Experimental gel containing bioactive glass-ceramic to minimize the pulp damage caused by dental bleaching in rats

Objectives: This study evaluated if the use of a bioactive glass-ceramic-based gel, named Biosilicate (BS), before, after or mixed with bleaching gel, could influence the inflammation of the dental pulp tissue of rats’ molars undergoing dental bleaching with hydrogen peroxide (H2O2). Methodology: The upper molars of Wistar rats (Rattus norvegicus, albinus) were divided into Ble: bleached (35% H2O2, 30-min); Ble-BS: bleached and followed by BS-based gel application (20 min); BS-Ble: BS-based gel application and then bleaching; BS/7d-Ble: BS-based gel applications for 7 days and then bleaching; Ble+BS: blend of H2O2 with BS-based gel (1:1, 30-min); and control: placebo gel. After 2 and 30 days (n=10), the rats were euthanized for histological evaluation. The Kruskal-Wallis and Dunn statistical tests were performed (P<0.05). Results: At 2 days, the Ble and Ble-BS groups had significant alterations in the pulp tissue, with an area of necrosis. The groups with the application of BS-based gel before H2O2 had moderate inflammation and partial disorganization in the occlusal third of the coronary pulp and were significantly different from the Ble in the middle and cervical thirds (P<0.05). The most favorable results were observed in the Ble+BS, which was similar to the control in all thirds of the coronary pulp (P>0.05). At 30 days, the pulp tissue was organized and the bleached groups presented tertiary dentin deposition. The Ble group had the highest deposition of tertiary dentin, followed by the Ble-BS, and both were different from control (P<0.05). Conclusion: A single BS-based gel application beforehand or BS-based gel blended with a bleaching gel minimize the pulp damage induced by dental bleaching

Evaluation of an experimental rat model for comparative studies of bleaching agents

Dental materials in general are tested in different animal models prior to the clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents, by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and Methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals were untreated (control). The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated through histomorphometric analysis with inflammatory cell count in the coronal and radicular thirds of the pulp. Fibroblasts were also counted. Scores were attributed to odontoblastic layer and vascular changes. Tertiary dentin area and pulp chamber central area were measured histomorphometrically. Data were compared by analysis of variance and Kruskal-Wallis test (

Evaluation of an experimental rat model for comparative studies of bleaching agents

ABSTRACT Dental materials, in general, are tested in different animal models prior to their clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals (control) were untreated. The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated by histomorphometric analysis with inflammatory cell counting in the coronal and radicular thirds of the pulp. The counting of fibroblasts was also performed. Scores were attributed to the odontoblastic layer and to vascular changes. The tertiary dentin area and the pulp chamber central area were histomorphometrically measured. Data were compared by the analysis of variance and the Kruskal-Wallis test (

Photobiomodulation reduces inflammation but does not influence the hypoxia-inducible factor-1α in pulp tissue of rats after bleaching

Objectives: To evaluate the influence of photobiomodulation with infrared laser (IRL) in the rat pulp tissue after bleaching, considering the immunolabeling of interleukin (IL)-23 and hypoxia-inducible factor (HIF)-1α. Methodology: The right and left molars of forty rats were divided into groups: Control – with placebo gel and Bleached – with 35% hydrogen peroxide (H2O2). Half of the rats received one IRL application on both sides, establishing a split-mouth design, which resulted in 4 groups with 20 hemi-maxillae each: Control, Bleach, IRL, and Bleached-IRL. Rats (n=10) from each group were euthanized, at 2- and 30-days mark, and the pulp tissue was evaluated using inflammation and immunolabeling scores. Wilcoxon and Mann-Whitney statistical tests were performed (p<0.05). Results: At the 2-days mark, the Bleached group had severe inflammation and necrosis in the occlusal thirds of the pulp, and moderate to severe inflammation in cervical third, whereas the Bleached-IRL had mild to moderate inflammation (p<0.05). At the 30-days mark, there was no inflammation, but tertiary dentine formation in the bleached groups. Regarding IL-23, severe immunolabeling was observed in the Bleached group (p<0.05) at the 2-days mark; at the 30-days mark, there was a reduction in immunolabeling, in which the Bleached group had moderate and the Bleached-IRL group had mild immunolabeling (p>0.05). HIF-1α was more evident at the 2-days mark in the Bleached group, without significant difference with the Bleached-IRL (p>0.05). The difference was observed between the bleached and control groups, without immunolabeling (p<0.05); at the 30-days mark, the Bleached group had reduction in HIF-1α immunolabeling, while the Bleached-IRL had an increase; the difference remained between the bleached and the controls groups (p<0.05). Conclusion: Photobiomodulation using IRL minimized the inflammation and IL-23 immunolabeling in the pulp tissue of rats after dental bleaching, but did not influence significantly the HIF-1α immunolabeling

