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This study aimed to evaluate the influence of temperature on torsional strength and angular deflection of two experimental NiTi rotary instruments manufactured from Blue and Gold thermal treatments and with identical cross-sections. A total of 40 experimental NiTi instruments 25.06 and with a triangular cross-section and manufactured from Blue and Gold thermal treatments were used (n=20). The torsional test was performed in the 3 mm from the tip of the instrument according to ISO 3630-1. The torsional test evaluated the torsional strength and angular deflection to failure at room temperature (21°C ± 1° C) and body temperature (36°C ±1°C). The fractured surface of each fragment was observed by using scanning electron microscopy (SEM). Data were analyzed using an unpaired t test for inter and intra-group comparison and the level of significance was set at 5%. The results showed that the body temperature did not affect the torsional strength and angular deflection of the instruments when compared with room temperature (P>0.05). However, at body temperature, the Blue NiTi instruments presented significantly lower angular deflection in comparison with Gold NiTi instruments (P0.05). The temperature did not affect the torsional strength of the instruments manufactured from Blue and Gold technology. However, the Blue NiTi instruments presented significantly lower angular deflection than Gold instruments at 36°C temperature.

Avaliar a resistência à fadiga torsional, qualidade do preparo e influência da temperatura corporal na instrumentação de canais simulados em blocos de acrílico com três instrumentos diferentes de NiTi tratados termicamente. Material e métodos: Foram utilizados 36 blocos padronizados. Estes foram digitalizados e divididos em três grupos (n=12): Reciproc Blue (grupo I); X1 Blue File (grupo II); ProDesign R (grupo III). Realizou-se a instrumentação com motor VDW Silver na função “reciproc all”. Metade dos blocos foi instrumentada num recipiente simulando a temperatura corporal (37ºC) e a outra em temperatura ambiente (20ºC). Finalmente, os instrumentos foram submetidos ao teste de fadiga torsional. Os blocos foram novamente escaneados, e calcularam-se a capacidade de centralização e a porcentagem do aumento de volume. Aplicaram[1]se os testes estatísticos, e o nível de significância adotado foi de 5%. Resultados: A porcentagem de aumento de volume do Reciproc Blue apresentou os menores valores na temperatura ambiente. Na temperatura corporal o ProDesign R teve o menor valor. Na comparação do mesmo instrumento nas diferentes temperaturas, o ProDesign R evidenciou o maior valor na temperatura ambiente. Avaliando a capacidade de centralização, houve diferença estatística entre os grupos no terço cervical, sendo o Reciproc Blue o mais centralizado. Conclusão: A temperatura influenciou na qualidade do preparo dos canais, mas não na resistência à fadiga torsional dos instrumentos. Diante disso, em estudos futuros é importante realizar a instrumentação dos canais em uma temperatura próximo à corporal, para os resultados serem o mais fiel possível da realidade clínica.

Background: The aim of this study was to evaluate the cyclic fatigue and torsional fatigue resistance of three thermally treated rotary instruments, such as: Logic 2 25.05 (LOG 25.05), Edge Taper Platinum 25.06 (EDT 25.06) and ProTaper Gold 25.08 (PTG 25.08).Methods: A total of 60 rotary instruments of LOG 25.05, EDT 25.06 and PTG 25.08 were used (n=20). Cyclic fatigue tests were performed at 36°C using an artificial stainless steel canal with a 60o angle and a 5-mm radius of curvature. The time (in seconds) and number of cycles to fracture (NCF) was recorded. The torsional test evaluated the torque and angle of rotation to failure at 3 mm from the tip according to ISO 3630-1. The fractured surface of each fragment was observed by using scanning electron microscopy (SEM). Data were analyzed using one-way ANOVA and Holm-Sidak’s tests for multiple comparison, the level of significance was set at 5%. Results: EDT 25.06 had highest cyclic fatigue resistance (time and NFC), followed by LOG 25.05 and PTG 25.08 (P0.05). In relation the torsional test, the LOG 25.05 and ETP 25.06 presented similar torque (P>0.05). The PTG presented greater torque than the other groups (P

