannan in a Periodontitis Mice Model: An In Vivo Study

Background. Periodontitis is an inflammatory disease caused by specific microorganisms that gradually damage the periodontal and tooth-supporting tissues, thereby reducing a person’s quality of life. Periodontal disease is closely associated with high reactive oxygen species (ROS) levels, with a high receptor activator of nuclear factor kβ ligand (RANKL)/osteoprotegerin (OPG) ratio. Konjac glucomannan (KGM) is produced from the porang root, which has several properties. For example, it can reduce oxidative stress. The current study analyzed the osteoclastogenesis inhibitory and antioxidant properties of KGM based on histomorphometric findings, RANKL/OPG ratio, and ROS levels in the Swiss Webster mouse periodontitis model. Methods. Eight-week-old male Swiss Webster mice were divided into the nonligation, nonligation + KGM, ligation + Porphyromonas gingivalis, and ligation + P. gingivalis + KGM groups. KGM suspension was administered for 14 days. Periodontitis induction was performed from 7th to 14th day. On the 14th day, maxillae, gingival, and gingival crevicular fluid samples were collected to assess the histomorphometry of bone damage, gene expression ratio of RANKL/OPG, and ROS protein levels. Results. The periodontitis group pretreated with KGM presented with significantly reduced alveolar bone damage, RANKL/OPG ratio, and ROS level than without KGM group. KGM treatment had no harmful/toxic effects in mice. Conclusion. Administration of KGM could act as an adjunctive in periodontal therapy by suppressing periodontal disease via osteoclastogenesis inhibitory and antioxidant properties.

The effect of zinc complex of N-isopropenylimidazole on the morphological characteristics of gum tissues in experimental endodontic-periodontal lesions in rats

Introduction: Combined inflammatory and destructive processes affecting the dental pulp and tissues of the periodontal complex are among the most problem diseases of the dental system. Current therapy with use of available pharmacological agents does not always allow achieving the expected positive result. In addition, often the lack of information about morphological processes in the tissues of the dental system, in particular the gums, with endodontic-periodontal lesion (EPL) limits the ability of dentists to carry out targeted pharmacotherapy with both traditional and, in particular, new medications. The aim of the study was to evaluate the morphological characteristics of gum tissues in a therapeutic context of N-isopropenylimidazole zinc complex derivative in experimental endodontic-periodontal lesion in rats. Materials and Methods: A simulation of EPL in rats was performed in two ways: simultaneous induction of acute periodontitis and parodontitis by pulp extraction and natural infection of the pulp cavity, as well as by ligation of the necks of lower incisors. The research protocols included 5 groups of animals: 1st – intact group (control-1); 2nd – animals with simulated EPL (control-2); 3rd – animals with simulated EPL and treated with Metrogyl Denta® gel (M-D); 4th – animals with simulated EPL and treated with N–isopropenylimidazole zinc complex derivative gel under the laboratory code Pilim-1; and 5th – animals with simulated EPL and treated with the combination of M-D + Pilim-1. The gum of the lower incisors was taken for morphological studies. Slides were stained with hematoxylin and eosin. Computer morphometry was performed using the ImageJ software. Results and Discussion: The substances M-D, Pilim-1 and, especially, the combination of M-D+Pilim-1 (against the background of chlorhexidine bigluconate used as oral rinse) for 14 days in rats with simulated EPL cause a significant improvement of the morphological structure of the gum with minimal residual dystrophy and sclerosis. The combination M-D + Pilim-1 led to a 1.3-time increase in epithelial thickness, and a 1.5-time decrease in acanthosis depth in comparison with M-D, while the number of capillaries and their diameter had no significant differences. Compared with Pilim-1, the epithelial thickness increased 1.5 times, and the acanthosis depth and the number of capillaries decreased 1.6 and 1.4 times, respectively, whereas the diameter of the capillaries did not change significantly. The pronounced protective effect of the combination M-D + Pilim-1 on the morphological structure of the gingival mucosa of rats with simulated EPL may be associated with antimicrobial, anti-inflammatory, regenerating, angioprotective and antioxidant properties of both M-D and Pilim-1 separately, and, possibly to a greater extent, of the combination M-D + Pilim-1. Conclusion: The substances M-D, Pilim-1 and, especially, the combination M-D + Pilim-1 (against the background of chlorhexidine bigluconate used as oral rinse) for 14 days in rats with simulated EPL have a protective effect on the epithelial structure and the connective tissue of the proper mucous plate, manifested in active normalization of pathological changes and significant restoration of their organotypic structure.

