Agregado trióxido mineral y cemento pórtland expuestos a irrigantes endodóncicos: pH, conductividad y solubilidad / Mineral trioxide aggregate and portland cement exposed to endodontic irrigants: pH, conductivity, and solubility

Objetivo: El objetivo de este estudio fue determinar, el pH, la conductividad y la solubilidad al someter el agregado trióxido mineral (MTA) y el cemento Pórtland (CP) a diferentes irrigantes utilizados en endodoncia. Material y Métodos: Se estudiaron un total de 210 muestras, 105 de cemento ProRoot MTA(R) blanco y 105 de CP blanco. Se seleccionaron los siguientes irrigantes: hipoclorito sódico al 2,5% y al 5%, ácido cítrico al 10% y al 20%, clorhexidina al 2%, EDTA al 17%, y suero fisiológico como control. Se expusieron 15 muestras de MTA y 15 de CP a cada tipo de irrigante. Se midieron los resultados a 1, 5, 15, 30 y 60 minutos. Resultados: La mayoría de cambios del pH y la conductividad fueron de pequeña magnitud, aunque estadísticamente significativos. Destacan la alcalinización del suero fisiológico y la acidificación del hipoclorito sódico. Con MTA disminuye la conductividad en hipoclorito sódico y aumenta la conductividad en EDTA. Con CP hubo una mayor pérdida de conductividad del hipoclorito sódico y del ácido cítrico. Todas las muestras disminuyeron el peso considerablemente después de la exposición a cualquiera de los irrigantes, y en general ésta fue mayor para el CP que el MTA. Conclusiones: El contacto del material de reparación con los irrigantes utilizados habitualmente en endodoncia altera poco el pH y la conductividad pero aumenta marcadamente su solubilidad. Estos cambios afectan menos al MTA que al CP

Objective. The aim of this study was to determine changes to pH, conductivity, and solubility when mineral trioxide aggregate (MTA) and Portland cement (PC) are exposed to different endodontic irrigants. Methods. The study included a total of 210 samples, 105 white ProRoot MTA® cement and 105 white PC cement. The following irrigants were tested: 2.5% and 5% sodium hypochlorite, 10% and 20% citric acid, 2% chlorhexidine, 17% ethylenediamine tetra-acetic acid (EDTA), and physiological serum as a control. Fifteen samples of each material were exposed to each irrigant. PH, conductivity, and solubility were measured at baseline and after 1, 5, 15, 30 and 60 minutes exposure to irrigants. Results. Most changes in pH and conductivity were of small magnitude, although statistically significant. For MTA and PC physical serum produced alkalinization, while sodium hypochlorite produced acidification. MTA lost conductivity when exposed to sodium hypochlorite but this increased with exposure to EDTA. PC underwent greater losses of conductivity when exposed to sodium hypochlorite and citric acid. All samples decreased in weight significantly after exposure to any of the irrigants, and the loss was generally greater for PC than MTA. Conclusions. When repair materials are exposed to the irrigants normally used in endodontics, pH levels and conductivity alter slightly, while solubility increases markedly. These effects were greater for PC than MTA

Rugosidad superficial del agregado de trióxido mineral y el cemento pórtland expuestos a irrigantes endodóncicos / Surface roughness of the mineral trioxide aggregate and Portland cement exposed to endodontic irrigants

Objetivo: El propósito de este estudio fue determinar la rugosidad superficial, al someter al agregado de trióxido mineral (MTA) y al cemento Pórtland (CP) a diferentes irrigantes utilizados en endodoncia. Material y Métodos: Se estudiaron un total de 210 muestras, 105 de cemento ProRoot MTA® blanco y 105 de CP blanco. Se seleccionaron los siguientes irrigantes: hipoclorito sódico al 2,5% y al 5%, ácido cítrico al 10% y al 20%, clorhexidina al 2%, EDTA al 17%, y suero fisiológico como control. Se expusieron 15 muestras de cada cemento por cada tipo de irrigante durante 15 minutos. El estudio de la rugosidad superficial se hizo con el microscopio Leica DCM 3D que permite una perfilometría con tecnología dual confocal e interferométrica. Se evaluó la rugosidad media (Ra), el valor cuadrático medio (RMS) y la profundidad de rugosidad máxima (PV) al inicio y a los 15 minutos de la inmersión de las muestras. Resultados: El CP aumentó significativamente la rugosidad en los parámetros Ra y RMS tras la irrigación con hipoclorito al 2,5%, ácido cítrico al 10% y al 20%, y suero fisiológico. En términos de PV el CP solo aumentó la rugosidad tras la irrigación con ácido cítrico al 20% y suero fisiológico. El MTA no mostró cambios significativos respecto a la rugosidad Ra, RMS y PV con ninguno de los irrigantes. Conclusiones: La rugosidad superficial del CP puede modificarse por la exposición a alguno de los irrigantes utilizados en endodoncia, mientras que la rugosidad del MTA no se modifica significativamente

