Radiographic changes in endodontically treated teeth submitted to drowning and burial simulations: is it a useful tool in forensic investigation?

Dental radiographs, endodontic treatment and materials are a source of useful forensic data. The response of dental materials to death-related events are widely studied and provide forensic evidence for experts. This study aimed to analyze the radiographic images of endodontically treated teeth submitted to burial and drowning simulation, verifying its forensic feasibility, applicability and usefulness. MATERIAL AND METHOD: n=20 bovine incisor teeth were endodontically treated then divided into two groups: burial and drowning scenarios. Teeth were radiographed two times (before and after scenario) with an aluminium stepwedge, and optical density (OD) was assessed in each root third, in both radiographs, and then compared (ANOVA and Tukey test) for each scenario. RESULTS: Burial scenario did not significantly alter radiopacity. As for the drowning scenario, there was no difference in radiopacity between the root thirds before the test. After drowning, the apical third demonstrated lower OD (p<.05) than the other two thirds. Comparing the OD before and after drowning, medium third presented lower and cervical third demonstrated higher means (p<.05) after drowning. CONCLUSION: We concluded that drowning conditions could alter the radiopacity of endodontically treated teeth, more specifically in the medium and cervical thirds. There is no evidence that this also occurs in burial situations. This has the potential to be useful in forensic casework as an initial sign of the type of ambient in which the body was supposedly exposed or set.

Colour stability of dental restorative materials submitted to conditions of burial and drowning, for forensic purposes.

The aim of this study was to evaluate the effect of earth and water on the colour stability of tooth-coloured dental restorative materials: composite resin (CR) and glass ionomer cement (GIC). Aiming to distinguish between one and another tooth-coloured material and to estimate the period in which they could be submitted to the factors earth and water, the proposed method may contribute to the proceedings of human identification of victims of burial and submersion in water. Forty bovine incisors were prepared (6 x 6 x 2mm) and restored with CR FiltekTM Z250 XT (3M ESPETM) and GIC KetacTM Fil Plus (3M ESPETM). After initial colour read-outs (VITATM Easyshade spectrophotometer), the samples were separated into two groups (n=10), according to the conditions to which they were submitted: simulations of burying and submersion in water, for periods of 1, 3, 6 and 12 months, when new read-outs were taken. The values of colour change (ΔE, ΔL*, Δa*, and Δb*) were subjected to 3-way ANOVA statistical analysis, repeated measures, Bonferroni (p<.05), and it was verified that both factors produced colour changes in the restorative materials, which were higher for glass ionomer cement (p<.05) after 12 months of burial, and 6 months of submersion in water. The authors concluded that the analysis of colour change in the material contributed to the forensic odontology casework depending on the time during which the victim was submitted to the condition of burial or submersion in water.

Evaluación de una resina epóxica experimental como material alternativo para obtención de modelos odontológicos / Evaluation of an experimental epoxy resin as an alternative material for dental casts

El objetivo de este estudio fue comparar la fidelidad de copia y estabilidad dimensional entre modelos de resina epóxica y modelos de yeso (Fuji Rock EP - GC Europe; Implant Stone - Polidental). Fue realizada la impresión de una matriz de acero para obtener 30 especímenes (n=10). La matriz simulaba dos piezas dentarias talladas para recibir coronas totales, sobre éstas fueron adaptados dos copings metálicos con aletas horizontales. Se evaluó al microscopio (Microscopio Measurescope, Nikon) la distancia entre el coping y la línea de terminación de las piezas talladas (en adelante, "desadaptación vertical") y la distancia entre las aletas horizontales de los copings (en adelante, "desadaptación horizontal"), las medidas obtenidas entre la matriz de acero y copings metálicos fueron consideradas como grupo control. Los copings metálicos fueron después adaptados sobre los modelos de yeso y sobre la resina experimental y fue realizada la evaluación al microscopio del mismo modo que el descrito anteriormente. Fueron realizadas 3 mediciones en dos tiempos (24 y 48 horas). Respecto a la desadaptación horizontal, el yeso FujiRock presentó una mejor estabilidad dimensional después de 24 horas, ya que la desadaptación fue similar estadísticamente a la desadaptación de la matriz (control) (p>0,05). Después de 48 horas, todos los grupos presentaron valores similares a la matriz (p>0,05). Respecto a la desadaptación vertical, todos los materiales presentaron diferencia estadísticamente significante en relación a la matriz (p?0,05), sin embargo, no hubo diferencia entre los materiales evaluados (p>0,05). La resina epóxica experimental puede ser una alternativa viable para la obtención de modelos odontológicos...

The aim of this study was to compare the accuracy of surface detail reproduction and dimensional stability of casts made from an experimental epoxy resin and gypsum (Fuji Rock EP - GC Europe; Implant Stone - Polidental). A steel matrix was molded to obtain 30 cast samples (n=10). The matrix simulated two teeth prepared to receive total crowns on which two metal copings with horizontal flaps were adapted. Three readings were performed (Measurescope microscope, Nikon) in order to measure the vertical and horizontal misfit and those readings were used as control. Metal copings were adapted over the gypsum and epoxy resin casts and three measurements were made in two periods (24 and 48 hours). Regarding the horizontal misfit, Fujirock had better dimensional stability after 24 hours, being statistically similar to the matrix (p> 0.05). After 48 hours, all groups had statistically similar values to the matrix (p> 0.05). Regarding the vertical misfit, all materials were statistically different in relation to the matrix (p ? 0.05). However, there was no statistically significant difference between the materials evaluated (p> 0.05). The experimental epoxy resin could be a suitable alternative to obtain dental casts...

Influence of artificial accelerated aging on the color stability and opacity of composites of different shades.

AIM: The aim of this study was to evaluate the influence of artificial accelerated aging on the color stability and opacity of composites of different shades. METHODS: Four composites for direct use (Heliomolar, 4 Seasons, Tetric EvoCeram; QuiXfil) and one for indirect use (SR Adoro) in two shades were used: light (A2) and dark (C3 for direct, and D4 for indirect composite). QuiXfil was obtained in Universal shade. A Teflon matrix (12 X 2 mm) was used to obtain 54 specimens (N=6), which were submitted to color and opacity analysis (Spectrophotometer PCB 6807, Byk Gardner) before and after artificial accelerated aging for 384 hours. RESULTS: After the statistical analysis (2-way ANOVA - Bonferroni - P<0.05), significant color alteration was observed in the light and dark composites studied (P<0.05), with the exception of QuiXfil. Composite 4 Seasons/C3 showed less color alteration (ΔE=0.91). The opacity alteration (ΔOP) was higher for light composites. CONCLUSION: Artificial accelerated aging interfered in the optical properties assessed; however, the alterations seemed to be more related to the composites composition than to their shade.