Biological investigation of resinous endodontic sealers containing calcium hydroxide.

The purpose of this study was to evaluate, in vivo, the biocompatibility, biomineralization, collagen maturation and the in vitro antibacterial and cytotoxicity of resinous endodontic sealers containing calcium hydroxide. Forty rats were implanted with polyethylene tubes containing Sealer 26, Sealer Plus, Dia-ProSeal and an empty tube, examined after 7, 15, 30 and 60 days. Antimicrobial activity was evaluated against Enterococcus faecalis by Agar Diffusion Test (ADT) through inhibition zones. For cytotoxicity, undifferentiated pulp cells (OD-21) were cultured and assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, exposed to dilution of serial extracts at 6, 24, 48h. Cytotoxicity was analyzed by two-way ANOVA and Bonferroni correction. Kruskal-Wallis test followed by Dunn test was performed for nonparametric data (p<0.05). MTT assay revealed cell proliferation affected by sealers extract in all periods (p<0.0001), except for Dia-Proseal and Sealer Plus ⅛ dilution. Subcutaneous analysis showed at day 7th moderate inflammatory infiltration. After 30 days, Sealer 26 still showed moderate inflammatory infiltrate compared to mild inflammation from control and Dia-ProSeal (p = 0.006). At day 60th, all groups showed similar mild inflammatory infiltrate (p>0.05). Sealer 26 induced more biomineralization than other sealers in all periods. At 7 and 15 days, all sealers had significant percentage of immature collagen fibers. After 60 days Sealer 26 showed more mature fibers compared to other sealers (p<0.001). All sealers had a smaller zone of inhibition than chlorhexidine, but with no significant difference among any group (p>0.05). All sealers showed satisfactory biological responses with in vitro/in vivo biocompatibility and antimicrobial activity against planktonic bacteria. Sealer 26 induced more biomineralization than Sealer Plus and Dia-ProSeal.

Inflammatory profile of apical periodontitis exacerbated by cigarette smoke inhalation: Histological and immunohistochemical analysis in rats.

AIM: The aim of this study was to evaluate the effects of cigarette smoke inhalation (CSI) on inflammation, pro-inflammatory mediators and haematological parameters in rats with induced apical periodontitis (AP). METHODOLOGY: Thirty-two 3-month-old male Wistar rats were divided into four experimental groups (n = 8): C-Control; S-rats with CSI; AP-rats with AP; and SAP-rats with CSI + AP. Animals in groups S and SAP inhaled cigarette smoke by remaining inside a smoking chamber for 8 min, three times daily, for 50 days. After 20 days of smoke inhalation, animals in AP and SAP groups had the pulps of the lower right first molar exposed to oral environment for 30 days to induce AP. In these subsequent 30 days, animals in group S and SAP continued with CSI. On Day 50, animals were euthanized and mandibles were histologically processed to assess inflammatory infiltrate, immunohistochemical interleukins (IL-1ß, IL-6 and TNF-α), and blood samples collected for laboratory analysis. The Mann-Whitney test was performed for non-parametric data and the pairwise analyses of Student's t-test for parametric data, with a significance level of p < .050. RESULTS: Inflammatory infiltrate was moderate in AP group and more severe in the SAP (p = .010). The interleukins IL-6, IL-1ß and TNF-α were higher in SAP group (p < .001) when compared to the AP group. A greater number of red blood cells (p = .010), haemoglobin (p = .007) and neutrophils (p = .014) were observed in the SAP group in comparison with the AP group. CONCLUSION: Cigarette smoke inhalation induced a more severe inflammatory infiltrate, with increased levels of pro-inflammatory cytokines and changes in haematological parameters in rats with induced AP. Thus, CSI aggravated AP, exacerbating the inflammatory response.

Tracing the toxic ions of an endodontic tricalcium silicate-based sealer in local tissues and body organs.

