ABSTRACT
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
Subject(s)
Humans , Dental Instruments , Equipment Failure Analysis/methods , Root Canal Preparation/instrumentation , Tooth Permeability , Root Canal Preparation/methodsABSTRACT
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.
Subject(s)
Mandible/physiology , Mastication/physiology , Sex , Adult , Female , Humans , Male , Reference ValuesABSTRACT
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)
Subject(s)
Humans , Dental Leakage , Biocompatible Materials , Dental Materials , Dental Restoration, Permanent , Apicoectomy/methodsABSTRACT
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)
Subject(s)
Filtration/methods , Dental Restoration, Permanent , Composite Resins , Light , Polymers/chemistry , PhotochemistryABSTRACT
Mice exposed to surgical stress induced by laparotomy and treated with chronic alprazolam (0.5-2 mg/kg) showed a dose-dependent reduction in stress-induced suppression of the natural killer (NK) cell activity. These immunoenhancing effects of alprazolam were more intense when it administered before the surgery was performed.
Subject(s)
Alprazolam/pharmacology , Killer Cells, Natural/drug effects , Stress, Physiological/immunology , Animals , Antibody Formation/drug effects , Dose-Response Relationship, Drug , Killer Cells, Natural/immunology , Male , Mice , Mice, Inbred BALB C , Stress, Physiological/drug therapy , Stress, Physiological/etiology , Surgical Procedures, Operative/adverse effectsSubject(s)
Composite Resins , Incisor/injuries , Post and Core Technique , Tooth Fractures/therapy , Adolescent , Adult , Child , Humans , Root Canal TherapyABSTRACT
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.
Subject(s)
Root Resorption , Tooth Root/abnormalities , Humans , Incisor/abnormalities , Male , Middle Aged , Periodontitis/complications , Root Canal Therapy , Tooth Fractures/etiologyABSTRACT
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.
Subject(s)
Dental Enamel/ultrastructure , Molar, Third/ultrastructure , Adult , Amelogenesis , Humans , Microscopy, Electron, Scanning , Surface Properties , Tooth, Unerupted/ultrastructureABSTRACT
A scanning electron microscope study was made to study the morphological changes in the human enamel surface produced by low and high temperatures. Cracked dental enamel was observed when the teeth were exposed at low and high temperatures. When the time of exposition was increased, there are more enamel cracks which may be considered as enamel fractures.
Subject(s)
Dental Enamel/ultrastructure , Tooth Fractures/etiology , Bicuspid , Cold Temperature , Dental Enamel/pathology , Hot Temperature , Humans , Microscopy, Electron, Scanning , Surface PropertiesABSTRACT
In this paper we report a Gorlin's syndrome in a patient, who was first diagnosed as a case of a large odontogenic keratocyst. Posterior analysis demonstrate the presence of other keratocyst in the maxilla and in the mandible, as well as lumbar scoliosis, lack and malformation of ribs, calcification of the brain sickle and folicles of 8 mm of diameter in the right ovary. The possible presence of nevoid basal cell carcinomas will be also considered.
Subject(s)
Basal Cell Nevus Syndrome/pathology , Carcinoma, Basal Cell/pathology , Jaw Cysts/pathology , Child , Diagnosis, Differential , Female , Humans , Jaw Cysts/diagnostic imaging , Odontogenic Cysts/diagnosis , Odontogenic Cysts/diagnostic imaging , RadiographyABSTRACT
This paper report a scanning electron microscope study of the dentinal surface after treatment with sodium N-monochloro-DL2-aminobutyrate (NMAB). The carious cavity shows a rugous and irregular surface. There are detaching plates of the dentin dissolved by the NMAB. At high magnification the compact dentin and the detaching plates show a acid-etched surface.
