Resumo O objetivo deste estudo foi avaliar a influência da temperatura nas propriedades de torção (resistência à torção e deflexão angular) de dois instrumentos rotatórios experimentais de NiTi fabricados com secção triangu.ar e tratamentos térmicos Blue e Gold. Quarenta instrumentos experimentais de NiTi 25.06 com tratamento térmico Blue e Gold foram usados (n= 20). Foi avaliada a resistência torcional e a deflexão angular até a fratura na temperatura ambiente (21°C ± 1°C) e corporal (36°C ± 1°C). O teste torcional foi realizado nos 3 mm da ponta dos instrumentos de acordo com a ISO 3630-1. A superfície fraturada de cada instrumento foi observada pelo microscópio eletrônico de varredura (MEV). Os dados foram analisados por meio do teste t não pareado para a comparação inter e intragrupos e o nível de significância à 5%. Os resultados demonstraram que a temperatura corporal não afetou a resistência a torção e deflexão angular quando comparada com a temperatura ambiente (P>0.05). No entanto, na temperatura de 36°C o instrumento com tratamento térmico Blue apresentou menor deflexão angular quando comparado com o Gold (P<0.05). Não houve diferença significante entre os dois instrumentos em relação a resistência à torção. A temperatura corporal não modificou a resistência torcional dos instrumentos fabricados com tecnologia Blue e Gold. No entanto, os instrumentos com NiTi Blue apresentaram menor deflexão angular do que o Gold a 36°C. trianguar triangu ar 2506 25 06 25.0 n= n (n 20. 20 . 20) 21°C 21C C 21 1°C 1C 1 36C 36 1°C. 36301. 36301 3630 1. 3630-1 MEV. MEV (MEV) 5 5% P>0.05. P005 P P>0.05 0 05 (P>0.05) entanto P<0.05. P<0.05 (P<0.05) 250 2 25. 363 3630- (MEV P00 P>0.0 (P>0.05 P<0.0 (P<0.05 P0 P>0. (P>0.0 P<0. (P<0.0 P>0 (P>0. P<0 (P<0. P> (P>0 P< (P<0 (P> (P< (P

Abstract 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 (P<0.05). There was no significant difference regarding the torsional strength of the instruments at body temperature (P>0.05). 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. crosssections. crosssections cross sections. sections cross-sections 4 2506 25 06 25.0 crosssection section n=20. n20 n n=20 . 20 (n=20) 36301. 36301 3630 1. 1 3630-1 21°C 21C C 21 36C 36 ±1°C. 1C ±1°C ±1°C) SEM. SEM (SEM) intragroup intra group 5 5% P>0.05. P005 P P>0.05 0 05 (P>0.05) However P<0.05. P<0.05 (P<0.05) technology 250 2 25. n2 n=2 (n=20 363 3630- (SEM P00 P>0.0 (P>0.05 P<0.0 (P<0.05 n= (n=2 P0 P>0. (P>0.0 P<0. (P<0.0 (n= P>0 (P>0. P<0 (P<0. (n P> (P>0 P< (P<0 (P> (P< (P

