Development Of Periapical Lesions Research Articles

Periapical Lesions Associated with Demographic Variables, Dental Conditions, Systemic Diseases, and Habits.

The aim of this study was to analyze the prevalence of periapical lesions and possible associations with demographic, dental conditions, systemic diseases, and habit variables in patients from a private Brazilian university. Data from 452 patients of both sexes, aged 18-78 years, from a Brazilian university were evaluated. Panoramic radiographs were analyzed, and the presence of periapical lesions was recorded. In these cases, the dental condition was assessed for the presence or absence of endodontic treatment. Medical records provide information related to general health (diabetes, cardiovascular diseases, altered cholesterol, autoimmune diseases, gallstones, or kidney stones) and habits (smoking or alcoholism). The data were descriptively analyzed, and then logistic regression and the Wald test were performed in Stata/SE v.14.1. A rate of 58.4% of participants were women, and the mean age was 36.4 (±14.6) years. Periapical lesions prevailed in 193 (42.7%) patients, and 281 (72.4%) teeth were not previously endodontically treated. Mandibular first molars (19%) and men (48.9%) were the most affected. The adjusted model showed that the age group of 26-45 years was 5 times more likely [odds ratio (OR) = 5.01; 95% confidence interval (CI): 2.85-8.82] to have lesions than those aged ≤25 years. Participants aged above 46 years were 19.1 times more prone (OR = 19.1; 95% CI: 10.2-36.0) to morbidity than younger ones (≤25 years). The studied sample showed that periapical lesions were more prevalent in males, in mandibular molars, and without prior endodontic treatment. There was no observed association between periapical lesions and comorbidities or habits; however, a significant correlation occurred with advancing age. Comorbidities and habits were not associated with the presence of periapical lesions. However, aging has been identified as a significant risk factor for the development of periapical lesions. This finding is clinically relevant as it highlights the importance of monitoring and maintaining oral health in patients with advanced age. How to cite this article: dos Santos VC, de Oliveira Kublitski PM, Marques da Silva B, et al. Periapical Lesions Associated with Demographic Variables, Dental Conditions, Systemic Diseases, and Habits. J Contemp Dent Pract 2023;24(11):864-870.

Reduction of NrF2 as coadjuvant during the development of persistent periapical lesions.

Persistent periapical lesions (PPL) are the result of pulpar necrosis induced by bacterial infection resulting in bone degradation and culminating with the loss of dental piece. Pathological changes in the peripapice are associated with the presence of free radicals. The transcription factor Nrf2 is the main regulator of the endogenous antioxidant response against oxidative stress and has been implicated in the regulation of osteoclastogenesis.The aim is to determine the oxidative condition in samples from patients with Persistent Periapical Injuries as a detonating factor of tissue damage. An observational, descriptive, cross-sectional study was carried out in samples with PPL (cases) and samples by removal of third molars (controls) obtained in the clinic of the specialty in endodontics, University of Guadalajara. Samples were submitted to histological staining with Hematoxylin-Eosin, lipoperoxide analysis, Superoxide Dismutase (SOD), Glutathione-Peroxidase (GPx) and Catalase (CAT) activities were determined by immunoenzymatic assays and NrF2 by Western Blot analysis. Samples from PPL patients histologically showed an increased presence of lymphocytes, plasma cells, and eosinophils, as well as a decrease in extracellular matrix proteins and fibroblast cells. There was a rise in lipid peroxidation, GPx and SOD activities, but an important decline (36%) in Catalase activity was observed (p<0.005); finally, NrF2-protein was diminished at 10.41%. All comparisons were between cases vs controls. The alterations in antioxidants endogenous NrF2-controlled are related to osseous destruction in patients with PPL.

