Hypochlorous acid inactivates oral pathogens and a SARS-CoV-2-surrogate.

BACKGROUND: Droplets and aerosols produced during dental procedures are a risk factor for microbial and viral transmission. Unlike sodium hypochlorite, hypochlorous acid (HOCl) is nontoxic to tissues but still exhibits broad microbicidal effect. HOCl solution may be applicable as a supplement to water and/or mouthwash. This study aims to evaluate the effectiveness of HOCl solution on common human oral pathogens and a SARS-CoV-2 surrogate MHV A59 virus, considering the dental practice environment. METHODS: HOCl was generated by electrolysis of 3% hydrochloric acid. The effect of HOCl on human oral pathogens, Fusobacterium nucleatum, Prevotella intermedia, Streptococcus intermedius, Parvimonas micra, and MHV A59 virus was studied from four perspectives: concentration; volume; presence of saliva; and storage. HOCl solution in different conditions was utilized in bactericidal and virucidal assays, and the minimum inhibitory volume ratio that is required to completely inhibit the pathogens was determined. RESULTS: In the absence of saliva, the minimum inhibitory volume ratio of freshly prepared HOCl solution (45-60 ppm) was 4:1 for bacterial suspensions and 6:1 for viral suspensions. The presence of saliva increased the minimum inhibitory volume ratio to 8:1 and 7:1 for bacteria and viruses, respectively. Applying a higher concentration of HOCl solution (220 or 330 ppm) did not lead to a significant decrease in the minimum inhibitory volume ratio against S. intermedius and P. micra. The minimum inhibitory volume ratio increases in applications of HOCl solution via the dental unit water line. One week of storage of HOCl solution degraded HOCl and increased the minimum growth inhibition volume ratio. CONCLUSIONS: HOCl solution (45-60 ppm) is still effective against oral pathogens and SAR-CoV-2 surrogate viruses even in the presence of saliva and after passing through the dental unit water line. This study indicates that the HOCl solution can be used as therapeutic water or mouthwash and may ultimately reduce the risk of airborne infection in dental practice.

The use of omega-3 fatty acids in the treatment of oral diseases.

Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) have been reported to exert important roles in the inflammatory response. There are many inflammatory diseases in dentistry which support the administration of ω-3 PUFAs as an adjunct therapy during the treatment of these diseases. The aim of this review was to evaluate the use of ω-3 PUFAs as an adjuvant therapy during the treatment of buccal diseases. The review showed that supplementation with ω-3 PUFAs was used for treatment of gingivitis, periodontal diseases, apical periodontitis, stomatitis, and orthodontic tooth movement. The results indicate that ω-3 PUFAs decreased the number of pro-inflammatory mediators in the gingival tissues of individuals with gingivitis and periodontitis. In apical periodontitis, the supplementation suppressed bone resorption and promoted bone formation in the periapical area of rats. During orthodontic movement, the supplementation showed a decrease of bone resorption in rats. It also showed that painful symptoms of recurrent aphthous stomatitis were alleviated in supplemented patients. In conclusion, the ω-3 PUFAs may be used as an adjuvant therapy in the treatment of inflammatory diseases that affect the oral cavity. However, more studies are required to elucidate the role of ω-3 PUFAs in decreasing oral cavity inflammatory processes.

Curcumin reduces inflammation in rat apical periodontitis.

