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.

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.

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)