BACKGROUND: This study aimed to track the toxic ions released by MTA Fillapex, BioRoot RCS, and an experimental tricalcium silicate-based sealer (CEO) into local and distant tissues as well as to investigate their potential adverse effects. In addition, the chemical constituents of the sealers were also evaluated. The main components of the dry powders, pastes, and mixed sealers were characterized. MATERIAL AND METHODS: Dry powder and sealer discs were each set for 72 h and their main components were characterized by energy dispersive X-ray spectroscopy. Polyethylene tubes filled with sealers were used to measure silicon and calcium ions. Polyethylene tubes filled with sealers or empty tubes were implanted into the dorsal connective tissue of Wistar rats. On days 7, 15, 30, and 45, the animals were euthanized and their brains, livers, kidneys, and subcutaneous tissues were removed and processed to determine the concentrations of chromium, cobalt, copper, lead, iron, magnesium and nickel using an inductively coupled plasma optical emission spectrometer. RESULTS: The main compounds in all sealers were carbon, oxygen, silicon, and calcium. MTA Fillapex release more Si while highest levels of Si were found in presence of BioRoot. The release of Si and Ca ions promoted by MTA Fillapex raise by time. No traces of cobalt, chromium, or magnesium were detected in any tissue. Irrespective of the sealer, no traces of copper and lead were found in the subcutaneous tissue; however, they were observed in the organs. The highest concentration of iron was identified in the liver. All sealers exhibited similar nickel traces in the brain, kidney, and liver except for MTA Fillapex, which demonstrated levels higher than CEO in the subcutaneous tissue on day 7. Tracing nickel ions over time revealed that lowest concentrations were found in subcutaneous tissue. CONCLUSION: Taken together, our data demonstrate that CEOs have chemical compositions similar to those of other commercial sealers. Furthermore, none of them exhibited a threat to systemic health. Moreover, the minimal amounts of iron and nickel detected were not related to the sealers.

Accuracy of Root ZXII, E-PEX and FIND apex locators in teeth with vital pulp: an in vivo study.

This research evaluated, in vivo, the accuracy of three electronic apex locators - EALs (Root ZXII, E-PEX and FIND) in teeth with vital pulp submitted to biopulpectomy, preserving the periodontal stump. For this study, 90 single-rooted teeth with extraction indication were selected. After positive pulpal cold sensitivity test, pulp chamber access was performed. The cervical and middle thirds of root canals were instrumented with Reciproc R25, and the K#15 file was used as a standard instrument to determine working length, forming 2 groups: Constriction (insertion of the instrument until the apical constriction limit) and Foramen (insertion of the instrument until the foramen and then repositioning at constriction, without removing the file from the canal). The hand file was stabilized with a light-cured flow resin. After extraction, the samples were analyzed through microCT SkyScan 1272, with CTAN software, which evaluated the proximity between the tip of the file to the apical constriction, providing data for comparative analysis using Kruskal-Wallis and Dunn tests (p<0.05). There was a statistically significant difference in the abilities of the EALs to detect the apical constriction after reaching the foramen with Root ZX II showing higher accuracy (89%). However, there was no difference in the accuracy of the three EALs in detecting the apical constriction without reaching the foramen. Based on the present results, we conclude that EALs may show accurate measures in detecting apical constriction and foramen, even without damaging the periodontal stump in biopulpectomy.

Accuracy of Root ZXII, E-PEX and FIND apex locators in teeth with vital pulp: an in vivo study

Abstract: This research evaluated, in vivo, the accuracy of three electronic apex locators - EALs (Root ZXII, E-PEX and FIND) in teeth with vital pulp submitted to biopulpectomy, preserving the periodontal stump. For this study, 90 single-rooted teeth with extraction indication were selected. After positive pulpal cold sensitivity test, pulp chamber access was performed. The cervical and middle thirds of root canals were instrumented with Reciproc R25, and the K#15 file was used as a standard instrument to determine working length, forming 2 groups: Constriction (insertion of the instrument until the apical constriction limit) and Foramen (insertion of the instrument until the foramen and then repositioning at constriction, without removing the file from the canal). The hand file was stabilized with a light-cured flow resin. After extraction, the samples were analyzed through microCT SkyScan 1272, with CTAN software, which evaluated the proximity between the tip of the file to the apical constriction, providing data for comparative analysis using Kruskal-Wallis and Dunn tests (p<0.05). There was a statistically significant difference in the abilities of the EALs to detect the apical constriction after reaching the foramen with Root ZX II showing higher accuracy (89%). However, there was no difference in the accuracy of the three EALs in detecting the apical constriction without reaching the foramen. Based on the present results, we conclude that EALs may show accurate measures in detecting apical constriction and foramen, even without damaging the periodontal stump in biopulpectomy.