Objectives: This study set out to determine changes to surface roughness when mineral trioxide aggregate (MTA) and Portland cement (PC) are exposed to the different irrigants used in endodontics. Material and Methods: The study included a total of 210 samples, 105 white ProRoot MTA® cement and 105 white PC cement. The following irrigants were tested: 2.5% and 5% sodium hypochlorite, 10% and 20% citric acid, 2% chlorhexidine, 17% ethylenediamine tetra-acetic acid (EDTA), and physiological serum as a control. Fifteen samples of each material were exposed to each irrigant for 15 minutes. Surface roughness evaluation was performed using a Leica DCM 3D microscope for dual system (confocal and interferometric) profilometry. Mean roughness (Ra), root mean square (RMS) and maximum roughness depth (PV) were evaluated before and after 15 minutes sample immersion in each irrigant. Results: PC significantly increased roughness for Ra and RMS parameters after irrigation with 2.5% sodium hypochlorite, 10% and 20% citric acid, and physiological serum. PC underwent an increase in the PV parameter after immersion in 20% citric acid and physiological serum. MTA did not show significant changes in Ra, RMS or PV with any of the irrigants. Significance. The surface roughness of PC may be modified by exposure to some of the irrigants used in endodontics, while the roughness of MTA is not modified significantly

Knowledge, aptitudes, and preferences in implant dentistry teaching/training among undergraduate dental students at the University of Barcelona.

BACKGROUND: Oral implant rehabilitation should be considered a treatment option for any edentulous patient and Implant Dentistry is currently a discipline taught in the undergraduate formation. The level of knowledge acquired and how the students perceive the quality of training in Implant Dentistry could assess to know if it is necessary to improve the syllabus. MATERIAL AND METHODS: A questionnaire was developed with 11 questions: Basic knowledge (7); Perception of training received (2); Ways in which students would receive training (2). To be responded anonymously and voluntarily for undergraduates students in the Faculty of Dentistry (University of Barcelona, Spain). RESULTS: One hundred and seven students, 76 third year (Group A) and 31 fourth year (Group B) answered the questionnaire. In Group A, 98.68% of students and in Group B 93.54% believed they were poorly informed; 100% of both groups would prefer to receive more training as part of the degree or as postgraduate training through modular courses imparted by experts (A: 71,05%, B: 70,96%) Training through postgraduate programs or training given by private businesses were the least desirable options (A: 42%, B: 64.51%). Questions about basic knowledge acquired received varying responses, which might indicate a certain level of confusion in this area. CONCLUSIONS: The undergraduate syllabus must be revised to include sufficient content and training to allow the student to indicate implant-based treatments based on evidence. Students would prefer training to be included in the undergraduate syllabus.

Actualización en endodoncia 2010 / 2010 Update in Endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2010, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published in the most relevant journals concerning endodontics during the last year 2010, making a comparison between them, as well as with other older one and with classic concepts in endodontics (AU)

Acutalización en Endodoncia 2009 / 2009 Update in Endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2009, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published int he most relevant journals concerning endodontics during the last year 2009, making a comparison between them, as well as with other older ones and with classic concepts in endodontics (AU)

Actualización en endododoncia 2008 / 2008 Update in endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2008, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the article published in the most relevant journals concerning endodontics during the last year 2008, making a comparison between them, as well as with other older ones and with classic conepts in endodontics (AU)

Actualización en Endodoncia 2007 / 2007 Update in Endodontics

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2007 comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published in the most relevant journals concerning endodontic during the last year 2007, making a comparison between them as well as with other older ones and with classic concepts in endodontics (AU)

Actualización en endodoncia 2006 / No disponible

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2006, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia (AU)

The authors review the articles published in the most relevant journals concerning endodontics during the last year 2006, making a comparison between them, as well other older ones and with classic concepts in endodontics (AU)

Actualización en endodoncia 2005 / 2005 update in endodontics2

Los autores revisan los artículos publicados en las revistas científicas más significativas en el ámbito de la endodoncia durante el año 2005, comparándolos entre ellos, con otros anteriores y con los conceptos clásicos de la endodoncia

The authors review the articles published inthe most relevant journals concerning endodontics during the last years 2005, making a comparison between them, as well as with other ones and with classic concepts in endodontics

Apical sealing using two thermoplasticized gutta-percha techniques compared with lateral condensation.

This study was conducted to compare the apical sealing capacity of three filling techniques, a multiphase gutta-percha obturation technique, JS Quickfill, and lateral gutta-percha condensation. A four-stage stepback preparation was executed with circumferential filing in a total of 70 recently extracted permanent maxillary incisors and canines. Three experimental groups (20 teeth in each group) and two control groups (5 teeth in each group) were formed at random. Each experimental group was obturated with a different technique. The positive control group was not obturated. In the negative control group, the whole root was covered with two full nail varnish layers. Teeth were immersed in India ink for 48 h, demineralized, cleared with methyl salicylate, and examined with a stereomicroscope. None of the specimens obturated with the multiphase gutta-percha obturation system showed any penetration of India ink beyond the end of the preparation. In the groups of teeth obturated by JS Quickfill or lateral gutta-percha condensation, leakage was detected in one specimen from each group. No statistically significant differences were seen among groups. We conclude that the newer thermoplasticized filling techniques can be used successfully to obturate root canals in large, straight roots.

