Effect of chlorhexidine mouthwashes on periodontal parameters and extrinsic tooth staining in orthodontic patients.

INTRODUCTION: Periodontal health and biofilm control are primordial to success in orthodontic treatment. This study aimed to evaluate the effect of chlorhexidine (CHX) mouthwashes on periodontal status and extrinsic tooth staining in orthodontic patients. METHODS: Thirty-three patients of both sexes, aged 11-33 years, under orthodontic treatment with fixed appliances at <16 months, were randomly distributed into 2 groups. In the control group, patients received mechanical hygiene instruction, and in the experimental group, patients also used CHX wash twice a week for 60 days. The effectivity of the protocols was evaluated using the plaque, gingival, gingival bleeding, and discoloration indexes before the hygiene protocol was applied, 15, 30, and 60 days after protocol implementation. RESULTS: In the experimental group, there was a decrease in the plaque, gingival, and gingival bleeding indexes at the different evaluation periods (P <0.05). In addition, there was a significant difference in the discoloration index at 60 days compared with initial time points after implementing hygiene protocols in the experimental group (P <0.05). In contrast, there were no significant differences in plaque, gingival, gingival bleeding, and discoloration indexes in the control group at any time (P >0.05). CONCLUSIONS: CHX mouthwash administered 30 days, twice a week, significantly improved the periodontal status with mild brown staining. After this period, expressive extrinsic tooth staining was observed.

Photoelastic, microhardness and roughness analysis of zirconia and stainless steel crowns for primary molars.

PURPOSE: To compare the stress distribution through photoelasticity, microhardness and roughness of intact crowns of primary molars (CC) and the preformed crowns of stainless steel (SSC) and zirconia (ZC) used in dental restorations in pediatric dentistry. METHODS: Six healthy primary molars were selected. For the photoelastic models, the teeth were fixed in photoelastic resin. A load of 100 N was applied, and the models were analyzed by transmission polariscope. The Tardy method was used to quantify the fringe order which calculates the maximum stress (T) value in each selected point. The teeth were prepared for cementation of the crowns. The photoelastic test was repeated for each experimental crown. Knoop microhardness was assessed on the buccal surfaces of the CCs, SSCs, and ZCs using a microhardness tester. Parameters were 50 gf for 5 seconds. Roughness was evaluated using a confocal 3-D laser scanning microscope/software at 216x magnification. Roughness average (Ra) values from each model (expressed in µm) were collected and group means were calculated. The stress distribution, microhardness, and roughness data were compared by using one-way ANOVA and the Tukey's test (α= 0.05). RESULTS: There was no difference in the stress distribution for the CCs, SSCs and ZCs. For the microhardness analysis, the ZCs obtained the highest values compared to the CCs and the SSCs (P< 0.001). The CCs were significantly higher than the SSCs (P= 0.027). There was no difference in roughness for the three models (P= 0.615). The SSCs and ZCs showed satisfactory mechanical behavior. CLINICAL SIGNIFICANCE: The use of preformed crowns, especially those made of esthetic materials, is currently increasing in the field of pediatric dentistry. The knowledge of mechanical properties of stainless steel- and zirconia-prefabricated crowns provides scientific foundation for safe clinical application, especially in primary teeth.

Mechanical, chemical and antimicrobial properties of a bisphenol A-free pit-and-fissure sealant.