Cyclic fatigue resistance of novel Genius and Edgefile nickel-titanium reciprocating instruments.

This study aimed to assess the cyclic fatigue resistance of Genius and EdgeFile X1 reciprocating instruments compared with WaveOne Gold Primary. Twenty Genius (Ultradent) 25.04, 20 Genius 30.04, 20 EdgeFile X1 (EdgeEndo) and 20 WaveOne Gold Primary (Dentsply Maillefer) instruments were included in this study and tested in a static cyclic fatigue testing device, which has an artificial stainless steel canal with a 60° angle of curvature and a 5-mm radius of curvature. All instruments were operated in reciprocation mode until fracture occurred. The number of cycles to failure (NCF) was calculated and time to fracture (TF) was recorded in seconds using a digital chronometer. The mean and standard deviations of NCF and TF were calculated for each reciprocating system and the data were subjected to Kruskal-Wallis one-way analysis of variance and to Dunn's test (p < .05) using SigmaPlot software (Systat software, CA, USA). The fractured surfaces of five instruments from each brand were randomly examined and microphotographed by a low-vacuum environmental scanning electron microscopy - SEM (Tabletop Microscope TM3030, Hitachi, Japan) to confirm the cyclic fatigue fracture. EdgeFile exhibited the highest cyclic fatigue resistance, followed by both Genius files (p < .05). Within the limitations of this in vitro study, EdgeFile X1 instruments had significantly higher cyclic fatigue resistance than did Genius and WaveOne Gold Primary instruments. The cyclic fatigue resistance of both Genius files was higher than that of WaveOne Gold Primary.

Cleaning effectiveness of a nickel-titanium ultrasonic tip in ultrasonically activated irrigation: a SEM study.

In endodontic treatment, regardless of the instrumentation technique, the presence of a smear layer covering contaminated dentin walls is always a concern. Thus, irrigation plays an essential role in reducing bacterial load. To enhance irrigation effectiveness, different ultrasonic activation methods and the use of different tips have been studied. This study assessed the cleaning capacity of the novel NiTi ultrasonic tip for smear layer removal using ultrasonically activated irrigation (UAI) with passive or continuous ultrasonic irrigation (PUI or CUI, respectively), compared with conventional irrigation. Forty-five single-rooted human mandibular premolars were decoronated to a standardized length of 16 mm. Instrumentation was performed using the Genius system up to size 50.04 and irrigated with 3% NaOCl. The specimens were divided into three groups (n = 15) according to the final irrigation activation technique: conventional irrigation (CI), as control group; PUI; and CUI, following the manufacturer's protocol. The samples were longitudinally cleaved and analyzed under a scanning electron microscope for smear layer removal according to a cleanliness score for the cervical, middle, and apical thirds. Data were evaluated by means of the Kruskal-Wallis and Tukey's tests, with a 5% level of significance. UAI enhanced cleaning compared to conventional irrigation, mainly at the apical third. CUI showed the best results, with statistically significant lower scores than PUI and CI (p < 0.05). Final irrigant activation with the NiTi tip showed better cleaning capacity than conventional irrigation. In addition, CUI resulted in better smear layer removal than PUI.

Biocompatibility and biomineralization assessment of mineral trioxide aggregate flow.

