Léa Assed Bezerra da Silva

The aim of this study was to evaluate the effect of the probiotic Bifidobacterium animalis subsp. lactis HN019 as a root canal irrigant on the polarization of macrophages into M1 and M2 subtypes in periapical lesions induced in rats, using immunohistochemical analysis. Forty-eight adult male Wistar Hannover rats were divided into six groups: Group I (4 animals/8 teeth): sound teeth; Group II (4 animals/4 teeth): 2.5% sodium hypochlorite as the irrigation solution (3 days); Group III (4 animals/4 teeth): probiotic solution as the irrigant (3 days); Group IV (12 animals/24 teeth per period): periapical lesions without irrigation (7, 21, and 42 days); Group V (12 animals/24 teeth per period): 2.5% sodium hypochlorite irrigation (7, 21, and 42 days); Group VI (12 animals/24 teeth per period): probiotic irrigation (7, 21, and 42 days). The animals were euthanized following the experimental periods. Immunohistochemical analysis was performed using NOS2 and CD163 markers for the M1 and M2 subtypes, respectively. The findings showed no significant differences in NOS2 and CD163 expression across the experimental periods (3, 7, 21, and 42 days) or between the irrigated groups, except at 42 days, when NOS2 expression was higher in the probiotic-treated group than in the control group. The probiotic Bifidobacterium animalis subsp. lactis HN019 demonstrated the potential to modulate the immune-inflammatory response in periapical lesions by increasing NOS2 expression 42 days after pulp exposure.

The goal of this study was to evaluate, in vivo, the synthesis of inflammatory and repair mediators in dental pulp after capping with a reparative bioactive material. Pulp capping was performed with mineral trioxide aggregate (n = 20) and gutta-percha (n = 10) on mandibular first molars of C57Bl6 mice. After 7 and 70 days, tissues were stained with hematoxylin and eosin for histopathological, histometric, and immunohistochemical evaluation to investigate the synthesis of ALP, IL-1β, IL-4, IL-6, PECAM-1, and VEGF. Data regarding measurement of the area of newly formed mineralized tissue, number of inflammatory cells in dental pulp, and intensity of immunostaining were compared using Student’s t-test at a significance level of 5%. At 7 days, an inflammatory response was found in contact with MTA and gutta-percha, while at 70 days, inflamation was reduced in both groups. However, mineralized tissue formation was observed only with MTA. IL-1β, VEGF, and PECAM-1 were detected in cells in close contact with MTA at 7 days, which reduced overtime. On the other hand, synthesis of ALP, IL-4, and IL-6 was mild at 7 and 70 days without difference between the periods. Mineralized tissue formation was observed only with MTA. IL-1β, VEGF, and PECAM-1 were synthesized by dental pulp and inflammatory cells in close contact with the material, whereas IL-4, IL-6, and ALP synthesis were scarcely found. Understanding the molecular and cellular responses elicited by MTA can enhance the development of more effective treatments, potentially leading to improved long-term outcomes for patients with dental pulp injuries or diseases.

The expression of hBD-3 and quantification of immune and inflammatory response cells (non-degranulated and degranulated mast cells, mature and immature plasmacytoid dendritic cells, mature and immature Tregs, T lymphocytes, cytotoxic T lymphocytes, and B lymphocytes) were evaluated in the radicular cysts (epithelium/capsule) of primary and permanent teeth. The relationship between the size of the radiographic lesion and expression of hBD-3 was also evaluated. Radicular cysts were subjected to immunohistochemical analysis to quantify the immune and inflammatory response cells and to evaluate hBD-3 staining and its relationship with radiographic lesion size. The results were analyzed using the D’Agostino & Pearson, Mann–Whitney, t-test, Kruskal–Wallis, and Dunn's post-tests (5%). hBD-3 was expressed in cysts of primary and permanent teeth. In primary teeth, hBD-3 expression was higher in small lesions than in large lesions (p < 0.05). All the evaluated cell types were detected in all radicular cysts. Cysts of primary teeth showed a higher expression of plasmacytoid dendritic cells, B lymphocytes, and T lymphocytes (p < 0.05), whereas those of permanent teeth showed a higher expression of T lymphocytes, immature plasmacytoid dendritic cells, cytotoxic T lymphocytes, and B lymphocytes (p < 0.05). hBD-3 was expressed in the epithelium/capsule of primary and permanent teeth radicular cysts. Immature plasmacytoid dendritic cells were the predominant cells in radicular cysts of primary teeth, whereas T lymphocytes were more abundant in permanent teeth.