PURPOSE: To evaluate, in vitro, mechanical, chemical and antimicrobial properties of Embrace Wetbond bisphenol A (BPA)-free pit-and-fissure sealant. METHODS: For the shear bond strength and microleakage tests, 135 healthy third molars were randomly divided into six groups, according to sealant [Fluroshield (FS) and Embrace Wetbond (EWB)] and contamination conditions (no contamination, contamination with saliva and contamination with water). In addition, EWB sealant was subjected to the following analyses: fluoride release using direct potentiometry, antimicrobial activity using the agar well diffusion method and quantification of BPA using gas chromatography and mass spectrometry. Data were analyzed statistically by ANOVA, Kruskal-Wallis test, Tukey's post-test, Dunn's post-test and Bonferroni post-test (α= 0.05). RESULTS: For shear bond strength, there was a statistically significant difference among the groups (P< 0.05), and FS presented the best results. Analysis of the microleakage results showed statistically significant differences among the groups (P< 0.05), except for EWB non-contaminated, contaminated with saliva, and contaminated with water (P> 0.05). FS without contamination presented the lowest microleakage of all groups (P< 0.05), followed by FS contaminated with saliva, and three groups in which EWB was used under different conditions. FS contaminated with water presented the highest microleakage (P< 0.05). EWB showed higher fluoride release in water and artificial saliva on the first day (P< 0.05). EWB had greater antimicrobial activity than FS. BPA and Bis-GMA were not detected in EWB. When used according to the manufacturer's instructions (i.e., under conditions of moisture contamination), EWB showed high fluoride release, high antimicrobial activity, no release of BPA or Bis-GMA and shear bond strength close to the minimum acceptable value. However, this sealant presented statistically significantly more microleakage than the other tested materials. CLINICAL SIGNIFICANCE: Knowing the adverse effects of BPA in the body, the present study has clinical relevance since it demonstrates some mechanical, chemical and antimicrobial properties of a BPA-free pit-and-fissure sealant.

Effect of ultrasonic, sonic and rotating-oscillating powered toothbrushing systems on surface roughness and wear of white spot lesions and sound enamel: An in vitro study.

PURPOSE: To evaluate the effect of ultrasonic, sonic and rotating-oscillating powered toothbrushing systems on surface roughness and wear of white spot lesions and sound enamel. METHODS: 40 tooth segments obtained from third molar crowns had the enamel surface divided into thirds, one of which was not subjected to toothbrushing. In the other two thirds, sound enamel and enamel with artificially induced white spot lesions were randomly assigned to four groups (n=10) : UT: ultrasonic toothbrush (Emmi-dental); ST1: sonic toothbrush (Colgate ProClinical Omron); ST2: sonic toothbrush (Sonicare Philips); and ROT: rotating-oscillating toothbrush (control) (Oral-B Professional Care Triumph 5000 with SmartGuide). The specimens were analyzed by confocal laser microscopy for surface roughness and wear. Data were analyzed statistically by paired t-tests, Kruskal-Wallis, two-way ANOVA and Tukey's post-test (α= 0.05). RESULTS: The different powered toothbrushing systems did not cause a significant increase in the surface roughness of sound enamel (P> 0.05). In the ROT group, the roughness of white spot lesion surface increased significantly after toothbrushing and differed from the UT group (P< 0.05). In the ROT group, brushing promoted a significantly greater wear of white spot lesion compared with sound enamel, and this group differed significantly from the ST1 group (P< 0.05). None of the powered toothbrushing systems (ultrasonic, sonic and rotating-oscillating) caused significant alterations on sound dental enamel. However, conventional rotating-oscillating toothbrushing on enamel with white spot lesion increased surface roughness and wear. CLINICAL SIGNIFICANCE: None of the powered toothbrushing systems (ultrasonic, sonic and rotating-oscillating) tested caused significant alterations on sound dental enamel. However, conventional rotating-oscillating toothbrushing on enamel with white spot lesion increased surface roughness and wear.

Genetic Polymorphisms in DEFB1 and miRNA202 Are Involved in Salivary Human ß-Defensin 1 Levels and Caries Experience in Children.