Comparative evaluation between conventional endodontic therapy and a non-instrumental technique

Aim: Dental pulp necrosis is a complication caused mainly by dental caries and lesions. No consensus has been reached on the best technique and materials for endodontic treatment in the primary dentition. The objective was to present a clinical case report in which different endodontic approaches were performed in traumatized and necrotic homologous teeth. Methods: A one-year-and-eight-month-old boy suffered dentoalveolar trauma after a fall and sought out the Deciduous Trauma Dental Center of the Federal University of Minas Gerais in October 2018 for clinical and radiographic evaluation. The left maxillary central incisor presented enamel and dentin fracture without pulp exposure, while the right maxillary central incisor presented a small intrusive dislocation. Both presented the development of periapical lesions. Results: The teeth were treated respectively, using the non-instrumental technique with CTZ paste and the conventional endodontic therapy with Guedes-Pinto paste. Clinical and radiographic follow-ups after treatments revealed asymptomatic teeth and evidence of periapical healing. Conclusion: The use of CTZ paste in this case report presented satisfactory and similar results to traditional therapy in the short term.

Macrophages in periapical lesions: Potential roles and future directions.

Periapical lesions are infectious diseases that occur in the apical region of teeth. They result in the destruction of alveolar bone and are usually accompanied by swelling, pain, and possible systemic impacts. A complex interaction between pathogens and the host immune system determines the development, progression, and outcome of periapical lesions. The lesions, if not treated promptly, may cause resorption of bone tissue, destruction of the periodontal ligament, and loss of the affected teeth, all of which can severely worsen the quality of life of patients, often at considerable economic cost to both patients and medical organizations. Macrophages are a group of heterogeneous cells that have many roles in the development of infections, destruction and reconstruction of bone tissues, and microbe–host interactions. However, the differential and comprehensive polarization of macrophages complicates the understanding of the regulatory mechanism of periapical lesion progression. This report provides a comprehensive review of recent advances in our knowledge of the potential role of macrophages in determining the turnover of human periapical lesions. For example, macrophage differentiation might indicate whether the lesions are stable or progressing while the extent of bacteria invasion could regulate the differentiation and function of macrophages involved in the periapical lesion. In addition, alternative strategies for the treatment of apical periodontitis are discussed.

Effects of Anti–Receptor Activator of Nuclear Factor Kappa B Ligand Antibody and Zoledronic Acid on Periapical Lesion Development in Mice

IntroductionAntiresorptive drugs are widely used to treat osteoporosis and other systemic bone diseases, although their efficacy for local bone resorption after localized inflammation has not been fully elucidated. We examined the effects of an anti–receptor activator of nuclear factor kappa B ligand (RANKL) antibody and the bisphosphonate zoledronic acid (ZOL) on periapical lesion (PL) development in mice. MethodsDental pulp of lower first molars in mice was removed, with the exposed dental pulp chambers left open to the oral environment to induce apical periodontitis. An anti-RANKL antibody or ZOL was intraperitoneally injected once per week until postoperative day 21, and then micro–computed tomographic imaging and histologic analyses were performed. ResultsPL enlargement was inhibited by both the anti-RANKL antibody and ZOL in a dose-dependent manner, and a reduction of inflammatory cell infiltration in apical tissues inhibited periapical bone resorption. The anti-RANKL antibody decreased the number of osteoclasts in periapical tissues, whereas ZOL suppressed periapical bone resorption with osteoclast numbers maintained. Although the administration of each of the antiresorptive drugs increased femoral bone mass, femoral bone mineral density in the PL group was lower compared with the sham-operated group. ConclusionsThese results suggest that an antiresorptive drug administered systemically is distributed to areas of local inflammation in the jaw can prevent PL development.

Expression of epithelial growth factors and of apoptosis-regulating proteins, and presence of CD57+ cells in the development of inflammatory periapical lesions.

