Antimicrobial action and cytotoxicity of hypochlorous acid obtained from an innovative electrolytic device - An in vitro study.

OBJECTIVE: This study evaluated the antimicrobial effect and cytotoxicity of hypochlorous acid(HClO) obtained from an innovative electrolytic device. DESIGN: The root canals of fifty extracted human teeth were inoculated with Enterococcus faecalis and divided into 5 groups (n = 10): DW (control); 2% chlorhexidine gel(CHX); 2.5% sodium hypochlorite(NaOCl); 250 ppm HClO and 500 ppm HClO. The counting of colony forming units evaluated the decontamination potential of each group. Cytotoxicity was evaluated after inoculation of tested protocols in fibroblastic cells for 3 min, calculating the cell viability. Specific statistical analysis was performed (α = 5%). RESULTS: The highest bacterial reduction was observed in experimental groups, with no statistical differences from each other (p > 0.05). The highest number of viable cells was observed in control group, followed by 250 ppm HClO and 500 ppm HClO groups, with statistical differences from each other (p < 0.05). CONCLUSIONS: It could be concluded that HClO presented high antimicrobial activity and low cytotoxicity at both tested concentrations.

Effectiveness of ultrasonic activation associated to glycolic acid on smear layer removal, dentin structure and bond strength to root dentin

This study evaluated the effects of ultrasonic activation (US) associated to glycolic acid (GA) on smear layer, dentin structure and bond strength (BS) of filling/restorative material to root dentin. The roots were used for antimicrobial activity, dentin structure and BS evaluation, being distributed into seven groups, according to irrigation protocols: G1:DW+US; G2:17% EDTA; G3:QMix; G4:17% GA; G5:17% EDTA+US; G6:QMix+US; G7:17% GA+US. Scanning electronic microscopy, transmission electronic microscopy and push-out were performed, with specific statistical analysis for each evaluation. The highest smear layer removal occured in Groups 6 and 7 (p<0.05), and the largest collagen dispersion in Group 7, being similar to Group 2 and 5 (p>0.05). The highest BS of filling and restorative material occurred in Groups 6 and 7, and Groups 5, 6 and 7, respectively, being similars between them (p>0.05). The use of GA+US promoted effective smear layer removal and dentin structure preservation, improving the BS of filling/restorative material to root dentin.

Análise comparativa das características composicionais, técnicas e comerciais dos cimentos endodônticos obturadores à base de silicato de cálcio / Comparative analysis of compositional, technical and commercial characteristics of calcium silicate-based endodontic root canal sealers

Introdução: os cimentos endodônticos obturadores à base de silicato de cálcio têm sido amplamente utilizados na endodontia, principalmente em razão de suas reconhecidas propriedades bioativas. Como consequência, uma quantidade expressiva de marcas comerciais foi lançada no mercado, dificultando a compreensão do profissional, principalmente no que diz respeito às diferentes composições químicas, apresentações, formas de uso e custo-benefício. Objetivos: o Objetivo deste trabalho foi analisar as diferenças composicionais, técnicas (indicações e apresentação comercial) e comerciais (custo e disponibilidade de venda) dos cimentos endodônticos obturadores à base de silicato de cálcio, disponíveis para uso e comercialização no Brasil. Metodologia: foi realizada uma busca sistemática no site da Anvisa, sendo identificados sete cimentos endodônticos obturadores biocerâmicos para uso no Brasil. As bulas dos produtos foram analisadas para verificação de composição, apresentação e indicação de uso. Sites especializados foram consultados para verificação de preço dos produtos. Resultados: observou-se que a composição química varia bastante, a depender do fabricante, sendo os silicatos tricálcico e dicálcico os componentes mais frequentes. A maioria dos cimentos é apresentada comercialmente pronta para uso, e possui óxido de zircônio como agente radiopacificador. A venda através de sites especializados ainda é restrita a alguns produtos, e o custo varia de acordo com a quantidade de material por embalagem. Conclusão: este trabalho apresentou as características composicionais, técnicas e comerciais de sete cimentos endodônticos obturadores à base de silicato de cálcio registrados na ANVISA e autorizados para uso no Brasil.

