Scanning electron microscopic evaluation of microgap size in Morse taper implants with straight and angled abutments.

The aim of this study was to compare the sizes of the implant-abutment microgap in Morse taper implants with a straight abutment (ISA group) and Morse taper implants with an angled abutment (IAA group). A total of 19 Morse taper dental implants (3.8 × 11.0 mm) were used with their respective abutments; 10 abutments were angled at 20°, and 9 were straight. The implant-abutment units were immersed in an epoxy resin to form a base and then cross-sectioned until about 50% of the volume was removed. The specimens were analyzed under a scanning electron microscope, and the size of the microgap was measured at 3 regions on each side of the implant, for a total of 6 measurements per specimen. Mann-Whitney U and Kruskal-Wallis tests were used for statistical analysis. In the ISA group, there were no statistically significant differences in the median sizes of the microgap at the different regions of the interface (P > 0.05; Kruskal-Wallis test). The mean (SD) values of the largest and smallest microgaps in the ISA group were 1.64 (1.38) and 0.83 (0.41) µm, respectively. In the IAA group, there was a statistically significant difference in the median sizes of the microgaps at the upper and middle regions on the left side (P = 0.031; Kruskal-Wallis test). The mean (SD) values of the largest and smallest micrograps were 1.43 (0.062) and 0.61 (0.27) µm, respectively. Comparison of the different regions in the ISA and IAA groups revealed that the only statistically significant difference was at the lower region on the right side (P = 0.027; Mann-Whitney U test). The sizes of the microgaps in the ISA and IAA groups were statistically similar in an overall analysis (P > 0.05; Mann-Whitney U test); however, the IAA group showed greater sealing ability. In addition, in both groups in vitro titanium oxide formation was observed at the interface, characterizing a type of cold-weld joint that provides effective implant-abutment sealing.

Avaliação da interface entre o componente protético reto e a conexão interna tipo Cone Morse do implante dentário por meio da microscopia eletrônica de varredura / Evaluation of the interface between the straight prosthetic component and the Morse Cone-type internal connection of the dental implant in cross section by scanning electron microscopy

Resumo Introdução A interface implante-pilar protético e a formação dos seus microgaps são aspectos relevantes na transferência das cargas e na resposta biológica, estando ligadas ao sucesso da reabilitação. Objetivo Avaliar microgaps na interface entre a conexão interna do implante do tipo Cone Morse e a superfície do componente protético por meio da microscopia eletrônica de varredura (MEV). Material e método Foram utilizados 20 implantes dentários de tamanho 3,75 × 11,0mm do tipo Cone Morse com seus respectivos pilares protéticos da Singular® (Singular Implants, RN, Brasil). Os munhões retos foram acoplados aos implantes com torque de 32N/cm2 e o conjunto resultante foi emergido em base de Resina Epóxi ES260, para permitir secção longitudinal da amostra. As amostras foram analisadas e os microgaps mensurados no MEV (JEOL JCM-5700, MA, USA), e posteriormente os dados foram analisados. Resultado A média e o desvio padrão dos maiores microgaps foram observados na parte apical do implante nos lados direito e esquerdo, sendo 1,44±2,68 e 1,16±1,49 μm, respectivamente. Os menores microgaps foram na parte superior do implante nos lados direito e esquerdo, sendo 0,60±0,73 e 0,66±0,67 μm, respectivamente. Contudo, no teste de Kruskal-Wallis, não houve diferença estatisticamente significativa entre as regiões dos implantes, tanto para o lado esquerdo (p=0,692) como para o direito (p=0,865). No teste de Mann-Whitney, não houve diferenças estatisticamente significativas entre os lados para as diferentes regiões dos implantes. Conclusão Mesmo com a presença de microgaps na interface implante-pilar protético, estes apresentam tamanho inferior ao que causaria problemas biológicos e mecânicos. As amostras analisadas quanto à sua compatibilidade de encaixe foram satisfatórias.