The mechanisms that stimulate the proliferation of epithelial cells in inflammatory periapical lesions are not completely understood and the literature suggests that changes in the balance between apoptosis and immunity regulation appear to influence this process.Objective:To evaluate the expression of the epidermal growth factor (EGF), its receptor (EGFR) and of the keratinocyte growth factor (KGF), the presence of CD57+ cells, the epithelial cell proliferation index, and the expression of the Bcl-2 protein in inflammatory periapical lesions (IPL) at different stages of development.Methodology:Our sample was composed of 52 IPLs (22 periapical granulomas - PG - and 30 periapical cysts - PC), divided into three groups: PGs, small PCs, and large PCs. Specimens were processed for histopathologic and immunohistochemical analyses. Sections were evaluated according to the amount of positive staining for each antibody.Results:We found no significant differences among the groups regarding Bcl-2 (p=0.328) and Ki-67 (p>0.05) expression or the presence of CD57+ cells (p=0.748). EGF (p=0.0001) and KGF (p=0.0001) expression was more frequent in PCs than in PGs, and CD57+ cells were more frequent in IPLs with intense inflammatory infiltrates (p=0.0001). We found no significant differences in KGF (p=0.423), Bcl-2 (p=0.943), and EGF (p=0.53) expression in relation to inflammatory infiltrates or to the type of PC epithelial lining, but observed greater KGF expression (p=0.0001) in initial PCs. EGFR expression was similar among the groups (p>0.05).Conclusion:More frequent EGF and KGF expression in PCs and the greater presence of CD57+ cells in lesions with intense inflammatory infiltrates suggest that these factors influence IPL development. The greater KGF expression in initial PCs suggests its importance for the initial stages of PC formation.

Effect of chronic unpredictable stress on the progression of experimental apical periodontitis in rats.

To establish an experimental model combining chronic stress and apical periodontitis by assessing the development of periapical lesions in rats in three different time points. Forty-eight male Wistar rats were randomly assigned into two equal groups: Apical periodontitis (AP) and AP+Stress (AP+S). The animals of the AP group were not exposed to stressful conditions whereas the AP+S group were exposed to a variety of stressors on a daily basis until the end of the experiment. After three weeks of chronic unpredictable stress, apical periodontitis was induced in both groups by exposing the pulpal tissue of the mandibular first molar to the oral environment. Each group was further subdivided into three subgroups according to the euthanasia period: 14, 21 and 28days after pulp exposure. The animals were weighed, and the blood was collected for corticosterone serum dosage by radioimmunoassay. The mandibles were removed and submitted to histopathological and microtomography analyses to assess the inflammatory response and the progression of periapical lesions. Comparisons between the AP and AP+S groups were performed using Student's t-test and Mann-Whitney U-test for parametric and nonparametric data, respectively. The one-way anova test followed by Tukey's test (parametric data) and Kruskal-Wallis followed by Dunn's test (nonparametric data) were used for comparisons between the three time points within the same group (P<0.05). The AP+S group had a significantly lower average percentage of weight gain at 14days and 21days after AP induction (P<0.05). Significantly higher levels of corticosterone were found in the AP+S group at 21days (P<0.05). The AP+S group had a significantly greater intensity and extension of inflammatory infiltrate with larger areas of bone loss compared to the AP groups at 21days (P<0.05). The volume of the periapical lesions in the AP+S group was significantly larger than that of the AP group 21days following pulp exposure (P<0.05). The chronic unpredictable stress model applied for 6weeks exacerbated the inflammatory response and increased bone loss associated with AP, especially 21days after its induction. This model appears to be suitable for investigating the bidirectional relationship between apical periodontitis and chronic stress.

Immunohistochemical analysis of ADAMTS-1, versican and pEGFR expressions in periapical granuloma and radicular cyst