AIM: The aim of the study was to evaluate the effect of systemic curcumin administration on the severity of apical periodontitis (AP). METHODOLOGY: Forty male Wistar rats weighing 250-280 g each, age 2.5 months, were distributed into four groups (n = 10): control untreated rats (C), control rats treated with curcumin (CUR), rats with pulp exposure-induced apical periodontitis (AP) and rats with pulp exposure-induced apical periodontitis treated with curcumin (AP-CUR). Curcumin treatment was administered orally once daily for 15 days before pulp exposure and continued for 30 days after pulp exposure. The rats were sacrificed at 30 days, and the jaws were collected and reconstructed in a programme specific for micro-CT. The jaws were processed for analysis of the inflammatory process using haematoxylin and eosin staining and immunohistochemical assays for interleukin tumour necrosis factor alpha (TNF-α), interleukin (Il)-6 and Il-1ß. Tartrate-resistant acid phosphatase (TRAP) and osteocalcin (OCN) staining were used to analyse the resorptive process on the bone surface of periapical area. Kruskal-Wallis with Dunn's test was performed for nonparametric data and anova with Tukey's test for parametric data, p < .05. RESULTS: Micro-CT revealed no statistically significant differences in bone resorption between the AP and AP-CUR groups (p > .05). The levels of inflammatory cell infiltration and immunoreactivity for the proinflammatory cytokines TNF-α, Il-6 and Il-1ß were significantly higher in the periapical lesions of the AP group than in the AP-CUR group (p < .05). The number of TRAP-positive multinucleated cells was higher in the AP group than in the AP-CUR group (p < .05). In OCN-positive cells, no differences were observed between the AP and AP-CUR groups (p > .05). CONCLUSIONS: Oral supplementation with curcumin had a significant effect on the AP severity in rats, suggesting an anti-inflammatory effect of curcumin on AP development.

Elevated Expression of Macrophage Migration Inhibitory Factor Promotes Inflammatory Bone Resorption Induced in a Mouse Model of Periradicular Periodontitis.

Locally produced osteoclastogenic factor RANKL plays a critical role in the development of bone resorption in periradicular periodontitis. However, because RANKL is also required for healthy bone remodeling, it is plausible that a costimulatory molecule that upregulates RANKL production in inflammatory periradicular periodontitis may be involved in the pathogenic bone loss processes. We hypothesized that macrophage migration inhibitory factor (MIF) would play a role in upregulating the RANKL-mediated osteoclastogenesis in the periradicular lesion. In response to pulp exposure, the bone loss and level of MIF mRNA increased in the periradicular periodontitis, which peaked at 14 d, in conjunction with the upregulated expressions of mRNAs for RANKL, proinflammatory cytokines (TNF-α, IL-6, and IL-1ß), chemokines (MCP-1 and SDF-1), and MIF's cognate receptors CXCR4 and CD74. Furthermore, expressions of those mRNAs were found significantly higher in wild-type mice compared with that of MIF-/- mice. In contrast, bacterial LPS elicited the production of MIF from ligament fibroblasts in vitro, which, in turn, enhanced their productions of RANKL and TNF-α. rMIF significantly upregulated the number of TRAP+ osteoclasts in vitro. Finally, periapical bone loss induced in wild-type mice were significantly diminished in MIF-/- mice. Altogether, the current study demonstrated that MIF appeared to function as a key costimulatory molecule to upregulate RANKL-mediated osteoclastogenesis, leading to the pathogenically augmented bone resorption in periradicular lesions. These data also suggest that the approach to neutralize MIF activity may lead to the development of a therapeutic regimen for the prevention of pathogenic bone loss in periradicular periodontitis.

Endogenous acid ceramidase protects epithelial cells from Porphyromonas gingivalis-induced inflammation in vitro.

Ceramidases are a group of enzymes that degrade pro-inflammatory ceramide by cleaving a fatty acid to form anti-inflammatory sphingosine lipid. Thus far, acid, neutral and alkaline ceramidase isozymes have been described. However, the expression patterns of ceramidase isoforms as well as their role in periodontal disease pathogenesis remain unknown. In this study, expression patterns of ceramidase isoforms were quantified by real-time PCR and immunohistochemistry in gingival samples of patients with periodontitis and healthy subjects, as well as in EpiGingivalTM-3D culture and OBA-9 gingival epithelial cells both of which were stimulated with or without the presence of live Porphyromonas gingivalis (ATCC 33277 strain). A significantly lower level of acid ceramidase expression was detected in gingival tissues from periodontal patients compared to those from healthy subjects. In addition, acid-ceramidase expression in EpiGingival™ 3D culture and OBA-9 cells was suppressed by stimulation with P. gingivalis in vitro. No significant fluctuation was detected for neutral or alkaline ceramidases in either gingival samples or cell cultures. Next, to elucidate the role of acid ceramidase in P. gingivalis-induced inflammation in vitro, OBA-9 cells were transduced with adenoviral vector expressing the human acid ceramidase (Ad-ASAH1) gene or control adenoviral vector (Ad-control). In response to stimulation with P. gingivalis, ASAH1-over-expressing OBA-9 cells showed significantly lower mRNA expressions of caspase-3 as well as the percentage of Annexin V-positive cells, when compared with OBA-9 cells transduced with Ad-control vector. Furthermore, in response to stimulation with P. gingivalis, ASAH1-over-expressing OBA-9 cells produced less TNF-α, IL-6, and IL1ß pro-inflammatory cytokines than observed in OBA-9 cells transduced with Ad-control vector. Collectively, our data show the novel discovery of anti-inflammatory and anti-apoptotic effects of acid ceramidase in host cells exposed to periodontal bacteria, and the attenuation of the expression of host-protective acid ceramidase in periodontal lesions.