Zoledronic Acid Modulates Cytokine Expression and Mitigates Bone Loss during the Development of Induced Apical Periodontitis in a Mice Model

IntroductionBisphosphonates are antiresorptive drugs used worldwide to treat systemic bone pathologies. This study aimed to assess the impact of zoledronic acid on the progression of induced apical periodontitis and the expression of cytokines interleukin (IL)-1β, IL-10, IL-6, and tumor necrosis factor alpha (TNF-α) in a mouse model. MethodsSixteen female isogenic BALB/c mice 6 weeks of age were distributed into 2 groups: mice with induced apical periodontitis (the AP group, n = 8) and mice with induced apical periodontitis treated with zoledronic acid (the AP-ZA group, n = 8). The AP-ZA group received a dose of 125 μg/kg zoledronic acid diluted in sterile saline solution administered intraperitoneally once a week for 4 weeks before pulp exposure, whereas the AP group received only saline solution. Pulp exposures were performed on the maxillary first molars for the induction of apical periodontitis, and mice were euthanized after 7 and 21 days. The jaws were collected; scanned using micro–computed tomographic imaging; and processed for polymerase chain reaction analysis of IL-1β, IL-10, IL-6, and TNF-α. The Student t test was performed for parametric data, and Mann-Whitney U tests were used for nonparametric data. The level of significance was set at 5%. ResultsMicro–computed tomographic imaging revealed higher bone resorption in the AP group compared with the AP-ZA group at both time points (P < .05). Real-time polymerase chain reaction demonstrated higher TNF-α expression in the AP group at both time points and higher IL-6 and IL-1β expression in the AP group at the 7- and 21-day time points, respectively, compared with the AP-ZA group (P < .05). No differences were observed regarding IL-10 expression between the groups. ConclusionsZoledronic acid had significant anti-inflammatory and antiresorptive effects on apical periodontitis in mice.

Sodium alendronate is an effective adjunctive therapy for treating periodontitis in male rats treated with anticancer chemotherapy

ObjectivesTo assess sodium alendronate as a local adjunctive therapy for treating experimental periodontitis in male rats treated with chemotherapy. DesignOne-hundred-eighty male rats were randomly divided into two groups (n = 90) based on the systemic treatments: PSS, physiological saline solution; and 5-Fluorouracil, and then, subdivided into three subgroups (n = 30): NT, no treatment; scaling and root planing; and sodium alendronate. Treatments were performed 7 days after induction of experimental periodontitis. Specimens were collected at 14, 22, and 37 days after induction. Alveolar bone level, percentage of bone in the furcation, percentage of non-vital bone in the furcation, histopathologic features, and immunolabeling pattern for tartrate-resistant acid phosphatase (TRAP) and osteocalcin (OCN) were evaluated. ResultsThe lowest amount of alveolar bone and highest amount of non-vital bone was found in group 5-Fluorouracil when no treatment was performed. In animals receiving 5-Flurouracil and subjected to periodontal treatment, adjunctive sodium alendronate resulted in higher percentage of bone in the furcation and higher alveolar bone loss, when compared with scaling and root planing alone. Better structural and cellularity patterns were found in the periodontal tissues when sodium alendronate was used, regardless of systemic treatment. Higher TRAP-expression was found when no treatment was performed. Sodium alendronate didn’t affect the immunolabeling pattern of osteocalcin in the presence of 5-Fluorouracil. ConclusionAdjunctive therapy with local sodium alendronate prevented alveolar bone loss and improved the histopathological features of the periodontal tissues following scaling and root planing in male rats with experimental periodontitis receiving anticancer chemotherapy with 5-Fluorouracil.