BackgroundADAMTS expression can be associated with several inflammatory processes, and has been correlated with tumorigenesis of some neoplasms, but its participation in the development of periapical lesions has not been investigated. Therefore, our objective was to verify the expression of ADAMTS-1, versican and pEGFR in Periapical Granuloma (PG) and in the Radicular Cyst (RC) since they are the most common lesions of the periapex.Methods25 samples of RC and 10 of PG were used. As a control, 10 samples of inflammatory fibrous hyperplasia (IFH) and 10 of dental follicle (DF) were used. The expression of these proteins was investigated using immunohistochemistry.ResultsIn the epithelium of RC, IFH and DF, the expression of ADAMTS-1 was greater in DF than in RC (p < .001). Versicano showed greater expression in IFH than in RC, DF than in RC (p < .001). pEGFR showed greater expression in IFH and RC than in DF (p < .01 and p < .05, respectively). In connective tissue, ADAMTS-1 expression was greater in PG and RC than in IFH and DF (p < .001). Versicano showed greater expression in PG, RC and IFH compared to DF (p < .001). In pEGFR there was a higher expression in PG when compared to RC, IFH and DF (p < .001). Greater immunostaining occurred in the RC than in the DF (p < .001).ConclusionsOur results suggest that the studied proteins may participate in the pathogenesis of PG and RC, through the interaction of these proteins, in the remodeling of the ECM (versican) by ADAMTS-1, producing bioactive fragments, which could activate EGFR, contributing to the formation, growth and maintenance of injuries.

Penatalaksanaan Gigi 36 dengan Diagnosis Nekrosis Pulpa disertai Abses Periapikal Kronis

The main goal of endodontic treatment is to remove the entire microbial flora from the root canal system and promote periapical healing. Microorganisms that settle in the root system play an important role in the development and persistence of periapical lesions. Necrotic canals provide a very favorable environment for the growth of microorganisms in the root canal system. Thus, elimination of these bacteria is essential for apical and periapical healing after endodontic treatment. This case report discusses the endodontic treatment using calcium hydroxide in a necrotic pulp with chronic periapical abscess.

Penatalaksanaan Gigi 36 dengan Diagnosis Nekrosis Pulpa disertai Abses Periapikal Kronis

The main goal of endodontic treatment is to remove the entire microbial flora from the root canal system and promote periapical healing. Microorganisms that settle in the root system play an important role in the development and persistence of periapical lesions. Necrotic canals provide a very favorable environment for the growth of microorganisms in the root canal system. Thus, elimination of these bacteria is essential for apical and periapical healing after endodontic treatment. This case report discusses the endodontic treatment using calcium hydroxide in a necrotic pulp with chronic periapical abscess.

Alteration of the oral microbiota may be a responsible factor, along with estrogen deficiency, by the development of larger periapical lesions.

To answer the questions: (1) Does reducing estrogen levels influence the microbial composition of the oral cavity? (2) Does the presence of periapical lesion (PL) cause changes in the oral microbiota? (3) Since estrogen deficiency alters the oral microbiota, can this be one of the factors that contribute to the increase of the PL? Thirty-six rats were divided into four groups: sham (control), ovariectomy (OVX), control with PL (Sham + PL), and OVX + PL. After 9 weeks of OVX, the lower first molars were submitted to PL induction. After 21 days, the microbiological collection of the oral cavity was performed, and the animals were euthanized. The contents were evaluated by the checkerboard DNA-DNA hybridization method, to verify the prevalence of 40 bacterial species (divided into 7 microbial complexes). The blocks containing the lower first molars were submitted to histotechnical processing and staining with hematoxylin and eosin (HE), for the measurement of the periapical lesion area. The results were submitted to ANOVA and Kruskal-Wallis tests and Tukey and Dunn post-tests, with a significance level of 5%. In conditions of estrogen deficiency, there was alteration of the oral microbiota. The OVX groups had a higher amount of bacteria compared to the SHAM group in most of the microbial complexes (p < 0.001). The animals in the control group (with or without lesion) did not present a statistically significant difference (p > 0.001) in any of the microbial complexes. The PLs in OVX animals were significantly higher compared to SHAM animals (p < 0.001). Hypoestrogenicity conditions interfere in the oral microbiota by increasing the amount of bacteria in the saliva and influencing the progression of periapical lesions. This inedited study shows that deficiency of estrogen leads to alteration of the oral microbiota.

The NFκB Expression on Apical Dental Granuloma: An Immunohistochemistry Analysis.