Endodontic infections increase leukocyte and lymphocyte levels in the blood.

OBJECTIVES: The aim of this study was to determine whether the presence of single or multiple apical periodontitis (AP) alters blood cell counts and cytokine production. MATERIAL AND METHODS: Thirty rats were divided into three groups: a control group comprising rats without AP, a group called 1AP comprising rats with AP in one tooth, and a group called 4AP comprising rats with AP in four teeth. Endodontic infection was induced by pulp exposure of the first right maxillary molar in the 1AP group or by exposing the first and second right maxillary and mandibular molars in the 4AP group. A blood count and cytokine levels were obtained 30 days after infection by collecting blood by cardiac puncture. The maxillae were dissected and stained with hematoxylin and eosin to evaluate the inflammatory infiltrate. The data were tabulated and subjected to statistical analysis (P < 0.05). RESULTS: Histological analysis showed a predominance of mononuclear inflammatory cells. In blood, significant increase of leukocytes, lymphocytes, and tumor necrosis factor alpha (TNF-α) in 4AP compared with the control and 1AP groups (P < 0.05) was observed. In addition, significant decrease of interleukin-4 (IL-4) in 1AP and 4AP groups compared with the control was observed (P < 0.05). CONCLUSIONS: In the rat model, the presence of multiple AP can affect health by increasing lymphocyte and TNF-α levels in the blood. CLINICAL RELEVANCE: The presence of endodontic infections can interfere with the blood profile, altering systemic health.

Apical periodontitis and periodontal disease increase serum IL-17 levels in normoglycemic and diabetic rats.

OBJECTIVES: This study aimed to evaluate the influence of apical periodontitis (AP) and/or periodontal disease (PD) on serum interleukin-17 (IL-17) levels in a rat model of diabetes mellitus (DM). METHODS: Eighty male Wistar rats were divided into eight groups of ten animals each: normoglycemic, AP, PD, AP+PD, DM, DM+AP, DM+PD, and DM+AP+PD. DM was induced using streptozotocin, AP by dental pulp exposure to the oral environment, and PD by periodontal ligature. The animals were sacrificed after 30 days, and venous blood samples were collected via cardiac puncture to determine the serum IL-17 and neutrophil levels. The maxillae were dissected and processed for radiographic analysis. The periapical lesion areas were quantified in pixels. The total assessed values were tabulated according to each experimental group and were statistically analyzed using Spearman's correlation and Kruskal-Wallis test (p < 0.05). RESULTS: A significant difference in the serum IL-17 levels was observed between the groups without oral infections and the groups with AP+PD-associated lesions, regardless of the presence of DM (p < 0.05). Diabetes increased the neutrophil levels, regardless of the presence of oral infection. However, a combination of two oral infections increased the neutrophil levels in DM rats (p < 0.05). The level of bone resorption lesions was greater in DM rats than in normoglycemic rats (p < 0.05). CONCLUSION: The combination of AP and PD increased the serum IL-17 levels in DM and normoglycemic rats and increased the neutrophil levels in DM rats. Diabetes increased the neutrophil levels and bone resorption in rats. CLINICAL SIGNIFICANCE: AP is capable of potentiating systemic inflammatory changes when associated with PD, and increases in blood glucose can accelerate the pathogenesis of oral infections.

Pulpal and periodontal diseases increase triglyceride levels in diabetic rats.

