Abstract The aim of this study was to investigate the effect of acid challenge on the activation of matrix metalloproteinases (MMPs) in the Dentinoenamel junction of primary and permanent teeth submitted to radiotherapy. For this purpose, a total of 178 dental fragments obtained from molars were used, and randomly divided into 2 groups (primary and permanent teeth) / 4 experimental subgroups (irradiated and non-irradiated, demineralized and non-demineralized). The fragments were exposed to radiation, with a dose fraction of 2 Gy, for 5 consecutive days, until a total dose of 60 Gy was reached, with a total of 30 cycles, for 6 weeks. To determine the activity of MMPs on the dentinoenamel junction (DEJ), in situ zymography assays on 0.6mm dental fragments were performed. To assess whether MMP activity would be impacted by an acidic environment, the fragments were placed in a demineralizing solution (pH of 4.8). The finding was that irradiation activated MMPs in DEJ and these effects were more evident in permanent when compared with primary teeth. When the effect of an acid challenge on MMPs activity was investigated, demineralization was observed not to increase MMPs activity in non-irradiated teeth, but it did increase MMPs activity in irradiated teeth. In conclusion, an acid challenge was found to exacerbate activation of MMPs in DEJ of permanent teeth submitted to irradiation, but not in primary teeth. (MMPs radiotherapy purpose 17 used nonirradiated, nonirradiated non irradiated, nondemineralized. nondemineralized . non-demineralized) radiation days reached 3 cycles weeks DEJ, , (DEJ) 06mm mm 0 6mm performed environment pH 4.8. 48 4.8 8 4.8) investigated conclusion 1 non-demineralized (DEJ 4.

ABSTRACT Objective: To evaluate an imaging protocol for use as a diagnostic and calibration tool for dentists before and after practical activity. Material and Methods: Thirty photos of children's teeth with or without changes in dental enamel were selected and evaluated by a group of experienced dentists previously calibrated to establish the diagnosis defined as the gold standard. After instructions, the images were shown to a group of postgraduate dentists for free identification of dental changes. Subsequently, a lecture on molar incisor hypomineralization (MIH) was carried out, and, at 14 days and all calibration was performed using the criteria previously. The retest was performed at 28 days. After experience in clinical activity in the following two weeks, the post-test was performed at 49 days. Data were analyzed using Cohen's kappa coefficient. Results: Theoretical learning on the subject showed low inter-examiner agreement when the diagnosis of defects was made from images obtained from intraoral photographs. After clinical practice, there was greater intra-examiner agreement. After theoretical training, dentists started to identify different types of enamel alteration, although with low agreement between them. Conclusion: Clinical experience in theoretical and imaging training favored the identification of defects. However, it is necessary to improve the protocol to establish a reliable and viable diagnostic method for calibration in MIH. Objective Methods childrens children s standard instructions Subsequently MIH (MIH out 1 2 weeks posttest post test 4 Cohens Cohen coefficient Results interexaminer inter examiner photographs practice intraexaminer intra alteration them Conclusion However

Resumo O objetivo deste trabalho foi Investigar a formação de osteoclastos in vivo e se o leucotrieno B4 (LTB4) incorporado em microesferas (MS) poderia ser usado como estratégia terapêutica para promover uma entrega sustentada do mediador e prevenir a diferenciação dos osteoclastos. Métodos: In vivo, a periodontite apical foi induzida em camundongos para investigar a diferenciação e sinalização de osteoclastos na ausência de 5-lipoxigenase (5-LO). In vitro, LTB4-MS foi preparado usando um processo de evaporação e extração de solvente de emulsão de óleo em água. A caracterização e a eficiência do encapsulamento do LTB4 foram investigadas. Macrófagos J774A.1 foram cultivados na presença de fator estimulador de colônia de monócitos (M-CSF) e ligante para o receptor ativador do fator nuclear kappa B (RANKL) e, então, estimulados com LTB4-MS. Citotoxicidade, captação in vitro de MS-LTB4, formação de osteoclastos e expressão gênica foram avaliadas. Resultados: A via 5-LO regula negativamente a formação de osteoclastos in vivo durante o desenvolvimento da periodontite apical. In vitro, LTB4-MS foram fagocitadas pelos macrófagos e não foram citotóxicos para as células. LTB4-MS inibiu a formação de osteoclastos e a síntese dos genes pró-osteoclastogênicos Acp5, Mmp9, Calcr e Ctsk. Conclusões: LTB4-MS inibiu a diferenciação de macrófagos em um fenótipo osteoclástico e a ativação celular sob estímulo de M-CSF e RANKL.

