Shaping ability of Reciproc and TF Adaptive systems in severely curved canals of rapid microCT-based prototyping molar replicas

Objective: To evaluate the shaping ability of Reciproc and Twisted-File Adaptive systems in rapid prototyping replicas. Material and Methods: Two mandibular molars showing S-shaped and 62-degree curvatures in the mesial root were scanned by using a microcomputed tomography (μCT) system. The data were exported in the stereolitograhic format and 20 samples of each molar were printed at 16 µm resolution. The mesial canals of 10 replicas of each specimen were prepared with each system. Transportation was measured by overlapping radiographs taken before and after preparation and resin thickness after instrumentation was measured by μCT. Results: Both systems maintained the original shape of the apical third in both anatomies (P>;0.05). Overall, considering the resin thickness in the 62-degree replicas, no statistical difference was found between the systems (P>;0.05). In the S-shaped curvature replica, Reciproc significantly decreased the thickness of the resin walls in comparison with TF Adaptive. Conclusions: The evaluated systems were able to maintain the original shape at the apical third of severely curved mesial canals of molar replicas

Characterization of the file-specific heat-treated ProTaper Ultimate rotary system

Funding Information: FMBF acknowledges the funding of CENIMAT/i3N by national funds through the FCT‐Fundação para a Ciência e a Tecnologia, I.P., within the scope of Multiannual Financing of R&D Units, reference UIDB/50025/2020‐2023. Publisher Copyright: © 2022 The Authors. International Endodontic Journal published by John Wiley & Sons Ltd on behalf of British Endodontic Society.Aim: To compare design, metallurgy and mechanical performance of the ProTaper (PT) Ultimate system with instruments of similar dimensions from the ProGlider, PT Gold and PT Universal systems. Methodology: New PT Ultimate instruments (n = 248) were compared with instruments of similar dimensions from ProGlider (n = 31), PT Gold (n = 155) and PT Universal (n = 155) systems regarding their number of spirals, helical angle, blade symmetry, tip geometry, surface finishing, nickel/titanium ratio, phase transformation temperatures and mechanical performance. One-way anova and nonparametric Mood's median tests were used for statistical comparison (α = 5%). Results: All instruments had symmetrical blades without radial lands or flat sides, similar surface finishing and an almost equiatomic nickel/titanium ratio, whilst the number of spirals, helical angles and the tip geometry were different. PT Ultimate instruments showed 3 distinct heat treatments that matched with the colour of their metal wire. Slider and ProGlider instruments had similar R-phase start (Rs) and R-phase finish (Rf) temperatures. SX, F1, F2, F3 and Shaper instruments showed equivalent heat treatments (Rs ~45.6°C and Rf ~28.3°C) that were similar to their PT Gold counterparts (Rs ~47.9°C and Rf ~28.2°C), but completely distinct to the PT Universal ones (Rs ~16.2°C and Rf ~−18.2°C). Amongst the PT Ultimate instruments, the lowest maximum torques were observed in the SX (0.44 N cm), Slider (0.45 N cm) and Shaper (0.60 N cm) instruments, whilst the highest was noted in the FXL (4.90 N cm). PT Ultimate Slider and ProGlider had similar torsional (~0.40 N cm) and bending loads (~145.0 gf) (p = 1.000), whilst the other PT Ultimate instruments showed statistically significantly lower maximum torque, higher angle of rotation and lower bending load (higher flexibility) than their counterparts of the PT Universal and PT Gold systems. Conclusions: The PT Ultimate system comprises instruments with 3 distinct heat treatments that showed similar phase transformation temperatures to their heat-treated analogues. PT Ultimate instruments presented lower torsional strength and superior flexibility than their counterparts, whilst maximum torque, angle of rotation and bending loads progressively increased with their sizes.publishersversionpublishe

Laminotomia por separação do processo espinhoso: uma abordagem minimamente invasiva no acesso à coluna vertebral para colocação de eletrodos de estimulação da medula espinhal