Abstract This study aimed to assess the self-reported levels of confidence and knowledge related to non-odontogenic pain among a group of Brazilian endodontists. Methodology A total of one hundred and forty-six endodontists affiliated with the Brazilian Society of Endodontics participated in the survey. The questionnaire, distributed via email or WhatsApp, contained inquiries designed to gauge self-perceived confidence and knowledge concerning non-odontogenic pain. The practitioners were categorized into four groups based on their self-reported familiarity with various orofacial pain types, classified as either sufficient or insufficient, and on their engagement in ongoing educational programs related to orofacial pain. Data were analyzed by Chi-Square Test and Fischer’s exact test (p<0.05). Results Overall, self-reported confidence about non-odontogenic pain was high, especially for endodontists who considered their knowledge about orofacial pain sufficient, regardless of whether they had (71.1% - 97.8%) or not (35.7% - 96.4%) been continuously involved in education courses on orofacial pain. In general, self-reported knowledge about non-odontogenic pain was insufficient (0% - 42%), except in the question about how they would act in cases of pain that persists beyond the normal healing time after an endodontic procedure (70.6% - 81.9%). In general, endodontists are confident in their diagnosis and treatment of non-odontogenic pain. Nonetheless, this confidence did not correlate with a commensurate knowledge depth of. Thus, specialization courses in endodontics should highly consider training and qualifying these professionals in the diagnosis of non-odontogenic pain. selfreported self reported nonodontogenic non odontogenic fortysix forty six survey questionnaire WhatsApp selfperceived perceived types ChiSquare Chi Square Fischers Fischer s p<0.05. p005 p p<0.05 . 0 05 (p<0.05) Overall high 71.1% 711 71 1 (71.1 97.8% 978 97 8 35.7% 357 35 7 (35.7 96.4% 964 96 4 general 0% (0 42%, 42 42% , 42%) 70.6% 706 70 6 (70.6 81.9%. 819 81.9% 81 9 81.9%) Nonetheless Thus p00 p<0.0 (p<0.05 71.1 (71. 97.8 35.7 3 (35. 96.4 ( 70.6 (70. 81.9 p0 p<0. (p<0.0 71. (71 97. 35. (35 96. 70. (70 81. p<0 (p<0. (7 (3 p< (p<0 (p< (p

Abstract This study aimed to evaluate physicochemical properties of three ready-to-use calcium silicate-based endodontic sealers: Endosequence BC Sealer, Bio C Sealer, and Sealer Plus BC. Radiopacity was evaluated using specimens of 10 mm in diameter and 1 mm in height, along with an aluminum step wedge. For the flow test, 0.5 mL of each sealer was deposited between glass plates and the mean of the measurement of two diameters was considered the cement flow value. For pH and calcium release, root canals of 30 prototypes of upper incisor acrylic resin teeth were filled with sealer and gutta percha point and then immersed in containers with 13 mL of ultrapure water. Both pH and release of calcium ions (atomic absorption spectrophotometer) were measured at 3, 24, 72, and 168 h. Acrylic resin teeth were scanned by Micro-CT 1174 at the time of pH and calcium ion readings for volumetric change analysis. The data were analyzed by ANOVA, Tukey’s, Kruskal-Wallis, and Dunn’s tests. Endosequence BC Sealer presented the lowest, and Bio C Sealer the highest volumetric change after 72 h and 168 h (p < 0.05). Endosequence BC Sealer presented higher radiopacity (p < 0.05). All materials showed alkalinization capacity. All of them presented calcium ion release, with a higher value for Sealer Plus BC. All materials presented alkalinization, calcium release capacity, radiopacity, and flow above the minimum values required by the ISO standard. The highest volumetric loss was experienced by Bio C Sealer and the lowest one by Endosequence BC Sealer.

Abstract The aim of this study was to evaluate the quality of curved root canal preparation, torsional fatigue, and cyclic fatigue of rotary systems manufactured with different NiTi alloys. Ninety single-rooted canals with curvatures of 15° to 30o were scanned and divided into three groups according to the rotary system used: BT-Race (BTR) – 10.06, 35.00, 35.04; SequenceRotaryFile (SRF) – 15.04, 25.06, 35.04; and ProDesignLogic (PDL) – 25.01, 25.06, 35.05. Each system was used on three specimens. The teeth were prepared, scanned, and analyzed to assess increase in volume, transportation, and centering ability of the root canal. Torsional fatigue of glide path instruments (BTR 10.06, SRF 15.04 and PDL 25.01) and cyclic fatigue of the finishing instrument (BTR 35.04, SRF 35.04 and PDL 35.05) were obtained by analyzing completely new instruments (n = 10) and instruments after they had been used three times (n = 10). After the torsional and cyclic fatigue tests, the fractured surface of the new and used instruments were examined by scanning electron microscopy. Increase in volume, canal transportation, and centering ability showed no significant differences among the groups (p > 0.05). The torsional test showed that SRF 15.04 produced the highest torque values for both new and used instruments, followed by PDL 25.01 and BTR 10.06 (p < 0.05). PDL 25.01, both new and used, exhibited higher values of angular deflection followed by SRF 15.04 and BTR 10.06 (p < 0.05). As regards cyclic fatigue, use of PDL 35.05, both new and used, required a longer time and larger number of cycles than did SRF 35.04 and BTR 35.04 (p < 0.05). Clinical use affected the torsional fatigue of BTR; however, cyclic fatigue was not significantly affected (p < 0.05). All rotary systems were able to prepare the curved canals satisfactorily and were used safely on the three specimens. Relative to torsional fatigue, SRF 15.04 exhibited a higher torque, and PDL 25.01, higher angular deflection. BTR 10.06 was the most affected by clinical use. PDL 35.05 showed greater resistance to cyclic fatigue.