OBJECTIVES: The aim of this study was to evaluate triglyceride and cholesterol levels in diabetic rats and their relationship with pulpal and periodontal diseases. METHODS: Eighty male rats (Rattus norvegicus albinus, Wistar) were divided into the following eight groups comprising ten animals each: normal rats (G1), rats with pulpal diseases (G2), rats with periodontal diseases (G3), rats with both pulpal and periodontal diseases (G4), diabetic rats (G5), diabetic rats with pulpal diseases (G6), diabetic rats with periodontal diseases (G7), and diabetic rats with both periodontal and pulpal diseases (G8). Diabetes was induced by injecting streptozotocin, periapical lesions were induced by exposing pulpal tissue to the oral environment, and periodontal diseases were induced by periodontal ligature. The animals were killed after 30 days, and lipid profile was enzymatically measured using Trinder's method. The total assessed values were statistically analyzed by analysis of variance and Tukey test (p < 0.05). RESULTS: The triglyceride levels of diabetic rats with periodontal disease and of diabetic rats with both periodontal and pulpal diseases were significantly higher than those of normal rats and nondiabetic group rats, respectively. The differences in the cholesterol levels among the groups were not significant. CONCLUSIONS: We found that the association of pulpal and periodontal diseases with diabetes increased triglyceride levels in rats. CLINICAL SIGNIFICANCE: Changes in lipid profile may be related to the presence of oral infections and diabetes.

Accuracy of radiographic pixel linear analysis in detecting bone loss in periodontal disease: Study in diabetic rats.

INTRODUCTION: Periodontitis, a complex infectious disease that may lead to irreversible loss of periodontium, is considered a predisposing agent for developing insulin resistance due to the release of inflammatory mediators, showing a bilateral relationship with diabetes mellitus. The investigation of periodontal disease requires a clinical approach and complete intraoral radiographs, even with increasing concerns about radiation exposure. Thus, this study assesses pixel linear analysis accuracy using digital radiography via Digora® in detecting alveolar bone destruction in diabetic rats with periodontal disease. METHODOLOGY: 40 rats were divided into groups (n = 10): control (C), rats with periodontal disease (PD), experimental diabetic rats (ED), experimental diabetic rats with periodontal disease (ED-PD). Diabetes was induced by streptozotocin and periodontal disease by periodontal ligature. After 30 days, maxillae bone destruction was obtained by linear analysis of vertical bone loss using digital radiography and then assessed by micro-CT and histology. Data were analyzed by ANOVA and Tukey's test (p < 0.05). RESULTS: Radiographic, micro-CT and histological analysis presented accurate and similar results. PD and ED-PD groups showed higher bone destruction than C and ED groups (p < 0.05). Moreover, the ED-PD group had higher bone loss than the PD group (p < 0.05). CONCLUSION: The pixel linear analysis via digital radiography was an accurate, low-cost alternative in detecting alveolar bone loss in this rat model. Micro-CT and histological analysis may also be used to obtain linear measures to assess and compare periodontal bone destruction in diabetic rats.

Omega-3 Fatty Acids Alter Systemic Inflammatory Mediators Caused by Apical Periodontitis.

INTRODUCTION: This study investigated the effects of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) on serum inflammatory mediators of rats with pulp exposure-induced apical periodontitis. METHODS: Forty male Wistar rats were divided into the following groups: control, untreated rats (C); control rats treated with ω-3 PUFAs (C-O); rats with pulp exposure-induced apical periodontitis (AP); and rats with pulp exposure-induced apical periodontitis treated with ω-3 PUFAs (AP-O). ω-3 PUFAs were administered orally once a day for 15 days before pulp exposure and continued for 30 days after pulp exposure. The rats were sacrificed, and then blood and jaw samples were collected. Blood analysis was conducted to determine the total number of leukocytes including neutrophils, monocytes, and lymphocytes. Proinflammatory cytokines tumor necrosis factor alpha, interleukin (IL) 6, and IL-17 were quantified by enzyme-linked immunosorbent assay. Histologic analysis was performed to confirm the development of apical periodontitis. The data were statistically evaluated using analysis of variance and the Tukey posttest. The significance level was set at 5%. RESULTS: The development of apical periodontitis was confirmed in all infected groups. Bone destruction was larger in the AP group compared with the AP-O group (P < .05). Blood analysis showed that the AP and AP-O groups showed higher numbers of lymphocytes, leukocytes, monocytes, eosinophils, and expressions of tumor necrosis factor alpha and IL-6 compared with the C and C-O groups (P < .05). In contrast, the presence of leukocytes, lymphocytes, and the expression of IL-6 decreased in the AP-O group compared with the AP group (P < .05). CONCLUSIONS: ω-3 PUFA supplementation influences the systemic effects caused by apical periodontitis, decreasing the number of leukocytes, lymphocytes, and IL-6 in rat blood.