Cytotoxicity, inflammation, biomineralization, and immunoexpression of IL-1β and TNF-α promoted by a new bioceramic cement

Aim: To evaluate the cytotoxicity, biocompatibility and mineralization capacity of BIO-C PULPO, and MTA. Methodology: L929 fibroblasts were cultured and MTT assay was used to determine the material cytotoxicity on 6, 24, and 48 h. A total of 30 male rats (Wistar) aged between 4 and 6 months, weighing between 250 and 300 g were used. Polyethylene tubes containing BIO-C PULPO, MTA, and empty tubes were implanted into dorsal connective tissue. After the experimental periods (7, 15, 30, 60, and 90 days) the tubes were histologically analyzed using hematoxylin-eosin (H&E), immunolabeling of IL-1β and TNF-α, and von Kossa staining, or without staining for polarized light analysis. The average number of inflammatory cells was quantified; the mineralization assessment was determined by the area marked in μm2 and semiquantitative immunolabeling analyses of IL-1β and TNF-α were performed. Then, data underwent statistical analysis with a 5% significance level. Results: It was observed that BIO-C PULPO and MTA presented cytocompatibility at 6, 24, and 48 similar or higher than control for all evaluated period. On periods 7 and 15 days, BIO-C PULPO was the material with the highest number of inflammatory cells (p<0.05). On periods 30, 60, and 90 days, BIO-C PULPO and MTA presented similar inflammatory reactions (p>0.05). No statistical differences were found between Control, BIO-C PULPO, and MTA for immunolabeling of IL-1β and TNF-α in the different periods of analysis (p<0.05). Positive von Kossa staining and birefringent structures under polarized light were observed in all analyzed periods in contact with both materials, but larger mineralization area was found with BIO-C PULPO on day 90 (p<0.05). Conclusion: BIO-C PULPO was biocompatible and induced mineralization similar to MTA

Análise histológica e imunoistoquímica do tecido pulpar de ratos Wistar submetidos a procedimento clareador com duas concentrações de peróxido de hidrogênio

Studies have shown damage to tooth pulp, and your capacity of tissue repair, after dental bleaching. This study investigated the necrosis process, the level of cell proliferation (immunolabeling with PCNA) and apoptosis (Caspase-3, cleaved), and inflammatory response (IL-17, IL-6 and CD5) generated in the pulp tissue after this procedure. Wistar rats were divided into Control (placebo gel), BLUE (20% H2O2,1x50min), and MAXX (35% H2O2, 3x15min) groups. At 2 and 30 days, the rats were killed (n=10).The jaws were removed and processed for histology analysis (H&E) and immunohistochemistry. Statistical tests were performed for each case, considering p0.05). The MAXX group presented...Estudos demonstram danos causados à polpa dentária, e sua capacidade de reparo tecidual, após procedimento de clareação dentária. Este estudo investigou o processo de necrose, o nível de proliferação celular (imunomarcação com PCNA) e apoptose (Caspase-3-clivada), e a resposta imune inflamatória (IL-17, IL-6 e CD5) no tecido pulpar após este procedimento. Foram utilizados dois protocolos de clareação dentária com peróxido de hidrogênio (H2O2) nos molares superiores de 40 ratos Wistar, formando os grupos Controle (gel placebo), BLUE (H2O2 a 20% 1x50min) e MAXX (H2O2 a 35%, 3x15min). Após 2 e 30 dias, os ratos foram eutanasiados e as maxilas processadas para avaliação histológica (H.E.) e imunoistoquímica. Foram realizados os testes estatísticos referentes a cada caso, considerando p<0,05. Aos dois dias, foi observada necrose no terço oclusal do grupo MAXX, e infiltrado inflamatório moderado no BLUE (p<0,05). Aos 30 dias, não houve infiltrado inflamatório nos grupos, e grande área da câmara pulpar foi ocupada por dentina terciária. A marcação para PCNA aos 2 dias, demonstrou maior nível de proliferação celular no terço médio do grupo BLUE (p<0,05) e no terço cervical do MAXX (p<0,05), com redução significativa aos 30 dias no terço cervical (p<0,05). Caspase-3-clivada foi presente em todos os grupos, apresentando maior nível de apoptose nos grupos clareados quando comparados com o controle, nos dois períodos de análise (p<0,05); quando comparados os grupos aos 2 e 30 dias, foi observada redução significativa do nível de apoptose apenas no grupo BLUE (p<0,05). Células CD5 positivas foram presentes em todos os grupos, em ambos períodos de análise; aos dois dias, o grupo BLUE apresentou maior imunomarcação para CD5 no terço oclusal quando comparado aos demais grupos (p<0,05); nos demais terços...Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Pterodon emarginatus Seed Preparations: Antiradical Activity, Chemical Characterization, and In Silico ADMET Parameters of β-caryophyllene and Farnesol