OBJECTIVES:The study aimed to evaluate the potential for dissolution of organic tissue in areas of simulated complexity and cleaning of root walls of the new iVac® endodontic irrigation system. MATERIAL AND METHODS: Thirty mandibular premolars were evaluated by scanning electron microscopy before and after biomechanical preparation. Then, they were distributed according to the final irrigation protocol into groups with conventional irrigation, passive ultrasonic irrigation with metallic insert (PUI), and iVac® system, and new photomicrographs were obtained. For tissue dissolution analysis, glass capillaries filled with catgut were attached to the cervical and apical thirds of twenty prototyped upper incisors. They were weighed before and after the previously mentioned irrigation protocols. The data were statistically compared with a significance level of 5%. RESULTS:The final irrigation provided greater cleaning of the walls in the cervical, middle, and apical thirds of the root canals (PCONCLUSIONS:The iVac® system showed wall cleaning and tissue dissolution similar to PUI with a metallic insert, and both were superior to conventional irrigation. CLINICAL RELEVANCE: The new irrigation system iVac is more effective than conventional irrigation and has similar wall cleaning and tissue dissolution to PUI.

Professor Titular de Endodontia, Faculdade de Odontologia, Universidade de São Paulo (São Paulo/SP, Brasil). Doutor em Odontologia, área de concentração em Endodontia, Universidade de São Paulo (São Paulo/SP, Brasil). E-mail para contato: celcalde@usp.br

Objective To evaluate the obturation quality of mandibular molars flattened distal canals using ultrasonic certical condensatio (UVC) compared to the continuous wave of condensation (CWC) technique through micro-computed tomographic (micro-CT) assessment. Methods Mandibular molars were micro-CT scanned for sample homogenization, and the volume and flattening (B-L/M-D > 4) of the distal canals were determined. Thirty-six canals were then prepared with Protaper Gold instruments up to #F3 associated with 2.5% sodium hypochlorite, followed by passive ultrasonic irrigation. After instrumentation, the canal volume was determined in a new scan, and the roots were randomly divided and allocated to UVC and CWC groups. Fourteen days after obturation with gutta-percha and AH Plus sealer, the specimens were scanned again to evaluate the filling quality. Results None of the fillings performed completely filled the canal area. Obturation values of 83.33% (UVC) and 89.97% (CWC) were observed; the Student’s t-test exhibited no significant difference between the techniques (P > 0.05). Conclusion Under the conditions of this study, it was observed that none of the evaluated techniques was able to completely obturate the canals; nevertheless, UVC achieved similar results compared to the CWC technique. Clinical Relevance: Despite not being able to completely obturate the complex root canal anatomy, both techniques yielded satisfactory fillings. Ultrasonic vertical condensation could be an interesting clinical option for filling flattened canals, achieving a similar outcome to that of the continuous wave of condensation technique.

This study evaluated the resistance to flexural fatigue and torsional strength of files for glide path preparation in continuous rotation or Optimum Glide Path motion (OGP). ScoutRace 15.02 and ProGlider 16.02 files were used in a dynamic testing device during preparation of simulating curved root canals (40-degree curvature and 5 mm radius). For the torsional test, a machine was used to test torsion measured maximum torsional strength (N.cm). Two-way anova and Tukey's multiple comparisons test were used for statistical analysis. Files in OGP motion had a statistically better resistance to flexural fatigue (P < 0.05). ProGlider files took longer time to failure than ScoutRace files only when OGP was used (P < 0.05). The torsional test revealed that OGP produced significantly less torsional stress than rotary motions for both types of glide path files (P < 0.05) In conclusion, OGP motion increased substantially the mechanical safety of endodontic glide path files.