The antimicrobial peptides human ß-defensins (hBDs) are encoded by ß-defensin genes (DEFBs) and are possibly involved in caries susceptibility. In this study we aimed (1) to investigate the relationship between salivary hBDs and caries and (2) to evaluate the association of genetic polymorphisms in DEFB1 and microRNA202 (miRNA202) with salivary levels of hBDs and caries experience. Two data sets were available for this study, totalizing 678 Brazilian children. Dental examination and saliva collection were performed in all included children. The salivary level for hDB1, hBD2, and hBD4 was assessed by ELISA sandwich technique in 168 children. The DNA was extracted from saliva, and polymorphisms in DEFB1 and miRNA202 were analyzed by real-time PCR. Statistical analysis was performed to investigate the associations between caries experience, hBD salivary level, genotype, and allele distribution, with an alpha of 0.05. The hBD1 level was significantly higher in caries-free children (p < 0.0001). The miRNA202 was associated with a lower level of salivary hBD1 (p < 0.05). Also, the polymorphic distribution of miRNA202 was associated with caries (p = 0.006). The polymorphisms in DEFB1 were not associated with hBD salivary level and caries experience (p > 0.05). In conclusion, our results indicate that genetic polymorphism in miRNA202 is involved in hBD1 salivary level as well as caries experience in children.

Effect of EGCG-based paste as intracanal dressing, in MMPs 2 and 9 expression in dog's periapical lesions.

High expression of MMP-2 and MMP-9 in periapical lesions plays an important role in the degradation of the extracellular matrix. This study aimed to investigate the effect of epigallocatechin-3-gallate (EGCG)-based endodontic paste as an intracanal dressing on the expression of MMP-2 and MMP-9 in periapical lesions. Periapical lesions were experimentally induced in 35 mature beagle dog premolars randomly divided into healthy teeth, untreated periapical lesions, periapical lesions treated in a single session (control groups), and periapical lesions treated in two sessions with EGCG or calcium hydroxide-based pastes (experimental groups). After 120 days, specimens were obtained for histopathologic and immunofluorescence analyses to assess the expression of MMP-2 and MMP-9. The statistical analysis was performed using a p-value of 0.05. Endodontic treatment in two sessions using medication with EGCG and calcium hydroxide-based pastes provided similar repair of the apical and periapical tissues and neoformation of periodontal ligament fibers, cementum, and alveolar bone (p>0.05). The experimental groups treated in two sessions with both medications presented expression of MMP-2 and MMP-9 similar to that in healthy teeth (p>0.05), and significantly lower than teeth treated in a single session or untreated periapical lesions (p <0.001). Expression of MMP-2 and MMP-9 was observed in the cytoplasm of fibroblasts, osteoblasts, cementoblasts, cementocytes, and vascular endothelium. The use of EGCG-based endodontic paste reduced the expression of MMP-2 and MMP-9 and allowed repair of periapical lesions, similar to calcium hydroxide-based paste, and superior to treatment performed in a single session.

Outpatient dental procedures carried out by Pediatric Dentists within Brazil's public healthcare system.

Brazil's public healthcare system (SUS) offers specialized oral health services to Brazilians, but the productivity of specialists, such as Pediatric Dentists, has not been characterized. Therefore, the objective of this study was to characterize the outpatient dental procedures (ODPs) carried out by Pediatric Dentists within the SUS. An epidemiological study with an ecological, longitudinal, retrospective, and quantitative approach was conducted. The ODPs carried out by Pediatric Dentists within the SUS were characterized based on type of procedure, complexity level, and circumstance (urgent or elective). Data were analyzed using a descriptive and analytical approach, considering a significance level of 5%, as well as the impact of the COVID-19 pandemic (the 2020-2022 years were not included in secondary analyses). In the last 15 years, 29,234,972 ODPs were carried out by Pediatric Dentists within the SUS. Clinical procedures were the majority (55.4%), significantly more frequent than all other types of procedures (all p <0.05). Among these, restorative and periodontal procedures were the most common (30.7% and 21.0%, respectively). From 2008 to 2019, excluding COVID-19 pandemic years, the trend over the last 15 years was constant for all types of procedures (all p >0.05). In addition, low complexity ODPs were the majority (90.1%), significantly more frequent than medium (9.7%) and high complexity procedures (0.1%) (both p <0.05). At last, most ODPs were not characterized by circumstance in the outpatient production reports (96.9%). Therefore, it was possible to conclude that Pediatric Dentists carried out diverse ODPs within the SUS over the past 15 years, although there was a dominant pattern of type and complexity.

