Cobalt-chromium alloys in dentistry: An evaluation of metal ion release.

STATEMENT OF PROBLEM: Metal ions released into the oral cavity from dental prosthesis alloys may damage the cellular metabolism or proliferation and cause hypersensitivity or allergies. The oral cavity environment is particularly prone to corrosion due to saliva, microorganisms, and pH variations. PURPOSE: The purpose of this in vitro study was to evaluate the ion release of chromium, cobalt, and iron from the Co-Cr alloys used for traditionally cast and computer-aided design/computer-aided manufacturing dental devices after interaction with oral bacteria and different pH conditions. MATERIAL AND METHODS: All specimens were prepared from currently available alloys, polished, and immersed in 3 different pH media (artificial saliva [pH 2.3] and 6.5% and 0.9% saline solution [pH 7.1]). Specimens were also incubated in the presence of the bacterium Eikenella corrodens. Solutions were analyzed with an atomic absorption spectrometer after 15 and 30 days in the chemical corrosion test and 30 days in the biocorrosion test to detect ions released in different solutions. An ANOVA test was used to evaluate statistically significant differences among the percentages of metal corrosion ion release values. RESULTS: The greatest amount of element release was seen after 30 days: 4.964 ppm of casting alloy, 2.642 ppm of milling alloy, and 2.351 ppm of laser metal sintering. CONCLUSIONS: With the exception of casting alloy under acidic conditions, no significant differences were found, even after exposure to bacteria.

Forensic interlaboratory evaluation of the ForFLUID kit for vaginal fluids identification.

Identification of vaginal fluids is an important step in the process of sexual assaults confirmation. Advances in both microbiology and molecular biology defined technical approaches allowing the discrimination of body fluids. These protocols are based on the identification of specific bacterial communities by microfloraDNA (mfDNA) amplification. A multiplex real time-PCR assay (ForFLUID kit) has been developed for identifying biological fluids and for discrimination among vaginal, oral and fecal samples. In order to test its efficacy and reliability of the assay in the identification of vaginal fluids, an interlaboratory evaluation has been performed on homogeneous vaginal swabs. All the involved laboratories were able to correctly recognize all the vaginal swabs, and no false positives were identified when the assay was applied on non-vaginal samples. The assay represents an useful molecular tool that can be easily adopted by forensic geneticists involved in vaginal fluid identification.