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The methods used for disaster victim identification is comparative postmortem profiling of dental and fingerprint data. Twelve dental concordant features are normally required for dental identification. The radiographic image of dental amalgam restorations has been shown to be highly significant for identification purposes. The aim of this study was to investigate the radiological morphology of standardized radio-opaque composite fillings in premolar teeth with regard to their discriminatory potential for identification purposes. Thirty lower first premolar teeth ("Typodont" acrylic teeth) that were filled with 3- surface fillings (MOD) radio-opaque composite resin (Z100) by 4th year dental students were used for this study. Bitewing radiographs were taken of all thirty fillings and labeled Set 1. A second set (Set 2) consisted of 10 randomly selected duplicate radiographs of Set 1, plus 2 other radiographic images not from Set 1. Instructions were given to 20 dentally trained examiners to match the 12 radiographic images of Set 2 with the 30 images of Set 1. The results showed that 18 of the 20 examiners correctly matched the 12 radiographic images, one scored 11 out of 12 and one scored 10 out of 12. This study shows that if the ante-mortem and post-mortem radiographs of a single composite filling have exactly the same morphology, this image is unique and 12 concordant features are not necessary for dental identification.

The standard dental bitewing radiograph is used to detect interproximal caries but it also provides a specific view of the dental restorations that can be duplicated for identification purposes. The antemortem and postmortem bitewing radiographs are often not at the same angle and result in distorted images of the restorations. The aim of this study was to investigate the progressive increase in angulations of a bitewing radiograph of the same restoration and to determine at what angle the image is distorted sufficiently as not to be recognized. Bitewing radiographs were taken of the same two restorations at 5 ̊, 10 ̊, 15 ̊ and 20 ̊ superior, inferior, mesial and distal to the original 0 ̊bitewing radiograph. Twenty examiners were required to determine at what angle the distortion prevented matching of the image with the original bitewing radiograph. The results showed that the image distortion at 15 ̊became suspect but at 20 ̊none of the images could be matched to the original bitewing radiograph.

The dental identification of human remains utilizes the matching of dental restorations. The radiographic images of amalgam restorations are paramount in this process. The compound amalgam restoration has a unique radiographic morphology and can be readily identified in both antemortem and postmortem data. To test the radiographic morphology of compound amalgam restorations, 10 out of 40 Typodont teeth, restored by students, were tested for their discriminatory potential by 12 examiners. The results showed that the radiographic morphology of compound amalgam restorations can be accurately matched by dentally trained personnel. This suggests that in cases where accurate radiographic material is used for dental comparison, less than 12 concordant features are necessary for positive dental identification. If the antemortem and postmortem radiographic images of a compound amalgam restoration are exactly the same then this feature is unique and identification can be achieved by a single concordant feature.

The composite resin, compomer and glass ionomer restorative materials used in modern dental practice are fire resistant and remain radiopaque. They shrink significantly and are likely to fall out of the cavities after being burnt, but they remain extremely important for identification purposes and it may be possible to identify the white filling materials used to restore teeth by their radiopacity and morphology. The radiographic density of these filling materials do not change significantly when exposed to heat and although they may be difficult to see with the naked eye, they will remain visible when radiographed. Furthermore, special care has to be taken when handling heated materials as their compressive strengths decrease significantly depending on temperature and time of exposure and damage is possible.