Caries-related hospital morbidity in the Brazilian Unified Health System from 2008 to 2022.

Dental caries is an important Public Health issue. However, the treatment of this disease in tertiary dental care requires further investigation. Therefore, the objective of this study was to evaluate caries-related hospital morbidity in the Brazilian Unified Health System (SUS) from 2008 to 2022. An ecological study was conducted with secondary data on caries-related Hospital Admission Authorizations (AIH) and in-hospital dental procedures (IDP). Data were collected nationwide and statistical analysis was performed with a significance level (p) of 5%. In the last 15 years, 3,474 caries-related AIH and 63,657 IDP were approved within SUS. There was a significant upward trend in the number of caries-related AIH (p = 0.018) and a stationary trend in the number of caries-related IDP (p = 0.841). Moreover, from 2008 to 2022, R$ 1,160,843.09 was allocated for caries-related AIH. Hospital mortality was 0.29% (10 deaths), and 75.1% were elective inpatient admissions. Among SUS users, adults constituted the majority (49%), with a higher frequency of males (59.8%) and whites (46.2%). The most frequent type of caries-related IDP was restoration of permanent teeth (55.3%). Nonetheless, during the COVID-19 pandemic years, significant reductions in caries-related AIH and IDP within the SUS were observed (all p <0.05). Thus, within the SUS, caries-related tertiary dental care has shown a specific pattern over the last 15 years, including an increase in hospitalizations and a high number of in-hospital dental procedures, especially before the COVID-19 pandemic onset.

Efficacy of ClinproTMXT Varnish surrounding brackets on the enamel surface of white spot lesion.

Orthodontics patients usual develop demineralization and present cavity caries lesions after six months. Minimally invasive procedures have been the goal in modern dental practice. The aim of this study was to evaluate the effect of ClinproTMXT Varnish, on the enamel surface roughness and severity of white spot lesions. Twenty premolars were submitted to bond brackets and experimental induction of demineralization and randomly divided into 2 groups: GI - fluoride varnish (Colgate Duraphat®); GII - Ionomeric Sealant (ClinproTMXT Varnish). The treatment was applied around the brackets. The surface roughness of specimens was analyzed, before treatment and 12 weeks after treatment by laser confocal microscopy, and the severity of the white spot lesion was by laser fluorescence device. The data were analyzed by non-parametric Wilcoxon and Mann-Whitney Test, at 5% significance, roughness percentage reduction was performed. The severity of demineralization decreased in both, GI (p = 0.005) and GII (p = 0.019). Enamel superficial roughness levels decreased in GI and GII. As well as the roughness percentage, being more expressive in the ClinproTMXT Varnish group (85,09%). Colgate Duraphat® or Clinpro™ XT Varnish reduced the severity of the demineralization and decreased the superficial roughness on the enamel. The Clinpro™ XT Varnish was superior to superficial roughness on enamel.

Reparative Dentin Formation Following Dental Pulp Capping is Mediated by TNFR1 In Vivo.

