Release of metals from osteosynthesis implants as a method for identification: post-autopsy histopathological and ultrastructural forensic study

Assessment protocol of mesothelioma and relevance of SEM-EDS analysis through a case studies of legal medicine of Brescia (Italy)

INTRODUCTION

This study evaluates the assessment protocol that allows the correlation between the development of mesothelioma to a specific exposure, with particular focus on investigations with Scanning Electron Microscope with Energy Dispersion Spectroscopy.

METHODS

This retrospective study includes 80 subjects who died from mesothelioma in the period 2001-2019. A judicial autopsy was performed for each case to confirm cause of death and correlate the disease with specific asbestos exposure. In 28 cases investigations were carried out to determine the pulmonary load of the asbestos fibres and corpuscles in the lung tissue through microscopic investigations, in order to confirm the suspicion of occupational exposure.

RESULTS

Our data agree with the scientific literature reported, but it is interesting to underline how the present study uses a different systematic approach than others, which are mainly based on epidemiological and environmental studies without considering the lung content of fibres and corpuscles.

CONCLUSION

It would be desirable that the use of the microscopic analysis was introduced in the evaluation protocol: it should always be carried out if the suspicion of asbestos-related disease is raised and not only as a possible integration to the less expensive anamnestic evaluation, even more so if the work or personal history should be suggestive of exposure to asbestos fibres.

Spectrometric Analysis of the Wear from Metallic and Ceramic Dental Implants following Insertion: An In Vitro Study

Titanium wear is a growing area of interest within dental implantology. This study aimed to investigate titanium and zirconium wear from dental implants at the time of insertion using X-ray-fluorescence spectrometry (XRF) and an in vitro protocol utilizing artificial bovine bone plates. Five groups were analyzed using XRF-spectrometry: groups 1–4 (titanium implants) and group 5 (zirconia implants). The implants were inserted into two bone blocks held together by a vice. The blocks were separated, and the insertion sites were analyzed for titanium (Ti) and zirconium (Zr). Statistical descriptive analyses of Ti and Zr concentrations in the coronal, middle and apical bone interface were performed. A comparative analysis confirmed differences between the implant’s surface stability and Ti accumulation within the insertion sites of the bone block. There was a direct relationship between implant length and the quantity of titanium found on the bone block. The data generally indicates greater quantities of titanium in the coronal thirds of the implants, and less in the apical thirds. The titanium and zirconium found in the bone samples where the group 5 implants were inserted was not of statistical significance when compared to control osteotomies. The results of this study confirm wear from metallic, but not ceramic, dental implants at the time of insertion.

Titanium Wear of Dental Implants from Placement, under Loading and Maintenance Protocols

The objective of this review was to analyze the process of wear of implants leading to the shedding of titanium particles into the peri-implant hard and soft tissues. Titanium is considered highly biocompatible with low corrosion and toxicity, but recent studies indicate that this understanding may be misleading as the properties of the material change drastically when titanium nanoparticles (NPs) are shed from implant surfaces. These NPs are immunogenic and are associated with a macrophage-mediated inflammatory response by the host. The literature discussed in this review indicates that titanium NPs may be shed from implant surfaces at the time of implant placement, under loading conditions, and during implant maintenance procedures. We also discuss the significance of the micro-gap at the implant-abutment interface and the effect of size of the titanium particles on their toxicology. These findings are significant as the titanium particles can have adverse effects on local soft and hard tissues surrounding implants, implant health and prognosis, and even the health of systemic tissues and organs.

Forensic - Pathological SEM/EDX analysis in prosecution of medical malpractice

The retention of gauze within the mediastinum is considered an exceptional finding. We are presenting the case of a woman, affected by aorto-mitral valvulopathy, in whose mediastinum was found, during the autopsy, a gauzome without signs of active phlogosis, which had been "forgotten" in a previous surgery, acted 14 years before the death. A 39 y.o. woman had received surgical treatment of double aorto-mitral valve substitution and tricuspid plastic. At age 53, she successfully received surgery once again at a different hospital; she then started rehabilitation therapy, during which she deceased due to sudden hematemesis with infectious multi organ failure. During the autopsy, a 5 cm long surgical gauze was found in the mediastinum. A SEM/EDX (Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy) exam was ran on the foreign body and a sample of the same gauze used in the cardiac-surgical department of the hospital the victim had passed away in, to act a comparison between the two kinds of material. The exam showed a morphological difference between exogenous fibers incorporated within the gauzome and the control gauze. This case highlights the diagnostic and interpretative challenges in finding a foreign body within the mediastinum without signs of active phlogosis. SEM/EDX investigations executed on the gauzome and a "control gauze" allowed the attribution of malpractice to the first hospital the victim had been operated in 14 years before the exitus. The SEM/EDX exam confirms its importance in correctly identifying the case, which becomes an example for similar happenings.

Characterisation of the weapon used in a patricide by SEM/EDS analysis of a microscopic trace from the object

This article presents a case of patricide. The murder was characterised by multiple blunt traumas and asphyxia. A mass of contused wounds was localised to the head and neck, and included the complete avulsion of the left eye (by an unknown tool), which was recovered near the cadaver. This case is of interest due to the possibility of identifying microscopic traces of the object that was used for the homicide by examining the skin margins around the ocular injury. The analysis was conducted using scanning electron microscopy combined with energy dispersive X-ray analysis (SEM/EDX). Analysis of the skin margins allowed microscopic inorganic traces to be detected, which were identified as ceramic material. This result focused the attention of the investigation on a small fish-shaped statue that had been previously found by the police when examining the crime scene. The use of SEM/EDX was therefore essential in determining a match between the microscopic traces detected on the perilesional skin and the composition of the statue. This led to the suspicion that the statue was the murder weapon.