Effect of sterilization methods on the absorption capacity of absorbent paper points / Efeito dos métodos de esterilização na capacidade de absorção de pontas de papel absorvente

The purpose of the present study was to analyze the influence of sterilization methods on the absorption capacity of different brands of standardized absorbent paper points, testing the hypothesis that there is a positive correlation between the percentage of increased absorption capacity and sterilization method. Standardized endodontic absorbent paper points (size rank from #15 to #40) from three different brands of three manufacturers were used for this study (Dentsply, Endopoints, Tanari). Twenty absorbent paper points of each size were used. The initial weight (iw) of each absorbent paper point was recorded using a digital scale. After sterilization, the dry weight (dw) of each absorbent paper point was determined. Each paper point was then introduced into a 2% methylene blue solution during 20 seconds until complete saturation. The paper points were removed from the solution and the wet weight (ww) was determined, with absorption capacity calculated from a difference between ww-dw. Data was statistically analyzed using Tukey’s test and the Student’s t-test (p<0.05). Tanari paper points exhibited the best absorption capacity among the brands analyzed, but the difference was non-significant. Sterilization process did not influence the absorption capacity of absorbent paper points

O objetivo do presente estudo foi analisar a influência dos métodos de esterilização sobre a capacidade de absorção de diferentes marcas de cones de papel absorvente, testando a hipótese de que existe uma correlação positiva entre o percentual de maior capacidade de absorção e o método de esterilização. Cones de papel absorvente padronizados (calibre de # 15 a # 40) de três marcas comerciais diferentes foram usados para este estudo (Dentsply, Endopoints, Tanari). Vinte pontas de papel absorvente de cada calibre foram utilizadas. O peso inicial de cada cone de papel absorvente foi aferido utilizando uma balança digital. Após a esterilização, o peso seco de cada cone de papel absorvente foi determinado. Em seguida, cada cone de papel foi introduzido em uma solução de azul de metileno a 2% durante 20 segundos até a saturação completa. Os cones de papel foram removidos da solução e o peso úmido foi determinado, e a capacidade de absorção calculada a partir da diferença entre peso úmido menos o peso seco. Os dados foram analisados estatisticamente pelo teste de Tukey e o teste t de Student (p <0,05). Os cones Tanari exibiram a melhor capacidade de absorção entre as marcas analisadas, mas a diferença não foi significativa. O processo de esterilização não influenciou a capacidade de absorção dos cones de papel absorvente>

Comparison of the centering ability of the ProTaper Universal, ProFile and Twisted File Rotary Systems

Aim: To determine the centering ability of Twisted File™ rotary system compared with ProTaperUniversal™ and ProFile™ rotary systems by evaluating pre- and postoperative cross-sectionalimages of the apical root canals third. Methods: Thirty mesiobuccal canals of human mandibularfirst molars were divided into three groups with 10 root canals each according to the instrumentused: group 1, ProTaper Universal™ rotary system; group 2, ProFile™, and group 3, TwistedFile™. Pre- and postoperative images of the apical thirds were viewed with a stereoscopicmagnifier with ×10 magnification and were captured digitally for further analysis using the ImageTools Software. The results were analyzed statistically by the Kruskal-Wallis test and the Mann-Whitney test. A level of significance of 0.05 was adopted. Results: The means of the buccolingualmeasurement ranged from 0.79 to 1.5. The largest deviation was registered to instrument 25.06in group 2. The means of the mesiodistal measurement ranged from 0.86 to 1.52, with the largestdeviation being registered to instrument 25.04 in group 3; however, there were no statisticallysignificant differences (p>0.05) among the three groups or among the instruments in the samegroup in terms of centering ability. Conclusions: None of the rotary systems evaluated in thisstudy was totally effective in performing biomechanical preparation of the root canals.

Assessment of canal walls after biomechanical preparation of root canals instrumented with protaper universalTM rotary system

OBJECTIVE: The aim of this study was to examine the instrumented walls of root canals prepared with the ProTaper UniversalTM rotary system. MATERIAL AND METHODS: Twenty mesiobuccal canals of human first mandibular molars were divided into 2 groups of 10 specimens each and embedded in a muffle system. The root canals were transversely sectioned 3 mm short of the apex before preparation and remounted in their molds. All root canals were prepared with ProTaper UniversalTM rotary system or with NitiflexTM files. The pre and postoperative images of the apical thirds viewed with a stereoscopic magnifier (X45) were captured digitally for further analysis. Data were analyzed statistically by Fisher's exact test and Chi-square test at 5 percent significance level. RESULTS: The differences observed between the instrumented and the noninstrumented walls were not statistically significant (p<0.05). CONCLUSIONS: The NitiflexTM files and the ProTaper UniversalTM rotary system failed to instrument all the root canal walls.

Morfologia interna do primeiro molar inferior através da radiografia e da diafanização / Internal morphology of the first mandibular molar by radiography and transparent teeth

Na presente pesquisa foram utilizados 103 primeiros molares inferiores obtidos no Banco de Dentes do Curso de Odontologia da UFPE com o objetivo de avaliar, através de radiografias periapicais e da diafanização, a morfologia interna das raizes mesial e distal e classificá-las de acordo com Vertucci (1984). Na raiz mesial foram identificados dois canais em 96,12% dos casos, curvos para a distal em 79,91%, tipo II em 60,20%. A raiz distal apresentou canal único em 91,26% dos casos, reto em 73,15%, tipo I em 69,90%. A técnica radiográfica e a diafanização mostraram-se bastante efetivas para o estudo e visualização da morfologia interna do sistema de canais radiculares.

In this research were selected hundred three human mandibular molars, obtained from Banco de Dentes do Curso de Odontologia da UFPE, the root canal morphology were evaluated by X-rays examination and of the transparent teeth of the mesial and distal of the first mandibular molar root, and classifying them according to Vertucci (1984). Two channels into the mesial root were detected at 96,12%, curved for the distal at 79,91%, type II of the Vertucci at 60,20%. The distal root presented a single root channel at 91,26%, straight at 73,15% and the Vertucci's type I at 69,90%. The radiographic technique and the transparent teeth were effective for the study and observation of the internal morphology of root canals system.