INTRODUCTION: Tumor necrosis factor (TNF)-α is a pro-inflammatory cytokine that promotes biomineralization in vitro in dental pulp cells. However, the role of TNF-α-TNF receptor 1 (TNFR1) signaling in reparative dentin formation and related inflammatory pathways is not known. Therefore, the aim of this study was to evaluate the role of the TNF-α-TNFR1 axis in dental pulp repair following pulp capping in vivo. METHODS: Dental pulp repair response of genetically deficient TNF-α receptor-1 mice (TNFR1-/-; n = 20) was compared with that of C57Bl6 mice (wild type [WT]; n = 20). Pulp capping was performed with mineral trioxide aggregate on the mandibular first molars of mice. After 7 and 70 days, tissues were collected and stained with hematoxylin and eosin for histopathological and histometric evaluation, and assessed by the Brown and Brenn methods for histomicrobiological analysis and by immunohistochemistry to localize TNF-α, Runt-related transcription factor 2, Dentin Sialoprotein (DSP) and Osteopontin (OPN) expression. RESULTS: Compared with WT mice, TNFR1-/- mice showed significantly decreased reparative dentin formation with a lower mineralized tissue area (P < .0001). Unlike WT mice, TNFR1-/- mice also exhibited significant dental pulp necrosis, neutrophil recruitment, and apical periodontitis formation (P < .0001) without bacterial tissue invasion. TNFR1-/- animals further exhibited decreased TNF-α, DSP, and OPN expression (P < .0001), whereas Runt-related transcription factor 2 expression was unchanged (P > .05). CONCLUSION: The TNF-α-TNFR1 axis is involved in reparative dentin formation following dental pulp capping in vivo. Genetic ablation of TNFR1 modified the inflammatory process and inhibited the expression of the DSP and OPN mineralization proteins, which culminated in dental pulp necrosis and development of apical periodontitis.

Effect of systemic administration of Bifidobacterium animalis subsp. lactis HN019 on apical periodontitis.

This study aimed to evaluate the effect of Bifidobacterium animalis subsp. lactis (B. lactis) HN019 in drinking water on the development of apical periodontitis (AP) in rats. In total 60 animals were divided into a control group (sound teeth); Group I - regular water without AP; Group II - probiotic water without AP; Group III - regular water with AP; Group IV - probiotic water with AP. AP was induced after 3 days in the control groups and after 7, 21, and 42 days in groups III and IV. The animals were euthanized, and the mandibles were subjected to histotechnical processing. Samples were stained with hematoxylin & eosin (H&E) to identify root canal features, apical and periapical regions. Additionally, histoenzymology was performed to detect osteoclasts, immunohistochemistry was used to identify osteoclastogenesis markers, and the Brown & Brenn technique was applied for microbiological analysis. The data were analyzed using GraphPad Prism 8.0.1 with a significance level of 5%. Although no statistical differences were observed, the groups administered with probiotics showed better conditions in terms of histological aspects seen microscopically. Furthermore, there were no differences in the number of osteoclasts (p > 0.05). The RANKL marker was not found in the probiotic group at 42 days, unlike in group III.

Online teaching, quality of life and anxiety of Brazilian dental professors during the COVID-19 outbreak.

The COVID-19 pandemic led to changes in academic teaching and dental education, but the impact on dental professors' mental health and quality of life remains poorly understood. Thus, the objective of this study was to evaluate the impacts of social distancing and online teaching related to COVID-19 on the quality of life and anxiety of Brazilian dental professors. This was a cross-sectional study conducted from August 2020 to October 2020. Three instruments were used in an online version: a questionnaire about personal data, academic information and online teaching activities, the Generalized Anxiety Disorders 7 (GAD7) scale, and the Abbreviated World Health Organization Quality of Life (WHOQOL-bref) scale. All instruments were sent by e-mail, social media, and messaging apps to private and public universities and professors. Of the 318 responses, 187 (58.8%) were from female professors. Moreover, lack of good internet access and adequate place for online teaching, difficulties in producing teaching materials, and housework roles had a significant impact on the quality of life and anxiety scores (all p-values < 0.05). Also, Brazilian dental professors who declared that they would make greater efforts if the activities were face-to-face had significantly worse quality of life and anxiety scores, and female professors had significantly higher anxiety scores (all p-values < 0.05). These results provide evidence of a negative effect of social distancing and online teaching activities related to COVID-19 outbreak on the health-related quality of life and mental health of Brazilian dental professors.

Genetic, Cellular and Molecular Aspects involved in Apical Periodontitis.