Introduction: calcium silicate-based endodontic sealers have been widely used in endodontics, mainly because of their recognized bioactive properties. As a result, a significant number of commercial brands were launched on the market, making it difficult for professionals their comprehension, especially with regard to different chemical compositions, presentations, forms of use and cost-effectiveness. Objective: the Objective of this work was to analyze the compositional, technical (indications and commercial presentation) and commercial (cost and availability) differences of calcium silicate-based endodontic sealers, available for use and commercialization in Brazil. Methodology: a systematic search was carried out on the Anvisa website, and seven bioceramic endodontic sealers for use in Brazil were identified. Product leaflets were analyzed to verify composition, presentation and indication of use. Specialized websites were consulted to verify the price of the products. Results: it was observed that the chemical composition varies a lot, depending on the manufacturer, with tricalcium and dicalcium silicates being the most frequent components. Most sealers are commercially available ready-to-use, and have zirconium oxide as a radiopacifying agent. The sale through specialized websites is still restricted to some products, and the cost varies according to the amount of material per package. Conclusion: this work presented the compositional, technical and commercial characteristics of seven calcium silicate-based endodontic sealers registered at ANVISA and authorized for use in Brazil.

Decision-making for dental pulp exposure: a survey in graduate programs at Brazilian universities.

Clinical decision-making tends to be based on what clinicians have been taught during undergraduate and graduate programs. The aim of the present study was to assess the clinical approach and to identify the factors that influence the decision-making for dental pulp exposure among graduate students and coordinating professors in endodontics programs offered at Brazilian universities. The study used a mail-out survey developed in the Qualtrics platform, based on seven clinical reports in which dental pulp exposure was evidenced. Descriptive statistics showing vital pulp therapy (VPT) and root canal treatment (RCT) were calculated for each clinical report. Data on the participants' (n = 113) profile and variables related to clinical and radiographic characteristics of the cases were evaluated as to their potential to affect decision-making and analyzed by logistic regression (p < 0.05). VPT was likely to be indicated in cases of patients with immature teeth (OR = 0.017; 95%CI = 0.004 -0.073). RCT indications were related to the presence of symptoms (OR = 5.326; 95%CI = 1.429-19.852) and old age (OR = 21.057; 95%CI=6.809-65.120). In pulp exposure secondary to trauma, time of pulp exposure was significantly associated with RCT indication (OR=3.267; 95%CI=1.332-8.012). The present study demonstrated that patient age, root development, and symptom features were the main factors affecting participants' decision-making.

Decision-making for dental pulp exposure: a survey in graduate programs at Brazilian universities

Abstract Clinical decision-making tends to be based on what clinicians have been taught during undergraduate and graduate programs. The aim of the present study was to assess the clinical approach and to identify the factors that influence the decision-making for dental pulp exposure among graduate students and coordinating professors in endodontics programs offered at Brazilian universities. The study used a mail-out survey developed in the Qualtrics platform, based on seven clinical reports in which dental pulp exposure was evidenced. Descriptive statistics showing vital pulp therapy (VPT) and root canal treatment (RCT) were calculated for each clinical report. Data on the participants' (n = 113) profile and variables related to clinical and radiographic characteristics of the cases were evaluated as to their potential to affect decision-making and analyzed by logistic regression (p < 0.05). VPT was likely to be indicated in cases of patients with immature teeth (OR = 0.017; 95%CI = 0.004 -0.073). RCT indications were related to the presence of symptoms (OR = 5.326; 95%CI = 1.429-19.852) and old age (OR = 21.057; 95%CI=6.809-65.120). In pulp exposure secondary to trauma, time of pulp exposure was significantly associated with RCT indication (OR=3.267; 95%CI=1.332-8.012). The present study demonstrated that patient age, root development, and symptom features were the main factors affecting participants' decision-making.

Pulp capping with mineral trioxide aggregate or Biodentine: a comparison of mineralized barrier formation and inflammatory and degenerative events.