Objective: To evaluate the effect of different prophylaxis systems on the surface of sound enamel and in induced white spot lesions using confocal microscopy analysis. Material and Methods: 40 specimens were obtained from sound premolars, and the buccal surface was divided into two parts: sound enamel and with an induced white spot lesion. The specimens were randomly divided into 4 groups (n=10/group): Group I: ClinproTM Prophy Paste (Perlite Particles); Group II: Extra-thin Pumice Stone; Group III: ClinproTM Prophy Powder (Glycine Amino Acid Powder); and Group IV: Sodium Bicarbonate Jet Powder. The specimens were analyzed by a confocal laser scanning microscope for surface roughness, preand post-prophylaxis. Data were analyzed by T-test and ANOVA (α= 0,05%). Results: Confocal microscopy analysis showed that ClinproTM Prophy Paste and ClinproTM Prophy Powder did not cause an increase in the surface roughness (p > 0.05). On the other hand, the Sodium Bicarbonate Jet Powder caused a significant increase in the surface roughness only in the induced white spot lesion (p = 0.015). Conclusion: Professional prophylaxis with Sodium Bicarbonate Jet Powder should be avoided in case of white spot lesions, and the ClinproTM Prophy Paste and ClinproTM Prophy Powder seem to be a good option for professional dental prophylaxis, especially in these cases.

The aims of this retrospective radiographic study were to assess the occurrence of dental anomalies in children and patients with disabilities and to investigate the association of these anomalies with pre-, peri-, and post-natal medical history. A total of 289 panoramic radiographs of children (0–14 years) and patients with disabilities (including all age groups) were used to identify developmental dental anomalies, and information was collected from medical records for statistical analysis. Data were expressed as relative frequency (percentage). The chi-square test, Fisher’s exact test, relative risk calculation, and the Mann-Whitney test were used for statistical comparisons with a significance level of 5%. Occurrence of dental alterations was 50.34% in children and 37.50% in patients with disabilities. Agenesis was the most common alteration (24.14% in children and 30.55% in patients with disabilities). The study found a relative risk of 2.6 for agenesis in children with a history of prematurity (p = 0.02). The variable “performing medical treatment” was a risk factor for the presence of dental alterations in children. The age and the medical conditions of the patients with disabilities varied greatly, with neurological diseases being the most prevalent disability. However, the health history of mothers during pregnancy was not associated with dental alterations in patients with disabilities (p > 0.05). Developmental dental anomalies were frequently observed in both groups, with agenesis being the most common condition. Prematurity was identified as a predictive factor for agenesis.

Objective: To preliminarily evaluate the endodontic treatments in primary teeth carried out by Brazilian dental practitioners. Materials and Methods: A preliminary nationwide cross-sectional e-survey was conducted. The data collection took place from December 2023 to January 2024. The sample consisted of 77 dental practitioners, based on their initial responses to a 32-item self-administered questionnaire that addressed the features of treatments provided in Portuguese. The instrument was made available online, and its link was distributed via messaging apps and social media campaigns. The significance level was set at 5% (α = 0.05), and Pearson's chi-squared test was used to assess associations. Results: Among the respondents, 61% carry out indirect pulp capping, 53.2% carry out direct pulp capping, 40.3% carry out pulpotomy, and 31.2% carry out pulpectomy in primary teeth. Respondents aged up to 35, working in public dental services, and self-assessing their knowledge as 'very good' or 'good' were more likely to provide some endodontic treatment in primary teeth (all p <0.05). Furthermore, 41.6% of the respondents did not rate their knowledge about endodontic treatments in primary teeth as 'very good' or 'good', and 49% of the providers reported referring children in need of endodontic treatments 'frequently' or 'occasionally'. Calcium hydroxide was the most commonly used material for direct or indirect pulp capping (78.7% and 68.1%, respectively) and pulpectomies (54.2%). In pulpotomies, Mineral Trioxide Aggregate (MTA) was the most frequently used material (45.2%), with its usage similar to that of calcium hydroxide (38.7%). Conclusion: There was notable variability in the characteristics of endodontic treatment providers for primary teeth among Brazilian dental practitioners.