Graduado em Odontologia pela Universidade de Uberaba – UNIUBE. Curso de atualização em Endodontia pela Faculdade de Odontologia de Araraquara - FOAr-UNESP. Especialista em Endodontia pela Faculdade de Odontologia de Araraquara - FOAr-UNESP. Curso de atualização em Patologia pela Faculdade de Medicina da Universidade Federal do Triângulo Mineiro - FM-UFTM. Doutor em Endodontia pela Faculdade de Odontologia de Araraquara - FOAr-UNESP. Pós-Doutor em Física e Ciência dos Materiais pelo Instituto de Física de São Carlos - IFSC-USP. Pós-Doutor em Endodontia pela Faculdade de Odontologia de Araçatuba - FOA-UNESP. Professor Responsável pela disciplina de Endodontia da Faculdade de Odontologia de Araçatuba - FOA-UNESP. Professor do curso de Especialização em Endodontia da Faculdade de Odontologia de Araçatuba - FOA-UNESP. Professor e Orientador dos cursos de Mestrado e Doutorado no Programa de Pós-Graduação em Ciência Odontológica, Área de Endodontia, da Faculdade de Odontologia de Araçatuba - FOA-UNESP.

The aim of this study was to evaluate the cyclic fatigue resistance of different heat-treated nickel-titanium reciprocating instruments in 2 different situations: new and used instruments after preparing 3 curved canals.A total sample of 60 nickel-titanium instruments of 3 systems (n = 20 per system) were used in this study: ProDesign R (tip 25, 0.06 taper; Easy Dental Equipment, Belo Horizonte, Brazil), Reciproc Blue (tip 25, 0.08v taper; VDW, Munich, Germany), and WaveOne Gold (tip 25, 0.07v taper; Dentsply Sirona, Ballaigues, Switzerland). Thirty new instruments (n = 10 per system) were used to prepare 90 curved single-rooted mandibular premolars (n = 30). Each instrument was used to prepare 3 root canals, and after each canal preparation the instrument was ultrasonic cleaned and submitted to autoclave sterilization procedures. The other 30 instruments (n = 10 per system) were kept without use. Then, the new and used instruments were subjected to the cyclic fatigue test in an artificial canal with a 30° angle and a 5-mm radius of curvature. The time and number of cycles to fatigue were recorded. Data were analyzed using the unpaired t test for intragroup comparison. For intergroup comparison, analysis of variance and the Tukey test for multiple comparisons were used.The intergroup comparison of new instruments showed that ProDesign R had the highest cyclic fatigue resistance followed by Reciproc Blue and WaveOne Gold (P.05). Regarding the used instruments, WaveOne Gold had the lowest cyclic fatigue resistance (P.05). The intragroup comparison between new and used instruments showed that WaveOne Gold and ProDesign R presented a significant reduction in the cyclic fatigue resistance after simulated clinical use (P.05); no difference was found with the Reciproc Blue instruments (P.05).ProDesign R had the highest cyclic fatigue resistance, whereas WaveOne Gold had the lowest for new and used instruments. Simulated clinical use affected the cyclic fatigue resistance of ProDesign R and WaveOne Gold but not of Reciproc Blue instruments.

Graduado em Odontologia pelo Centro Universitário da Fundação Educacional de Barretos (UNIFEB, 1997). » Especialista em DTM e Dor Orofacial, Conselho Federal de Odontologia. » Mestre em Odontologia, área de concentração em Fisiologia Oral (FOP/UNICAMP, 2000-2001). » Doutor em Odontologia, área de concentração em Fisiologia Oral (FOP/UNICAMP, 2002-2004). » Pós-doutorado em Ciências Odontológicas Aplicadas (FOB/USP, 2011). » Professor Associado (Livre-Docente) da Faculdade de Odontologia de Bauru-SP (FOB/USP). » Professor e orientador de Mestrado e Doutorado no Programa de Pós-graduação em Ciências Odontológicas Aplicadas (FOB/USP). » Bolsista Produtividade em Pesquisa CNPq (PQ 2). » Membro da Diretoria (Secretário) da Sociedade Brasileira de Disfunção Temporomandibular e Dor Orofacial (SBDOF).

