Accuracy in osteotomy drilling using a new universal and disposable drill-stop device for dental implant drills: an in vitro study using a bovine rib model.

BACKGROUND: This study aimed to evaluate the surgical accuracy of a new universal disposable stop system for implant drills (FCA Universal Drill Stop). MATERIAL AND METHODS: A total of 60 bovine ribs were included in this in vitro study. The ribs were randomized into three study groups (n=20 ribs per group). In each study group (Group1: drills without stop or control group, Group 2: prefabricated drills with stop or gold standard group, and Group 3: drills with FCA Universal Drill Stop) a total of 100 osteotomies were performed with implant drills in each group, following the drilling sequence for the placement of a dental implant of 10 mm length and 4 mm diameter. The accuracy of the depth of the osteotomies was quantified clinically (with periodontal probe) and radiologically, using ImageJ version 1.48v software. RESULTS: The order of highest to lowest accuracy (clinical and radiological) in the depth of osteotomies was: FCA Universal Drill Stop> prefabricated drills with a stop>drills without stop, with statistically significant differences being observed between both systems with stop with respect to the control group, although not between them. CONCLUSIONS: The new universal disposable stop system for implant drills, offers similar accuracy to prefabricated drills with stop, with both systems being much more accurate than implant drills without stop. Although this experimental evaluation showed favourable results, further clinical studies are necessary.

Epidemiology of central nervous system tumors at the Instituto Nacional de Neurología y Neurocirugía in Mexico City.

The purpose of this study was to determine the frequency of different Central Nervous System Tumors (CNST) diagnosed at the Instituto Nacional de Neurología y Neurocirugía (National Institute of Neurology and Neurosurgery) from Mexico City over a 10-year period (1990 to 1999) by means of a hospital survey. This institute is a reference hospital that provides medical attention to a very high number of adult neurological patients every year (approximately 6,000 new patients per year besides emergency cases). From a total number of 2,041 CNST cases, we found that the most frequent tumors were those affecting the neuroepithelial tissue (32.8 %), followed by tumors of the anterior pituitary gland (26.2 %) and tumors of the meninges and similar tissues (24.1 %). In both, male and female patients the higher frequency of CNST was found in patients whose age ranged from 25 to 44 years, and CNST were slightly more frequent in women than in men. Most of the CNST patients lived in the southern districts of Mexico City, it could be because of the great number of people living in the southern districts of the city, or perhaps due to the presence of certain yet unidentified environmental carcinogenic substance in this area. Since CNST are among the more frequent malignant neoplasms, it is necessary to improve the registration system to include frequency, prevalence, incidence and mortality of these diseases in Mexico, in order to plan health policies like in developed countries.

Epidemiología de los tumores del sistema nervioso central en el Instituto Nacional de Neurología y Neurocirugía de la Ciudad de México / Epidemiology of central nervous system tumors at the Instituto Nacional de Neurología y Neurocirugía in Mexico City

El objetivo de este estudio ha sido determinar la frecuencia de diferentes tumores del sistema nervioso central (TSNC) diagnosticados en el Instituto Nacional de Neurología y Neurocirugía en la Ciudad de México durante un período de 10 años (1990 a 1999) utilizando una encuesta hospitalaria. Este instituto es un hospital de referencia que proporciona cada año asistencia médica neurológica a un número elevado de pacientes adultos (aproximadamente 6.000 nuevos pacientes anuales además de los casos de emergencia).De un total de 2.041 casos de TSNC hemos encontrado que los tumores más frecuentes fueron aquellos que afectaban el tejido neuroepitelial (32,8 por ciento), seguidos de tumores de la glándula pituitaria anterior (26,2 por ciento) y tumores de las meninges y de los tejidos semejantes (24,1 por ciento). Se encontró la frecuencia más alta de TSNC en pacientes cuyas edades varían de 25 a 44 años, tanto en pacientes femeninos como masculinos, y los TSNC fueron ligeramente más frecuentes en mujeres que en hombres. La mayoría de los pacientes de TSNC vivían en los distritos del sur de la Ciudad de México. Esto puede deberse al mayor número de personas que vivían en los distritos del sur de la ciudad o quizá debido a la presencia de una sustancia carcinogénica ambiental hasta ahora no identificada en esta área.Ya que los TSNC se encuentran entre los neoplasmas malignos más frecuentes, es necesario mejorar el sistema de registro, incluyendo la frecuencia, prevalencia, incidencia y mortalidad de estas enfermedades en México, para planificar la política sanitaria tal y como se realiza en los países desarrollados. (AU)