Effect Of Coenzyme Q10 On Osteoblasts Cells Number In Male Wistar Rats Gingiva Undergoing Periodontitis

Inflammatory conditions in periodontitis can lead to increased production of free radicals. This study aims to determine the effect of coenzyme Q10 on the number of osteoblast cells in the gingiva of male wistar rats with periodontitis. The method used in this research is true experimental laboratory with posttest only control group design. 24 male wistar rats were divided into 4 groups, negative control group and treatment group on days 7 and 14 with each group of 6 rats. Induction of periodontitis by tying using silk ligature in the subgingival area and induced Porphyromonas gingivalis bacteria around the mandibular incisors teeth given every 2 days for 7 days. The treatment group was applied coenzyme Q10 0.1ml twice a day. 6 rats from each group were decapitated on day 7 and 14 then processed into histological preparations and then measured the number of osteoblasts. Data were analyzed using one-way ANOVA and LSD test. Conclusion: Application of coenzyme Q10 has an effect on increasing the number of osteoblast cells in the gingiva of male wistar rats with periodontitis

Effect of 10% kepok banana peel extract gel (musa paradisiaca linn. kepok) application on periodontal regeneration process in periodontal healing of wistar rat (rattus norvegicus): In vivo study

Objective: The aim of our study was to determine the effect of application of 10% Kepok banana peel extract gel (Musa paradisiaca linn. Kepok) on periodontal regeneration process in periodontal healing of wistar rat (Rattus norvegicus).&#x0D; Methods: Fourty-eight wistar rats were divided into 3 groups, namey 16 rats as the positive control group (Aloclair gel), 16 rats as the negative control group (CMC-Na gel 2%) and 16 rats as the treatment group (10% Kepok banana peel extract gel). The induction of periodontitis was performed using modified ligation technique for 7 days with additional injection of Aggregatibacter actinomycetemcomitans bacteria on the first day. Wistar rats were euthanized on days 1, 3, 5, 7, 14 for histological analysis to evaluate the number of macrophages, lymphocytes, osteoclasts, osteoblasts and fibroblasts. Radiographs were taken on day 21 using digital periapical radiograph (PaloDex Oy). Data were analyzed using Two-Way ANOVA and Post Hoc LSD tests.&#x0D; Results: Data analysis showed a significant difference in the cell numbers among the groups. A decreasing number of lymphocytes, macrophages, and osteoclasts could already be observed since the 1st day, so could an increasing number of fibroblasts and osteoblasts. The fibroblasts and osteoblasts of the treatment group already reached their peak on the 5th day, faster than the negative control and positive control groups that reached their peaks on the 7th day.&#x0D; Conclusion: The application of 10% Kepok banana peel extract gel (Musa paradisiaca linn. Kepok) caused significant acceleration of periodontal regeneration process in periodontal healing of wistar rat (Rattus norvegicus).

Induction of Periodontitis Using Bacterial Strains Isolated from the Human Oral Microbiome in an Experimental Rat Model.

Periodontal disease is that condition resulting in the destruction of periodontal tissues, bone resorption, and tooth loss, the etiology of which is linked to immunological and microbiological factors. The aim of this study was to evaluate the potential trigger of periodontal disease in a rat model using bacterial species incriminated in the pathology of human periodontitis and to establish their optimal concentrations capable of reproducing the disease, with the idea of subsequently developing innovative treatments for the condition. In this study, we included 15 male Wistar rats, aged 20 weeks, which we divided into three groups. In each group, we applied ligatures with gingival retraction wire on the maxillary incisors. The ligature and the gingival sac were contaminated by oral gavage with a mixture of fresh cultures of Aggregatibacter actinomycetemcomitans (A.a), Fusobacterium nucleatum (F.n) and Streptococcus oralis (S.o) in concentrations of 108, 109, and 1010 CFU/mL each for 5 days a week for 4 weeks. During the clinical monitoring period of 28 days, overlapped with the period of oral contamination, we followed the expression of clinical signs specific to periodontitis. We also monitored the evolution of body weight and took weekly samples from the oral cavity for the microbiological identification of the tested bacteria and blood samples for hematological examination. At the end of the study, the animals were euthanized, and the ligated incisors were taken for histopathological analysis. The characteristic symptomatology of periodontal disease was expressed from the first week of the study and was maintained until the end, and we were able to identify the bacteria during each examination. Hematologically, the number of neutrophils decreased dramatically (p < 0.0001) in the case of the 109 group, unlike the other groups, as did the number of lymphocytes. Histopathologically, we identified neutrophilic infiltrate in all groups, as well as the presence of coccobacilli, periodontal tissue hyperplasia, and periodontal lysis. In the 109 group, we also observed pulpal tissue with necrotic bone fragments and pyogranulomatous inflammatory reaction. By corroborating the data, we can conclude that for the development of periodontal disease using A.a, F.n, and S.o, a concentration of 109 or 1010 CFU/mL is required, which must necessarily contaminate a ligature thread applied to the level of the rat's dental pack.