Effects of incineration to different dental materials used in prosthodontics: a systematic literature review / Efeitos da incineração em diferentes materiais odontológicos usados em prótese dentária ­ revisão sistemática de literatura

Comprehensive data for the detectable changes occurring when various prosthodontic devices are exposed to elevated temperatures is still poorly recorded. The present study aimed to revisit the scientific literature in order to systematically review and assess experimental studies that analyze the effects of high temperature on different materials used in prosthodontics. A systematic literature review was structured according to PRISMA. Four primary electronic databases and one source of grey literature were searched. Only academic and peer-reviewed original experimental studies and proceedings of scientific conferences were included. The risk of bias was assessed using formulated questions by the authors adapted from the strategy proposed by Onofre et al. 2014. The search resulted in 1526 scientific articles, from which met the eligibility criteria. Out of the eligible studies, 60% exhibited a medium risk of bias, which demonstrates a positive characteristic of the present study. Results showed that the detectable changes due to extreme heat observed in the included studies were dependent on the type of prosthodontic device exposed and the type of material used in its fabrication. The data gathered from this study could aid further in the analysis and identification when dealing with incinerated remains

Dados abrangentes sobre as mudanças detectáveis que ocorrem quando vários dispositivos protéticos são expostos a temperaturas elevadas ainda são pouco registrados. O presente estudo teve como objetivo revisitar a literatura científica a fim de revisar e avaliar sistematicamente estudos experimentais que analisam os efeitos da alta temperatura em diferentes materiais utilizados em prótese. Uma revisão sistemática da literatura foi estruturada de acordo com PRISMA. Quatro bases de dados foram pesquisadas e uma fonte de literatura cinzenta (grey literature) foi selecionada. Apenas estudos acadêmicos de revisão, experimentais, originais e revisados por pares e anais de conferências científicas foram incluídos. O risco de viés foi avaliado por meio de questões formuladas pelos autores e adaptadas usando a estratégia proposta por Onofre et al. (2014). A busca resultou em 1526 artigos científicos, dos quais atenderam aos critérios de elegibilidade. Dos estudos elegíveis, 60% apresentaram risco médio de viés, o que demonstra uma característica positiva do presente estudo. Os resultados mostraram que as alterações detectáveis devido ao calor extremo observadas nos estudos incluídos foram dependentes do tipo de dispositivo protético exposto e do tipo de material utilizado em sua fabricação. Os dados coletados neste estudo podem auxiliar ainda mais na análise e identificação quando se trata de restos incinerados

Cambios microscópicos in vitro de cuerpos de prueba de amalgama de plata sometidos a altas temperaturas observados mediante microscopía electrónica de barrido / In vitro microscopic changes of dental amalgam test bodies subjected to high temperatures observed by scanning electron microscopy

Objetivo: describir los cambios microscópicos in vitro de 27 cuerpos de prueba elaborados en amalgama de plata de tres marcas comerciales (Contour® Kerr®, Admix® SDI® y Nu Alloy® Newstethic®) sometidos a altas temperaturas (200ºC, 400ºC y 600ºC) observados mediante microscopia electrónica de barrido. Materiales y métodos: estudio observacional descriptivo, de corte transversal y de naturaleza pseudo-experimental que analizó el comportamiento in vitro de 27 cuerpos de prueba elaborados en tres marcas comerciales de amalgama de plata (Contour® Kerr®, Admix® SDI® y Nu Alloy® Newstethic®) sometidos a altas temperaturas (200ºC, 400ºC, 600ºC). Resultados: las tres marcas comerciales de amalgama de plata empleadas en este estudio tuvieron un comportamiento similar, excepto en el comportamiento de los nódulos de plata. Estos aparecieron a los 200ºC en Admix® SDI® y a los 400ºC en Contour® Kerr® y Nu Alloy® Newstethic®. El análisis en microscopía electrónica de barrido y espectrofotometría de la superficie de los cuerpos de prueba evidenció el aumento estadísticamente significativo (p<0,05) del porcentaje de peso atómico de Hg, Cu y Sn. Conclusiones: los cuerpos de prueba de las tres marcas comerciales de amalgama de plata sufren cambios en su microestructura en la medida que aumenta la temperatura. La formación de los nódulos de Ag fue explicada como una consecuencia del comportamiento de la fase gamma 1 de Ag-Hg al aumentar la temperatura, la cual empieza a disociarse a los 200ºC en Admix® SDI® y a los 400ºC en Contour® Kerr® y Nu Alloy® Newstethic®.