The development, establishment and repair of apical periodontitis (AP) is dependent of several factors, which include host susceptibility, microbial infection, immune response, quality of root canal treatment and organism's ability to repair. The understanding of genetic contributions to the risk of developing AP and presenting persistent AP has been extensively explored in modern Endodontics. Thus, this article aims to provide a review of the literature regarding the biochemical mediators involved in immune response signaling, osteoclastogenesis and bone neoformation, as the genetic components involved in the development and repair of AP. A narrative review of the literature was performed through a PUBMED/MEDLINE search and a hand search of the major AP textbooks. The knowledge regarding the cells, receptors and molecules involved in the host's immune-inflammatory response during the progression of AP added to the knowledge of bone biology allows the identification of factors inherent to the host that can interfere both in the progression and in the repair of these lesions. The main outcomes of studies evaluated in the review that investigated the correlation between genetic polymorphisms and AP in the last five years, demonstrate that genetic factors of the individual are involved in the success of root canal treatment. The discussion of this review gives subsides that may help to glimpse the development of new therapies based on the identification of therapeutic targets and the development of materials and techniques aimed at acting at the molecular level for clinical, radiographic and histological success of root canal treatment.

Cytotoxicity and Inflammatory Mediators Release by Macrophages Exposed to Real Seal XT and Sealapex Xpress.

This study evaluated the cytotoxicity of Sealapex Xpress and Real Seal XT and their effect on macrophage activation. J774.1 macrophages were incubated with Sealapex Xpress and Seal Real XT (0.1, 1.0, and 10 mg/mL) for 24 and 48 h. Cell viability was assessed by the MTT assay and macrophage activation was measured by pro- and anti-inflammatory cytokine production using ELISA. Data were analyzed using one-way ANOVA and Tukey's post-test (a=0.05). Cell viability was not affected with 0.1 or 1.0 mg/mL of extracts of Sealapex Xpress and Real Seal XT at 24 and 48 h (p>0.05), but was significantly lower when cells were exposed to 10 mg/mL of both sealers (p<0.05). Sealapex Xpress inhibited the production of TNF-a, whereas Real Seal XT induced TNF-a secretion at 24 h (p<0.05). IL-6 production was induced by Real Seal XT, but not by Sealapex Xpress (p<0.05). Real Seal XT and Sealapex Xpress induced the secretion of anti-inflammatory IL-10. IL-4 was not detected in any group. In conclusion, both sealers had low toxicity but differentially activated macrophages. Macrophage activation by Sealapex Xpress was characterized by inhibition of TNF-a and induction of IL-10, whereas Real Seal XT induced IL-6 solely.

Sports mouthguards: Contamination, roughness, and chlorhexidine for disinfection - A randomized clinical trial.

The aim of the present in vivo study was to evaluate the bacterial contamination of sports mouthguards, surface roughness, and the efficacy of chlorhexidine gluconate spray in the disinfection of these devices. A randomized, blinded cross-over clinical trial was performed with twenty 9 to 13 years old children who practiced martial arts and participated in all phases of the study. They were instructed to wear mouthguards 3 alternated days a week for 1 hour and, after use, to spray sterile tap water or chlorhexidine 0.12%. The mouthguards were analyzed by MTT assay, Checkerboard DNA-DNA hybridization, and confocal laser microscopy prior and after use for 2 weeks. Data were analyzed by Wilcoxon and t-Student, and Pearson correlation tests, with 5% significance level. Were observed that mouthguards of the control group were more contaminated with cariogenic microorganisms than those of the chlorhexidine group (p<0.05). The mouthguards use of spray of chlorhexidine reduced significantly the bacteria contamination compared with control group (p = 0.007). The surface roughness of the mouthguards increased significantly after use, irrespective of application of chlorhexidine spray. A moderate correlation (r=0.59) was observed between surface roughness and the cariogenic microorganism's contamination only for control group. Sports mouthguards had intense microbial contamination and increased surface roughness after its use. The use of chlorhexidine spray was effective for reducing the mouthguards contamination used by children.

Negative Pressure Irrigation Presents Mineralizing Potential in Dogs' Immature Teeth with Periapical Lesion.

