Primer premolar maxilar con tres conductos. A propósito de un caso / Maxillary first premolar with three canals. A case report

El éxito en el tratamiento de conductos radiculares va a depender entre otras cosas, del conocimiento de la morfología interna y externa de los dientes. Los primeros premolares maxilares presentan una amplia variación en la configuración de las raíces y los conductos radiculares, que debemos estudiar para el correcto diagnóstico y plan de tratamiento. Presentamos un caso clínico de un primer premolar superior con dos raíces y tres conductos

The success of root canal treatment depends on the knowledge of the internal and external tooth morphology among other things. Maxillary first premolars are said to exhibit large variation in root canal morphology we must know to make a proper diagnosis and treatment plan. This article reports a case of an upper left first premolar with two roots and three Canals

Amoxicillin-Loaded Sponges Made of Collagen and Poly[(methyl vinyl ether)-co-(maleic anhydride)] for Root Canal Treatment: Preparation, Characterization and In Vitro Cell Compatibility.

The difficulty of eliminating Enterococcus faecalis and other bacteria infecting dental root canals makes it desirable to develop formulations capable of sustained release of antibiotics within the canal. With this function in view, in this work we compared the mechanical, drug release and biocompatibility properties of amoxicillin-loaded collagen (CL) and CL complexed with poly[(methyl vinyl ether)-co-(maleic anhydride)] (PVMMA), with or without glutaraldehyde (GTA) or the natural product genipin (GN) as cross-linker. Collagen was not denatured by complexation with PVMMA. Only CL-PVMMA-GN sponges did not disintegrate during 7 days exposure to cell culture medium (un-cross-linked CL disintegrated within 24 h and un-cross-linked CL-PVMMA within 4 days), and CL-PVMMA-GN sponges also exhibited the most appropriate combination of mechanical properties (hardness, modulus of deformability and plasticity). CL-PVMMA-GN sponges absorbed aqueous medium faster than other cross-linked formulations, but their maximum uptake was less; and drug release from CL-PVMMA-GN sponges tended to be faster than from any other, except un-cross-linked CL-PVMMA, maximum release taking about 4 days. No formulation significantly altered the viability of L929 fibroblast-like mouse connective tissue cells, but cells growing on sponges showed signs of non-adherence. It is concluded that genipin-cross-linked CL-PVMMA sponges merit further investigation as antibiotics vehicles and aids to tissue regeneration in the dental root canal.

The corrosion of nickel-titanium rotary endodontic instruments in sodium hypochlorite.

AIM: To evaluate the corrosion resistance of nickel-titanium (NiTi) endodontic rotary instruments immersed in 5.25% sodium hypochlorite (NaOCl) solution. METHODOLOGY: The corrosion performance of NiTi instruments (S1 25 mm, ProTaper Dentsplay Maillefer, Ballaigues, Switzerland) was evaluated using commercial 5.25% NaOCl solution (pH = 12.3), and the same solution partially neutralized adding H2SO4 to reach pH = 10.1. Electrochemical measurements were carried out using a potentiostat equipped with a five-channel zero resistance ammeter (ZRA) for galvanic current measurements. The instruments were sectioned into three parts (cutting part, noncutting part and shank) and degreased with acetone and rinsing with demineralized water prior to being immersed in NaOCl solution for testing. Each set of the three parts constituted one 'virtual' instrument through the ZRA, giving access to the galvanic currents that circulate between the three parts. Nine instruments were employed to check the reproducibility of the electrochemical measurements. RESULTS: The corrosion potential (E(corr)) of the NiTi alloy reached the passive domain in approximately 20 s of immersion in the solution having a pH 10.1. After this initial period the potential remained steady, indicating that stable passivation was achieved. However, at pH 12.3 no stationary state was achieved even after 6000 s of immersion time. Thus, the alloy was not stable in this medium from a corrosion point of view. CONCLUSIONS: The corrosion resistance of NiTi alloy was enhanced by lowering the pH of NaOCl solution to 10.1, which allows the system to reach the stability domain of the passivating species TiO2 and NiO2.

La influencia de la permeabilidad manual en el porcentaje de separación de los instrumentos rotatorios de NiTi / The influence of a manual glide path on the separation rate of Niti rotary instruments

El propósito doble de este estudio fue evaluar el porcentaje de fracturas de los instrumentos rotatorios de Ni-ti al seguir una permeabilidad preparada manualmente con limas manuales de acero inoxidable antes de la instrumentación con limas rotatorias y comparar los resultados en este estudio con los obtenidos en dos análisis previos en que no se empleó la técnica de permeabilidad manual. Se dividieron un total de 208 conductos radiculares obtenidos de una muestra de molares humanos superiores e inferiores recientemente extraídos en tres grupos que correspondieron a K3, ProFile y ProTaper. Se emplearon los 2/3 coronales de cada diente. En los tres grupos la porción apical de las muestras se preparó con limas manuales K de acero inoxidable de calibres 10-20. Los topes apicales se prepararon con instrumentos rotatorios K3, ProFile y ProTaper. El análisis del modelo de regresión logística indicó que la rotura estaba significativamente asociada con el ángulo de curvatura del conducto (OR= 1.078; 95% CI= 1.032-1.12; p= 0,001) y con el número de usos clínicos (las limas empleadas más de ocho veces se rompieron más frecuentemente que las empleadas de 1 a 2 veces; OR= 22.686; CI 95%: 2,6-191.3; p= 0,004). El porcentaje de rotura obtenido en este estudio es significativamente menor que en nuestros estudios previos, en que el ángulo de curvatura era también mayor de 30° y la velocidad constante de rotación de 350 rpm, pero en que los conductos no se prepararon inicialmente con limas manuales (25/205= 12% frente a l6/6l = 26%, p= 0,007). Basándose en los resultados de este estudio, recomendamos el uso de limas manuales de acero inoxidable para preparar el tercio apical de los conductos curvados antes de emplear las limas rotatorias