OBJECTIVE: Evaluate, in vivo, the biocompatibility via subcutaneous inflammatory tissue response and mineralization ability of the new MTA Flow compared to MTA Angelus and ProRoot MTA. MATERIALS AND METHODS: Forty male Wistar rats were assigned and received subcutaneous polyethylene tube implants containing the test materials and a control group with empty tube (n = 10 animals/group). After days 7, 15, 30, and 60, the animals were euthanized and the polyethylene tubes were removed with the surrounding tissues. Inflammatory infiltrate and thickness of the fibrous capsule were histologically evaluated. Mineralization was analyzed by Von Kossa staining and under polarized light. Data were analyzed via Kruskal-Wallis and Dunn's test with a significance level of 5%. RESULTS: MTA Angelus induced the mildest reaction after 7 (P > .05) and 15 days (P < .05) followed by MTA Flow, both cements achieving mild inflammatory reaction after 15 days. ProRoot MTA induced a severe inflammation on day 7 and was reducing after day 15 (P > .05). No difference was observed after days 30 or 60 (P > .05). Von Kossa staining and birefringent structures were positive to all materials. CONCLUSIONS: At the end of the experiment, the novel MTA Flow showed biocompatibility and induced biomineralization in all time periods. CLINICAL RELEVANCE: The final consistence obtained in MTA Flow may facilitate several procedures, indicating that the MTA Flow has a promising application in endodontics.

Cleaning effectiveness of a nickel-titanium ultrasonic tip in ultrasonically activated irrigation: a SEM study

Abstract In endodontic treatment, regardless of the instrumentation technique, the presence of a smear layer covering contaminated dentin walls is always a concern. Thus, irrigation plays an essential role in reducing bacterial load. To enhance irrigation effectiveness, different ultrasonic activation methods and the use of different tips have been studied. This study assessed the cleaning capacity of the novel NiTi ultrasonic tip for smear layer removal using ultrasonically activated irrigation (UAI) with passive or continuous ultrasonic irrigation (PUI or CUI, respectively), compared with conventional irrigation. Forty-five single-rooted human mandibular premolars were decoronated to a standardized length of 16 mm. Instrumentation was performed using the Genius system up to size 50.04 and irrigated with 3% NaOCl. The specimens were divided into three groups (n = 15) according to the final irrigation activation technique: conventional irrigation (CI), as control group; PUI; and CUI, following the manufacturer's protocol. The samples were longitudinally cleaved and analyzed under a scanning electron microscope for smear layer removal according to a cleanliness score for the cervical, middle, and apical thirds. Data were evaluated by means of the Kruskal-Wallis and Tukey's tests, with a 5% level of significance. UAI enhanced cleaning compared to conventional irrigation, mainly at the apical third. CUI showed the best results, with statistically significant lower scores than PUI and CI (p < 0.05). Final irrigant activation with the NiTi tip showed better cleaning capacity than conventional irrigation. In addition, CUI resulted in better smear layer removal than PUI.

Avaliação in vivo da precisão de localizadores foraminais preservando o coto periodontal / In vivo evaluation of the accuracy of apical locators preserving the periodontal stump

O objetivo deste trabalho foi avaliar in vivo a precisão dos localizadores foraminais Root ZXII, E-PEX e FIND ao alcançarem o limite da constrição apical, preservando o coto periodontal ou atingindo o forame apical em biopulpectomia. Para o estudo foram selecionados 90 dentes unirradiculados indicados para exodontia de pacientes que consentiram com a pesquisa. Após teste de sensibilidade pulpar positivo, foi realizado o acesso à câmara pulpar e a exploração com uma lima K#15, sob isolamento absoluto. Seguido do preparo cervical e médio com Reciproc R25, uma lima #15 foi utilizada como instrumento padrão para a odontometria, introduzida no canal, formando 2 grupos: inserção da lima até o limite da constrição apical (marca 0.5); e inserção da lima até o forame (marca 0.0) e recuar até a constrição (marca 0.5), sem remover a lima do canal. A lima foi estabilizada pelo preenchimento do canal com resina tipo flow e após fotopolimerização teve sua haste metálica cortada. Após a exodontia, os dentes foram imersos em hipoclorito de sódio 5,25% por 10 minutos para remoção de tecidos orgânicos remanescentes e então armazenados em solução fisiológica. Os dentes foram escaneados em microtomógrafo SkyScan 1272, com o auxilio do software CTAN, e realizada medida da ponta da lima ao centro da constrição e do forame apical, fornecendo dados para análise comparativa. Houve diferença estatística em detectar a constrição, após alcançar o forame, onde RootZX II mostrou maior precisão (P<0.05). Contudo, não houve diferença (P>0.05) na precisão dos três localizadores foraminais em detectar a constrição apical sem alcançar o forame, dispensando a necessidade de lesar o coto periodontal ao realizar odontometria em biopulpectomia(AU)