The objective of this in vivo study was to assess the effect of the root canal irrigation by negative and positive apical pressure on the expression of molecules that are an indicative of cell differentiation with mineralizing phenotype in teeth of dogs with incomplete rhizogenesis and induced periapical lesion. A total of 30 teeth (60 roots) were distributed into 3 groups (n=20): EndoVac®, Conventional and Control. After 90 days, the routine histotechnical procedures were performed and the sections were submitted to immunohistochemical technique for the staining of osteopontin (OPN), alkaline phosphatase (ALP) and the RUNX2 transcription factor in the apical and periapical regions of the roots. A semi-quantitative analysis of the positive immunostaining was performed and the intensity of the expression was classified in absent (0), mild (1), moderate (2), or intense (3). Scores data were statistically analyzed by the Kruskal-Wallis non-parametric test and Dunn post-test, and the significance level was set at 5%. RUNX2 immunostaining revealed that in the negative pressure group there was a significantly stronger (p<0.05) immunostaining in comparison to the control group. Regarding the OPN expression, it was not possible to detect a statistically significant difference between the groups (p>0.05). After analyzing ALP immunostaining, a statistically significant difference was observed between the groups (p<0.05), and the negative pressure group showed a markedly stronger mark immunostaining than the control group. The results of the present in vivo study allowed concluding that negative apical pressure irrigation presents mineralizing potential in immature teeth with apical periodontitis.

Root canal contamination or exposure to lipopolysaccharide differentially modulate prostaglandin E 2 and leukotriene B 4 signaling in apical periodontitis.

Purpose To evaluate the kinetics of apical periodontitis development in vivo , induced either by contamination of the root canals by microorganisms from the oral cavity or by inoculation of bacterial lipopolysaccharide (LPS) and the regulation of major enzymes and receptors involved in the arachidonic acid metabolism. Methodology Apical periodontitis was induced in C57BL6 mice (n=96), by root canal exposure to oral cavity (n=48 teeth) or inoculation of LPS (10 µL of a suspension of 0.1 µg/µL) from E. coli into the root canals (n= 48 teeth). Healthy teeth were used as control (n=48 teeth). After 7, 14, 21 and 28 days the animals were euthanized and tissues removed for histopathological and qRT-PCR analyses. Histological analysis data were analyzed using two-way ANOVA followed by Sidak's test, and qRT-PCR data using two-way ANOVA followed by Tukey's test (α=0.05). Results Contamination by microorganisms led to the development of apical periodontitis, characterized by the recruitment of inflammatory cells and bone tissue resorption, whereas inoculation of LPS induced inflammatory cells recruitment without bone resorption. Both stimuli induced mRNA expression for cyclooxygenase-2 and 5-lipoxygenase enzymes. Expression of prostaglandin E 2 and leukotriene B 4 cell surface receptors were more stimulated by LPS. Regarding nuclear peroxisome proliferator-activated receptors (PPAR), oral contamination induced the synthesis of mRNA for PPARδ, differently from inoculation of LPS, that induced PPARα and PPARγ expression. Conclusions Contamination of the root canals by microorganisms from oral cavity induced the development of apical periodontitis differently than by inoculation with LPS, characterized by less bone loss than the first model. Regardless of the model used, it was found a local increase in the synthesis of mRNA for the enzymes 5-lipoxygenase and cyclooxygenase-2 of the arachidonic acid metabolism, as well as in the surface and nuclear receptors for the lipid mediators prostaglandin E2 and leukotriene B4.

Association between Estrogen, Vitamin D and Microrna17 Gene Polymorphisms and Periapical Lesions.