Biodentine in endodontic practice has been widely investigated, but comprehensive histological descriptions of degenerative and inflammatory responses are not covered in most of the studies that compare pulp capping materials. This study aimed to evaluate pulpal responses to mineral trioxide aggregate (MTA Angelus) and Biodentine, focusing on mineralized barrier formation and on inflammatory and degenerative events. 80 male Wistar rats were assigned to 5 groups, according to the materials used for pulp capping and coronal sealing (n=8 per group/period). The lower first molars were mechanically exposed, capped with either MTA or Biodentine, and restored with silver amalgam. In an additional test group, the teeth were capped and sealed with Biodentine. The teeth capped with gutta-percha and restored with silver amalgam served as positive control, whereas untreated teeth served as negative control. Pulpal responses and coronal sealing were evaluated after 14 or 21 days. Data was statistically analyzed by the Kruskal-Wallis and Dunn's post hoc tests (p<0.05). Biodentine and MTA presented satisfactory results, showing a milder inflammatory response (p<0.0001) and more pronounced formation of mineralized barrier (p<0.0001) compared to the teeth capped with gutta-percha. As a restorative material, Biodentine kept coronal sealing in only 37.5% of the samples. Biodentine showed favorable properties in vital pulp therapy, being similar to MTA. However, it was not effective in protecting dental pulp from microleakage during the experimental period.

Fluorescence-Enhanced Theragnosis: A Novel Approach to Visualize, Detect, and Remove Caries.

Fluorescence tools have shown to be highly valuable for precise diagnosis of caries and other lesions in dentistry. In the form of ultraviolet (UV) headlights and special loupes with high levels of magnification and observational capacity, these instruments can even be used during treatment for a more preventive and minimally invasive treatment strategy. Fluorescence, a type of luminescence, absorbs light of shorter wavelength and re-emits it as longer-wavelength light. This changes the color, for example from blue to red. The fluorescence spectra of carious lesions are typical for fluorescent porphyrins, mainly protoporphyrin IX. A possible source of these porphyrins within carious tissues is bacterial biosynthesis. Streptococcus mutans induces enamel and dentin lesions and modifies the fluorescence in the red and green spectral regions, with a stronger signal in the red region, due to porphyrin gradient signals. This article describes the concept of fluorescence-enhanced theragnosis for removal of caries and preservation of sound dental tissues.

Pulp capping with mineral trioxide aggregate or Biodentine: a comparison of mineralized barrier formation and inflammatory and degenerative events

Abstract: Biodentine in endodontic practice has been widely investigated, but comprehensive histological descriptions of degenerative and inflammatory responses are not covered in most of the studies that compare pulp capping materials. This study aimed to evaluate pulpal responses to mineral trioxide aggregate (MTA Angelus) and Biodentine, focusing on mineralized barrier formation and on inflammatory and degenerative events. 80 male Wistar rats were assigned to 5 groups, according to the materials used for pulp capping and coronal sealing (n=8 per group/period). The lower first molars were mechanically exposed, capped with either MTA or Biodentine, and restored with silver amalgam. In an additional test group, the teeth were capped and sealed with Biodentine. The teeth capped with gutta-percha and restored with silver amalgam served as positive control, whereas untreated teeth served as negative control. Pulpal responses and coronal sealing were evaluated after 14 or 21 days. Data was statistically analyzed by the Kruskal-Wallis and Dunn's post hoc tests (p<0.05). Biodentine and MTA presented satisfactory results, showing a milder inflammatory response (p<0.0001) and more pronounced formation of mineralized barrier (p<0.0001) compared to the teeth capped with gutta-percha. As a restorative material, Biodentine kept coronal sealing in only 37.5% of the samples. Biodentine showed favorable properties in vital pulp therapy, being similar to MTA. However, it was not effective in protecting dental pulp from microleakage during the experimental period.

The COVID-19 Pandemic and Planetary Health. A Critical Review of Epidemiology, Prevention, Clinical Characteristics and Treatments for Oral, Head and Neck Health Professionals. Do We Have a Roadmap?

Introduction Coronavirus disease 19 (COVID-19) is potentially the greatest global public health crisis of this century. This disease emerged as an outbreak of pneumonia of unknown cause in Wuhan, the capital city of the Hubei province in China, in December 2019. Otolaryngologists, head and neck surgeons and dentists are at an increased risk of occupational disease. Objective The present review summarizes currently published evidence of Covid-19 epidemiology, clinical characteristics, treatment and prevention. No proven effective treatments for this disease currently exist. Data Synthesis COVID-19 started from a zoonotic transmission event associated with a large seafood market that also traded in live wild animals, and it soon became clear that efficient person-to-person transmission was also occurring. Symptoms are varied, and not all patients develop all of them. Conclusion Social distancing seems to have been successful in several places in the world. However, this recommendation alone is not enough to contain the disease, and it is not a long-term solution. Large-scale testing by health professionals of representative samples of the population may give an estimate of the progression of the disease. Different treatments are under test and bring hope of a cure to the population. However, no current treatments (April 27, 2020) have been proven to be the key to success in the treatment of patients with COVID-19. Planetary health is a useful concept to understand the current drivers of this pandemic and to draw a roadmap for science and healthcare that may guide actions to fight economic depression and ensure a healthy recovery.