Objective: The aim of this study was to evaluate the cyclic fatigue, torsional behavior and bending resistance of EdgeTaper Platinum [ETP (tip 25, taper 0.06)], Flex Gold [FG (tip 25, taper 0.08)], Pro-T [PT (tip 25, taper 0.08)] and ProTaper Gold [PTG (tip 25, taper 0.08)] systems. Methods: Rotary instruments of ETP, PT, FG, and PTG were used (n=30). Cyclic fatigue tests were performed using an artificial stainless-steel canal with a 60o angle and a 5-mm radius of curvature at body temperature (35°±1°C). The time and number of cycles to fracture (NCF) was recorded. The torsional test evaluated the torque and angle of rotation to failure at 3 mm from the tip according to ISO 3630-1. The fractured surface of each fragment was observed by using scanning electron microscopy (SEM). The bending test evaluated the torque required to bend the instruments at an angular deflection of 60°. Data were analyzed using one-way ANOVA and Tukey tests, and the level of significance was set at 5%. Results: The ETP had highest time until fracture and NCF than all the groups (P

Objetivo: O objetivo do presente estudo foi avaliar a influência da liga (NiTi convencional e M-Wire) e do movimento (reciprocante e rotação contínua) na resistência à fadiga cíclica. Métodos: Quinze limas Reciproc R25 (VDW GmbH, Munique, Alemanha) foram usadas em movimento reciprocante (MR), enquanto trinta limas Mtwo 25.07 (VDW GmbH, Munique, Alemanha) foram usadas em MR (n=15) ou em rotação contínua (RC) (n=15). Os instrumentos foram submetidos a ensaios dinâmicos movidos por motor elétrico, que permitiram reproduzir o movimento de pecking motion, a 300rpm de velocidade. Os instrumentos simularam a instrumentação de um canal radicular curvo com 40o e 5mm de raio de curvatura. A fratura dos instrumentos foi detectada por um sensor digital, e o tempo e o número de ciclos foram registrados. Os dados foram analisados estatisticamente pelos testes ANOVA e de Tukey (p

Objective: The aim of this study was to evaluate the use of Self-adjusting file (SAF) system and Hedström (H) file for removing remaining filling material (RFM) from C-shaped canals. Methods: 20 C-shaped mandibular second molars with C1 configurations were instrumented, filled with tagger´s hybrid technique. Samples were divided into 2 groups (n=10). Reciproc R25 and a Mtwo 35/04 file were used for retreatment in both groups. Then, a 2.0 SAF file (group I) and a #35 H file (group II) were used as supplementary steps for RFM removal. Micro-CT scanning was performed after every procedure. Total volumes were calculated and converted into percentages. Also, the minimum wall thickness at 3, 5, 7 mm from apex was calculated. The Prism 7.0 software was used as the analytical tool with a significance of 5%. Results: Initial obturation removal was approximately 64% in group I and 67% in Group II. The apical third had the highest values of RFM. The use of a H file significantly reduced the RFM compared to SAF in the total canal length respectively (30% vs 18%) and at 1-3 mm and 3-6 mm when compared to the use of SAF. A statistically significant decrease of RFM and minimum wall thickness were observed in both groups (P

Compare canal transportation and dentin removal using micro computed tomography (micro-CT) and measure instrumentation time in the root canal preparation of primary molars using K-files, ProDesign Logic and Reciproc files. A representative sample of 81 root canals of primary molars was randomised into three groups: K-files (#15-40), ProDesign Logic (#25) and Reciproc (R25). A single-trained operator prepared all root canals. A standardised micro-CT evaluation was performed before and after instrumentation using the CTan® program. Instrumentation time was also recorded. Statistical analysis involved one-way ANOVA, Tukey’s post hoc test, Kruskal–Wallis test and Dunn’s test, considering a 5% level of significance. Reciproc led to more canal transportation than K-files and ProDesign Logic (p

