Analysis of the surface roughness and microhardness of dental restorative materials exposed to heat sources and cold temperatures for human identification purposes

Roberto Cesar Biancalana,Fernanda Carvalho Panzeri Pires-De-Souza,Sergio Augusto De Freitas Vincenti,Ricardo Henrique Alves Da Silva

doi:10.1186/s41935-019-0114-x

Roberto Cesar Biancalana, Fernanda Carvalho Panzeri Pires-De-Souza + Show 2 more

Open Access

https://doi.org/10.1186/s41935-019-0114-x

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Abstract

BackgroundFatal accidents involving the action of heat, such as burns, explosions, automobile accidents, and aircraft crashes, among others, or action of cold, such as collisions in snowy locations, severe blizzards, cold waves, earthquakes, and avalanches, are frequent day-to-day occurrences. During post-mortem dental examination of victims, restorative materials such as the composite resin (CR), glass ionomer cement (GIC), and amalgam may be found. The action of the heat or cold on these materials may change their properties. This study aimed to evaluate the changes occurred in the surface roughness and Knoop microhardness of the dental restorative materials of freezing or burnt victims, supporting an adequate comparison with the antemortem data, helping on human identification process.MethodsOne hundred eighty caries-free bovine teeth were prepared and separated into groups, according to the restorative material, temperature, and period for analysis. The surface roughness and microhardness were analyzed by a profilometer and a microhardness tester, before and after the action of the heat (100 °C, 200 °C, 300 °C) and the cold temperatures (2.5 °C, − 20 °C, − 80 °C).ResultsThe results demonstrated that there was no alteration on properties of CR after the heat that caused significant changes in the surface roughness of GIC and amalgam and the microhardness of GIC. The low temperatures produced no significant differences in any of the properties of the restorative materials studied.ConclusionThe surface roughness and Knoop microhardness tests could distinguish the tooth-colored restorative materials irrespective of the action of the heat or cold temperatures.

Highlights

Fatal accidents involving the action of heat, such as burns, explosions, automobile accidents, and aircraft crashes, among others, or action of cold, such as collisions in snowy locations, severe blizzards, cold waves, earthquakes, and avalanches, are frequent day-to-day occurrences
Considering the scarcity of literature that correlates the properties of dental restorative materials to the forensic field, this study aimed to evaluate the effect of the heat and cold on the surface roughness and Knoop microhardness of composite resin (CR), glass ionomer cement (GIC), and amalgam by simulating the behavior of these materials when they are present in the teeth of victims of these types of events, with the purpose of contributing to forensic odontology in the process of human identification
Relative to GIC, the group exposed to 300 °C presented significant difference (p < .05) in comparison with the group exposed to 100 °C so that the higher the temperature to which the tooth was subjected, the higher was the surface roughness values found

Summary

Introduction

Fatal accidents involving the action of heat, such as burns, explosions, automobile accidents, and aircraft crashes, among others, or action of cold, such as collisions in snowy locations, severe blizzards, cold waves, earthquakes, and avalanches, are frequent day-to-day occurrences. This study aimed to evaluate the changes occurred in the surface roughness and Knoop microhardness of the dental restorative materials of freezing or burnt victims, supporting an adequate comparison with the antemortem data, helping on human identification process There are situations such as air crashes or car accidents with explosions and fires that can result in carbonized remnants of fatal burn victims (Skinner and Sterenberg 2005). Other types of accidents, such as landslides, heavy snowstorms, collisions, or snow avalanches, in which death occurs as a result of low temperatures or from severe traumas and polytraumas (Boyd et al 2009), may make it difficult to identify the corpses adequately In these accidents, it can be difficult to access victims due to the climatic and geographic conditions of the site, and a longer time to locate the bodies may be required (Blau and Briggs 2011). Forensic odontology may be an appropriate and feasible solution for human identification, decreasing the working time and material costs, in addition to being highly reliable, provided that careful, meticulous, and organized work is done (Valenzuela et al 2000)

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