Dendritic cells and their relation to apical peridontitis.

The purpose of this manuscript was to re-discuss apical periodontitis, apical biofilm, and its possible relationship with dendritic cells (DC). DCs are potent regulators of the immune system and their function is divided into three categories that involve the presentation of antigens: the presentation of antigens and activation of T cells; a not well established category suggested that DCs induce and maintain immunological tolerance; and the maintenance of the immune memory in conjunction with B cells. DCs in periapical inflammatory lesions are composed of at least two subpopulations that can be distinguished on the basis of ultrastructure and phenotype. These populations might differ in lineage, state of maturation, differentiation, activation, and/or function. The authors hereby analyzed the root apexes of teeth under SEM, after performing apicoectomy due to the failure of conventional endodontic treatment. Microbial biofilm with multispecies and areas of resorption with the presence of Howship lacunae, and images suggestive of denditric cells could be observed. The presence of DCs in periapical lesion could be an indication of the severity of the lesion, with a constant presence of antigen in the periradicular region.

Effectiveness of photodynamic therapy associated with irrigants over two biofilm models.

BACKGROUND: This study aimed to evaluate the antibacterial effect and the biofilm disruption promoted by antimicrobial photodynamic therapy (aPDT) associated with sodium hypochlorite (NaOCl) and chlorexidine (CHX) over monospecies and multispecies biofilms. METHODS: In monospecies model, forty-six premolars were inoculated with Enterococcus faecalis for 21days and divided into three groups: saline, CHX and NaOCl. After irrigation, aPDT was performed. Samples were collected at baseline (S1) and after irrigation (S2) and aPDT (S3). Colony-forming unit (CFU) counts were performed. In multispecies model, sixty bovine dentin blocks were infected intraorally for 72h and divided into six groups: saline, saline/aPDT, CHX, CHX/aPDT, NaOCl and NaOCl/aPDT. The percentage and the biovolume of live cells and the total biovolume were assessed using confocal laser scanning microscopy. RESULTS: CHX and NaOCl showed the lowest CFU counts (P<0.05). aPDT reduced the bacterial counts in saline (S2-S3; P<0.05). The lowest amount of live cells was observed in CHX, CHX/aPDT, NaOCl and NaOCl/aPDT. aPDT did not reduce the total biovolume (P>0.05). CONCLUSION: aPDT associated with saline reduced the bacterial load in root canals infected with E. faecalis. aPDT did not reduce the total biovolume in situ; however, the irrigant was decisive to disrupt multispecies biofilms.

Biological Tissue Response to a New Formulation of a Silicone Based Endodontic Sealer.

Satisfactory biological behavior is a necessary requirement for clinical application of endodontic materials. In this study, the connective tissue responses to silicone (GuttaFlow 2), epoxy resin (AH Plus) and zinc oxide and eugenol (Endofill) based sealers were compared. Twelve Wistar rats had polyethylene tubes (four per animal) containing one of the tested sealers and empty tubes (negative control) implanted in their subcutaneous tissue. The tubes were randomly placed 2 cm from the spine and at least 2 cm apart from one another. Tissue samples with implants were processed for histological analysis after 7 or 60 days (n=6 animals per period). Inflammatory cells, fibrous condensation and abscess were scored according to their intensity. Friedman, followed by Dunn's post hoc, was used to compare sealers. Differences between the two experimental periods were verified using Mann-Witney U test (p<0.05). At 7 days, most of the histological parameters showed no significant differences amongst groups. Endofill group scored higher than the others for giant cells (o<0.05) and promoted a greater number of samples presenting abscess formation. GuttaFlow 2 tended to show a less intense inflammatory infiltrate compared to the other materials. At 60 days, there were no significant differences between groups in most of the histological parameters evaluated. However, it was observed that Endofill scored higher for macrophages (p<0.05) compared to the control group, and GuttaFlow 2 tended to present lower scores than the others for neutrophils and abscess. GuttaFlow 2 showed proper biological behavior and should be considered adequate for clinical practice.