: The study of medicinal plants and their active compounds is relevant to maintaining knowledge of traditional medicine and to the development of new drugs of natural origin with lower environmental impact. From the seeds of the Brazilian plant Pterodon emarginatus, six different preparations were obtained: essential oil (EO), ethanol extract (EthE) prepared using the traditional method, and four extracts using solvents at different polarities, such as n-hexane, chloroform, ethyl acetate, and methanol (HexE, ChlE, EtAE, and MetE). Chemical characterization was carried out with gas chromatography, allowing the identification of several terpenoids as characteristic components. The two sesquiterpenes β-caryophyllene and farnesol were identified in all preparations of Pterodon emarginatus, and their amounts were also evaluated. Furthermore, the total flavonoid and phenolic contents of the extracts were assessed. Successively, the antiradical activity with DPPH and ORAC assays and the influence on cell proliferation by the MTT test on the human colorectal adenocarcinoma (HT-29) cell line of the preparations and the two compounds were evaluated. Lastly, an in silico study of adsorption, distribution, metabolism, excretion, and toxicity (ADMET) showed that β-caryophyllene and farnesol could be suitable candidates for development as drugs. The set of data obtained highlights the potential medicinal use of Pterodon emarginatus seeds and supports further studies of both plant preparations and isolated compounds, β-caryophyllene and farnesol, for their potential use in disease with free radical involvement as age-related chronic disorders

Pulp response of rats submitted to bleaching and the use of different anti-inflammatory drugs.

This study aimed to evaluate neuropeptide expression after bleaching treatment using histopathological and immunohistochemical analyses and the effects of hydrocortisone and acetaminophen on pulp inflammation, sine dental bleaching and inflammation first occur, and only then, the treatmentt. Sixty-three rats were divided into three groups (n = 21) according to the pain-relieving therapy used: I-control; II-topical application of Otosporin for 10 min after the bleaching treatment; III-oral administration of paracetamol 30 min before whitening and then every 12h. In all the study groups, placebo gel was applied to the left upper jaw (control) and a 35% H2O2-based whitening gel was applied to the right upper jaw for 45 min. Seven animals from each group were euthanized at different time points: 0h after treatment, 24h, and 48h. After euthanasia, the first molar on each side was analyzed by histology and immunohistochemistry to assess the degree of inflammation and verify the presence of the neuropeptides, substance P (SP) and calcitonin gene-related peptide (CGRP). The data were analyzed using the statistical nonparametric Kruskal-Wallis test followed by Dunn's test for individual comparisons. Extensive areas of necrosis were observed in the groups that received bleaching treatment only, whereas reduced damage were obtained in the group treated with Otosporin. The immunohistochemical analysis showed positive immunolabeling in all groups, including the control, but this was stronger in the groups that received bleaching treatment. The best results were obtained in the group that received treatment with Otosporin. The use of Otosporin after dental bleaching minimized the side effects of this treatment