The dual purpose of this study was, to evaluate the fracture rate of Ni-Ti rotary instruments when following a manual glide path and using stainless steel band files before carrying out instrumentation by means of rotary files and, to compare the results in this study with those obtained in two previous analyses, in which the glide path technique was not used. A total of 208 canals obtained from a pool of freshly extracted human mandibular and maxillary molars was divided into three groups corresponding to; K3, ProFile and ProTaper. The coronal 2/3 of each tooth were used. In all three groups the apical portion of the samples was prepared with size 10-20 stainless steel K-type hand files. The apical stops were prepared using K3, ProFile and ProTaper rotary instruments. Logistic regression model analysis indicated that breakage was significantly associated with the angle of curvature of the canal (OR = 1.078; 95% Cl= 1.032-1.12;p = 0.001), and with the number of clinical uses (files used more than eight times broke more frequently that those used 1 o 2 times; OR: 22.686; 95% Cl: 2.6-191.3; p= 0.004). The breakage rate obtained in the present study is significantly lower than in our previous studies, in which the angle of curvature was also greated than 30° and rotational speed a constant 350 rpm, but in which the canals were not first prepared with hand files (25/205 = 12% versus 16/61 = 26%, p = 0.007). Based on the results of this study, were recommend the use of stainless steel band files to prepare the apical 1/3 of curved canals before introducing rotary files

Analysis of the area and length of masticatory cycles in male and female subjects.

It is difficult to determine the existence of a normal or physiological masticatory cycle, because there exists great individual diversity. This study presents some data about two parameters of masticatory cycles according to the frontal plane, i.e. the area and length of right-sided and left-sided cycles in a group of 30 young people, 18 women and 12 men. For our study the Myotronics K6-1 kinesiograph was used. It registers the magnetic field and allows us to obtain graphic recordings of the jaw movement in the three space planes. Other authors have analysed these parameters, but none of those reviewed provides information about the distribution to each side or according to the gender of sampling subjects selected for the analysis. We have tried to describe the normal morphology of the masticatory cycles and, also, establish a reference so as to provide help in the diagnosis of the functional pathology of the masticatory system.

Estudio de la filtración en materiales de obturación a retro / Study of leakage in retrofilling materials

Introducción: La elección de un material biocompatble adecuado en la obturación a retro es uno de los objetivos para el éxito en una apicetomía. Objetivos: Valorar la filtración en los materiales más utilizados en las obturaciones a retro. Material y métodos: Estudiamos la filtración de MTA® (Maillefer), gutapercha (Dentsply Detrey), amalgama (Tytin©), IRM© (Dentsply Detrey) como materiales en obturaciones a retro, con azul de metileno y posterior diafanización para ser estudiados en lupa estereoscópica. Previamente se estandarizaron los niveles de filtración por medio de un programa de medición digital por ordenador (Micro Image© 3.0). El análisis estadístico de filtración se realizó por medio de la comparación global o Kruskal-wallis y la comparación dos a dos o de Bonferroni. Resultados: El cemento MTA® (Maillefer) junto con la amalgama Tytin® Kerr poseen los índices más bajos de filtración- en las obturaciones-. a. retro (AU)

Estudio comparativo de microfiltración con tres sistemas de foto olimerización / Comparative study of microfiltration with three fotopolymerizer systems

La aparición de nuevas energías ionizantes como el láser de argón, el gas xenón (luz plasma), luz halógena de intensidad progresiva junto con la mejora de las resinas compuestas nos permitirá acortar el tiempo de curado, la colocación de mayores espesores de material y una menor contracción de polimerización. El objetivo de este estudio es observar el grado de filtración in vitro de cavidades de clase 11 obturadas con composite y polimerizadas con luz halógena continua, luz halógena de intensidad progresiva y luz plasma: Se realizaron 60 cavidades de clase 11 estandarizadas y se dividieron aleatoriamente en tres grupos polimerizando cada grupo con una de las siguientes lámparas: Wavelight®, Astralis® 7 y Heliolux© GTE siguiendo las indicaciones de las casas comerciales. Se sometieron a un proceso de termociclado y posteriormente se sumergieron en azul de metileno durante 24h. Tras la observación con lupa estereoscópica encontramos una menor filtración con la Astralis 7 aunque las diferencias no son estadísticamente significativas (AU)

[A case of appendicular supplementary root with external root resorption]. / Raíz supernumeraria con reabsorción radicular externa. Caso clinico.

The case of a lateral maxillary incisor with a supplementary root fractured by external root resorption, is presented. The role played for the periodontal disease is shown in the clinical and radiographic achievements, and their implications in the pulpal disease. Endodontic therapy was performed and the diagnosis confirmed in the specimen histological research.

[Scanning electron microscope study of unerupted enamel surface in adult patients]. / Estudio con microscopia electrónica de barrido de la superficie del esmalte no erupcionado en pacientes adultos.

We have undertaken a scanning electron microscope study of the enamel surface of the third molar in adult patients. The enamel surface are partially covered by a thin cuticle. The arrangement of the enamel prisms was clearly observed in the basal region of the cusps.