Biological Tissue Response to a New Formulation of a Silicone Based Endodontic Sealer

Abstract Satisfactory biological behavior is a necessary requirement for clinical application of endodontic materials. In this study, the connective tissue responses to silicone (GuttaFlow 2), epoxy resin (AH Plus) and zinc oxide and eugenol (Endofill) based sealers were compared. Twelve Wistar rats had polyethylene tubes (four per animal) containing one of the tested sealers and empty tubes (negative control) implanted in their subcutaneous tissue. The tubes were randomly placed 2 cm from the spine and at least 2 cm apart from one another. Tissue samples with implants were processed for histological analysis after 7 or 60 days (n=6 animals per period). Inflammatory cells, fibrous condensation and abscess were scored according to their intensity. Friedman, followed by Dunn's post hoc, was used to compare sealers. Differences between the two experimental periods were verified using Mann-Witney U test (p<0.05). At 7 days, most of the histological parameters showed no significant differences amongst groups. Endofill group scored higher than the others for giant cells (o<0.05) and promoted a greater number of samples presenting abscess formation. GuttaFlow 2 tended to show a less intense inflammatory infiltrate compared to the other materials. At 60 days, there were no significant differences between groups in most of the histological parameters evaluated. However, it was observed that Endofill scored higher for macrophages (p<0.05) compared to the control group, and GuttaFlow 2 tended to present lower scores than the others for neutrophils and abscess. GuttaFlow 2 showed proper biological behavior and should be considered adequate for clinical practice.

Resumo Um dos requisistos para a aplicação clínica de materiais endodônticos é apresentar comportamento biológico satisfatório. Neste estudo, as respostas do tecido conjuntivo a cimentos endodônticos à base de silicone (GuttaFlow 2), resina epóxica (AH Plus) e óxido de zinco e eugenol (Endofill) foram comparadas. Doze ratos Wistar tiveram tubos de polietileno (4 em cada animal) contendo um dos materiais e tubos vazios (controle negativo) implantados no tecido conjuntivo subcutâneo. Os tubos foram randomicamente posicionados pelo menos 2 cm distantes entre si e da espinha dorsal do animal. Amostras de tecido contendo os implantes foram processadas para análise histológica após 7 e 60 dias (n=6 animais por período). Células inflamatórias, condensação fibrosa e formação de abscesso foram classificadas em escores de acordo com sua intensidade. O teste Friedman, seguido por post hoc de Dunn, foi empregado para comparar os cimentos. O teste de Mann-Witney U foi empregado para verificar diferenças entre os períodos experimentais em cada grupo (p<0,05). Após 7 dias, a maior parte dos parâmetros histológicos não mostrou diferenças estatísticas entre os grupos. O cimento Endofill promoveu escores mais altos que os outros materiais para a variável células gigantes (p<0,05), além de apresentar um maior número de amostras com formação de abscesso. O GuttaFlow 2 tendeu a apresentar infiltrado inflamatório menos intenso comparado aos outros materiais. Após 60 dias, não houve diferenças estatisticamente significantes entre os grupos na maioria dos parâmetros avaliados. Entretanto, observou-se que o EndoFill apresentou escores mais altos para os macrófagos em comparação ao controle (p<0,05) e que o GuttaFlow 2 apresentou tendência a escores mais baixos que os demais materiais para as variáveis neutrófilos e abscesso. O GuttaFlow 2 apresentou propriedades biológicas apropriadas e pode ser considerado adequado para a prática clínica.

LPS levels in root canals after the use of ozone gas and high frequency electrical pulses.

The present study aims to verify the effect of ozone gas (OZY® System) and high frequency electric pulse (Endox® System) systems on human root canals previously contaminated with Escherichia colilipopolysaccharide (LPS). Fifty single-rooted teeth had their dental crowns removed and root lengths standardized to 16 mm. The root canals were prepared up to #60 hand K-files and sterilized using gamma radiation with cobalt 60. The specimens were divided into the following five groups (n = 10) based on the disinfection protocol used: OZY® System, one 120-second-pulse (OZY 1p); OZY® System, four 24-second-pulses (OZY 4p); and Endox® System (ENDOX). Contaminated and non-contaminated canals were exposed only to apyrogenic water and used as positive (C+) and negative (C-) controls, respectively. LPS (O55:B55) was administered in all root canals except those belonging to group C-. After performing disinfection, LPS samples were collected from the canals using apyrogenic paper tips. Limulus Amoebocyte Lysate (LAL) was used to quantify the LPS levels, and the data obtained was analyzed using one-way ANOVA. The disinfection protocols used were unable to reduce the LPS levels significantly (p = 0.019). The use of ozone gas and high frequency electric pulses was not effective in eliminating LPS from the root canals.