This research evaluated, in vivo, the accuracy of Root ZXII, E-PEX and FIND foramen locators at the apical constriction limit, preserving the periodontal stump or until the apical foramen in biopulpectomy. For this study, 90 singlerooted teeth with extraction indication and patients' consent were selected. After positive pulpal cold sensitivity test, pulp chamber access was performed and a hand file K#15 was used to explore orifice entrance, under rubber dam. After cervical and middle instrumentation with Reciproc R25, the K#15 file was used as a standard instrument to determine working length, introduced in the root canal, forming 2 groups: insertion of the instrument until the apical constriction limit (mark 0.5); and insertion of the instrument until the foramen (mark 0.0) and repositioning at constriction (mark 0.5), without removing the file from the canal. The hand file was stabilized inside the canal with a light-cured flow resin and, after polymerization, the metal handle was cut. After extraction, teeth were immersed in 5.25% sodium hypochlorite for 10 minutes to remove remaining organic tissues and then stored in saline. The samples were analyzed through microCT SkyScan 1272, with CTAN software, which evaluated the proximity between the tip of the file to the apical constriction, providing data for comparative analysis. There was a statistical difference in detecting the constriction after reaching the foramen, where Root ZX II showed elevated accuracy (P<0.05). However, there was no difference (P>0.05) in the accuracy of the three foraminal locators in detecting the apical constriction without reaching the foramen, dismissing the need to injure the periodontal stump when performing odontometry in biopulpectomy(AU)

Calcium hydroxide associated with a new vehicle: Psidium cattleianum leaf extracts. Tissue response evaluation.

The aim of this study was to evaluate edemogenic activity and subcutaneous inflammatory reaction induced by Psidium cattleianum leaf extracts associated with Ca(OH)2. Thirty male Wistar rats, split equally into three groups [aqueous extract + Ca(OH)2; ethanolic extract + Ca(OH)2; and propylene glycol + Ca(OH)2], were assessed every 3 h or 6 h (five animals in each period). Under general anesthesia, 0.2 mL of 1% Evans blue per 100 g of body weight was injected into the penile vein and each combination to be evaluated was subcutaneously injected into the dorsal region 30 min thereafter. Edemogenic activity was analyzed by spectrophotometry (λ=630 nm). For inflammatory reaction analysis, 50 rats received four polyethylene tubes (three experimental groups) and an empty tube (control group). The assessments were made at 7, 15, 30, 60, and 90 days, followed by hematoxylin-eosin staining and by the assignment of scores for evaluation of tissue response intensity. Ethanolic extract + Ca(OH)2 yielded the largest edemogenic activity at 3 h. Intergroup differences at 6 h were not significant. The histological analysis showed progressive repair over time (p<0.05) and aqueous and ethanolic extracts produced similar responses to those of the control and Ca(OH)2 + propylene glycol groups. Psidium cattleianum leaf extracts used as Ca(OH)2 vehicles evoked similar tissue response when compared to Ca(OH)2 associated with propylene glycol.

Calcium hydroxide associated with a new vehicle: Psidium cattleianum leaf extracts. Tissue response evaluation

