Evaluation of the anesthetic effect of epinephrine-free articaine and mepivacaine through quantitative sensory testing

INTRODUCTION: Long lasting anesthesia of the soft tissue beyond the dental treatment affects patients in daily routine. Therefore a sophisticated local anesthesia is needed. The purpose of this study was an evaluation of the clinical use of epinephrine-free local anesthetic solutions in routine short-time dental treatments. MATERIALS AND METHODS: In a prospective, single-blind, non-randomized and controlled clinical trial, 31 patients (16 male, 15 female patients) undergoing short-time dental treatment under local anesthesia (plain solutions of articaine 4% and mepivacaine 3%) in area of maxillary canine were tested with quantitative sensory testing QST. Paired-Wilcoxon-testing (signed-rank-test) and Mc Nemar tests have been used for statistical results. RESULTS: Significant differences in all tested parameters to the time of measurements were found. Mepivacaine showed a significantly stronger impact for the whole period of measurement (128 min) on thermal and mechanical test parameters and to the associated nerve fibers. CONCLUSION: Plain articaine shows a faster onset of action associated with a shorter time of activity in comparison to plain mepivacaine. In addition to this articaine shows a significant low-graded effect on the tested nerve-fibers and therefore a least affected anesthesia to the patient. The clinical use of an epinephrine-free anesthetic solution can be stated as possible option in short dental routine treatments to the frequently used vasoconstrictor containing local anesthetics. Patients may benefit from shorter numbness

Double-pass acousto-optic modulator system

A practical problem that arises when using acousto-optic modulators (AOMs) to scan the laser frequency is the dependence of the beam diffraction angle on the modulation frequency. Alignment problems with AOM-modulated laser beams can be effectively eliminated by using the AOM in the double-pass configuration, which compensates for beam deflections. On a second pass through the AOM, the beam with its polarization rotated by 90 degrees is deflected back such that it counterpropagates the incident laser beam and it can be separated from the input beam with a polarizing beam splitter. Here we present our design for a compact, stable, double-pass AOM with 75% double-pass diffraction efficiency and a tuning bandwidth of 68 MHz full width at half maximum for light transmitted through a single-mode fiber. The overall efficiency of the system (defined as the optical power out of the single-mode fiber divided by the optical power into the apparatus) is 60%

Cryogenic Fountain Development at NIST and INRIM: Preliminary Characterization

This paper describes the new twin laser-cooled Cs fountain primary frequency standards NIST-F2 and IT-CsF2, and presents some of their design features. Most significant is a cryogenic microwave interrogation region which dramatically reduces the blackbody radiation shift. We also present a preliminary accuracy evaluation of IT-CsF2