Immunomodulation Mediated by Azithromycin in Experimental Periapical Inflammation.

INTRODUCTION: The purpose of the present study was to compare the immunomodulatory effect of azithromycin (AZM), ampicillin (AMP), amoxicillin (AMX), and clindamycin (CLI) in vitro and AZM on preexisting periapical lesions compared with AMP. METHODS: The susceptibility of 4 common human endodontic pathogens (Parvimonas micra, Streptococcus intermedius, Prevotella intermedia, and Fusobacterium nucleatum) to AZM, AMP, AMX, and CLI was confirmed by agar disk diffusion assay. Preexisting periapical lesions in C57BL/6J mice were treated with AZM, AMP, or phosphate-buffered saline (PBS). Periapical bone healing and the pattern of inflammatory cell infiltration were evaluated after a 10-day treatment by micro-computed tomographic and histology, respectively. Besides, the effect of antibiotics in pathogen-stimulated nuclear factor kappa B activation and the production of interleukin 1 alpha and tumor necrosis factor alpha was assessed in vitro by luciferase assay and enzyme-linked immunosorbent assay. RESULTS: All examined endodontic pathogens were susceptible to AZM, AMP, AMX, and CLI. AZM significantly attenuated periapical bone loss versus PBS. PBS resulted in widely diffused infiltration of mixed inflammatory cells. By contrast, AZM brought about localized infiltration of neutrophils and M2 macrophages and advanced fibrosis. Although the effect of AMP on bone was uncertain, inflammatory cell infiltration was considerably milder than PBS. However, most macrophages observed seemed to be M1 macrophages. AZM suppressed pathogen-stimulated nuclear factor kappa B activation and cytokine production, whereas AMP, AMX, and CLI reduced only cytokine production moderately. CONCLUSIONS: This study showed that AZM led to the resolution of preexisting experimental periapical inflammation. Our data provide a perspective on host response in antibiotic selection for endodontic treatment. However, well-designed clinical trials are necessary to better elucidate the benefits of AZM as an adjunctive therapy for endodontic treatment when antibiotic therapy is recommended. Although both AZM and AMP were effective on preexisting periapical lesions, AZM led to advanced wound healing, probably depending on its immunomodulatory effect.

Th1/Th2/Th17/Treg Balance in Apical Periodontitis of Normoglycemic and Diabetic Rats.

INTRODUCTION: The aim of this study was to evaluate the inflammatory profile of T helper (Th) cells in normoglycemic (N) and diabetic rats with apical periodontitis (AP). METHODS: Twenty male Wistar rats were divided in 2 groups: N rats and rats with diabetes mellitus (DM). DM was induced using streptozotocin, and AP was induced by dental pulp exposure of the first mandibular molar to the oral environment. After 30 days, the mandibles were removed and processed for histologic analysis, bacterial analysis, and immunochemical assays for interleukin (IL)-6, tumor necrosis factor alpha, IL-17, IL-23, interferon gamma, and IL-10. The Mann-Whitney U test and Student t test were used for statistical analysis (P < .05). RESULTS: The DM group showed more intense inflammatory infiltrate with larger sizes of bone reabsorption and a greater presence of bacteria than the N group (P < .05). Proinflammatory cytokine levels in the DM group were also greater than those in the N group (P < .05). However, interferon gamma was more intense in the N group than in the DM group (P < .05). CONCLUSIONS: The inflammatory profile of AP in DM is different from that in the N group, suggesting that Th1 is a secondary strain and the Th17 strain is predominant in DM.