BackgroundEndodontic treatment on dental caries with dental granuloma on the periapical has the potential to flare. The symptoms of acute flare in dental granuloma are strongly related to the activation of macrophages that produce pro-inflammatory cytokine through nuclear factor kappa B (NFκB). However, the role of NFκB in dental granuloma has not been widely explained.PurposeTo compare NFκB expression in dental granuloma and dental nongranuloma in the periapical of dental caries.MethodsThe periapical lesion of dental granuloma and dental nongranuloma was obtained from patients with dental caries who were subjected to tooth extraction. The periapical lesion was confirmed by periapical radiography and then differentiated by histological and immunohistochemistry by analyzing the NFκB expression.ResultsMost dental granulomas were found in females (66.67%) between the ages 36 and 45 (61.11%). Dental granuloma showed higher NFκB expression compared to dental nongranuloma lesions in tooth caries (p=0.021).ConclusionThe dental granuloma tissue of dental caries showed an increase in NFκB expression. Understanding the role of NFκB might provide additional insights into the process of periapical lesion development.

Overexpression of Cyclophilin A in Human Periapical Lesions

IntroductionCyclophilin A (CypA) is a cytosolic protein involved in multiple biological functions, such as inflammation, tissue remodeling, tumorigenesis, and vascular diseases. Human periapical lesions are induced by bacterial infections. However, the expression of CypA in human periapical lesions remains unclear. This study aimed to investigate the presence of CypA in human periapical lesions and the possible association of CypA with angiogenesis, inflammatory cell infiltration, and alveolar bone degradation during inflammatory development. MethodsFifty-eight human periapical tissues, including periapical granulomas (PGs, n = 28), radicular cysts (RCs, n = 24), and healthy control tissues (control group, n = 6) were collected. Samples were fixed and analyzed. CypA expression was detected and analyzed by immunohistochemistry in different cross sections. Double immunofluorescence was assessed to colocalize CypA with CD34, CypA with matrix metalloproteinase 9 (MMP-9), and CD147 with MMP-9. ResultsCypA was significantly overexpressed in the RC and PG groups compared with the control group (P < .05), but the difference between the RC and PG groups was insignificant (P > .05). CypA-positive cells were mainly lymphocytes, endothelial cells, epithelial cells, and plasma cells. The double-labeling analysis of CypA with CD34 suggested that CypA expression was associated with angiogenesis during periapical lesions. MMP-9 colocalized with both CypA and CD147 indicated that CypA may colocalize with CD147 and may be associated with the degradation of soft and hard tissues around human periapical lesions. ConclusionsCypA may be involved in the development of periapical lesions with an increase in inflammatory cell infiltration, angiogenesis acceleration, and alveolar bone degradation.

Alendronate inhibits osteocyte apoptosis and inflammation via IL-6, inhibiting bone resorption in periapical lesions of ovariectomized rats.

To evaluate the effect of alendronate (ALN) on the development of periapical lesions induced in ovariectomized rats. Twenty-five rats were divided into three groups: sham (control), ovariectomy (OVX) and OVX+ALN. One day after OVX, animals from the OVX+ALN group received the medication via gavage. After 9weeks, the first molars of all animals were submitted to periapical lesion induction. After 21days, the animals were euthanized. Femurs were analysed for bone mineral density. The blocks of bone tissue containing the mandibular first molars were submitted to histotechnical processing and staining with haematoxylin and eosin (HE) for periapical lesion analysis under conventional microscopy. At the same time, the morphometric analysis of the periapical lesion area was performed in the fluorescence mode, as well as the histoenzimology for the quantification of osteoclasts and 4'-6-diamidino-2-phenylindole staining for the quantification of apoptotic osteocytes. In addition, the first maxillary molars were used for analysis of the gene expression of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) and osteoclastogenesis markers (RANKL/OPG). The results were submitted to ANOVA and Kruskal-Wallis tests and Tukey and Dunn post-tests (significance level of 5%). Ovariectomy reduced bone mineral density of the femur, and treatment with ALN was able to prevent bone loss (P<0.001). Regarding the microscopic analysis of the periapical region, the sham and OVX+ALN groups had moderately increased periodontal ligament and inflammatory infiltrate, while the OVX group had these parameters increased intensely. The periapical lesions of the OVX group were significantly larger in area in comparison to the other groups (P<0.001). The OVX group had the largest amount of apoptotic osteocytes, and ALN was able to prevent the apoptosisof these cells, in addition to significantly reducing IL-6 expression (P<0.05). OVX and ALN had no effect on RANKL/OPG expression and did not influence the number of osteoclasts around the periapical lesion (P>0.05). The hypoestrogenic condition induced by OVX aggravated bone resorption, inducing the death of osteocytes and provoking larger periapical lesions. ALN treatment inhibited osteocyte apoptosis and inflammation via IL-6, inhibiting bone resorption in periapical lesions of ovariectomized rats.

