Análise comparativa da radiopacidade de três cimentos endodônticos por meio de radiografia digital / Comparative analysis of radiopacity among three endodontic sealers by digital radiography

A radiopacidade consiste em uma propriedade importante requerida para um material obturador, pela qual se avalia o preenchimento do sistema de canais radiculares. Objetivo: Realizar análise comparativa da radiopacidade de três cimentos endodônticos por meio de radiografia digital. Material e método: Foram confeccionadas oito placas de acrílico com quatro cavidades cada, nas quais inseriu-se os seguintes materiais: I- cimento endodôntico à base de hidróxido de cálcio (Sealapex); II- cimento endodôntico resinoso (AH PLUS); III- cimento endodôntico à base de MTA (MTA Fillapex); IV- cones de guta-percha (controle positivo). Estas placas foram radiografadas digitalmente pelo método direto e as imagens obtidas foram analisadas pelos seus níveis de tons de cinza, utilizando-se o software Image Tool for Windows versão 3.0. Resultados: Verificou-se que o Sealapex apresentou radiopacidade menor que os demais cimentos testados e grupo controle (p<0,01); e o AH Plus e MTA Fillapex não foram diferentes entre si com relação à radiopacidade (p>0,05). Conclusão: Apenas o cimento Sealapex apresentou radiopacidade diferente dos demais materiais.

The radiopacity is an important property required for a root canal filling material, since it allows proper radiographic evaluation of the treated root canal system. Objective: To carry out a comparative analysis of the radiopacity of three endodontic sealers through digital radiography. Material and methods: Eight acrylic molds were filled with the following materials: (I) calcium hydroxide t-based cement (Sealapex); II-resin-based cement (AH PLUS); III-MTA-based cement (MTA Fillapex); IVgutta- percha cones (positive control). The molds filled with the materials were digitally radiographed using the direct method and the images obtained were analyzed using a grayscale from 0 to 255 dot points inch. Results: The Sealapex cement showed the lower values of radipacity than other cements and control (p<0.01). The AH Plus and MTA Fillapex cements were not different between each other (p>0.05). Conclusion: the cements tested showed radiopacity satisfactory, being lower to the Sealapex.

Pre-heating mitigates composite degradation

ABSTRACT Dental composites cured at high temperatures show improved properties and higher degrees of conversion; however, there is no information available about the effect of pre-heating on material degradation. Objectives This study evaluated the effect of pre-heating on the degradation of composites, based on the analysis of radiopacity and silver penetration using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Material and Methods Thirty specimens were fabricated using a metallic matrix (2x8 mm) and the composites Durafill VS (Heraeus Kulzer), Z-250 (3M/ESPE), and Z-350 (3M/ESPE), cured at 25°C (no pre-heating) or 60°C (pre-heating). Specimens were stored sequentially in the following solutions: 1) water for 7 days (60°C), plus 0.1 N sodium hydroxide (NaOH) for 14 days (60°C); 2) 50% silver nitrate (AgNO3) for 10 days (60°C). Specimens were radiographed at baseline and after each storage time, and the images were evaluated in gray scale. After the storage protocol, samples were analyzed using SEM/EDS to check the depth of silver penetration. Radiopacity and silver penetration data were analyzed using ANOVA and Tukey’s tests (α=5%). Results Radiopacity levels were as follows: Durafill VS<Z-350<Z-250 (p<0.05). The depth of silver penetration into the composites ranked as follows: Durafill VS>Z-350>Z-250 (p<0.05). After storage in water/NaOH, pre-heated specimens presented higher radiopacity values than non-pre-heated specimens (p<0.05). There was a lower penetration of silver in pre-heated specimens (p<0.05). Conclusions Pre-heating at 60°C mitigated the degradation of composites based on analysis of radiopacity and silver penetration depth.

Forensic importance of panoramic radiographs for human identification / Importância pericial das radiografias panorâmicas para a identificação humana

Human identification is a procedure of great importance for the proceedings instituted in the various spheres of law, and is also required by the community for cultural or religious reasons. Among the processes of identification, the technique of forensic dentistry is a comparativemethodology in which it is necessary for the person to be identified to have his dental characteristics recorded in some kind of documentationproduced during his lifetime. In this context, panoramic radiographs are extra-oral images often requested by dentists due to the broad viewstructures of the oral-maxillofacial complex, which assist in obtaining the diagnosis and definition of the treatment plan. In this study, a caseof human identification was reported using a panoramic x-ray, produced more than seven years earlier to support the planning of dentaltreatment. The radiographic comparison was made possible because a post-mortem panoramic x-ray was produced, allowing the viewing ofanatomical and reconstructive features with a quality and quantity sufficient to safely establish a positive correlation between the skeletonized corpse and the missing person.

A identificação humana constitui procedimento de grande importância para os processos instaurados nas várias esferas do Direito, tambémsendo exigida pela sociedade por questões culturais/religiosas. Dentre os processos de identificação pode-se citar a identificação odontolegal,uma metodologia comparativa na qual torna-se necessário que o indivíduo a ser identificado possua as suas particularidades odontológicasregistradas em algum tipo de documento produzido em vida. Neste contexto, as radiografias panorâmicas são exames imaginológicosextrabucais freqüentemente solicitados pelos Cirurgiões-dentistas devido à ampla visualização de estruturas do complexo bucomaxilofacial,que auxiliam na obtenção do diagnóstico e delimitação do plano de tratamento. No presente trabalho, foi relatado um caso de identificaçãohumana utilizando-se uma radiografia panorâmica, produzida há mais de sete anos para subsidiar um planejamento ortodôntico. O confrontoradiográfico foi viabilizado realizando-se uma radiografia panorâmica pós-morte que permitiu a visualização de particularidades anatômicas ereabilitadoras com qualidade e quantidade suficientes para estabelecer uma correlação positiva, com segurança, entre o corpo esqueletizadocomo pertencente à pessoa desaparecida.