Long-term sealing ability of GuttaFlow versus Ah Plus using different obturation techniques

Objective. To compare the long-term sealing ability of GuttaFlow® using different obturation techniques. Study Design. Three hundred teeth, prepared with a crown-down technique, were divided into thirty experimental groups (n=10) to evaluate the apical and coronal leakage, at 3, 30 and 120 days, of lateral compaction gutta-percha + AH Plus?, lateral compaction gutta-percha + GuttaFlow®, single cone + AH Plus?, single cone + GuttaFlow®, and GuttaFlow® only. Results. Both coronal and apical leakage, at the three times of measurement, no significant differences were found among GuttaFlow® + lateral compaction gutta-percha and GuttaFlow® + single cone groups, whereas the only GuttaFlow® reached the highest leakage values at 30 and 120 days. AH Plus?, using both techniques, showed high levels of leakage after 120 days to the coronal leakage and after 30 days to the apical leakage when compared silicon based sealer. Conclusion. GuttaFlow®, using with lateral compaction and single cone techniques, shows a greater apical and coronal sealing ability than AH Plus? over time. GuttaFlow® when used as only creates a poorer sealing than when used with lateral compaction gutta-percha or single cone techniques

Influence of adhesive systems on microtensile bond strength of resin-based endodontic sealers to the root dentin

Objective: The aim of this study was to determine the microtensile bond strength to root dentin of AH PlusTM and EndoREZ® with Clearfil Liner Bond 2V and Optibond SoloTM Plus adhesive systems. Study Design: The coronal and middle thirds of six single rooted bovine teeth was split longitudinally in a mesio- distal direction. The two halves were joined with AH Plus or EndoREZ, with and without the use of Clearfil Li - ner Bond 2V and Optibond SoloTM Plus adhesive systems. Build-ups were vertically sectioned into quadrangular (?1mmx1mm) compound bars and subjected to tensile tests at a constant crosshead speed (1 mm/min) until debon - ding. Results: Optibond ® Solo PlusTM in combination with AH PlusTM and EndoREZ ® showed the highest mean micro - tensile bond strength values, in both coronal and middle thirds. The lowest results were seen in the groups where no dentine adhesive was applied, and in those where the self-etching adhesive Clearfil Liner Bond 2V was used. Conclusion: The microtensile bond strength to root dentin of AH PlusTM and EndoREZ may be increased with the use of a total-etch adhesive

Cytotoxic effects of two acid solutions and 2.5% sodium hypochlorite used in endodontic therapy

Aim: To evaluate the cytotoxicity of 15% citric acid, 5% phosphoric acid and 2.5% NaOCl on cultured fibroblasts using MTT colorimetric assay. Methodology: Irrigating solutions of 5% phosphoric acid, 15% citric acid, and 2.5% NaOCl, diluted at 0.1% and 0.5%, were applied to cell cultures of 3T3L1 fibroblasts. The cell viability was determined by means of MTT colorimetric assay after a period of 1, 6 and 24 hours. Percentages of cell viability were analyzed using the Kruskal-Wallis test for global comparisons and the Mann-Whitney U-test for pairwise comparisons. Results: The percentage of cell viability diminished progressively over a 24 hour period in all solutions at both dilutions. At 0.1% dilution, 2.5% NaOCl (63.39%) and 15% citric acid (53.91%) showed the highest percentage of cell viability (p=0.083). At 0.5% dilution, 2.5% NaOCl again showed the highest cell viability value (48.51%). Conclusions: The irrigating solution with the highest percentage of cell viability was 2.5% NaOCl at both 0.1% and 0.5% dilutions. A very low percentage of cell viability was obtained with 15% citric acid and 5% phosphoric acid at 0.5% dilution

Apical seal comparison of low-temperature thermoplasticized gutta-percha technique and lateral condensation with two different master cones

