Analysis of procedures used in tooth avulsion by 100 dental surgeons

Accurate diagnosis and adequate treatment plan may constitute very complex tasks, particularly in tooth avulsion, because several variables are involved. In addition to the technical knowledge and clinical experience directed toward the quality of treatment, patient education may favorably influence the survival of replanted teeth. The aim of this study was to analyze the procedures used in the management of tooth avulsion by 100 dental surgeons (DSs). Thus, by means of a descriptive questionnaire, information was obtained about the profile of the professionals interviewed, procedures used in cases of tooth avulsion, and patient orientation and education. One hundred properly filled questionnaires were obtained. Descriptive statistics was used for the data, and the chi-squared statistics was employed (EPI-INFO 3.2 software). According to the results, this type of trauma is part of the routine of 15 DSs, although 71 have reported some experience with avulsed,teeth. Great deficiencies were found regarding root surface treatment and occlusal adjustment. Positive findings were related to socket treatment, adjunctive therapy, and patient education and orientation (extra-alveolar period, storage medium, manipulation of the avulsed tooth, replantation by the own patient). It was possible to conclude that 47.5% of the procedures reported by, 100 professionals interviewed are adequate, and patient education is favorable in 87.7% of cases, a fact that can positively interfere with the prognosis of tooth replantation.

The effects of anxiety on visual search, movement kinematics, and performance in table tennis: A test of Eysenck and Calvo's processing efficiency theory

Processing efficiency theory predicts that anxiety reduces the processing capacity of working memory and has detrimental effects on performance. When tasks place little demand on working memory, the negative effects of anxiety can be avoided by increasing effort. Although performance efficiency decreases, there is no change in performance effectiveness. When tasks impose a heavy demand on working memory, however, anxiety leads to decrements in efficiency and effectiveness. These presumptions were tested using a modified table tennis task that placed low (LWM) and high (HWM) demands on working memory. Cognitive anxiety was manipulated through a competitive ranking structure and prize money. Participants' accuracy in hitting concentric circle targets in predetermined sequences was taken as a measure of performance effectiveness, while probe reaction time (PRT), perceived mental effort (RSME), visual search data, and arm kinematics were recorded as measures of efficiency. Anxiety had a negative effect on performance effectiveness in both LWM and HWM tasks. There was an increase in frequency of gaze and in PRT and RSME values in both tasks under high vs. low anxiety conditions, implying decrements in performance efficiency. However, participants spent more time tracking the ball in the HWM task and employed a shorter tau margin when anxious. Although anxiety impaired performance effectiveness and efficiency, decrements in efficiency were more pronounced in the HWM task than in the LWM task, providing support for processing efficiency theory.

Light microscopy and computer three-dimensional reconstruction of the blood capillaries of the enamel organ of rat molar tooth germs

We performed a light microscope and a computer three-dimensional reconstruction study of serial sections of the molar enamel organ of 3- and 5-day-old rats perfused with Indian ink through the arterial system. The tooth germs were fixed in Bouin's solution, embedded in paraffin, sectioned and stained with haematoxylin and eosin. For the three-dimensional reconstruction, light micrographs of the serial sections were digitized, and aligned using the serial EM Align software downloaded from http://synapses.bu.edu/tools/. After alignment, the boundaries of the India-ink-filled blood vessels were manually traced with a mouse using the software IGL trace (version 1.26b), also downloaded from the above website. After tracing, a three-dimensional representation of the blood vessel contours was generated in a VRML format and visualized with the help of the software Cortona Web3D viewer (version 4.0) downloaded from http://www.parallelgraphics.com/products/cortona. Our results showed that in regions where ameloblasts are polarized the capillaries are arranged in three distinct levels: (1) penetrating and leaving capillaries in relation to the outer enamel epithelium; (2) capillaries crossing and branching inside the stellate reticulum; and (3) capillaries branching and anastomosing profusely within the stratum intermedium, thereby forming an extensive capillary plexus intimately associated with the cells of the stratum intermedium. The existence of a conspicuous capillary plexus intermingled with cells of the stratum intermedium, as shown in our results, suggests that some molecules produced by cells of the stratum intermedium could be released into the capillary plexus and thereafter carried to the dental follicle.

FRACTAL CHARACTERISTICS OF THE HORIZONTAL MOVEMENT OF WATER IN SOILS

Observed deviations from traditional concepts of soil-water movement are considered in terms of fractals. A connection is made between this movement and a Brownian motion, a random and self-affine type of fractal, to account for the soil-water diffusivity function having auxiliary time dependence for unsaturated soils. The position of a given water content is directly proportional to t(n), where t is time, and exponent n for distinctly unsaturated soil is less than the traditional 0.50. As water saturation is approached, n approaches 0.50. Macroscopic fractional Brownian motion is associated with n < 0.50, but shifts to regular Brownian motion for n = 0.50.