Vasoactive Intestinal Peptide Immunoregulatory Role at the Periapex: Associative and Mechanistic Evidences from Human and Experimental Periapical Lesions

IntroductionThe balance between the host proinflammatory immune response and the counteracting anti-inflammatory and reparative responses supposedly determine the outcome of periapical lesions. In this scenario, the vasoactive intestinal peptide (VIP) may exert a protective role because of its prominent immunoregulatory capacity. In this study, we investigated (in a cause-and-effect manner) the potential involvement of VIP in the development of human and experimental periapical lesions. MethodsPeriapical granulomas (n = 124) and control samples (n = 48) were comparatively assessed for VIP and multiple immunologic/activity marker expression through real-time polymerase chain reaction. Experimental periapical lesions (C57Bl/6 wild-type mice) were evaluated regarding endogenous VIP expression correlation with lesion development and the effect of recombinant VIP therapy in lesion outcome. CCR4KO and IL4KO strains and anti-glucocorticoid-induced TNFR-related protein inhibition were used to test the involvement of Treg and Th2 cells in VIP-mediated effects. ResultsVIP expression was more prevalent in periapical granulomas than in controls, presenting a positive association with immunoregulatory factors and an inverse association/correlation with proinflammatory mediators and the receptor activator of nuclear factor kappa B ligand/osteoprotegerin ratio. Endogenous VIP expression up-regulation was temporally associated with lesion immunoregulation and a decline of bone loss. VIP therapy in mice prompted the arrest of lesion development, being associated with an anti-inflammatory and proreparative response that limits the proinflammatory, Th1, Th17, and osteoclastogenic response in the periapex. The VIP protective effect was dependent of Treg migration and activity and independent of interleukin 4. ConclusionsOur results show that VIP overexpression in human and experimental periapical lesions is associated with lesion inactivity and that VIP therapy results in the attenuation of experimental lesion progression associated with the immunosuppressive response involving Treg cells.

Inhibition of Nuclear Factor Kappa B Prevents the Development of Experimental Periapical Lesions

IntroductionNuclear factor kappa B (NF-κB) is an important transcriptional regulator of angiogenesis involving B-cell lymphoma 2 (Bcl-2) and Bcl-2–associated X protein (Bax) signaling pathways. Thus, inhibition of NF-κB may suppress the development of periapical lesions via blockage of angiogenesis. Accordingly, we examined the effects of NF-κB decoy oligodeoxynucleotide (ODN) treatment on experimentally induced periapical lesions. MethodsPeriapical lesions were induced in the mandibular first molars of 5-week-old male Wistar rats by the application of lipopolysaccharide to the pulp. NF-κB decoy ODN or NF-κB decoy scramble (control) was injected intraperitoneally every 7 days, starting 1 day before pulp exposure. After 28 days, the samples were retrieved, and digital radiographs were taken for radiomorphometry. Samples were processed for (1) immunohistochemistry of CD31, Bcl-2, and Bax; (2) laser capture microdissection to analyze Bcl-2, Bax, chemokine (C-X-C motif) ligand 1 (CXCL1), CXC receptor 2 (CXCR2), and vascular endothelial cell growth factor receptor 2 (VEGFR2) messenger RNA (mRNA) expression in CD31+ endothelial cells; (3) enzyme-linked immunosorbent assay to determine NF-κB/p65 activity; and (4) Western blotting for vascular endothelial growth factor expression. ResultsNF-κB decoy ODN treatment significantly reduced lesion size, NF-κB/p65 activity, and the density of CD31+ endothelial cells in the lesion. NF-κB decoy ODNs also down-regulated CXCL1, CXCR2, and VEGFR2 mRNAs and up-regulated Bax mRNA in endothelial cells but did not affect Bcl2 mRNA in endothelial cells. Vascular endothelial growth factor protein expression in the lesions was significantly decreased. ConclusionsThe inhibition of NF-κB activity by decoy ODN treatment suppressed the development of experimentally induced periapical lesions with a concomitant reduction in angiogenic responses in endothelial cells.