LPS levels in root canals after the use of ozone gas and high frequency electrical pulses

Abstract The present study aims to verify the effect of ozone gas (OZY® System) and high frequency electric pulse (Endox® System) systems on human root canals previously contaminated with Escherichia colilipopolysaccharide (LPS). Fifty single-rooted teeth had their dental crowns removed and root lengths standardized to 16 mm. The root canals were prepared up to #60 hand K-files and sterilized using gamma radiation with cobalt 60. The specimens were divided into the following five groups (n = 10) based on the disinfection protocol used: OZY® System, one 120-second-pulse (OZY 1p); OZY® System, four 24-second-pulses (OZY 4p); and Endox® System (ENDOX). Contaminated and non-contaminated canals were exposed only to apyrogenic water and used as positive (C+) and negative (C-) controls, respectively. LPS (O55:B55) was administered in all root canals except those belonging to group C-. After performing disinfection, LPS samples were collected from the canals using apyrogenic paper tips. Limulus Amoebocyte Lysate (LAL) was used to quantify the LPS levels, and the data obtained was analyzed using one-way ANOVA. The disinfection protocols used were unable to reduce the LPS levels significantly (p = 0.019). The use of ozone gas and high frequency electric pulses was not effective in eliminating LPS from the root canals.

Bovine Pulp Tissue Dissolution Ability of Irrigants Associated or Not to Ultrasonic Agitation.

The aim of this study was to evaluate the tissue dissolution ability of different irrigating solutions associated or not to ultrasonic agitation. Ninety bovine pulp fragments (n=10 per group) were weighed and then placed individually in Eppendorf test tubes containing the following irrigants: G1- 2.5% sodium hypochlorite (NaOCl); G2- 2.5% NaOCl + ultrasonic agitation (US); G3- 2.5% NaOCl + 0.2% cetrimide (CTR); G4- 2.5% NaOCl + 0.2% CTR + US; G5- 400 ppm Sterilox (SX); G6- SX + US; G7- 0.2% CTR; G8- 0.2% CTR + US; G9- saline solution. Two blinded observers assessed the samples continuously for the first 4 h, and then every hour for the next 12 h. Dissolution speed was calculated by dividing the initial pulp weight (mg) by the period of time until complete dissolution (min). Data were compared by ANOVA and Tukey post hoc test with a 5% significance level. G1 to G4 dissolved pulp fragments completely and G2 was significantly faster than the other groups. G5 to G9 did not exhibit dissolving activity. In conclusion, only groups containing NaOCl were capable of pulp tissue dissolution, which was enhanced by ultrasonic agitation, but did not alter when 0.2% cetrimide was associated. This isolated solution and Sterilox showed no dissolving capacity, regardless the use of ultrasound.

Bovine Pulp Tissue Dissolution Ability of Irrigants Associated or Not to Ultrasonic Agitation

Abstract: The aim of this study was to evaluate the tissue dissolution ability of different irrigating solutions associated or not to ultrasonic agitation. Ninety bovine pulp fragments (n=10 per group) were weighed and then placed individually in Eppendorf test tubes containing the following irrigants: G1- 2.5% sodium hypochlorite (NaOCl); G2- 2.5% NaOCl + ultrasonic agitation (US); G3- 2.5% NaOCl + 0.2% cetrimide (CTR); G4- 2.5% NaOCl + 0.2% CTR + US; G5- 400 ppm Sterilox (SX); G6- SX + US; G7- 0.2% CTR; G8- 0.2% CTR + US; G9- saline solution. Two blinded observers assessed the samples continuously for the first 4 h, and then every hour for the next 12 h. Dissolution speed was calculated by dividing the initial pulp weight (mg) by the period of time until complete dissolution (min). Data were compared by ANOVA and Tukey post hoc test with a 5% significance level. G1 to G4 dissolved pulp fragments completely and G2 was significantly faster than the other groups. G5 to G9 did not exhibit dissolving activity. In conclusion, only groups containing NaOCl were capable of pulp tissue dissolution, which was enhanced by ultrasonic agitation, but did not alter when 0.2% cetrimide was associated. This isolated solution and Sterilox showed no dissolving capacity, regardless the use of ultrasound.