Aim: To evaluate the impact of polymorphisms in SOCS‐1, TNF‐α and RANKL on gene expression of RANK , RANKL , TNFRSF1, SOCS‐1, IL‐10 , IL‐1β and TNF‐α , and to evaluate the histopathological, immunohistochemical and microbiological aspects of persistent apical periodontitis (PAP) after root canal treatment (RCT) in Brazilian individuals. Methodology: Patients with pulp necrosis and apical periodontitis at the time of the non‐surgical RCT (NSRCT) were followed up for at least 1 year after NSRCT. In view of the need for surgical intervention (cases assessed with a CBCTPAI score of 4 and 5, with the presence of symptoms), 20 patients were selected for endodontic surgery, which was planned using cone beam computed tomography images. Initially, saliva was collected as a source of genomic DNA, and the individuals were genotyped for SOCS‐1 , TNF‐α and RANKL polymorphisms by real‐time PCR. After collecting the biological material, the periapical lesions obtained were subjected to analysis of gene expression levels for RANK , RANKL , TNFRSF1, SOCS‐1, IL‐10 , IL‐1β and TNF‐α , and histopathological evaluation for characterisation and differentiation into periapical granulomas and cysts; immunohistochemical evaluation for SOCS‐1 and IL‐1β protein labeling; and microbiological analysis to identify the microorganisms involved in persistent periapical infection. The relative mRNA expression values of each gene in each group, according with genotypes in different SNPs, were analysed using one‐way analysis of variance followed by Tukey's post‐test or T ‐test ( α = 5%). Results: Different expression values of the genes evaluated were observed according to the genotypes of the polymorphisms evaluated in relation to PAP ( p < 0.05). Among the cases submitted for histopathological evaluation, 66.7% were diagnosed as periapical granuloma and 33.3% as periapical cyst. Immunohistochemical analysis showed strong positivity for SOCS‐1 and IL‐1β in the lesions classified as periapical cyst, while the lesions diagnosed as periapical granuloma were not labelled. In the microbiological analysis, four different species of bacteria were isolated: Pseudomonas aeruginosa , Staphylococcus epidermidis , Enterococcus faecalis and Bacillus cereus . Conclusions: This exploratory study indicates that genetic polymorphisms can modulate gene expression and protein activity in PAP, shaping the host's inflammatory and reparative response. These findings highlight their potential as biomarkers and establish a basis for future translational studies.

This study aimed to investigate the role of Toll‐like receptor 2 (TLR2) in the progression of periapical lesions by evaluating NLRP3 inflammasome and interleukin‐1 beta (IL‐1β) expression in wild‐type (WT) and TLR2 knockout (KO) mice. A total of 55 mice (28 WT, 27 TLR2‐KO) underwent pulpal exposure of mandibular first molars and were euthanised at 7, 21, or 42 days post‐exposure. Histological and immunohistochemical analyses were performed. TLR2‐KO mice showed significantly larger periapical lesions and higher IL‐1β expression than WT mice after 21 and 42 days, respectively. In contrast, NLRP3 expression was significantly greater in WT mice at both time points. A weak but significant positive correlation between NLRP3 and IL‐1β expression was observed only in WT mice. These findings suggest that TLR2 plays a protective role in limiting periapical bone resorption and modulating inflammatory cytokine expression, independent of NLRP3 inflammasome activity.

Objective To evaluate the effect of the probiotic Bifidobacterium animalis subsp. lactis (B. lactis) HN019, as an irrigation solution, on the expression of neutrophil extracellular traps (NETs) and the antimicrobial peptide CRAMP, in rats with induced periapical lesions. Methodology Periapical lesions were induced in the first molars of forty-five Wistar Hannover rats, with an experimental period of 21 days. The animals were divided into groups based on the irrigating solution and the number of sessions. Semiquantitative analysis was performed using HE staining, neutrophil counts, and histomorphometric analysis of the periapical lesions. Additionally, immunohistochemistry for CRAMP and immunofluorescence for NETs markers such as H3Cit, MPO, and NE were conducted. qRT-PCR analysis was performed for CAMP, ELANE, MPO, and H3F3B. Results The probiotic irrigation groups showed better results for periodontal ligament parameters (p = 0.03) and inflammatory infiltrate (p = 0.004). A single probiotic irrigation resulted in the highest absence of cementum and bone resorption (85.71% and 71.43%). The periapical lesion area was smaller (p = 0.002), and neutrophil counts showed no difference (p = 0.064). Lower immunolabeling for H3Cit (p = 0.002), MPO (p < 0.001), and NE (p = 0.001) was observed in probiotic-irrigated groups, with reduced gene expression of CAMP (p < 0.001), MPO (p = 0.002), and ELANE (p = 0.001). Conclusion The probiotic-based irrigation solution was effective in reducing neutrophil extracellular trap formation. Additionally, the probiotic solution stimulated CRAMP expression and had a positive effect in preventing cementum and bone resorption. Clinical relevance. The results demonstrate the potential application of the probiotic-based irrigation solution as a promising therapeutic approach for the treatment of periapical lesions.