Cutting efficiency of K-files manufactured with different metallic alloys.

The aim of this study was to compare, in vitro, the machining efficiency of different triangular cross-section K-files made of nickel titanium (Nitiflex, Naviflex), titanium (Microtitane), and stainless steel (Flexofile, Flex-R). Ten instruments of each K-file from size 25 to 40 were tested. The cutting efficiency was assessed in a linear motion using an indentation caliper to measure the depth of grooves. The load applied (in grams) was equal to the ISO file size. Each file was allowed to do 100 back-and-forward movements. Files made of stainless steel were the most effective, in particular Flexofile. There were statistically significant differences between Flexofile and Flex-R in all sizes. In the group of nickel titanium instruments, Nitiflex was significantly more efficient than Naviflex in all sizes. The machining ability of titanium files was higher than that of Naviflex but lower than that of Nitiflex and stainless steel files.

Torsional and bending properties of stainless steel and nickel titanium Canal Master U and Flexogate instruments.

The purpose of this study was to assess and to compare the torsional and bending properties of the Canal Master U (CMU) and Flexogate instruments made of stainless steel and nickel titanium. The bending moment, the torsional moment and angular deflection were measured according to ANSI/ADA specification number 28 and ISO reference number 3630. Ten instruments of each size, sizes 25 to 40 were used for each test. Nickel titanium instruments were significantly more flexible than stainless steel files. With regard to the torsional moment, values obtained were below the standards in all sizes except stainless steel CMU sizes 25, 35 and 40, and nickel titanium CMU size 25. Nickel titanium instrument also showed the highest angular deflection values. There were statistically significant differences between nickel titanium files and stainless steel Flexogates and between stainless steel Flexogates and stainless steel CMU. Based on these findings, the use of nickel titanium CMU and Flexogates is encouraged. Given the perceived advantages of both CMU and Flexogate instruments over conventional files for canal preparation, it would appear desirable to have the torque resistance of these instruments improved.

A comparison of bending and torsional properties of K-files manufactured with different metallic alloys.

The purpose of this study was to compare bending (bending moment) and resistance to fracture by twisting (torsional moment and angular deflection) of triangular cross-section K-files made of either nickel titanium (Nitiflex, Naviflex), titanium (Microtitane) or stainless steel (Flexofile, Flex-R). A total of 200 files were tested, 10 instruments for each type from size 25 to 40, according to ANSI/ADA specification no. 28 and ISO reference no. 3630. Files made of nickel titanium, especially Nitiflex, were the most flexible. Stainless steel instruments presented a higher bending moment than files made of nickel titanium and titanium, particularly Flex-R sizes 35 and 40. With regard to resistance to fracture, measured by angular deflection at the failure point, Flexofile followed by Flex-R were the most resistant to fracture and Nitiflex were the least resistant. Differences in angular deflection among file groups were greater than those for torsional moment. Thus, it seems that angular deflection is a more specific measurement for assessing resistance to fracture by twisting.

[Radioactive isotope evaluation of apical seal of two types of thermoplasticized gutta-percha at high and low temperature]. / Evaluation à l'aide d'isotopes radio-actifs de l'étanchéité apicale de deux types de gutta-percha thermoplastifiée à haute et basse température.

The aim of this study was to evaluate the apical seal obtained using root canal filling techniques based on low and high temperature thermoplasticized gutta-percha, comparing them with the lateral condensation technique. The roots of thirty permanent upper canines and incisors were used, they were instrumented and obturated using each of the above techniques. The apical leakage was measured using a radioactive isotope and an external detection technique. No significant difference was found in the apical seal obtained by the three techniques.

[Bone densitometry of periapical lesions]. / Densitométrie osseuse dans les lésions périapicales.

The aim of the work was to evaluate the bone density of chronic periapical lesions in the area of maxillary incisors and canines. Twenty-six radiographies were made in a systematic way in patients with periapical lesions and were valued using densitometry (0-256), the grey levels by computer and the analysis program image (IBAS 2000 Kontron, Germany), taking four values in each periapical lesion from the center to the periphery within the same radiography, by using the pseudocolor to identify the four areas, always in the same coloration. Correlation was proved with significative statistically results between lower densitometric values and osteolysis and radiolucency areas.

[The surface of various files of quadrangular, triangular and rhomboidal section using scanning electron microscopy]. / Estudio de la superficie de diversas limas de sección cuadrangular, triangular y romboidal mediante microscopio electrónico de barrido.

Using a scanning electron microscope, 45 new files were examined, taken at random, of 5 different brands, of 3 different calibres and with rectangular, triangular and rhomboidal sections. Various defects were observed in the surface of all of them, such as adhered metallic fragments, burrs, deformed teeth, pores and ridges. These defects were more evident on the smaller diameter files of those studied and on those of triangular or rhomboidal section.