Production of immunoregulatory cytokines in clinically asymptomatic periapical lesions depends on the lesions size

Bacground/Aim. Development of periapical lesions (PLs) involves a complex cross-talk between pathogenic microorganisms from the root canal and host immune mechanisms. In these processes proinflammatory cytokines are involved in stimulation of inflammation and osteodestructive mechanisms, whereas anti-inflammatory cytokines, with the immunoregulatory functions, have the opposite effects. How this balance is controlled is still the subject of numerous studies. The aim of this study was to examine whether the local production of interleukin (IL)-10, IL-27 and transforming growth factor (TGF)-? in human asymptomatic PLs depends on the lesion size and how levels of these immunoregulatory cytokines correlate with the cellular composition of PLs. Methods. The study was conducted on 30 PLs which were collected at the Clinic for Stomatology of the Military Medical Academy, Belgrade, Serbia. The PLs were divided according to their size into small- and largesize lesions (n = 12 and n = 18, respectively). The inflammatory cells (PL-ICs) were isolated from PLs and cultivated for 24 hours in culture medium supplemented with phorbol myristate acetate and Ca2+ ionophore. Cytospins were processed for immunocytology by using monoclonal antibodies to cell subsets. The levels of cytokines in culture supernatants were determined by the ELISA method. Statistical analysis was performed using the Student t-test and the Spearman?s correlation test. The values of p &lt; 0.05 were considered to be significant. Results. The levels of IL-10 and TGF-? were significantly higher in the PL-ICs cultures of large-size lesions than in small ones (p &lt; 0.01 and p &lt; 0.05, respectively). In contrast, the levels of IL-27 were higher in the cultures of small-size lesions than in small ones (p &lt; 0.05). Although the total number of PL-ICs and the proportion of mononuclear phagocytes were higher in the large-size PLs (p &lt; 0.01 and p &lt; 0.05, respectively), their main composition was not significantly different between the groups. The proportions of B cells/plasma cells (CD19/CD38+ cells), CD8+ T cells and CD14+ cells were significantly higher in the large-size PLs (p &lt; 0.005; p &lt; 0.05; p &lt; 0.05, respectively). In contrast, the proportion of total T cells (CD3+ cells) was higher in the small-size lesions (p &lt; 0.05). No statistically significant correlation was found between the levels of these cytokines and the composition/ phenotype of PL-ICs. Conclusion. This study suggests that IL-10, IL-27 and TGF-? may play different roles in suppression of unwanted immune/inflammatory reactions in asymptomatic PLs, depending on the extension of pathological process as judged by the size of lesions.

Cytokines and chemokines associated with Treg/Th17 response in chronic inflammatory periapical disease