Resumo: O objetivo deste estudo foi avaliar a capacidade de dissolução tecidual de diferentes soluções irrigadoras associadas ou não à agitação ultrassônica. Noventa fragmentos de polpa bovina (n=10 por grupo) foram pesados e em seguida colocados individualmente em tubos tipo Eppendorf contendo os seguintes irrigantes: G1- hipoclorito de sódio (NaOCl) a 2,5%; G2- NaOCl a 2,5% + agitação ultrassônica (US); G3- NaOCl a 2,5% + cetramida (CTR) a 0,2%; G4- NaOCl a 2,5% + CTR a 0,2% + US; G5- 400 ppm Sterilox (SX); G6- SX + US; G7- CTR a 0,2%; G8- CTR a 0,2% + US; G9- solução salina. Dois observadores cegados em relação aos grupos experimentais avaliaram as amostras continuamente durante as primeiras 4 h e depois a cada hora pelas próximas 12 h. A velocidade de dissolução foi calculada dividindo o peso inicial da polpa (mg) pelo período de tempo até sua dissolução completa (min). Os dados foram comparados por ANOVA e teste post hoc de Tukey com nível de significância de 5%. Os grupos G1 a G4 dissolveram os fragmentos de polpa completamente e G2 foi significativamente mais rápido do que os outros. Os grupos G5 a G9 não apresentaram atividade de dissolução. Em conclusão, apenas grupos contendo NaOCl foram capazes de dissolver tecido pulpar, o que foi melhorado pela agitação ultrassônica, mas não alterado quando CTR a 0,2% foi associada. Esta solução isolada e o Sterilox não mostraram nenhuma capacidade de dissolução, independentemente da utilização do ultrassom.

Efeito da irrigação endodôntica, com e sem ultrassom, na remoção de smear layer e bioflme / Effect of endodontic irrigation, with or without ultrasound, in removing smear layer and bioflme

Investigou-se o efeito da irrigação endodôntica, com ou sem a ativação por ultrassom, na limpeza e descontaminação dos três terços do canal radicular. Dentes foram inoculados com E. faecalis e permaneceram em cultura por 50 dias, para a formação do biofilme. Os dentes foram divididos em oito grupos de acordo com o irrigante endodôntico e o uso da ativação ultrassônica: G1 = NaOCl a 2,5% + ultrassom; G2 = clorexidina solução a 2% + ultrassom; G3 = clorexidina gel a 2% + ultrassom; G4 = H2O + ultrassom; G5 = NaOCl a 2,5%; G6 = clorexidina solução a 2%; G7 = clorexidina gel a 2% e G8 = H2O. As raízes foram clivadas e analisadas por microscopia eletrônica de varredura (MEV). As imagens foram classificadas de acordo com o nível de limpeza (presença de smear layer , 2.000x) e descontaminação (presença de bactérias, 10.000x) nos terços coronário, médio e apical. O ultrassom melhorou a habilidade de limpeza e descontaminação de todos os irrigantes endodônticos testados, principalmente do hipoclorito de sódio e da clorexidina solução. A clorexidina gel sem ultrassom teve os mais baixos valores de limpeza, contudo, seu uso combinado com o ultrassom promoveu limpeza similar ao NaOCl a 2,5%. Quanto à descontaminação, no terço apical, a clorexidina solução sem ultrassom apresentou melhores resultados do que a clorexidina gel com ultrassom. O ultrassom melhorou a habilidade de limpeza nos três terços do canal radicular, por levar o irrigante em contato com os microrganismos e debris dentinários dentro do sistema de canal, otimizando a remoção desses.

Are bovine teeth a suitable substitute for human teeth in in vitro studies to assess endotoxin load in root canals?