Cytotoxicity and biocompatibility of a new bioceramic endodontic sealer containing calcium hydroxide.

This study evaluated the cytotoxicity and biocompatibility of a new bioceramic endodontic sealer (i.e., Sealer Plus BC) in comparison with those of MTA Fillapex and AH Plus. L929 fibroblasts were cultured and Alamar Blue was used to evaluate cell viability of diluted extracts (1:50, 1:100, and 1:200) from each sealer at 24 h. Polyethylene tubes that were filled with material or empty (as a control) were implanted in the subcutaneous tissue of rats. The rats were killed after 7 and 30 d (n = 8), and the tubes were removed for histological analysis. Parametric data was analyzed using a one-way ANOVA test, and nonparametric data was analyzed via the Kruskal-Wallis test followed by the Dunn test (p < 0.05). A reduction in cell viability was observed in the extracts that were more diluted for Sealer Plus BC when compared to that of Control and AH Plus (p < 0.05). However, the 1:50 dilution of the Sealer Plus BC was similar to that of the Control (p > 0.05). Conversely, more diluted extracts of MTA Fillapex (1:200) and AH Plus (1:100 and 1:200) were similar to the Control (p > 0.05). Histological analysis performed at 7 d did not indicate any significant difference between tissue response for all materials, and the fibrous capsule was thick (p > 0.05). At 30 d, Sealer Plus BC was similar to the Control (p > 0.05) and MTA Fillapex and AH Plus exhibited greater inflammation than the Control (p < 0.05). The fibrous capsule was thin for the Control and for most specimens of Sealer Plus BC and AH Plus. Thus, Sealer Plus BC is biocompatible when compared to MTA Fillapex and AH Plus, and it is less cytotoxic when less-diluted extracts are used.

Endodontic medicine: interrelationships among apical periodontitis, systemic disorders, and tissue responses of dental materials.

Endodontic medicine, which addresses the bidirectional relationship between endodontic infections and systemic diseases, has gained prominence in the field of endodontics. There is much evidence showing that while systemic disease may influence the pathogenesis of endodontic infection, endodontic infection can also cause systemic alterations. These alterations include more severe bone resorption and inflammation in the periapical area as well as enhanced systemic disease symptoms. Similarly, many reports have described the impact of systemic diseases on the tissue responses to dental materials. Conversely, the local use of dental materials may show systemic effects in the form of altered production of biomarkers. Thus, studies to better understand the mechanisms related to those connections are extremely important. In this context, the objective of this review was to analyze and discuss the current literature regarding the connections among these three factors-systemic diseases, endodontic infection, and endodontic dental materials-and determine how these connections may interfere in the systemic health status and the endodontic treatment outcomes, which are represented by periapical wound healing.

Omega 3 Fatty Acids Reduce the Triglyceride Levels in Rats with Apical Periodontitis.

The aim of this study was to evaluate the influence of the prophylactic and therapeutic supplementation with omega 3 polyunsaturated fatty acids (w-3 PUFAs) on the lipid profile and periapical bone resorption in rats with apical periodontitis. Forty male rats were divided into groups: control rats (C), rats treated with w-3 PUFAs (C+O), rats with pulp exposure-induced apical periodontitis (AP), and rats with AP treated with w-3 PUFAs (AP+O). The administration of w-3 PUFAs was carried out orally once a day for 15 days before pulp exposure and, subsequently, for an additional 30 days after pulp exposure. AP was induced by exposing pulpal tissues to the oral environment. The samples were collected after 30 days. Triglycerides and cholesterol levels were enzymatically measured using the Trinder method. The jaws were collected and submitted for histological analysis. Two-way analysis of variance and Kruskal-Wallis tests were used for statistical analysis, and the significance was set at p<0.05. The triglyceride levels of the AP group were significantly higher than those of the C, C+O and AP+O groups (p<0.05). However, the difference in the cholesterol levels among the groups was not significant (p>0.05). Rats with AP showed larger areas of bone resorption as well as higher inflammatory intensity compared with rats with AP supplemented with w-3 PUFAs. It may be concluded that the presence of multiple AP foci increased the triglyceride levels. In addition, omega 3 supplementation might reduce these levels in rats with AP, as well as the bone resorption areas of periapical tissues.