Objetivo: comparar el sellado apical en conductos mesio-vestibulares de molares obturados con gutapercha termoplastificada a baja temperatura o con técnica de condensación lateral usando un cono maestro de gutapercha de conicidad .06 o .02. Como objetivo secundario se evaluó la penetración del espaciador en los conductos cuando se utilizó un cono de conicidad .02 o .06. Metodología: cuarenta y cuatro conductos mesio-vestibulares curvos (25-40º) fueron preparados con instrumentos rotatorios del niquel-titanio de conicidad .06 y distribuidos aleatoriamente en dos grupos control (n=4) y tres grupos experimentales (n=12) para obturarlos con el sistema Ultrafil® 3D o técnica de condensación lateral de gutapercha en frío con conos maestros de conicidad .06 o.02. AH-Plus fue utilizado como cemento sellador. La profundidad de penetración del espaciador fue registrada en milímetros. Las raíces fueron cubiertas con dos capas de barniz de uñas, sumergidas en tinta china durante 7 días, seccionadas transversalmente y examinadas con un estereomicroscopio. Para determinar si existían diferencias en la penetración del espaciador entre grupos se utilizó el test de la T de Student. La prueba de Kruskal-Wallis fue utilizada para determinar si existían diferencias en la penetración del tinte. Resultados: no hubo diferencias en la microfiltración entre los tres grupos de estudio (p= 0.396), que mostraban una media muy similar (0.42. 0.75 y 0.42). La comparación de la profundidad de penetración del espaciador en los grupos obturados mediante condensación lateral fue significativamente superior cuando se usó un cono de conicidad .02 (p= 0.001). Conclusión: el sistema Ultrafil®3D y la técnica de condensación lateral de la gutapercha con conos maestros de conicidad .06 o .02 fueron igualmente eficaces en el sellado apical de conductos curvos. El espaciador penetró en el conducto significativamente más cuando se empleó un cono de conicidad .02

Effects of storage temperature and length of the storage period on hatchability and performance of red-legged partridge (Alectoris rufa) eggs

The aim of the present study was to investigate, in red-legged partridge (Alectoris rufa) eggs, the effects of 7- and 42-d storage periods with different storage temperatures (15, 12, and 9°C) on egg weight loss, hatchability, chick weight at hatch, incubation length, and development stage at embryonic mortality. A total of 420 red-legged partridge eggs were arranged in a 2 × 3 factorial design with 2 levels of storage length and 3 levels of storage temperature, resulting in 6 treatments consisting of 10 replications of 7 eggs each. We found that the storage length significantly reduced hatchability of the fertile eggs (P = 0.001), increasing late embryonic mortality (P = 0.001). Storage temperature did not influence on the embryonic mortality at any stage (P > 0.05). Egg weight loss during storage increased with the storage length (P 0.05). Nevertheless, incubation period decreased with the storage temperature for 7-d storage, and increased with the storage temperature for 42-d storage (P = 0.005). It can be concluded that in this study red-legged partridge eggs stored well with little deterioration up to 42 d at 9 and 12°C and 80% RH, in contrast to the lesser durability of eggs described in the literature for other poultry species. In case of 7-d storage periods, hatchability of A. rufa fertile eggs is higher when they are stored at 15°C. These findings are useful to address specific demands of game farms that require fertile eggs for hatching whose shelf-life should be long enough to maintain hatchability until further incubation. And, due to the marked reproductive seasonality of red-legged partridge, long-term storage of hatching eggs could permit the distribution of batches of chicks throughout the year.Junta de Andalucía AGR-23

Metacognitive Knowledge and Skills in Students with Deep Approach to Learning. Evidence from Mathematical Problem Solving

Student approaches to learning and metacognitive strategies are two important conditioning factors in solving mathematical problems. The evidence suggests that it is the deep approach to learning which leads to student success in such tasks. The present study focused on analyzing the differences in metacognitive knowledge and skills in a sample of 524 fifth and sixth grade students divided into three groups based on their different levels of use of a deep a pproach (241 = low; 152 = medium; and 131 = high). Metacognitive knowledge was assessed using the Learning Strategies Knowledge Questionnaire, while evidence about metacognitive skills was gathered by means of process measures (Triple Tasks Procedure) during students’ solving of two mathematical word problems. Statistically significant differences in metacognitive knowledge were found among groups while differences in metacognitive skills were only found in the second task, with a low effect size.; El enfoque de aprendizaje y las estrategias metacognitivas son importantes condicionantes en la resolución de problemas matemáticos. La investigación ha puesto de relevancia que el enfoque profundo de aprendizaje dirige al estudiante al éxito en la ejecución de estas tareas. Este trabajo ha pretendido analizar las diferencias en el conocimiento y habilidades metacognitivas de 524 estudiantes de quinto y sexto de primaria clasificados en tres grupos en función del nivel de uso del enfoque profundo (241 = bajo; 152 = medio; 131 = alto). El conocimiento metacognitivo fue evaluado con el cuestionario de conocimiento de estrategias de aprendizaje, y las habilidades metacog nitivas con medidas del proceso (Triple Tarea) durante la resolución de dos problemas matemáticos. Los resultados mostraron diferencias estadísticamente significativas en el conocimiento metacognitivo y, en las habilidades metacognitivas en la segunda tarea con un bajo tamaño del efecto