» Graduado em Odontologia pela FOJOP (Unievangélica, Anápolis/GO, 1983). » Especialista em Endodontia pela ABO-GO (1986-1987). » Mestre em Endodontia pela Faculdade de Odontologia da Universidade Federal de Pelotas (1988-1989). » Doutor em Endodontia pela Faculdade de Odontologia da Universidade de São Paulo (1992-1993). » Livre-Docente em Endodontia pela Faculdade de Odontologia de Ribeirão Preto da Universidade de São Paulo (1997). » Professor Titular em Endodontia da Faculdade de Odontologia da Universidade Federal de Goiás, Disciplina de Endodontia, desde 1995. » Coordenador do Laboratório de Pesquisa em Ciência Endodôntica da Faculdade de Odontologia da UFG. » Professor e orientador de Mestrado e Doutorado nos Programas de pós-graduação em Odontologia (Faculdade de Odontologia) e Ciências da Saúde (Faculdade de Medicina) da UFG. » Bolsista de Produtividade em Pesquisa CNPq (PQ 1B).

» Graduado em Odontologia pela USP, Faculdade de Odontologia de Bauru (1987). » Mestre em Endodontia pela USP, Faculdade de Odontologia de Bauru (1992). » Professor Assistente da UNESP, Faculdade de Odontologia de Araraquara, Disciplina de Endodontia, desde 1992. » Doutor em Endodontia pela UNESP, Faculdade de Odontologia de Araraquara (1996). » Livre-Docente em Endodontia pela UNESP, Faculdade de Odontologia de Araraquara (2001). » Professor Associado da UNESP, Faculdade de Odontologia de Araraquara, Disciplina de Endodontia, desde 2001. » Professor Titular em Endodontia pela UNESP, Faculdade de Odontologia de Araraquara, Disciplina de Endodontia, desde 2010. » Coordenador do Programa de Pós-Graduação em Odontologia da UNESP, Faculdade de Odontologia de Araraquara (2010-2012). » Coordenador do Curso de Especialização em Endodontia da UNESP, Faculdade de Odontologia de Araraquara, desde 2016. » Bolsista de Produtividade em Pesquisa CNPq (PQ 1C).

» Graduado em Odontologia pela Faculdade de Odontologia de Araçatuba – Unesp (1997-2000). » Especialista em Endodontia pela Faculdade de Odontologia de Araçatuba – Unesp (2001-2002). » Mestre em Odontologia, área de Endodontia, pela Faculdade de Odontologia de Bauru – USP (2003-2005). » Doutor em Clínica Odontológica, área de Endodontia, pela Faculdade de Odontologia de Piracicaba – Unicamp (2005-2008). » Pós-doutor pela Universidade Estadual de Maringá – UEM (2011). » Livre-docente pela Faculdade de Odontologia de Araçatuba – Unesp (2014). » Professor Associado da Disciplina de Endodontia da Faculdade de Odontologia de Araçatuba – Unesp, desde 2010. » Coordenador do Curso de Especialização em Endodontia da Faculdade de Odontologia de Araçatuba – Unesp. » Coordenador do Programa de Pós-graduação em Ciência Odontológica da Faculdade de Odontologia de Araçatuba – Unesp.

This study evaluated the efficacy of 3 reciprocating systems and the effects of 2 instruments for irrigant activation on filling material removal.Forty mesiobuccal roots of maxillary molars were prepared up to size 25.06 and obturated. Micro-computed tomography (micro-CT) examination #1 was performed. Teeth were then divided into 4 groups (WaveOne Gold removed a significantly greater amount of filling material than the manual group (None of the tested instruments completely removed the filling material. X1 Blue size 25.06 reached the working length in the shortest time. XP Clean and Flatsonic improved the filling material removal.