The present study aimed to determine the feasibility of using bovine teeth as a suitable alternative for human teeth, in experiments involving in vitro endotoxin contamination. Twenty bovine central incisors and 20 human single-root premolars had their dental crowns removed and root lengths set at 16 mm. Root canals were prepared up to #60 K-file size and sterilized with cobalt-60 gamma irradiation (20 kGy, 6 h). The teeth were randomly divided into four groups: G1-bovine teeth (bovine negative control, n = 10), G2-human teeth (human negative control, n = 10), G3-bovine teeth, inoculated with Escherichia coli (055:B55) LPS, and G4-human teeth inoculated with E. coli LPS. The G1 and G2 groups were exposed to apyrogenic water. After the teeth had been incubated at 37 °C and atmospheric humidity for 24 h, the samples of solutions in the main canals were collected with apyrogenic absorbent paper tips. LPS levels were quantified using Limulus Amebocyte Lysate assay. The data obtained were statistically analyzed using one-way ANOVA, with a significance level of 5%. A high amount of endotoxin was detected in the inoculated human teeth (G4) when compared to the sterilized teeth (G2), as well as in the inoculated bovine teeth (G3) when compared to the inoculated human teeth (G4). However, there was no statistical difference between bovine teeth before and after the E. coli endotoxin inoculation. Therefore, under the mentioned experimental conditions, the use of bovine teeth should not be a choice for laboratory research on endotoxin contamination.

Effect of Different Irrigating Solutions and Photo-Activated Therapy for In Vivo Root Canal Treatment

This study aimed to evaluate histologically the effect of irrigation with 400 ppm Sterilox, 2% and 5% sodium hypochlorite (NaOCl), with and without photo-activated therapy (PAD), in a single-visit root canal treatment of dog's teeth with apical periodontitis (AP). Ten dogs were randomly divided into two groups (n=5): with and without PAD, and the root canals into four subgroups, according to the irrigating solution: SX (400 ppm Sterilox), SH2 (2% NaOCl), SH5 (5% NaOCl) and SS (saline solution) as positive control. A total of 134 root canals were opened and left exposed to the oral environment for 14 days and then sealed for 60 days for AP induction. Then, root canals were treated according to each proposed disinfecting protocol and filled in the same session. After 120 days, the dogs were euthanized and the periapical inflammatory events were evaluated under light microscopy. Qualitative data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05). PAD did not produce significant differences in the scores for apical inflammation when used after chemo-mechanical preparation (p>0.05). The irrigating solutions SX, SH2 and SH5 without PAD were statistically different from SS (p<0.05) that presented the greatest scores for apical inflammation. PAD did not show any additional effect for the treatment of root canals with pulp necrosis and AP in a single visit and 400 ppm Sterilox may be considered an alternative to NaOCl in root canal treatment.

Este estudo realizou uma avaliação histológica do efeito das soluções irrigadoras Sterilox 400 ppm e hipoclorito de sódio (NaOCl) a 2% e 5%, com e sem a terapia fotodinâmica (PAD), na endodontia em sessão única de dentes de cães associados a lesões periapicais (APs). Dez cães foram divididos de forma randomizada em dois grupos (n=5): com e sem PAD, e os canais radiculares em quatro subgrupos, de acordo com a solução irrigadora utilizada: SX (Sterilox 400 ppm), SH2 (NaOCl 2%), SH5 (NaOCl 5%) e SS (solução salina) como controle positivo. Cento e trinta e quatro canais foram abertos e deixados expostos ao meio oral por 14 dias e depois selados por 60 dias para a indução de APs. Na sequência, os canais foram tratados de acordo com cada protocolo de desinfecção proposto e obturados na mesma sessão. Após 120 dias, os cães foram mortos e os eventos inflamatórios periapicais foram avaliados em microscopia óptica. Os dados qualitativos foram analisados estatisticamente pelos testes Kruskal-Wallis e Mann-Whitney (α=0,05). A PAD, quando empregada após o preparo químico-mecânico, não promoveu diferenças significativas nos escores para inflamação apical (p>0,05). As soluções irrigadoras SX, SH2 e SH5 sem PAD apresentaram diferenças estatísticas do grupo SS (p<0,05) que apresentou os maiores escores para inflamação apical. A PAD não apresentou efeito adicional na endodontia em sessão única dos canais com necrose pulpar associados a lesão apical e a solução irrigadora Sterilox 400 ppm pode ser considerada uma alternativa ao NaOCl na terapia endodôntica.