Abstract Introduction The implant-prosthetic abutment interface and the formation of its microgaps are relevant aspects in load transfer and biological response and are linked to the success of the rehabilitation. Objective To evaluate microgaps at the internal connection interface of the Cone Morse implant and the prosthetic component surface by means of scanning electron microscopy (SEM). Material and method Twenty 3.75 x 11.0 mm Cone Morse dental implants with their respective Singular® prosthetic abutments were used (Singular Implants, RN, Brazil). The straight trunnions were attached to the implants with a 32N/cm2 torque and the ES260 Epoxy Resin-based set emerged to allow longitudinal sectioning of the sample. The samples were analyzed and the microgaps measured in SEM (JEOL JCM-5700, MA, USA), and later the data were analyzed. Result The mean and standard deviation of the largest microgaps were observed in the apical part of the right and left side 1.44±2.68 and 1.16±1.49 μm, respectively. The smallest microgaps were on the upper implant right and left sides 0.60±0.73 and 0.66±0.67 μm, respectively. However, in the Kruskal-Wallis test there was no statistically significant difference between the implant regions, both for the left side (p=0.692) and right side (p=0.865). The Mann-Whitney test, there were no statistically significant differences between the sides for the different regions of the implants. Conclusion Even with the presence of microgaps in the implant-post interface, it presents a smaller size than the one presenting biological and mechanical problems. The samples analyzed for their fitting compatibility were satisfactory.

Development and evaluation of a mobile application for teaching Dental Radiology / Desenvolvimento e avaliação de aplicativo móvel para ensino de Radiologia Odontológica

This study aimed to develop and evaluatea smartphone applicationwith a web content managementtoolforthe study of periapical radiographic anatomy. Design thinking activities werecarried outto better understand the proposed problem.Then, a questionnaire wasapplied via Google Formsto44 dentalstudents to assist in the development of an Appfor the teaching of radiology. Then, thebeta version of theApp was evaluated in January 2019by 51undergraduate dentalstudentsby means ofsatisfaction and usability questionnaires.The Cronbach's alpha coefficientwas applied to these questionnairesandvalues above 0.7were obtained, demonstrating theirreliability. In the evaluationof the App, which was called APPOLO,that means App of learning online, 98.04% of the students affirmed that the available contentwas certainlyimportant. The number of images wasconsidered either satisfactoryor very satisfactory by 94.19% of the participants, and 100% of them judged the qualityof theimages also satisfactoryor very satisfactory. The majority ofthe participants(94.11%)feltmotivated to complement their study using this type of methodology.The classification easy and very easy was attributed to the metricsusabilityby 98.04% of the participants, access to offered contentsby 100%of the participants, and access to the textsby 98%of the participants.The APPOLOApp provedto be practical and easy to understand, navigate, and use, as was considered a potential aid tosupport the teaching ofdental radiology students (AU).

Este estudo teve como objetivo desenvolver e avaliar um aplicativo para smartphone com uma ferramenta de gerenciamento de conteúdo da web para o estudo da anatomia radiográfica periapical. Atividades de Design Thinking foram realizadas para melhor compreender o problema proposto pelo grupo de pesquisa. Em seguida, foi realizadauma pesquisa exploratória via Google Forms com 44 estudantes de Odontologia, aplicando-se um questionário para auxiliar no desenvolvimento de um aplicativo para ensino de Radiologia. Com o aplicativo na versão inicial, beta, foram aplicados questionários de satisfação e usabilidade com 51 alunos do curso de graduação em Odontologia, para avaliação do App. O coeficiente alfa de Cronbach foi aplicado a esses questionários e valores acima de 0,7 foram obtidos, demonstrando sua confiabilidade. Na avaliação do aplicativo, denominado APPOLO, que significa "App of learning online", 98,04% dos alunos afirmaram que o conteúdo disponível era certamente importante. A quantidade de imagens foi considerada entre satisfatórias e muito satisfatórias por 94,19% dos participantes e 100% deles julgaram a qualidade das imagens também satisfatória ou muito satisfatória. A maioria dos participantes (94,11%) sentiu-se motivada em complementar seu estudo com esse tipo de metodologia. Quanto a usabilidade do aplicativo, 98,04% classificaram entre fácil e muitofácil o seu manuseio, 100% o acesso aos conteúdos ofertados e 98% o acesso aos textos, seguindo essa mesma métrica. O aplicativo APPOLO demonstrou ser prático, de fácil entendimento, navegação e utilização, e revelou auxiliar no apoio ao ensino dos alunosda disciplina de Radiologia Odontológica (AU).