Made available in DSpace on 2022-04-29T08:40:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Background: The association of scaffolds to repair extensive bone defects can contribute to their evolution and morphophysiological recomposition. The incorporation of particulate biomaterials into three-dimensional fibrin bioproducts together with photobiomodulation therapy (PBM) has potential and can improve regenerative medicine procedures. The objective of this experiment was to evaluate the effects of PBM therapy on critical size defects filled with xenogenic bone substitute associated with fibrin biopolymer. Methods: A critical defect of 8 mm was performed in 36 Wistar male adult rats that were divided into four groups. Groups BC and BC-PBM were defined as controls with defects filled by a clot (without or with PBM, respectively) and groups XS and XS-PBM that comprised those filled with biocomplex Bio-OssTM in association with fibrin biopolymer. PBM was applied immediately after the surgery and three times a week every other day, with the parameters: wavelength of 830 nm, energy density 6.2 J/cm2, output power 30 mW, beam area of 0.116 cm2, irradiance 0.258,62 W/cm2, energy/point 0.72 J, total energy 2.88 J. Fourteen and 42 days after the surgery, animals were euthanatized and subjected to microtomography, qualitative and quantitative histological analysis. Results: The BC-PBM and XS-PBM groups had a similar evolution in the tissue repair process, with a higher density of the volume of new formed bone in relation to the groups without PBM (p = 0.04086; p = 0.07093, respectively). Intense vascular proliferation and bone deposition around the biomaterial particles were observed in the animals of the groups in which biocomplex was applied (XS and XS-PBM). Conclusion: PBM therapy allowed an improvement in the formation of new bone, with a more organized deposition of collagen fibers in the defect area. Biocomplex favored the insertion and permanence of the particulate material in bone defects, creating a favorable microenvironment for accelerate repair process. Graduate Program in Structural and Functional Interactions in Rehabilitation University of Marilia (UNIMAR), SP Medical School University Center of Adamantina (UniFAI), SP Center for the Study of Venoms and Venomous Animals (CEVAP) São Paulo State University (UNESP), SP Department of Biological Sciences (Anatomy) Bauru School of Dentistry University of São Paulo (USP), SP Graduate Program in Tropical Diseases Botucatu Medical School (FMB) São Paulo State University (UNESP), SP Graduate Program in Clinical Research Center for the Study of Venoms and Venomous Animals (CEVAP) São Paulo State University (UNESP), SP Department of Dentistry Endodontics and Dental Materials Bauru School of Dentistry University of São Paulo (USP), SP Graduate Program in Applied Dental Sciences Bauru School of Dentistry University of São Paulo (USP), SP Department of Health Science Unisagrado University Center, SP Center for the Study of Venoms and Venomous Animals (CEVAP) São Paulo State University (UNESP), SP Graduate Program in Tropical Diseases Botucatu Medical School (FMB) São Paulo State University (UNESP), SP Graduate Program in Clinical Research Center for the Study of Venoms and Venomous Animals (CEVAP) São Paulo State University (UNESP), SP

This study aimed to use micro-computed tomographic imaging to analyze the quality of the endodontic preparation of mesial canals in mandibular molars provided by 3 instrumentation protocols.Forty-five extracted mandibular molars with 2 independent mesial canals were selected, and the initial micro-computed tomographic imaging was performed. The initial volume values of the canals were submitted to statistical analysis for paired division. The groups were determined according to the final enlargement of the canal and the working length adopted (ie, G25.06/+1 mm, G35.05/foramen, and G50.01/-1 mm). At the end of each instrumentation sequence, the root canals were scanned and analyzed with regard to the increase in the total and apical volume, centralization, and preparation transportation and the percentage of the total and apical uninstrumented walls.For the intragroup comparison, the Wilcoxon test was used, and for the intergroup analysis, the Kruskal-Wallis and Dunn tests were used (P .05). In the analysis of the canal total volume, a statistical difference was found between G25.06/+1 mm and the remaining groups (P .05). In the apical third, a statistical difference was observed between G25.06/+1 mm and G50.01/-1 mm (P .05). No statistical difference was found between the groups in terms of centralization and transportation of the preparation or in terms of the percentage of the total or apical uninstrumented walls.The preparation of the mesial canals of mandibular molars up to larger tip files but with a lower taper at 1 mm before the foramen resulted in a larger volume of apical preparation, kept the preparation centralized, and provided safe apical dentin wear without excessive cervical wear.