Caracterização de pessoas idosas hospitalizadas conforme Modelo de Sistemas

Objective: to characterize hospitalized elderly people according to the dimensions proposed by the Neuman Systems Model. Method: an extract from a qualitative study, based on the Convergent Care Research proposal, developed in a teaching hospital with 30 elderly people. Data production took place from November, 2016 to August, 2017 through a conversation interview, guided by a research protocol, and analyzed in the light of the Neuman Systems Model. Results: hospitalized elderly people were characterized according to the physiological (gender, age, diagnosis, comorbidities), psychological (changes in mood, feelings and behaviors), sociocultural (marital status, family structure, monitoring during hospitalization, work activity), development (years of study, cognitive function) and spiritual (religion, participation in the church, religious support and interference from hospitalization). Conclusion: identifying the interactive dimensions proposed by the Neuman Systems Model enables understanding the elderly person as an open client system and provides nurses with justifications for clinical judgment and decision making.Objetivo: caracterizar as pessoas idosas hospitalizadas quanto às dimensões propostas pelo Modelo de Sistemas de Neuman. Método: recorte de estudo qualitativo, ancorado na proposta da Pesquisa Convergente Assistencial, desenvolvido em hospital de ensino com 30 pessoas idosas. A produção dos dados ocorreu de novembro/2016 a agosto/2017 por meio de entrevista conversação, guiada por protocolo de pesquisa, analisada à luz do Modelo de Sistemas de Neuman. Resultados: pessoas idosas hospitalizadas foram caracterizadas conforme a dimensão fisiológica (sexo, idade, diagnóstico, comorbidades), psicológica (alterações de humor, sentimentos e comportamentos), sociocultural (estado civil, arranjo domiciliar, acompanhamento durante hospitalização, atividade laboral), de desenvolvimento (anos de estudo, função cognitiva) e espiritual (religião, participação na igreja, suporte religioso e interferência da hospitalização). Conclusão: identificar as dimensões interativas propostas pelo Modelo Sistemas de Neuman permite compreender a pessoa idosa como um sistema cliente aberto e proporciona ao enfermeiro justificativas para o julgamento clínico e tomada de decisão

Influence of ethylenediaminetetraacetic acid on regenerative endodontics: A systematic review

BackgroundThe effects of ethylenediaminetetraacetic acid (EDTA) on regenerative endodontic procedures (REPs) are controversial, because, despite releasing growth factors from dentine, some studies show negative effects on cell behaviour.ObjectivesThe aim of the study was to investigate the influence of the use of EDTA in REP on the growth factors’ release, cell behaviour and tissue regeneration.MethodsA systematic search was conducted (PubMed/Medline, Scopus, Cochrane Library, Web of Science, Embase, OpenGrey and reference lists) up to February 2021. Only in vivo and in vitro studies evaluating the effects of EDTA on the biological factors of dentine, pulp/periapical tissues and cell behaviour were eligible. Studies without a control group or available full text were excluded. The growth factors’ release was the primary outcome. Risk of bias in the in vitro and in vivo studies was performed according to Joanna Briggs Institute’s Checklist and SYRCLE’s RoB tool, respectively.ResultsOf the 1848 articles retrieved, 36 were selected. Amongst these, 32 were in vitro, three animal studies and one with both models. The EDTA concentrations ranged from 3% to 15%, at different times. Regarding growth factors’ release (17 studies), 15 studies found significant transforming growth factor (TGF)-β release after dentine conditioning with EDTA, and most found no influence on vascular endothelial growth factor release. Regarding cell behaviour (26 studies), eight studies showed no influence of EDTA-treated dentine on cell viability, whereas, five, nine and six studies showed higher cell migration, adhesion and differentiation respectively. No influence of EDTA conditioning was observed in animal studies. In vitro studies had a low risk of bias, whereas animal studies had high risk of bias. Meta-analysis was unfeasible.DiscussionThis review found that EDTA increased TGF-β release and improved cell activity. However, well-designed histological analyses using immature teeth models are needed.ConclusionsHigh-quality in vitro evidence suggests that EDTA-treated dentine positively influences TGF-β release, cell migration, attachment and differentiation; further research to evaluate its influence on tissue regeneration is necessary due to low methodological quality of the animal studies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/172256/1/iej13728.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/172256/2/iej13728_am.pd