Omega-3 Fatty Acids Reduce Inflammation in Rat Apical Periodontitis.

INTRODUCTION: The effects of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) on pro- and anti-inflammatory mediators were evaluated in a rat model of pulp exposure-induced apical periodontitis (AP). METHODS: Twenty-eight male Wistar rats were divided into 4 groups: control, untreated rats (group C); control rats treated with ω-3 PUFAs (group C-O); rats with pulp exposure-induced AP (group AP); and rats with pulp exposure-induced AP treated with ω-3 PUFAs (group AP-O). Omega-3 PUFAs were administered orally once a day for 15 days before pulp exposure; this treatment was continued for 30 days after pulp exposure. The rats were sacrificed 30 days after pulp exposure, and their dissected jaws were subjected to immunohistochemical analysis to detect immunoreactivity for tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-1ß, IL-17, and IL-10 on the periapical bone surface. The results were statistically evaluated using analysis of variance and the Tukey post-test. The significance level was set at 5%. RESULTS: Immunoreactivity for the proinflammatory cytokines TNF-α, IL-6, IL-1ß, and IL-17 was higher in the AP group than in the AP-O, C, and C-O groups (P < .05). Immunoreactivity for the anti-inflammatory cytokine IL-10 was lower in the AP group than in the AP-O group (P < .05). CONCLUSIONS: Supplementation with ω-3 PUFAs can modulate the inflammatory response in rat AP, decreasing levels of TNF-α, IL-6, IL-1ß, and IL-17 but increasing levels of IL-10.

Influence of Apical Periodontitis on Stress Oxidative Parameters in Diabetic Rats.

INTRODUCTION: In this study, we investigated if apical periodontitis (AP) associated with diabetes influenced the levels of endogenous antioxidants, the total antioxidant capacity (TAC), and the oxidant parameter in the serum of Wistar rats. METHODS: Forty male rats were divided into 4 equal groups: normal rats (N), rats with AP (AP), diabetic rats (D), and diabetic rats with AP (D + AP). Diabetes was induced by alloxan (150 mg/kg). AP was induced by exposing the pulpal tissue to the oral environment. After 36 days, blood and maxillae were collected. Albumin, bilirubin, uric acid, TAC, and malondialdehyde (MDA) levels were measured, and histologic analysis of the maxillae was performed. P < .05 was set as the threshold for statistical significance. RESULTS: Uric acid levels were higher in the D + AP group when compared with that of the N, D, and AP groups (P < .05). The MDA concentration was higher in the D and D + AP groups when compared with the N and AP groups (P < .05). The level of albumin was lower in the D + AP group when compared with the N, AP, and D groups. Inflammatory infiltration was more intense in the periapical region in the D + AP group compared with that in the AP group (P < .05). CONCLUSIONS: Our findings indicate that diabetes may change the antioxidant status, increase the concentration of MDA and uric acid, and decrease albumin levels in the serum. In addition, AP can potentiate the effects of diabetes by reducing the levels of albumin and increasing the levels of uric acid.

Diabetes increases interleukin-17 levels in periapical, hepatic, and renal tissues in rats.

OBJECTIVES: This study aimed to evaluate the association between endodontic infection and diabetes on interleukin-17 levels in periapical, hepatic, and renal tissues of rats. DESIGN: Forty male rats were divided into groups: normoglycemic rats (N), normoglycemic rats with apical periodontitis (N-AP), rats with experimental diabetes (ED), and rats with experimental diabetes and apical periodontitis (ED-AP). Diabetes was induced by intravenous streptozotocin injection, and blood sugar levels were monitored to confirm disease development. Apical periodontitis (AP) was induced by pulp exposure to the oral environment during 30days. After 30days, hepatic and renal tissues were obtained, and IL-17 levels were quantified by ELISA. The right hemi-jaw was used to quantify IL-17 levels by immunohistochemistry. The values obtained in parametric tests were tabulated and analyzed statistically by analysis of variance (ANOVA) and Tukey tests, and the values obtained for scores were statistically analyzed by using the Kruskal-Wallis and Dun tests. The level of significance was set at 5%. RESULTS: ED and ED-AP groups expressed significantly higher IL-17 levels in both hepatic and renal tissues (p<0.05), compared to N and N-AP groups. Apical periodontitis (AP) in ED-AP group was significantly more severe than that in N-AP group (p<0.05). Furthermore, there was a significantly larger increase in the IL-17 levels in ED-AP group compared to N group (p<0.05). CONCLUSION: Our results indicate that diabetes increases IL-17 levels in hepatic and renal tissues and also enhances IL-17 production in apical periodontitis area of rats.