Abstract To investigate osteoclast formation in vivo and if leukotriene B4 (LTB4) loaded in microspheres (MS) could be used as a therapeutical strategy to promote a sustained delivery of the mediator and prevent osteoclast differentiation. Methods: In vivo, apical periodontitis was induced in mice to investigate osteoclast differentiation and signaling in absence of 5-lipoxygenase (5-LO). In vitro, LTB4-MS were prepared using an oil-in-water emulsion solvent extraction-evaporation process. Characterization and efficiency of LTB4 encapsulation were investigated. J774A.1 macrophages were cultured in the presence of monocyte colony-stimulating factor (M-CSF) and ligand for receptor activator of nuclear factor kappa B (RANKL) and then stimulated with LTB4-MS. Cytotoxicity, in vitro MS-LTB4 uptake, osteoclast formation and gene expression were measured. Results: We found that 5-LO negatively regulates osteoclastic formation in vivo during apical periodontitis development. In vitro, LTB4-MS were up-taken by macrophages and were not cytotoxic to the cells. LTB4-MS inhibited osteoclast formation and the synthesis of osteoclastogenic genes Acp5, Mmp9, Calcr and Ctsk. LTB4-MS inhibited differentiation of macrophages into an osteoclastic phenotype and cell activation under M-CSF and RANKL stimulus.

Abstract: In this study, we evaluated the knowledge, attitudes, and psychosocial impacts among Brazilian pediatric dentists during the COVID-19 pandemic. A cross-sectional study with primary data collection was carried out using an online structured questionnaire. Data were submitted to descriptive analysis by using absolute and relative frequencies. A chi-square test was used for association analysis and log-linear regression models to estimate the prevalence ratio (5%). The population comprised mostly women and knowledge regarding COVID-19 was satisfactory (above 80% in most items). N95 masks and faceshields were used, albeit 64.22% reported difficulty in providing dental care to children due to the need for extra Personal Protective Equipment. Thirty eight percent provided urgency/emergency dental care, 59.78% performed invasive procedures, 59.56% used high speed handpieces, 8.44% started using cariostatics, and 6.22% introduced the use of chemomechanical caries removal agents. Fear for the future (PR = 1.21) and use of medications (for anxiety, depression, or insomnia) increased (PR = 1.16) among the ones who had wage losses. Brazilian pediatric dentists have knowledge about COVID-19, and attitudes in their clinical routines changed due the pandemic. Financial life was harmed and a negative impact of the pandemic in psychosocial aspects of workers was found.

Abstract Molar incisor hypomineralization (MIH) is often accompanied by dental hypersensitivity and difficulty in achieving effective analgesia. Objective: This study evaluated the effectiveness of preemptive analgesia in children with severe MIH, post-eruptive enamel breakdown, and hypersensitivity. Methodology: Ibuprofen (10 mg/kg child weight) or placebo was administered, followed by infiltrative anesthesia and restoration with resin composite. Hypersensitivity was evaluated in five moments. The data were analyzed using the chi-square test, Fisher’s exact test, and t-test. Results: Preemptive analgesia provided benefits for the treatment of severe cases of MIH, with an increase in the effectiveness of infiltrative anesthesia and improved patient comfort during the restorative procedure. Conclusion: Preemptive analgesia has shown efficacy in reducing hypersensitivity during restorative dental procedures, evidencing the significance of this study for patients with MIH and hypersensitivity.

Resumo O objetivo do presente estudo in vivo foi avaliar o efeito da irrigação do canal radicular por pressão apical negativa e por pressão positiva na expressão de moléculas que são indicativas de diferenciação celular com fenótipo mineralizador em dentes de cães com rizogênese incompleta e lesão periapical. Um total de 30 dentes (60 raízes) foi distribuído em 3 grupos (n=20): EndoVac, Convencional e Controle. Após 30 dias, foram realizados os procedimentos histotécnicos de rotina e os cortes foram submetidos à técnica de imunohistoquímica para marcação de Osteopontina (OPN), Fosfatase Alcalina (ALP) e para o fator de transcrição RUNX2 nas regiões apical e periapical das raízes. Foi realizada uma análise semi-quantitativa da imunomarcação positiva e a intensidade da expressão foi classificada em ausente (0), leve (1), moderada (2) ou intensa (3). Os dados por escores foram analisados estatisticamente pelo teste não-paramétrico de Kruskal-Wallis e pelo pós-teste de Dunn, e o nível de significância adotado foi de 5%. A imunumarcação para RUNX2 revelou que no grupo pessão negativa houve marcação significativamente mais intensa (p<0,05), em comparação ao grupo controle. Com relação à expressão de OPN, não foi possível observer diferença estatisticamente significante entre os grupos (p>0,05). Após análise da imunomarcação para ALP, foi observado diferença estatisticamente significante entre os grupos (p<0,05), e o grupo pressão negativa demonstrou uma marcação siginificativamente mais intensa do que o grupo controle. Os resultados do presente estudo in vivo permitiram concluir que a irrigação por pressão apical negativa apresenta potencial mineralizador em dentes com ápice aberto e lesão periapical.