Abstract The aim of this study was to evaluate edemogenic activity and subcutaneous inflammatory reaction induced by Psidium cattleianum leaf extracts associated with Ca(OH)2. Thirty male Wistar rats, split equally into three groups [aqueous extract + Ca(OH)2; ethanolic extract + Ca(OH)2; and propylene glycol + Ca(OH)2], were assessed every 3 h or 6 h (five animals in each period). Under general anesthesia, 0.2 mL of 1% Evans blue per 100 g of body weight was injected into the penile vein and each combination to be evaluated was subcutaneously injected into the dorsal region 30 min thereafter. Edemogenic activity was analyzed by spectrophotometry (λ=630 nm). For inflammatory reaction analysis, 50 rats received four polyethylene tubes (three experimental groups) and an empty tube (control group). The assessments were made at 7, 15, 30, 60, and 90 days, followed by hematoxylin-eosin staining and by the assignment of scores for evaluation of tissue response intensity. Ethanolic extract + Ca(OH)2 yielded the largest edemogenic activity at 3 h. Intergroup differences at 6 h were not significant. The histological analysis showed progressive repair over time (p<0.05) and aqueous and ethanolic extracts produced similar responses to those of the control and Ca(OH)2 + propylene glycol groups. Psidium cattleianum leaf extracts used as Ca(OH)2 vehicles evoked similar tissue response when compared to Ca(OH)2 associated with propylene glycol.

Mixing failures of endodontic sealers: an in vivo biocompatibility study / Falhas durante espatulação de cimentos endodônticos: um estudo de biocompatibilidade in vivo

Objectives: Evaluate, in vivo, the influence of mixing failures on endodontic sealers. Material and Methods: To alveolus analysis, 80 rats were divided into Sealapex® and AH Plus® groups. Within each group, the sealer was subjected to either partial (incomplete homogenization­ simulating handling failures) or total mixing (complete homogenization) over two periods of 7 and 30 days (n = 20). The maxillary incisor was extracted and a polyethylene tube containing the sealer was inserted. To quantify edema, 40 male rats were divided into four groups (n = 10). The animals received 2% Evans Blue intravenously, and either AH Plus® or Sealapex® was injected subcutaneously. The rats were euthanized after 3 or 6 hours and analyzed in a spectrophotometer (630 ƞm). To analyze the subcutaneous tissue, 20 rats received polyethylene tube implants with the sealers in the dorsal area (n=10), then euthanized after either 7 or 30 days, and inflammation was evaluated according to an inflammatory cells score. Results: In the alveolar 7-day group, control group presented an inflammation score 1, while all other groups presented a score 2, except AH plus® total mix group (3). After 30 days, all groups presented a score 1. The edemogenic test showed less edema in Sealapex® groups (p < 0.5). In subcutaneous 7-day period, all groups presented score 2. In 30 days, all groups revealed score 1, except AH Plus® partial mix group (2). Conclusion: Regarding mixing of the sealers, there were no significant differences among the groups (AU)

Objetivo: Avaliar, in vivo, a influência das falhas de espatulação de cimentos endodônticos. Material e Métodos: Para análise alveolar, 80 ratos foram divididos nos grupos Sealapex® e AH Plus®. Em cada grupo, o cimento foi espatulado de forma parcial (homogeneização incompleta, simulando falhas) ou total (homogeneização completa) em dois períodos de 7 e 30 dias (n=20). O incisivo superior foi extraído e um tubo de polietileno contendo o cimento foi inserido. Para quantificar edema, 40 ratos foram divididos em quatro grupos (n = 10). Os animais receberam Azul de Evans 2% intravenoso, e AH Plus® ou Sealapex® injetados no tecido subcutâneo. Após 3 ou 6 horas foram eutanasiados e analisados em espectrofotômetro (630 ƞm). Para analisar a resposta subcutânea, 20 ratos receberam implantes de tubo de polietileno com os cimentos na região dorsal (n = 10), eutanasiados após 7 ou 30 dias, e a inflamação foi avaliada de acordo com um escore de células inflamatórias. Resultados: Na análise alveolar em 7 dias, o grupo controle apresentou escore 1 de inflamação, enquanto que todos os outros grupos apresentaram 2, com exceção do AH plus® espatulação total (3). Após 30 dias, todos os grupos apresentaram escore 1. O teste edemogênico mostrou menor edema nos grupos Sealapex® (p < 0,5). No período subcutâneo de 7 dias, todos os grupos apresentaram escore 2. Em 30 dias, todos os grupos revelaram escore 1, exceto AH Plus® espatulação parcial (2). Conclusão: Não houve diferença estatística significante entre os cimentos quanto à espatulação. (AU)