Introdução: A dor crônica é uma condição debilitante que afeta uma grande parcela da população, sendo um constante desafio para os profissionais da saúde devido a seus desafios relacionados ao entendimento fisiologico e opções de tratamento. Nos últimos anos a estimulação da medula espinhal com eletrodos tem emergido como uma possibilidade de tratamento promissora para o tratamento da dor crônica refratária as condutas medicamentosas. Objetivo: Relatar um caso clínico-cirúrgico de indicação correta de uma abordagem minimamente invasiva para estimulação de medula espinhal em um paciente com dor crônica. Relato de caso: Os autores descrevem o caso de uma paciente do gênero feminino de 58 anos com neuropatia descrita como ciatalgia, irradiando para o membro inferior direito associado a um comprimetimento motor. A paciente já havia sido previamente tratada com medicamentos convencionais para dor e feito procedimentos invasivos, como artrodese e laminectomia, sem grandes melhoras. Após avaliação clínica por meio de exame físico, avaliação de exames de imagem e exames laboratoriais, foi optado por colocar as pás de estimulação por meio de um acesso minimamente invasivo, a laminectomia por secção do processo espinhoso. Conclusão: Com a abordagem cirúrgica minimamente invasiva, a paciente apresentou diminuição da necessidade de analgésicos no período pós-operatório e uma redução global da dor em apenas 2 semanas

Micro–computed tomography study of oval-shaped canals prepared with the self-adjusting file, reciproc, WaveOne, and ProTaper Universal Systems

The newly developed single-file systems claimed to be able to prepare the root canal space with only 1 instrument. The present study was designed to test the null hypothesis that there is no significant difference in the preparation of oval-shaped root canals using single- or multiple-file systems. Methods Seventy-two single-rooted mandibular canines were matched based on similar morphologic dimensions of the root canal achieved in a micro–computed tomographic evaluation and assigned to 1 of 4 experimental groups (n = 18) according to the preparation technique (ie, Self-Adjusting File [ReDent-Nova, Ra’anana, Israel], WaveOne [Dentsply Maillefer, Ballaigues, Switzerland], Reciproc [VDW, Munich, Germany], and ProTaper Universal [Dentsply Maillefer] systems). Changes in the 2- and 3-dimensional geometric parameters were compared with preoperative values using analysis of variance and the post hoc Tukey test between groups and the paired sample t test within groups (α = 0.05). Results Preparation significantly increased the analyzed parameters; the outline of the canals was larger and showed a smooth taper in all groups. Untouched areas occurred mainly on the lingual side of the middle third of the canal. Overall, a comparison between groups revealed that SAF presented the lowest, whereas WaveOne and ProTaper Universal showed the highest mean increase in most of the analyzed parameters (P < .05). Conclusions All systems performed similarly in terms of the amount of touched dentin walls. Neither technique was capable of completely preparing the oval-shaped root canal

Comparison of the cleaning efficacy of self-adjusting file and rotary systems in the apical third of oval-shaped canals

Introduction Cleaning and shaping of root canals are essential steps for the success of endodontic therapy. The purpose of this study was to evaluate the tissue debridement efficacy of the self-adjusting file (SAF) protocol in the apical third of oval-shaped canals of mandibular incisors in comparison with a nickel-titanium rotary system preparation. Methods Twenty-six single-rooted human mandibular incisor teeth were selected and assigned to a control (n = 4) and 2 experimental groups (n = 11) according to 1 of 2 instrumentation techniques, SAF and nickel-titanium rotary systems. After root canal preparation, the apical thirds of the specimens were submitted to histologic processing and analyzed by optical microscopy regarding the percentage of debris and uninstrumented root canal walls. The data were statistically compared by using unpaired t test with Welch's correction, and the level of significance was set at 5%. Results The percentage of remaining debris and uninstrumented canal perimeter was significantly lower in SAF group (2.18 ± 2.71 and 12.33 ± 7.85, respectively) than in rotary group (13.11 ± 12.98 and 53.54 ± 15.95, respectively) (P < .05). In the SAF group most of specimens were completely free of debris, whereas in the rotary group 53% of the canals presented debris. Conclusions SAF had significantly more contact to the dentin walls and removed more debris than rotary instrumentation in the apical third of mandibular incisors