Autologous bone grafts, used mainly in extensive bone loss, are considered the gold standard treatment in regenerative medicine, but still have limitations mainly in relation to the amount of bone available, donor area, morbidity and creation of additional surgical area. This fact encourages tissue engineering in relation to the need to develop new biomaterials, from sources other than the individual himself. Therefore, the present study aimed to investigate the effects of an elastin and collagen matrix on the bone repair process in critical size defects in rat calvaria. The animals (Wistar rats, n = 30) were submitted to a surgical procedure to create the bone defect and were divided into three groups: Control Group (CG, n = 10), defects filled with blood clot, E24/37 Group (E24/37, n = 10), defects filled with bovine elastin matrix hydrolyzed for 24 h at 37 °C and C24/25 Group (C24/25, n = 10), defects filled with porcine collagen matrix hydrolyzed for 24 h at 25 °C. Macroscopic and radiographic analyses demonstrated the absence of inflammatory signs and infection. Microtomographical 2D and 3D images showed centripetal bone growth and restricted margins of the bone defect. Histologically, the images confirmed the pattern of bone deposition at the margins of the remaining bone and without complete closure by bone tissue. In the morphometric analysis, the groups E24/37 and C24/25 (13.68 ± 1.44, 53.20 ± 4.47, respectively) showed statistically significant differences in relation to the CG (5.86 ± 2.87). It was concluded that the matrices used as scaffolds are biocompatible and increase the formation of new bone in a critical size defect, with greater formation in the polymer derived from the intestinal serous layer of porcine origin (C24/25).

Background: Infection control is mandatory for revascularization procedures, enabling to eliminate patient's clinical symptoms and signs. Despite presenting a complex morphology when compared to anterior teeth, if a strict disinfection protocol is adopted and the revascularization procedure's biological principles are followed, the therapy can be successful in molar teeth. Methods: This case report aims to present a clinical case of successful revascularization in an immature permanent necrotic second lower molar. Clinical decisions and explanations regarding possible mechanisms related to the treatment's success in a tooth with complex morphology are discussed. Results: Revascularization procedures were performed on a 12-year-old male patient diagnosed with symptomatic periapical periodontitis in a tooth 37. The case highlights the need for infection control and biological principles that surrounds the success of this therapy. Follow-up times presented in this case were six months, 1, 2, 4 and 4.5-years, respectively. Continued root development was observed, and the tooth remains intact and without symptoms. Conclusion: The association of infection control and the biological principles of revascularization procedures allow the maintenance and continuation of tooth development, even when these present complex morphologies.

The aim of this study was to compare the efficacy of UAI with ESI, sonic activation with Eddy® and syringe irrigation in removing debris, and dentin removal during canal irrigation. Twenty-four mandibular molars containing isthmus type V and with a mean curvature of 32.5o were instrumented and divided into three groups for final irrigation: UAI with ESI, sonic activation with Eddy and syringe irrigation. The samples were scanned in a SkyScan 1172 micro-CT device for pre-, post-instrumentation and post-irrigation images and analysis of dentin removal. Statistical analysis was performed using Wilcoxon, Kruskal-Wallis and Dunn tests. UAI and sonic activation significantly improved debris removal (P 0.05), although higher values were found for UAI. Sonic activation with Eddy® showed to be an effective and safe device since it was able to remove debris without causing damage to the canal walls.