Abstract This study aimed to evaluate the root canal real length (RL) changes due to the mechanical instrumentation use with different flaring magnitudes. After access cavity, 60 mesial root canals of mandibular molars were randomly separated in three groups: Hyflex EDM (HF; #25/.12, #10/.05 e #25/~), Reciproc Blue (RB; R25), and MTwo (M2; #10/.04, #15/.05, #20/.06 e #25/.06). The RL was defined as the apical limit, and 2.5% sodium hypochlorite irrigating solution was chosen. After the access cavity (RL 1), cervical flaring (RL 2), and complete chemical-mechanical preparation (RL 3), the RL was evaluated. The RL was evaluated by a blind examiner with the aid of a microscope (16x) placing the endodontic file stop at the coronary reference. When comparing length measurements, the RL was shorter before instrumentation than that after instrumentation. A reduction of 0.65 mm (HF), 0.61 mm (RB), and 0.48 mm (M2) was observed. However, among groups, no statistical differences were found (p > 0.05). Under the conditions tested, it can be inferred that all mechanical systems provoked RL variations, which emphasizes the need for constant verification of the odontometry, mainly before root canal obturation.

Abstract Filling materials should be restricted to the root canal space. However, sometimes it is impossible to control the apical extrusion, in this case, the fate of the filling material and the result of the treatment will depend on its physicochemical properties and biocompatibility. Objective To evaluate the tissue response and bone repair capacity of endodontic sealers that were implanted in the calvaria of Wistar rats, forming the groups (n=16): AH Plus and Sealer Plus, compared to the clot group. Methodology On days 30 and 60, the animals were euthanized, the calvaria was removed and processed for hematoxylin-eosin, immunohistochemistry for collagen type I, Picrosirus red and microtomographic analysis. Data were subjected to ANOVA and Tuckey tests (p<0.05). Results At 30 days, all groups showed an intense inflammatory reaction (p>0.05). At 60 days, the AH Plus and Sealer Plus maintained an intense inflammatory infiltrate compared to the clot group (p<0.05). We observed immunopositive areas for type I collagen in all groups at 30 days and 60 days (p>0.05). We observed more red collagen fibers for the Sealer Plus compared to the clot group at 30 days (p<0.05). Considering the total fibers, the clot group at 30 days compared to 60 days after surgery showed an increase in the amount of matrix (p<0.05). There were no statistical differences between groups for green and yellow fibers (p>0.05). Regarding morphometric parameters, at 30 days, the newly formed bone volume and number of bone trabeculae were higher in the groups with sealers compared to the clot group (p<0.05). At 60 days, AH Plus and Sealer Plus showed greater bone neoformation compared to the clot group (p<0.05). Conclusions Despite AH Plus and Sealer Plus induced an intense inflammatory reaction, they can be considered biocompatible materials, since they allowed bone repair.

Abstract: 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.

