In Vitro Description of Macroscopic Changes of Dental Amalgam Discs Subject to High Temperatures to Forensic Purposes

Abstract

Objective: To describe the behavior of 45 discs of dental amalgam of known dimension prepared from three commercially available brands of dental amalgam (Contour® Kerr®-USA, Admix® SDI®-Australia and Nu Alloy® Newstethic®-Colombia) when subjected to the action of high temperatures (200 °C, 400 °C, 600 °C, 800 °C, 1000 °C). It was hoped to establish parameters that could be used for human dental identification in cases of charred, burned or incinerated human remains.

Materials and methods: A pseudo-experimental descriptive in-vitro study was designed to describe the macroscopic physical changes to the surface of 45 discs of pre-prepared amalgam of three commercially available brands exposed to a range of high temperatures.

Results: Characteristic and repetitive physical changes were a noticeable feature of the discs of amalgam of each brand of amalgam subjected to the different temperature ranges. These physical changes included changes in dimensional stability, changes in texture, changes in colour, changes in the appearance of fissures and cracks and changes in the fracture and fragmentation of the sample.

Conclusions: The characteristics of dental amalgam may be of assistance in cases of human identification where charred, burned or incinerated human remains are a feature and where fingerprints or other soft tissue features are unavailable.

Fig.1

Disc elaborated in dental amalgam.

Fig. 2

Amalgam discs observed at 15X. A1 Contour® Kerr®–USA amalgam disc, A2 Admix® SDI®–Australia amalgam disc and A3 Newstethic®–Colombia amalgam disc. B1 Contour® Kerr® amalgam disc, B2 Admix® SDI®–Australia amalgam disc in which silver nodules were observed and B3 Newstethic®–Colombia amalgam disc subjected to a temperature of 200°C. C1 Contour® Kerr®–USA amalgam disc, C2 Admix® SDI®–Australia amalgam disc and C3 Newstethic®–Colombia amalgam disc subjected to a temperature of 400°C in which silver nodules were observed. D1 Contour® Kerr®–USA amalgam disc, D2 Admix® SDI®–Australia amalgam disc and D3 Newstethic®–Colombia amalgam disc subjected to a temperature of 600°C in which the silver nodules disappear. E1 Contour® Kerr®–USA amalgam disc, E2 Admix® SDI®–Australia amalgam disc and E3 Nu Alloy® Newsthetic®–Colombia amalgam disc subjected to a temperature of 800°C in which the conformation of silver spheres and bands was observed.

Fig. 3

Amalgam discs at 50X in which the appearance of silver nodules was notice between 200° and 400°C, the disappearance of the same at 800°C, and the conformation of silver spheres (E1 and E3) and bands (E2) at 1000°C.