Objective This study aimed to evaluate the cleaning efficacy of irrigant activation with a new ultrasonic tip in root-end preparations and to determine its influence on the bond strength of calcium silicate-based material. Materials and Methods Maxillary canines were prepared and filled, and their root ends resected. Root-end cavities were ultrasonically prepared and randomly distributed into four groups according to the final irrigation protocols: G1 (ultrasonic irrigation [UI] + saline solution [SS]), G2 (syringe irrigation [SI] + SS), G3 (UI + ethylenediaminetetraacetic acid [EDTA]), and G4 (SI + EDTA). Cleaning efficacy analysis employed 72 specimens (n = 18) split longitudinally for imaging of the same areas by scanning electron microscopy (SEM). The percentage of dentinal tubules opened before and after irrigation was used as evaluation parameter. Push-out testing employed 40 specimens (n = 10) sectioned apical region perpendicularly, which slice was placed on a testing machine for the bond strength measurement and failure mode was assessed by SEM. The data were statistically analyzed (α ≤ 0.05). Results G3 (UI + EDTA) removed the smear layer more effectively, showed the best tubule opening (p < 0.05), and presented the highest mean bond strength values (p < 0.05). Failure modes were predominantly adhesive, except for the G3 (UI + EDTA) group, in which they were mainly mixed (80%). Conclusion The results of this study suggest that EDTA 17% agitation promoted better cleaning and smear layer removal, improving the push-out bond strength of calcium silicate material in retrograde obturation.

AIM To evaluate in a laboratory setting the performance of two reciprocating glide path systems, WaveOne Gold Glider (WO) and R-Pilot (RP), to create a glide path in mesial root canals of mandibular molars and to assess the torsional resistance of instruments after performing the glide path. METHODOLOGY A total of 60 mesial root canals of extracted human mandibular molars were divided into two groups (n = 30) according to the glide path system to be used. The data from the volume of each canal, acquired by microcomputed tomography (micro-CT), were validated statistically for the anatomical pairing of the groups. Preparation time, frequency in gaining apical patency, plastic deformation rate of instruments, and canal transportation and centring ability were recorded and compared statistically. The torsional fatigue of the instruments after use was also evaluated. Data were analysed using Fisher's exact test and Mann-Whitney U-test with a 5% significance level. RESULTS No significant differences were found between groups regarding the time required to perform the glide path, the frequency distributions of the canals classified as patent and the instruments with plastic deformation after use (P > 0.05). No significant differences were found between groups regarding the degree of canal transportation and centring ability at the cervical, middle and apical thirds (P > 0.05). The RP groups had significantly greater maximum torsional strength values compared with the WO groups (P

This study aimed to evaluate the influence of large apical preparations with Reciproc (REC), Hyflex CM (HCM) and Twisted File Adaptive (TFA) systems using micro-computed tomography (MCT). Ninety mesiobuccal (MB) and distobuccal (DB) root canals of maxillary molars (n = 45) were scanned using MCT before and after the shaping procedures. The root canals (n = 15) were prepared until REC 40.06, HCM 40.04 and TFA 35.04. The root canal transportation (RCT), centring ability (CA), change in volume of the root canal and at different levels (VC), remaining dentine thickness (RDT), removal of dentine wall (RDW) and working time (WT) were evaluated. Data were analysed using the Kruskal-Wallis and Dunn tests, and the one-way ANOVA and Tukey tests with a level of significance set at 5%. No significant difference among the instruments was found regarding the RCT, CA, RDT, RDW and WT (P > 0.05), in larger apical preparations in curved MB and straight DB canals of maxillary molars.

Sixty moderately curved canals of mandibular molars classified as Vertucci’s type IV canal configuration were selected by micro-CT 1174. The teeth were divided into two groups according to the kinematics used, whether reciprocating or rotary motion (n=30, totaling 60 mesial root canals). The instruments used to perform the glide path procedures had identical features (0.15 mm of tip size, 0.04 mm/mm taper, thermal treatment, and square cross-section), but differed in the direction of the cutting blade. The duration of the procedure and the absolute and percentage frequency of the instruments to reach the full working length were recorded. The torsional test (3630-1; 1992) was performed on both used and unused instruments, to evaluate a possible reduction in the torsional resistance when using the glide path procedure. Statistical analysis was performed using the unpaired t-test and the chi-square test, and the level of significance was set at 5%. The type of kinematics used affected the duration of glide path procedures, and the reciprocating motion seemed to induce less torsional stress during glide path procedures.