Abstract 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.

Abstract 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.

O objetivo deste estudo foi avaliar os níveis de estresse transitório e o estado de ansiedade em crianças submetidas à anestesia dental convencional e computadorizada. Vinte crianças (7 a 12 anos de idade) foram randomicamente designadas para receber anestesia dental convencional e computadorizada. Para investigar a hipótese que o estresse transitório poderia ser menor após a anestesia computadorizada, comparada à anestesia convencional, os níveis de cortisol na saliva foram medidos antes e depois de cada técnica. A ansiedade também foi avaliada individualmente por meio do State-Trait Anxiety Inventory for Children (STAIC). Os dados numéricos foram analisados estatisticamente pelo teste não paramétrico de Mann-Whitney (nível de significância de 5%). Os níveis salivares de cortisol aumentaram em 8 (40%) pacientes após anestesia convencional e em 9 (45%) pacientes após anestesia computadorizada, sem diferença estatisticamente significante entre os dois tipos (p=0,34). Da mesma maneira, não foi encontrada diferença estatisticamente significante entre as técnicas (p=0,39) com relação à análise psicológica baseada nos escores STAIC. Anestesia local usando tanto a anestesia convencional quanto o sistema de aplicação computadorizado produziu nível similar de estresse/ansiedade em pacientes infantis, utilizando análises quantitativa e qualitativa.

The aim of this study was to evaluate the transitory stress levels and the anxiety state in children submitted to conventional and computerized dental anesthesia. Twenty children (7 to 12 years) were randomly assigned to receive conventional and computerized dental anesthesia. To investigate the hypothesis that transitory stress could be lower after using computerized anesthesia compared to conventional anesthesia, cortisol levels in saliva were measured before and after each technique. Anxiety was also evaluated individually by answering the State-Trait Anxiety Inventory for Children (STAIC). Numerical data were analyzed statistically by the Mann-Whitney non-parametric test (5% significance level). Salivary cortisol levels increased in 8 (40%) patients after conventional anesthesia and in 9 (45%) patients after computerized anesthesia, with no statistically significant difference between the two types (p=0.34). In the same way, no statistically significant difference was found between the techniques (p=0.39) related to the psychological analysis based on the STAIC scores. Local anesthesia using either conventional anesthesia or a computerized delivery system produced similar level of stress/anxiety in pediatric patients, using both quantitative and qualitative analyses.

Este artigo descreve dois casos clínicos de reconstrução de molares decíduos com extensa destruição coronária por meio de restaurações biológicas, em crianças de 4 e 5 anos. Após avaliação clínica e radiográfica, os fragmentos dentais heterógenos foram submetidos à colagem ao remanescente dental preparado usando sistema adesivo (Caso 1) ou cimento resinoso de presa dual (Caso 2) sobre uma camada de hidróxido de cálcio e uma base de ionômero de vidro. Foi realizado ajuste oclusal e aplicação tópica de flúor sobre a superfície dentária. Controles clínico e radiográfico foram realizados periodicamente e os dentes restaurados foram acompanhados por 4 e 3 anos respectivamente, até a exfoliação. Por meio destes dois relatos, os autores discutem os aspectos técnicos, além das vantagens e desvantagens das restaurações biológicas como tratamento alternativo para restauração de molares decíduos.

This article reports the cases of two young children aged 4 and 5 years, in whom biological restorations using tooth fragments were placed in primary molars with severely damaged crowns due to extensive carious lesions. After radiographic and clinical evaluation, tooth fragments obtained from extracted teeth in stock were autoclaved, adjusted to the prepared cavity and bonded to the remaining tooth structure with either adhesive system (Case 1) or dual-cure resin-based cement (Case 2) over a calcium hydroxide layer and a glass ionomer cement base. Occlusal adjustment was performed and topical sodium fluoride was applied to tooth surface. Periodical clinical and radiographic controls were carried out and the restored teeth were followed up for 4 and 3 years, respectively, until exfoliation. In these two reports, the technical aspects are described and the benefits and disadvantages of biological restorations as an alternative treatment for rehabilitation of severely destroyed primary molars are discussed.