Effect of preflaring on Root ZX apex locators.

The Root ZX apex locator is an example of a generation of apex locators that identify the terminus of the canal by measuring a ratio between two electrical impedances. Studies have shown this device to have a high degree of accuracy. However, the manufacturer warns that the performance of these devices is limited by the presence of calcifications and dentinal shaving obstructions. An in vitro study was designed to determine if preflaring of canals would facilitate the passage of files to the apical foramen by eliminating cervical interferences and to see what effect this would have on the performance of the Root ZX apex locator. Thirty-two canals were divided into two groups. Group 1 was not manipulated before use of the Root ZX apex locator and served as control. In group 2, the canals were preflared before the use of the Root Zx apex locator. The working length files were secured in place and measured with the linear measurement tool used by the Visilog 5 imaging program. Results of this study suggest that preflaring of canals will allow working length files to more consistently reach the apical foramen (p = 0.015), which in turn increases the efficacy of the Root ZX apex locator.

Rubber latex allergy and the endodontic patient.

Increasingly, patients with rubber latex allergy are being seen in dental offices. Health care workers, persons allergic to certain foods and those with certain medical histories are potentially latex-sensitive. This article presents the case of a patient with a history of severe rubber latex allergy and the associated management of an endodontically involved tooth. The possibility of the latex allergic patient being sensitive to gutta-percha obturation material is also raised.

Factors affecting the negotiability of second mesiobuccal canals in maxillary molars.

Factors affecting the negotiability of MB2 canals were evaluated by studying 87 extracted maxillary molars that had undergone previous endodontic treatment in the endodontic technique laboratory. The mesiobuccal roots were resected and radiographed, after which a #08 file was used in an attempt to negotiate those roots with the potential for a second mesiobuccal canal. The file was then intentionally separated in the MB2 canals that could be negotiated. The roots were decalcified, cleared, and observed under a stereomicroscope. Several factors that could interfere with the total or partial negotiation of MB2 canals were identified and included accumulation of debris and sealer that blocked access to these canals, dentinal debris produced with the pathfinding instrument, the presence of anatomical variations, diffuse calcifications, and pulp stones.

Assessing apical deformation and transportation following the use of LightSpeed root-canal instruments.

The LightSpeed root canal instrument is similar in design to the Canal Master instrument with the exception of being engine driven and fabricated from nickel-titanium alloy. The purpose of the design of these instruments is to reduce apical transportation of the canal during cleansing and shaping procedures. Twenty extracted human molar teeth with roots of varying degrees of curvature were used in this study. A double exposure radiographic technique was used to assess the presence or absence of apical transportation resulting between the initial instrument and the final instrument, a size 50 LightSpeed. Only one of the 20 teeth examined exhibited apical transportation. Results of this study suggest that little or no apical canal transportation could be expected when curved canals are instrumented using the LightSpeed root canal instruments.

Retrievability of Thermafil plastic cores using organic solvents.

Twenty distal roots of extracted mandibular first and second molars were instrumented, then obturated using Thermafil obturating material with solid plastic core carriers. To simulate a retreatment process, the gutta-percha was softened using one of four solvents, chloroform, xylene, eucalyptol, or halothane. A K file was used to advance the solvent into the gutta-percha and to engage the plastic carrier. In all but one case, the plastic carriers were easily removed from the root canal. It was concluded that the plastic carriers used with the Thermafil obturation media do not present a difficult obstacle for removal should the root require retreatment.

Angiodisplasia pancreatico-duodenal asociada a carcinoide del pancreas. / Pancreatic-duodenal angiodysplasia associated with carcinoid of the pancreas

Una mujer de 41 anos de edad se presento al hospital con sangrado gastro-intestinal cronico y anemia severa. Por arteriografia se demostro una malformacion arterio-venosa (angiodisplasia) de la segunda porcion del duodeno y la cabeza del pancreas con llenado prematuro de la vena porta. En la intervencion quirurgica realizada se encontraron vasos anormales originados en la arteria pancreaticoduodenal y ademas en la cabeza del pancreas se encontro un tumor de 3 x 3 cm. Se realizo pancreatoduodenectomia. Histologicamente se confirmo la presencia de un carcinoide maligno del pancreas con metastasis regionales y multiples vasos anormales

Inyeccion transendoscopica del fleboesclerosante hidroxi-polietoxi-dodecano en la mucosa esofagica del perro. / Transendoscopical injection of sclerosing hydroxypolyethoxydodecane in the mucosa of the esophagus of dogs

Con objeto de conocer los efectos sobre la pared esofagica del fleboesclerosante hidroxi-polietoxidodecano, se les inyecto a 10 perros, por via transendoscopica, 1 ml.de la substancia en la mucosa submucosa del esofago. Este fleoesclerosante a diferencia de otros tiene efecto trombogenico al ser aplicado en la luz de una vena o en el tejido perivenoso. Cuando la concentracion empleada es al 2 o 3% puede producir areas de inflamacion severa, isquemia o aun necrosis, por lo que se concluye que la inyeccion al 1% es la adecuada

[Usefulness of pancreatic scintilography in clinical diagnosis]. / Valor de la centelleografía pancreática en el diagnóstico clínico.

Our experience in pancreatic scintigraphy is presented in this paper. It was used as radioactive substance 75 semetionina. 21 patients with pancreatic pathology and 6 controls constituted the clinical material. The scintigraphy studies showed an homogenous distribution of the radioactive material in the control group. In 7 cases a defect of concentration was showed. The diagnosis of carcinoma were made with surgery in all of them. Similar findings were demonstrated in cases of pancreatic pseudocyst. Irregular distribution was noted in patients with pancreatitis. We concluded that in same instances pancreatic scintigraphy can be useful for differential diagnosis in the clinical field.