Cytokines and chemokines have a fundamental role in the maintenance of inflammation and bone response, which culminate in the development of chronic periapical lesions. Regulatory (Treg) and Th17 cytokines play a key role in regulating the immune response involved in this process. The aim of this study was to investigate the role of Treg and Th17 cells in chronic inflammatory periapical disease, by comparing the expression of the immunoregulatory mediators TGF-β, IL-10, CCL4, and the proinflammatory IL-17 and CCL20 in the periapical tissue of teeth with pulp necrosis, with and without associated chronic lesions. Eighty-six periapical tissue samples were obtained from human teeth. The samples were divided into three groups: pulp necrosis with a periapical lesion (n=26); pulp necrosis without a periapical lesion (n=30), and control (n=30). All samples were submitted to histopathological analysis and cytokine and chemokine measurement through ELISA. Statistical analyses were done with Kruskal-Wallis and Mann-Whitney tests and Spearman correlation. The group with pulp necrosis and a periapical lesion showed a higher expression of CCL4 and TGF-β in comparison with pulp necrosis without a lesion. CCL20 was higher in the group with a periapical lesion when compared to the control. In all groups there was a weak positive correlation between IL-17/CCL20, IL-10/CCL4, and IL-17/TGF-β. Both types of cytokines, pro-inflammatory and immunoregulatory, occur simultaneously in periapical tissue. However, a rise in immunosuppressive cytokines and chemokines (CCL4 and TGF-β) in periapical lesions suggests a role of these cytokines in stable periapical disease.

Regenerative Endodontics for Upper Permanent Central Incisors after Traumatic Injury: Case Report with a 3-year Follow-up

The aim of this article is to describe a one-visit approach to attempt revascularization in the upper right and left central incisors after traumatic injury. A single-visit conservative revascularization approach can be used to promote root growth and maturation following traumatic dental injury and loss of pulpal tissues. An eight-year-old female patient presented in Dentalia Clinics, Jeddah, Kingdom of Saudi Arabia, in 2016 with traumatic dental injury. Upon clinical and radiographic examination, it was found that the trauma resulted in loss of pulp vitality in two upper central incisors. Local anesthesia was administered, and a rubber dam was placed. Access cavity was done for each tooth separately. 2% chlorhexidine followed by sterile saline was used for irrigation with no instrumentation. Mineral trioxide aggregate (MTA) was used as the sealing material after blood clot formation. Follow-up showed continuous root maturation in the right central incisor, at 6 months, one year, two years, and three years. Root canal treatment was done in 2019 due to the development of periapical lesion. The 6-month follow-up radiograph also showed loss of the crown of the left central incisor due to a second trauma with retained apical root fragment. The fragment was embedded inside the bone and showed continuous maturation during the three years. A single-visit regenerative endodontic approach showed successful results in revascularizing the upper permanent central incisor after loss of pulpal tissue. Immature permanent teeth can be treated by a single-visit revascularization procedure to promote root maturation and increase in radicular dentin length and width.

The Expression of Interferon Regulatory Factor 8 in Human Periapical Lesions

IntroductionInterferon regulatory factor 8 (IRF8) is a critical transcription factor in innate immune responses that regulates the development and function of myeloid cells. Human periapical lesions are caused by endodontic microbial infections. However, the presence of IRF8 in human periapical lesions remains elusive. This study aims to explore the expression of IRF8 in human periapical lesions and the possible association of IRF8 with macrophages, nuclear factor kappa B (NF-κB) signaling, and the autophagy process. MethodsThirty-nine human periapical tissues, including healthy control tissues (n = 15), radicular cysts (RCs, n = 11), and periapical granulomas (PG, n = 13), were examined. Tissues were fixed in paraformaldehyde and analyzed. The inflammatory infiltrates of lesions were evaluated by hematoxylin-eosin, and the expression of IRF8 was analyzed by immunohistochemistry. Double immunofluorescence assessment was performed to colocalize IRF8 with CD68, NF-κB p65, and LC3B. ResultsThe expression of IRF8 was significantly higher in RCs and PGs than in the healthy control group, but no significant difference was found between RCs and PGs. There were significantly more IRF8-CD68 double-positive cells in RCs and PGs than in the healthy control group, but no significant difference was observed between RCs and PGs. Double-labeling analysis of IRF8 with NF-κB and LC3B indicated that IRF8 expression is associated with NF-κB signaling and the autophagy process during periapical lesions. ConclusionsIRF8 could be observed and might possibly be involved in macrophages in the development of periapical lesions.