Objective: describe the in vitro microscopic changes of dental amalgam test bodies subjected to high temperatures observed by scanning electron microscopy. Materials and methods: descriptive observational cross-sectional study of pseudo-experimental nature that analyzed by scanning electron microscopy (SEM) the in vitro behavior of 27 test bodies elaborated in three brands of dental amalgam (Contour® Kerr®, Admix® SDI® and Nu Alloy® Newstethic®) subjected to high temperatures (200ºC, 400ºC, 600ºC). Results: the three trademarks of dental amalgam used in this study had a similar behavior, except for the behavior of silver nodules. These appeared to 200ºC in the test bodies of Admix® SDI® and 400ºC in the test bodies of Contour® Kerr® and Nu Alloy® Newstethic®. The analysis of scanning electron microscopy and spectrophotometry at the surface of the test bodies showed the statistically significant increase (p<0.05) the percentage of atomic weight of mercury, copper and tin. Conclusions: the test bodies of the three trademarks of dental amalgam undergo changes in their microstructure so long as the temperature increases. The formation of silver nodules was explained as a consequence of the behavior of the gamma 1 phase silver-mercury with increasing temperature, which begins to dissociate at 200ºC in the test bodies of Admix® SDI® and 400ºC in the test bodies of Contour® Kerr® and Nu Alloy® Newstethic®.

Descripción radiográfica de postes de titanio y de fibra de vidrio, cementados en premolares humanos sometidos in vitro a altas temperaturas con fines forenses / Radiographic description of titanium and fiberglass posts cemented in human premolars subjected to high temperatures in vitro for forensic purposes

Introducción: durante el proceso de identificación forense de cadáveres y restos humanos quemados, carbonizados o incinerados, el análisis de los materiales empleados en los diferentes tratamientos odontológicos se constituye en un marcador fehaciente para lograr una identificación positiva. El objetivo de este trabajo fue describir los cambios radiográficos de postes de titanio y de fibra de vidrio cementados, en premolares humanos sometidos a altas temperaturas con fines forenses. Métodos: estudio pseudo-experimental in vitro que observó los cambios radiográficos de los tejidos dentales (esmalte, dentina y cemento), de los materiales de uso endodóncico gutapercha (Wave One® de Dentsply Maillefer®), material de obturación (Top Seal® de Dentsply Maillefer®), material de cementación de los postes (Relyx TM ARC de 3M ESPE®) y de los postes de titanio (Tenax® Endodontic Post System de Coltene®) y fibra de vidrio (Tenax® Fiber Trans de Coltene®) en 30 dientes humanos, sometidos a cinco rangos de temperatura 200, 400, 600, 800 y 1000ºC. Resultados: los tejidos y los materiales dentales estudiados presentan gran resistencia a las altas temperaturas, sin variar considerablemente su macro-estructura (fisuras, grietas, fracturas y fragmentación), de tal manera que los cambios físicos pueden identificarse a través de radiografía convencional, y asociarse a cada rango de temperatura específico. Conclusiones: los postes cementados en premolares humanos presentan gran resistencia a la acción de altas temperaturas, razón por la cual pueden ser visualizados a través de radiografía convencional, contribuyendo con el proceso de identificación y documentación de la necropsia médico-legal de un cadáver o restos humanos que hayan resultado quemados, incinerados o carbonizados

IIntroduction: during the process of forensic identification of corpses and burnt, carbonized, or incinerated human remains, the analysis of materials used in dental treatments is a reliable marker for accurate identification. The objective of this study was to describe the radiographic changes of titanium and fiberglass posts cemented in human premolars subjected to high temperatures for forensic purposes. Methods: this was a pseudo-experimental in vitro study to observe the radiographic changes of dental tissues (enamel, dentin, and cement) and the following endodontic materials: gutta-percha (Wave One® by Dentsply Maillefer®), obturation material (Top Seal® by Dentsply Maillefer®), post cementation material (Relyx TM ARC by 3M ESPE®), titanium posts (Tenax® Endodontic Post System by Coltene®), and fiberglass posts (Tenax® Fiber Trans by Coltene®) in 30 human teeth subject to five temperature ranges: 200, 400, 600, 800, and 1000° C. Results: the studied dental tissues and materials are highly resistant to high temperatures without significantly changing their macrostructure (fissures, cracks, fractures, and fragmentation), in such a way that the physical changes can be identified through conventional radiography and associated with each specific temperature range. Conclusions: posts cemented in human premolars have great resistance to the action of high temperatures, so they can be observed through conventional radiography thus contributing to the process of identification and documentation of the medico-legal autopsy of a corpse or human remains that have been burned, incinerated, or carbonized

Análisis mediante radiografía convencional de los tejidos dentales y periodontales de cerdo (Sus domesticus) sometidos a altas temperaturas / Conventional X-ray analysis of porcine (Sus domesticus) periodontal and dental tissue subjected to high temperature