Abstract: The present study investigated the intracanal decontamination and apical extrusion of bacteria and debris from root canals instrumented with rotary and reciprocating systems (ProDesign Logic or ProDesign R), with different file diameters and using conventional syringe irrigation (CSI) or passive ultrasonic irrigation (PUI). Eighty extracted mandibular premolars were contaminated with Enterococcus faecalis and randomly assigned to eight experimental groups according to the root canal instrumentation and irrigation technique employed (n = 10): G1: Prodesign Logic 25.06; G2: Prodesign R 25.06; G3 and G4 were instrumented with the same single-file systems, respectively, using 35.05 diameters and CSI. G5, G6, G7, and G8 were instrumented like the previous groups, but with PUI. Apically extruded debris during instrumentation was collected into pre-weighed microtubes. The weight of the empty microtube was subtracted from the final weight to establish the amount of extruded debris. Bacteria from root canals and extruded debris were collected for a microbiological evaluation of colony forming units (CFU/mL). For statistical analyses, the Mann-Whitney and Kruskal-Wallis followed by the Dunn's tests were used (α = 0.05). All instruments caused extrusion of debris. For irrigation techniques, PUI promoted greater debris and bacterial extrusion (p < 0.05). The CFU/mL count indicated that the instrumentation of the experimental groups were equally effective in the decontamination of the root canal (p > 0.05). The systems tested (regarding file diameter and kinematics) were associated with similar amounts of apically extruded debris and root canal decontamination. PUI was associated with greater debris and bacterial extrusion.

ABSTRACT: The aim of this in vitro study was to investigate the influence of ethylenediaminetetraacetic acid (EDTA) associated with the benzalkonium chloride (BAK) on the adhesion and formation of Enterococcus faecalis biofilms attached to coated dentin. Discs standard bovine dentin blocks were treated with the coating materials evaluated: Saline solution (control), 17 % EDTA, 17 % EDTA associated with 1 % BAK for 5 minutes and subsequently washed with saline solution. Afterwards, biofilms of E. faecalis (ATCC 29212) were grown on the surface of coated dentin blocks for time intervals of 1 hour and 7 days (n = 20) and were subsequently washed with phosphate-buffered saline (PBS). Bacterial viability and total biovolume were analyzed by confocal laser scanning microscopy (CLSM) using the Live/Dead technique. Nonparametric Kruskal-Wallis followed by Dunn tests were used to determine statistical differences (a = 5 %). The 17 % EDTA + 1 % BAK group showed significantly lower biovolume and bacterial viability values at the end of 1 hour (p < 0.05). After 7 days of contamination, the 17 % EDTA and 17 % EDTA + 1 % BAK groups showed similar results that differed statistically from those of the control group (p < 0.05). The saline solution group showed higher values. The use of BAK associated with EDTA on dentin blocks surfaces before exposure to contamination was able to interfere in the adhesion of E. faecalis to dentin. Also, dentin treatment by BAK associated with a chelating agent influences the secondary biofilm formation, which could have important effects on the long-term success of root canal treatment.

RESUMEN: El objetivo del estudio consistió en investigar in vitro, la influencia del ácido etilendiamino-tetraacético (EDTA) con cloruro de benzalconio (BAK) en la adhesión y formación de biopelículas de Enterococcus faecalis a la dentina. Discos de dentina bovina fueron tratadas con solución salina (control), 17 % de EDTA, 17% de EDTA asociado con 1 % de BAK durante 5 minutos y lavadas con solución salina. Las biopelículas de E. faecalis (ATCC 29212) se cultivaron sobre los discos de dentina durante intervalos de tiempo de 1 hora y 7 días (n = 20), lavados con solución salina tamponada con fosfato (PBS). La viabilidad bacteriana y el biovolumen total se analizaron mediante microscopía de barrido por láser (CLSM) utilizando la técnica Live / Dead. Se realizó prueba no paramétrica de Kruskal-Wallis, seguida por Dunn con una diferencia estadística (a = 5 %). El grupo de 17 % EDTA + 1 % BAK mostró valores significativamente menores de biovolumen y viabilidad bacteriana al final de 1 hora (p < 0,05). Después de 7 días de contaminación, los grupos de 17 % EDTA y 17 % EDTA + 1 % BAK mostraron resultados similares que diferían estadísticamente del grupo control (p < 0,05). La solución salina mostró valores más altos. La asociación de BAK con EDTA antes de la contaminación interfirió en la adhesión de E. faecalis. Además, el tratamiento de la dentina por BAK asociado con EDTA influye en la formación de biopelículas secundarias, lo que podría tener efectos importantes sobre el éxito a largo plazo del tratamiento del conducto radicular.