This study evaluated the association between polymorphisms in genes encoding estrogen receptors 1 (ESR1) and 2 (ESR2), vitamin D receptor (VDR) and in microRNA17 (which binds to ESR1 and VDR) with persistent apical periodontitis (PAP) after the endodontic treatment. We included 162 patients who completed endodontic treatment at least one year ago and presented apical periodontitis at the beginning of the root canal therapy. Clinical and radiographic exams were performed to evaluate the presence of PAP or healthy periradicular tissues (healed). Saliva samples were collected as a genomic DNA. The genotyping of ESR1 (rs2234693 and rs9340799), ESR2 (rs1256049 and rs4986938), VDR (rs739837 and rs2228570) and miRNA17 (rs4284505) were performed by real-time PCR. Chi-square test was used to the distribution of genotype and allele frequencies. Haplotype analysis was also performed. Eighty-nine patients were included in the "healed" group and 73 in the "PAP" group. No association was found between the allelic and genotypic polymorphisms studied and PAP (p>0.05). Haplotype analysis also did not demonstrated an association (p>0.05). In conclusion, the genetic polymorphisms in ESR1, ESR2, VDR and miRNA17 are not associated with PAP.

Radiographic and Immunohistochemical Evaluation of Root Canal Treatment Using Different Irrigation Systems.

The aim of this study was to evaluate the radiographic periapical repair and the synthesis of inflammatory mediators after endodontic treatment in a single session, using different irrigation protocols, in teeth with apical periodontitis. Experimental apical periodontitis were induced in dog's teeth randomly assigned into 4 groups: G1 - Irrigation by Negative Apical Pressure (n= 20); G2 - Passive Ultrasonic Irrigation (n= 20), G3 - Positive Pressure Irrigation (n= 20); G4 - apical periodontitis without treatment (n= 20). After 180 days, the animals were euthanized, the tissues removed and submitted to histotechnical processing for immunohistochemical analysis of osteopontin (OPN), tumor necrosis factor-a (TNF-a) and interleukin 1-a (IL-1a). Radiographic analysis was performed using the Periapical Index (PAI), obtained prior to and 180 days following endodontic treatment. Data were analyzed using Wilcoxon signed-rank test, Fisher's Exact test or Kruskal-Wallis test and Dunn's post-test (a = 5%). Radiographically, after endodontic treatment, apical periodontitis persisted in 35% of G1 specimens, 40% of G2 and 40% of G3 (p>0.05), although a PAI reduction was observed (p<0.05). By immunohistochemical evaluation, endodontic treatment resulted in lower synthesis of TNF-a and OPN in periapical region, compared to apical periodontitis without treatment (p<0.05). Production of IL-1 was not modulated by endodontic treatment (p>0.05). Periapical healing was observed in approximately 60% of the cases after endodontic treatment performed in a single session with lower synthesis of TNF-a and OPN in the periapical region, regardless of the irrigation protocol used.

Tissue Response after Subcutaneous Implantation of Different Glass Ionomer-Based Cements.

The aim of this study was to evaluate the subcutaneous connective tissue response of isogenic mice after implantation of different glass ionomer-based cements (EQUIA® Forte Fil, EQUIA® Fil and Ketac™ Universal Aplicap™). Eighty-seven isogenic BALB/c mice were allocated in 12 groups, 9 were considered as experimental groups (Ketac, E. Fil and E. Forte at 7, 21 and 63 days) and 3 controls (empty polyethylene tubes at 7, 21 and 63 days). After the experimental periods, the subcutaneous connective tissue surrounding the implanted material was removed and subjected to histotechnical processing and staining with hematoxylin and eosin. A histopathological description of the tissue reaction surrounding each material and a semi-quantitative analysis of collagen fiber formation and inflammatory infiltrate were performed. Additionally, the thickness of the granulomatous tissue in contact with each material was measured. Data were analyzed statistically (α=0.05) by the Kruskal-Wallis test, followed by Dunn post-test. Initially, the collagen fiber formation was not different among all the tested materials (p>0.05) but was different at 21 days with the control group presenting the most advanced stage of collagen fiber formation. At 63 days, EQUIA® Forte Fil group showed the most advanced stage of collagen fiber formation, compared to EQUIA® Fil group (p<0.05). The inflammatory infiltrate was not different among the tested materials in any experimental period (p>0.05). The thickness of the granulomatous tissue was greater in the E. Forte group, compared to control in all periods. All glass ionomer-based cements showed tissue compatibility, according to the evaluated parameters.