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

• Published in: Egyptian journal of forensic sciences 2019-02, Vol.9 (1), p.1-9, Article 8
• Main Authors: Biancalana, Roberto Cesar, Vincenti, Sergio Augusto de Freitas, da Silva, Ricardo Henrique Alves, Pires-de-Souza, Fernanda Carvalho Panzeri
• Format: Article
• Language: English
• Subjects: Cold; Cold temperature; Composite materials; Dental materials; Dental restorative materials; Forensic Medicine; Forensic odontology; Forensic sciences; Heat; Heat source; Human remains; Medicine; Medicine & Public Health; Original Article; Pathology; Surface roughness
• ISSN: 2090-5939; 2090-536X; 2090-5939
• DOI: 10.1186/s41935-019-0114-x

Background 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. 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. Methods One 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). Results The 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. Conclusion The surface roughness and Knoop microhardness tests could distinguish the tooth-colored restorative materials irrespective of the action of the heat or cold temperatures.