Resumo O objetivo deste estudo foi avaliar a influência de diferentes protocolos de pré-alargamento cervical (ausente, conservador e convencional) na precisão dos localizadores eletrônicos foraminais (LEFs) Root ZX II, Raypex 6 e RomiApex A-15. Vinte molares inferiores com raízes mesiais do tipo IV de Vertucci foram submetidos à exploração endodôntica e confirmação da patência foraminal. Sob ampliação de 16x, seus comprimentos reais (CR) foram medidos e registrados (CR1). Os canais foram então irrigados com hipoclorito de sódio a 2,5% e medidos eletronicamente (ME1) utilizando o modelo em alginato; todas as medidas foram realizadas em triplicata por um operador cego, utilizando limas endodônticas ajustadas introduzidas até o forame apical. Os procedimentos de pré-alargamento cervical foram realizados sequencialmente com os instrumentos #25/.06 (conservador) e #25/.12 (convencional); novas determinações de CRs foram realizadas após cada protocolo de preparação cervical (CR2/CR3), da mesma forma que as medidas eletrônicas (ME2/ME3). O erro dos dispositivos (mm) foi avaliado considerando a diferença entre CRs e MEs em cada estágio de preparação; sua precisão foi estabelecida adotando ± 0,5 mm como margem de tolerância. O erro dos LEFs reduziu significativamente após o protocolo convencional de alargamento cervical (p<0,05), o que não ocorreu após o conservador. Os melhores valores de precisão foram observados após a preparação convencional como 90% (Root ZX II), 97,5% (Raypex 6) e 92,5% (RomiApex A-15). Não foram encontradas diferenças significantes nas comparações entre os LEFs, independentemente do protocolo cervical testado (p>0,05). Sob as condições testadas, pode-se concluir que os LEFs avaliados foram precisos. Além disso, os protocolos de alargamento influenciam sua precisão, onde o menos conservador produziu os melhores resultados.

Abstract: The aim of this study was to evaluate the influence of different coronal preflaring protocols (absent, conservative and conventional) on the accuracy of Root ZX II, Raypex 6, and RomiApex A-15 electronic foramen locators (EFLs). Twenty mandibular molars with Vertucci’s type IV mesial roots were subjected to endodontic exploration and foraminal patency confirmation. Under 16x magnification, its real lengths (RL) were measured and registered (RL1). The canals were then irrigated with 2.5% sodium hypochlorite and electronically measured (EM1) employing the alginate model; all measurements were performed in triplicate by a blind operator using adjusted endodontic hand-files introduced until the apex foramen. Coronal preflaring procedures were sequentially performed with #25/.06 (conservative) and #25/.12 (conventional) instruments; new RLs extents were performed after each coronal preparation protocol (RL2/RL3), as same as electronic measurements (EM2/EM3). The devices error (mm) was evaluated considering the difference between RLs and EMs at each preparation stage; their precision was stablished adopting ±0.5 mm as tolerance margin. The EFLs error significantly reduced after conventional coronal preflaring protocol (p<0.05), which not occur after the conservative one. The best precisions values were noted after conventional preparation as 90% (Root ZX II), 97.5% (Raypex 6), and 92.5% (RomiApex A-15). No significant differences were found in EFLs comparisons, regardless of the coronal protocol tested (p>0.05). Under the conditions tested it can be concluded that the EFLs evaluated were precise. Moreover, the preflaring protocols influences its accuracy’s, where the less conservative one produced the best results.