Omega 3 Fatty Acids Reduce Bone Resorption While Promoting Bone Generation in Rat Apical Periodontitis.

INTRODUCTION: This study evaluated the effects of the dietary supplement omega 3 polyunsaturated fatty acids (ω-3 PUFAs) on pulp exposure-induced apical periodontitis (AP) in rats. METHODS: Twenty-eight male rats were divided into groups: control untreated rats (C), control rats treated with ω-3 PUFAs alone (C-O), rats with pulp exposure-induced AP, and rats with pulp exposure-induced AP treated with ω-3 PUFAs (AP-O). The ω-3 PUFAs were administered orally, once a day, for 15 days before pulp exposure and, subsequently, 30 days after pulp exposure. Rats were killed 30 days after pulp exposure, and jaws were subjected to histologic and immunohistochemical analyses. Immunohistochemical analyses were performed to detect tartrate-resistant acid phosphatase-positive osteoclasts and osteocalcin-positive osteoblasts on the bone surface of periapical area. Results were statistically evaluated by using analysis of variance and Tukey honestly significant difference, and P < .05 was considered statistically significant. RESULTS: The bone resorption lesion was significantly larger in the AP group compared with AP-O, C, and C-O groups (P < .05). The level of inflammatory cell infiltration was significantly elevated, and the number of tartrate-resistant acid phosphatase-positive osteoclasts was significantly higher in the periapical lesions of the AP group compared with AP-O, C, and C-O groups (P < .05). The number of osteocalcin-positive osteoblasts was significantly increased in the AP-O group compared with the AP group (P > .05). CONCLUSIONS: Supplementation with ω-3 PUFAs not only suppresses bone resorption but also promotes new bone formation in the periapical area of rats with AP in conjunction with downregulation of inflammatory cell infiltration into the lesion.

Multiple Apical Periodontitis Influences Serum Levels of Cytokines and Nitric Oxide.

INTRODUCTION: This study evaluated whether apical periodontitis (AP) in a single tooth or in multiple teeth affected serum levels of inflammatory mediators and influenced blood homeostasis. METHODS: Thirty male Wistar rats were divided into 3 groups of 10 rats each: control group, healthy rats; 1AP group, rats with AP in 1 tooth; and 4AP group, rats with AP in 4 teeth. After 30 days, the rats were anesthetized, and their blood was collected through cardiac puncture to quantify tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), interleukin (IL)-6, IL-17, IL-23, and nitric oxide (NO) levels. The rats were then sacrificed by administering an anesthetic overdose. Their maxillary and mandibular molars were collected and processed for histologic analysis with hematoxylin-eosin and for immunohistochemical staining of the cytokines and NO-producing enzyme nitric oxide synthase. Results of these analyses were statistically analyzed; P < .05 was considered statistically significant. RESULTS: Rats in the 1AP and 4AP groups showed increased IL-6, IL-17, IL-23, TNF-α, IFN-γ, and NO synthase expression; inflammatory cell infiltration; and moderate bone resorption in affected teeth. Serum TNF-α, IL-6, IL-17, and IL-23 levels were higher in rats in the 4AP group than in those in the control group (P < .05). Serum NO levels were significantly lower in rats in the 1AP and 4AP groups than in those in the control group (P < .05). Serum IFN-γ levels were not different among rats in the 3 groups (P > .05). CONCLUSIONS: These results suggested that AP affected blood homeostasis by altering the serum levels of inflammatory cytokines and NO.