Pedro Gregol da Silva

An In Vivo Study of Working Length Determination with a New Apex Locator

The success of an endodontic treatment relies on a correct working length determination. The canal terminus must be detected accurately and a precise control of the working length during the endodontic treatment must be maintained. The aim of this study was to investigate the working length determination in vivo with the Quill Apex Locator® for apical limit established at 1 mm short from the apical foramen (AF). Patients scheduled to dental extraction due to orthodontic or periodontal reasons were selected for this study, resulting in a sample of 24 root canals. Written informed consent was obtained from each patient before the treatment. After the administration of local anesthesia each tooth had its pulp cavity accessed. Next, the reading corresponding to the AF showed on the devices display was recorded and the file was removed. With the use of a digital caliper, 1 mm was subtracted from that first measurement. The file with the new measurement was introduced into to the root canal again then fixed with light curing flow composite and the tooth was extracted. Next, one of the apical third walls was worn out to visualize the instruments point and the AF. The distance from the file tip to the AF was measured by scanning electron microscopy. The average of the measurements was 1.089±0.437 mm. The Bicaudal t-test showed no significant difference (p=0.338) between the experimental values and the hypothetical value tested at 1 mm. The present investigation confirmed that the Quill Apex Locator® was able to determine the working length with good reliability for the endodontic treatment, established at 1 mm short from the AF.

Precisão e confiabilidade de um novo localizador foraminal eletrônico: estudo in vivo

Resumen pt: Objetivo: Verificar in vivo a precisao e confiabilidade de leitura do localizador foraminal eletronico Joypex 5® utilizando o microscopio eletronico de v...

Análise da Precisão de Dois Localizadores Foraminais de Fabricação Chinesa e o Root ZX II

Resumen pt: Objetivo: Avaliar a precisao e confiabilidade de dois modelos de localizadores apicais de fabricacao chinesa (Joypex 5 e Root SW), comparados ao aparelho...

Análise Qualitativa Pós Instrumentação Utilizando Instrumentos Manuais de Aço Inoxidável e Rotatórios de Níquel Titânio

Objective: To evaluate qualitatively (areas touched by the instruments) the manual instrumentation with stainless steel files compared to the rotatory by u...

Correlation between pH and surface structural changes on human enamel submitted to different tooth whitening agents

The intense valuation of an esthetic pleasant smile guided the dentistry to bleached tooth due the popularity of whitening treatments. The consequence of it is an increasing interest in searching the effect of peroxides in hard dental tissues. The aim of this work was to analyze qualitatively in vitro the human enamel after three different bleaching treatments: Opalescence PF 10%, White Class 7.5% and Opalescence Xtra Boost 38%, correlating the structural changes in the surface of the enamel with its respective pH. A total of 40 sound human pre-molars were randomly divided into four groups of 10 elements, which had been immersed in artificial saliva during all the experiment. Bleaching protocols followed the recommendations of the respective manufacturers. Each bleached sample and control group were submitted to a scanning electronic microscopy analysis and compared with one another. Bleaching agents used in this experiment had modified the morphologic aspect of the surface of the dental enamel; however, it did not have correlation between the degrees of severity of the alterations and pH. There is a correlation between hydrogen peroxide concentration and changes in the enamel, where G4 showed more severe alterations, followed for G3 and G2.

Comparação das Imagens Radiográficas Digitais e Convencionais em Reabsorções Ósseas Periodontais

Objetivo: Analisar os defeitos osseos periodontais, pela comparacao das imagens digitais (utilizando as ferramentas do Digora fmx 2.5) com as convencionais na angulacao de -10, 0 e +10o, pela analise de tres observadores. Metodos: Para obtencao das imagens foi utilizado um aparelho de Raio-X convencional, com padronizacao da tomada radiografica, pela utilizacao do posicionador do tipo Rinn® e moldagem de resina das superficies oclusais dos dentes a serem radiografados, nas tres incidencias radiograficas utilizadas. O contraste e a densidade foram padronizados no emprego do sistema digital Digora, com as exposicoes dos Raio-X adequadas a cada regiao. As radiografias convencionais foram realizadas com peliculas do tipo Insight da marca Kodak no 2. As imagens digitais foram analisadas no monitor do computador por meio do software do Digora 2.5, utilizando a ferramenta para alteracoes das imagens padrao, 3D e negativa e as convencionais observadas em um negatoscopio apropriado. Resultados: O resultado estatistico demonstrou diferenca significativa na analise entre os observadores, quanto as imagens obtidas, as digitais produziram imagens consideradas de qualidade inferior sem alteracoes das ferramentas em comparacao a radiografia convencional e quando a imagem digital era alterada (brilho, contraste, 3D), a qualidade aumentava significativamente, sendo comparavel a produzida pela pelicula convencional. Quanto ao ângulo de incidencia do feixe dos Raio-X, nao foram detectadas diferencas significativas entre os mesmos, ocorrendo o mesmo quanto ao lado radiografico. Conclusao: Os metodos radiograficos convencionais e digitais (quando da utilizacao das ferramentas para alteracao das imagens) nao demonstraram diferencas estatisticas na efetividade da quantificacao dos defeitos osseos periodontais.(AU) Objective: To assess periodontal bone defects, comparing the digital images (using the tools of Digora® fmx 2.5) with the conventional angle of -10, 0 and 10 degrees, through the three evaluators analysis. Methods: To obtain the images we used a conventional X -ray machine with standardized radiography, using the positioner type Rinn and resin molding of the occlusal surfaces of teeth to be X-ray in three radiographic. The contrast and density were standardized in the use of digital Digora with X-ray exposures appropriate to each region. The radiographs were performed with films Kodak Insight brand 2. Digital images were analyzed on the computer monitor through Digora 2.5 software, using the tool to change the default images, 3D and conventional negative and observed in an appropriate light box. Results: The results of statistical analysis showed significant difference between the observers in the images obtained, the digital images produced poor quality images without changing tools in comparison to conventional radiography and when the digital image was changed (brightness, contrast, 3D), the quality increased significantly, as compared to that produced by conventional film. As the angle of incidence of the x-rays beam, there were no significant differences between them, the same happened on the radiographic side. Conclusion: The conventional and digital radiographic methods (when using the tools to change the images), showed no statistical differences in the effectiveness of the quantification of periodontal bone defects.(AU)

Analise comparativa da porcentagem de area preenchida pela obturacao no terco apical dos canais radiculares em tres diferentes tecnicas

Resumen pt: Objeti vo: Comparar a porcentagem da area preenchida pela guta-percha, nos niveis 2 e 4mm do terco apical de canais mesiais de molares inferiores, nas te...