Abstract The aim of this study was to assess Brazilian endodontists’ level of knowledge about the coronavirus disease (COVID-19) and examine its professional repercussions. The link to the online survey that was created for this study was shared with Brazilian endodontists through social networking applications. The questionnaire contained questions that pertained to COVID-19 and its impact on dental practice. The collected data were analyzed using t-test, chi-square analysis, and analysis of variance, and the level of significance was set at 0.05. A total of 2,135 participants responded to the questionnaire, and all five Brazilian regions were represented in the sample. A total of 98.50% of endodontists reported that dental procedures can transmit COVID-19. Complete social distancing was practiced by 96.68% of the participants, and approximately 25% knew someone who had COVID-19. Moreover, in their daily practice, 72.13% of them implemented biosecurity measures that are ineffective in preventing COVID-19. Furthermore, 91.7% of them reportedly suspended elective dental procedures. Only 55.69% of them reported that they performed only emergency procedures in their workplaces. Those who believed that COVID-19 cannot be transmitted during dental procedures were less knowledgeable about the symptoms of COVID-19 (p = 0.0095). Endodontists who believed that personal protective equipment cannot prevent contamination were more knowledgeable about the symptoms of COVID-19 than their counterparts (p = 0.0003). The participating Brazilian endodontists demonstrated adequate knowledge about the risk of contamination during dental procedures and the main symptoms of COVID-19. Only some professionals reported providing emergency dental care during the pandemic.

Abstract To evaluate the influence of novel ultrasonic tips as an auxiliary method for the rotary preparation of flattened/oval-shaped canals. Forty-five mandibular incisors were selected and divided into one of three experimental groups (n = 15): Group PFCP – ProDesign Logic 25/.05 + Flatsonic + Clearsonic + Prodesign Logic 40/.01; Group FCP – Flatsonic + Clearsonic + ProDesign Logic 40/.01; and Group PP – Prodesign Logic 25/.05 + Prodesign Logic 40/.05. The teeth were scanned preoperatively and postoperatively using microcomputed tomography. The percentage values for increase in volume, non-instrumented surface area, dentin removal, degree of canal transportation, and centering ratio between the experimental groups were examined. Data were analyzed using the non-parametric Kruskal-Wallis and Dunn’s tests (p < 0.05). Group PFCP showed the greatest volume increase in the total portion of the root canal and the lowest percentage of non-instrumented surface area. Regarding the degree of transportation in the buccolingual direction, statistically significant differences between groups PFCP and PP were observed at the coronal third of the canal. In the mesiodistal direction, no statistically significant differences were observed at the coronal, middle, and apical thirds. As for the centering ratio, statistically significant differences were found in the buccolingual direction. In the mesiodistal direction, no statistically significant differences were observed at the coronal, middle, and apical thirds. The use of novel ultrasonic tips combined with rotary instruments in group PFCP provided a significant increase in volume and reduced the percentage of non-instrumented areas during the preparation of flattened/oval-shaped canals.

Abstract To evaluate the torsional properties of engine-driven pathfinding instruments manufactured from different NiTi alloys – R-Pilot (tip size 12.5;.04 taper; M-Wire) and One G (tip size 14;.03 taper; Conventional NiTi). A total of 40 NiTi instruments from engine-driven pathfinding instruments (n = 20) were used. The torsion tests followed ISO 3630-1 (1992). Three millimeters of each instrument tip was fastened to a small load cell by a lever arm linked to the axis of torsion. During the test, the torsion testing machine software measured the maximum torsional strength and angle of rotation (0) before instrument failure. The fractured surface of each instrument was assessed by scanning electron microscopy (SEM). In addition, a supplementary examination was performed to measure the cross-sectional area and the metal mass volume of each instrument 3 mm from the tip. Data were analyzed using a t-test, with significance level set at 5%. R-pilot had significantly higher torsional strength than did One G (p < 0.05). Regarding the angle of rotation to fracture, One G had higher angles than did R-Pilot (p < 0.05). The supplementary examination showed that R-Pilot had the highest cross-sectional area and volume of metal mass at 3 mm from the tip (p < 0.05). R-pilot (M-Wire NiTi alloy) had a significantly higher torsional strength and One-G (superelastic NiTi alloy) had the highest angle of rotation to fracture.