Introducción: La implementación de modelos animales para el estudio de los tejidos dentales y periodontales de dientes articulados en sus alvéolos sometidos a altas temperaturas permite el establecimiento de parámetros repetitivos que contribuyen con los procesos de identificación. Objetivo: Describir los cambios radiográficos de los tejidos dentales y periodontales de cerdo (Sus domesticus) sometidos a altas temperaturas. Material y métodos: Se realizó un estudio observacional descriptivo de naturaleza pseudo-experimental in vitro para observar los cambios radiográficos de los tejidos dentales y periodontales en 60 dientes de cerdo doméstico sometidos a altas temperaturas (200, 400, 600, 800 y 1,000 ºC). Resultados: Los tejidos dentales y periodontales estudiados presentan gran resistencia a las altas temperaturas sin variar considerablemente su microestructura, de tal manera que los cambios físicos (estabilidad dimensional, fisuras, grietas y fracturas) que ocurren en la medida que aumenta la temperatura pueden describirse a través de radiografía convencional. Conclusiones: El análisis radiográfico de los dientes articulados en sus respectivos alvéolos se constituye en un mecanismo para determinar la temperatura a la cual estuvo sometido un diente, lo que puede ser empleado durante el proceso de identificación odontológica y documentación de la necropsia médico-legal para el caso de cadáveres o restos humanos quemados, carbonizados e incinerados. El cerdo doméstico (Sus domesticus) se constituye en un modelo animal experimental adecuado para estudiar dichos cambios; sin embargo, se recomienda realizar un estudio en dientes humanos articulados en su respectiva unidad alveolar, para determinar si los hallazgos radiográficos descritos se repiten y son extrapolables.

Introduction: The implementation of animal models for the study of periodontal and dental tissues of teeth articulated into their sockets and subjected to high temperatures allows the establishment of repetitive parameters which might contribute to identification processes. Aim: To describe radiographic changes of pig's (Sus domesticus) periodontal and dental tissues subjected to high temperatures. Material and methods: An in vitro pseudo-experimental, descriptive and observational study was undertaken in order to assess radiological changes of periodontal and dental tissues of 60 domestic pig's teeth which had been subjected to high temperatures (200, 400, 600, 800 and 1,000 ºC). Results: The dental and periodontal tissues subject of this research article presented strong resistance to high temperatures without considerable variation of their micro-structure. Thus, physical changes (dimensional stability, fissures, cracks and fractures) which took place as temperature increased, could be described using a conventional X-ray. Conclusions: Radiographic examination of teeth articulated in their sockets can be established as a mechanism to determine the temperature at which the tooth was subjected. This could be used in processes of dental identification and medical-legal autopsy documentation in cases of burned, carbonized or incinerated human remains. Domestic pigs (Sus domesticus) can be regarded as a suitable experimental animal models to study the aforementioned changes. Nevertheless, a study involving human teeth articulated in their own socket is recommended in order to determine whether the radiographic findings herein described are replicated and can be extrapolated.

Análisis a través de microscopía electrónica de barrido de dos dientes con tratamiento endodóncico sometidos a altas temperaturas: estudio piloto / Scanning electron microscopy analysis of two endodontically treated teeth subjected to high temperatures: a pilot study

Introducción: el objetivo fue describir los cambios físico-químicos que ocurren en los tejidos y materiales dentales empleados en un tratamiento endodóncico convencional, al ser sometidos a altas temperaturas, a través de microscopía electrónica de barrido (MEB). Métodos: in vitro, se sometieron dos dientes premolares humanos a 200 y 400 ºC respectivamente, con el fin de estandarizar una técnica para la observación de los cambios físicos y químicos en los tejidos dentales (esmalte y dentina) y de los materiales de uso odontológico empleados comúnmente en endodoncia (gutapercha y cemento endodóncico a base de resina epóxica). Resultados: tanto los tejidos como los materiales dentales observados en este estudio piloto, presentaron gran resistencia a las altas temperaturas sin variar considerablemente su macroestructura, de tal manera que los cambios físicos (estabilidad dimensional, fisuras, grietas, fracturas, textura, carbonización) y químicos (elementos químicos constituyentes) pueden llegar a ser identificables y asociarse a cada rango de temperatura específico através del análisis MEB y espectrofotométrico. Conclusiones: los tejidos y los materiales dentales presentan gran resistencia a la acciónde altas temperaturas sin alterar su macroestructura de forma significativa. Del mismo modo, presentan cambios físicos y químicos que pueden contribuir con el proceso de identificación de un cadáver o restos humanos quemados, incinerados o carbonizados.

Introduction: the objective of this study was to describe the physicochemical changes occurring in dental tissues andmaterials used in a conventional endodontic treatment when subjected to high temperatures, by means of scanning electron microscopy(SEM) Methods: in vitro, two human premolar teeth were subjected to temperatures of 200°C and 400°C respectively, with the purpose ofstandardizing a technique for the observation of physical and chemical changes in dental tissues (enamel and dentin) and dental materialscommonly used in endodontic treatment (root canal gutta-percha and epoxy resin-based endodontic cement). Results: both the tissues and the dental materials analyzed in this pilot study presented great resistance to high temperatures without significantly changing their macrostructure; therefore, the physical changes (dimensional stability, cracks, crevices, fractures, texture, carbonization) and the chemical ones (constituent chemical elements) may turn out to be identifiable and associated with each specific temperature range by means of SEM and spectrophotometric analysis. Conclusions: dental tissues and materials display great resistance to the action of high temperatures, without significantly altering their macrostructure. Similarly, they experience physical and chemical changes that may contribute to theprocess of identification of a corpse or human remains that have been burned, incinerated or charred.