Decalcifying effects of antimicrobial irrigating solutions on root canal dentin

Objective: The aim of this study was to determine the decalcifying efficacy of 7% maleic acid (MA), 2% chlorhexidine (CHX), and combinations of 7% MA + 0.2% cetrimide (CTR) and 2% CHX + 0.2% CTR, in four time periods. Study Design: Four specimens per tooth were obtained from a 2-mm thick slice of the cervical third of the root of ten human incisors. At 1, 2, 3 and 5 minutes of immersion, the concentrations of Ca2+ were measured by atomic absorption spectrophotometry. The results were analyzed using the Mann-Whitney U-test. Results: Statistically significant differences were seen for the extracted calcium in all time periods. The amount of calcium extracted by 7% MA was the highest at all four immersion times, followed by 7% MA + 0.2% CTR. Two percent CHX and its combination with 0.2% CTR extracted virtually no calcium. Conclusions: The decalcifying capacity of 7% MA and 2% CHX diminished when combined with 0.2% CTR

An in vitro evaluation of two dentine adhesive systems to seal the pulp chamber using a glucose penetration model

Objectives: To evaluate the sealing capability of Cavit TM G with or without Clearfil TM S3 Bond and Prime & Bond NT placed in the pulp chamber. Study Design: Forty single rooted premolars, extracted for orthodontic and periodontal reasons, with intact coronal surface and mature apices, were standardized to a length of 15 mm. The teeth were instrumented, filled with a gutta-percha master cone and divided into three groups to obturate the pulp chambers: Cavit TM G; Clearfil TM S3 Bond plus Cavit TM G and Prime & Bond® NT plus Cavit TM G. A glucose leakage model was used for evaluating the coronal microleakage. The Mann-Whitney test was used to evaluate the differences in the means of the glucose leakage. Results: An increase in glucose penetration was observed during the first week in groups Cavit TM G and Cavit TM G+PBNT. The glucose penetration values of all groups were similar at 30 and 45 days, and there were no significant differences among them in both time periods (p=0.736 and p=0.581, respectively). Conclusions: The adhesive systems did not improve the capability of Cavit TM G to seal the pulp chamber over time © Medicina Oral S. L

Intraorifice sealing ability of different materials in endodontically treated teeth

Objectives: To evaluate Cavit? G, ProRoot? MTA and Tetric® EvoFlow as intraorifice barriers to prevent coronal microleakage in root canal treatment. Study Design: Forty-two human single rooted teeth were divided randomly in three experimental groups of 10 specimens each and two control groups. The experimental groups were prepared with hand instrumentation and cold lateral condensed technique of the gutta-percha. Four millimetres of coronal gutta-percha were removed and replaced by one of the following filling materials: Cavit? G, Tetric® EvoFlow or ProRoot? MTA. In the experimental groups, leakage was measured by the concentration of leaked glucose in the apical reservoir at 1, 7, 30, and 45 days, using the enzymatic glucose oxidase method. Data were analyzed by means of Mann-Whitney U and Kruskal-Wallis tests at ?=0.05. Results: The glucose penetration results of three experimental groups increased gradually over time. No significant differences were found among groups at 24 hours and 1 week. At thirty and forty-five days, Cavit? and Tetric® EvoFlow values were significantly different (p=0.007 and p=0.023, respectively). Conclusions: The sealing ability of the Cavit? G, ProRoot? MTA and Tetric® EvoFlow used as intraorifice materials tends to be similar over time

Eradication of enterococci biofilms by lactic acid alone and combined with chlorhexidine and cetrimide

Objective: The antimicrobial activity of lactic acid (LA) alone or in combination with chlorhexidine (CHX) and cetrimide (CTR) against three Enterococcus faecalis strains, E. faecalis ATCC 29212, E. faecalis EF- D1 and E. faecalis U-1765, one Enterococcus durans strain and one dual- species biofilm was investigated. Study Design: The irrigating solutions tested were 20%, 15%, 10%, 5% and 2.5% LA, alone and in combination with 2% CHX and with 0.2% CTR. The biofilms were grown in the MBEC TM high-throughput device for 24 hours and exposed to the solutions for 30 seconds and 1 minute. ?Eradication? was defined as 100% bacterial kill. Results: Twenty percent LA eradicated all enterococci biofilms after 30 seconds contact time. The association of LA + 0.2% CTR achieved better results than LA alone, in contrast with the results obtained using LA + 2% CHX. E. durans was eradicated by all the tested solutions at 1 minute. The dual- species biofilm, E. faecalis ATCC 29212 + E. durans, gave intermediate values of the pure cultures. Conclusions: LA is capable of eradicating enterococci biofilm at a concentration of 20%. The combination of lower concentrations with 0.2% CTR achieved eradication after 1 minute