Resumo Este estudo teve por objetivo avaliar as propriedades físico-químicas de um cimento à base de silicato de cálcio (Sealer Plus BC MK Life, Porto Alegre, Brasil) e compará-las a um cimento à base de resina epóxica (AH Plus, Dentsply DeTrey GmbH, Konstanz, Alemanha). Tempo de presa inicial e final foram avaliados com base na ISO 6876:2012 e ASTM C266:03. Liberação de íons cálcio e pH foram avaliados após o preenchimento de tubos de polietileno com os cimentos e imersão em 10 mL de água deionizada. Após os tempos experimentais de 1,24,72 e 168 horas, os valores de pH e liberação de íons cálcio foram mensurados utilizando um medidor de pH e um espectofotômetro colorimétrico, respectivamente. Escoamento foi avaliado com base na ISO 6876:2012. Moldes de 10 mm de diâmetro e 1 mm de espessura foram preparados para análise de radiopacidade (ISO 6876:2012 e ADA n.57), solubilidade (ISO 6876:2012). Os dados foram analisados por análise de variância, teste T de Student e teste de Tukey (p<0,05). A liberação de íons cálcio e os valores de pH foram significativamente maiores para o Sealer Plus BC em comparação com o AH Plus (p<0,05). Menores valores de tempo de presa, escoamento e radiopacidade foram observados para o cimento biocerâmico quando comparados com o AH Plus (p<0,05). Sealer Plus BC apresentou propriedades físico-químicas de tempo de presa, pH, liberação de íons cálcio, escoamento, radiopacidade de acordo com as normas exigidas, porém maior solubilidade que aquelas previstas pela ISO 6876:2012.

Abstract This study aimed to evaluate the physicochemical properties of a calcium silicate-based sealer (Sealer Plus BC; MK Life, Porto Alegre, Brazil) compared with an epoxy-resin sealer (AH Plus; Dentsply DeTrey GmbH, Konstanz, Germany). Initial and final setting time was assessed based on ISO 6876:2012 and ASTM C266:03. Calcium ion release and pH were evaluated by filling polyethylene tubes with sealers and then immersing them in 10 mL of deionized water. Following experimental periods of 1, 24, 72 and 168 hours, the samples were measured regarding pH and calcium ion release with a pH meter and a colorimetric spectrophotometer, respectively. The flow was examined based on ISO 6876:2012. Rings of 10 mm in diameter with 1 mm thickness were prepared to analyze the radiopacity (ISO 6876:2012 and ADA n.57) and solubility (ISO 6876:2012). The data were analyzed by variance analysis, Student-T and Tukey tests (p<0.05). The calcium ion release and pH values were significantly higher for the Sealer Plus BC compared with the AH Plus (p<0.05). Lower setting time, flow and radiopacity were observed for the bioceramic sealer than for AH Plus (p<0.05). Sealer Plus BC exhibited higher solubility compared with AH Plus (p<0.05). Sealer Plus BC showed physicochemical properties as setting time, pH, calcium release, flow, and radiopacity following the required standards, but higher solubility than the minimum values required by ISO 6876:2012.

Abstract Objective To evaluate the amount of apically extruded debris, percentage of foraminal enlargement and apical foramen (AF) deformation that occurred during root canal preparation with different reciprocation systems: Reciproc, WaveOne (M-Wire), and ProDesign R (Shape Memory Technology Wire) at two different working lengths (WLs): 0.0 and 1.0 mm beyond the AF. Material and methods The AF of 120 root canals in 60 mesial roots of mandibular molars were photographed with stereomicroscope and randomly assigned into four groups: manual, Reciproc (REC), WaveOne (WO), and ProDesign R (PDR); subsequently, they were further subdivided according to the WL (n=15). Teeth were instrumented, coupled to a dual collecting chamber, and then another photograph of each AF was captured. Extrusion was analysed by determining the weight of extruded debris. Each AF diameter was measured in pre- and post-instrumentation images to determine deformation, which was analysed, and afterwards the final format of AFs was classified (circular/oval/deformed). Results We found no significant differences when analysing each system at different WLs. When considering each WL, REC and WO showed highest extrusion values (P<.05); for AF enlargement, differences were observed only for WO, when it was used beyond the AF; differences were observed among M-Wire groups beyond the AF (P<.05). AF deformation was observed in all groups; PDR showed the lowest AF deformation values at both WLs; M-Wire groups showed 50% strain beyond the AF. Conclusion Authors concluded that beyond the apical limit, the alloy and taper are important aspects when considering extrusion and deformation.