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Durante as últimas décadas o ultrassom vem ganhando cada vez mais espaço na odontologia, especialmente na Endodontia. Esta ferramenta pode ser aplicada nas mais diferentes etapas do tratamento como: acesso e localização dos canais, desinfecção e modelagem, obturação de canais radiculares, remoção de retentores, retratamento e cirurgia parendodôntica. Tal aumento da utilização se dá em decorrência da alta eficiência de corte e efeitos biológicos resultando no aumento na qualidade e previsibilidade do tratamento de casos simples aos complexos. Sendo assim, a primeira seção desta revisão descreve a evolução, conceitos técnicos e variadas aplicações do ultrassom na endodontia. A segunda seção desta revisão descreve o uso do ultrassom durante procedimentos endodônticos específicos, desde o acesso até a resolução de casos complexos por meio de casos clínicos.

Aim To evaluate physicochemical properties and semi-quantitative elemental analysis of AH Plus Jet with samples from the beginning, middle and final portions of the automix syringe system. Methodology Three experimental groups based on the source of the material used (beginning, middle and final portion) were established for each of the evaluated properties. Setting time, flow and radiopacity were evaluate following ANSI/ADA n. 57 specification. Set specimens was used in the semi-quantitative elemental analysis in an energy-dispersive X ray spectroscopy and scanning-electron microscopy (EDS/SEM). Statistical analysis was performed using one-way ANOVA followed by Tukey test (P0.05). Radiopacity test showed significant differences in the beginning of the syringe comparing to the middle and final portions (P

To evaluate and synthesize the evidence from the individual reviews that evaluated the efficacy of PDT therapy in root canal disinfection by undertaking an umbrella review. The protocol of the review was registered in the PROSPERO database under number CRD42021214056. The literature search was conducted using the following electronic databases: PubMed, Scopus, Web of Science, BVS, Cochrane Database of Systematic Reviews, Embase, and Epistemonikos, from inception to July 2021. Systematic reviews that evaluated the efficacy of PDT for root canal disinfection were included. Two authors independently performed a literature search, data extraction, and quality assessment of the included studies. Any disagreements were resolved by a third reviewer. The quality of the reviews was assessed using the AMSTAR 2 tool and the final categorization of each systematic reviews was classified as of "high," "moderate," "low," or "critically low" quality. Six systematic reviews were included in the current umbrella review and all of them were graded as critically low quality. From the critically low-quality evidence available, this umbrella review showed that the efficacy of PDT in root canal disinfection remains yet undetermined.

The aim of this study was to evaluate the effect of glycolic acid (GA) and EDTA on dentin mechanical properties. For the cohesive strength, flexural strength and fracture strength tests, the hourglass of root dentin, dentin sticks and roots standardised to 1 mm thickness were used respectively. ANOVA and Tukey tests were used for statistical analysis (P 0.05). The results showed that EDTA and GA 17% reduced the cohesive strength values when compared to distilled water (control; P = 0.0022 and P = 0.0016 respectively), whereas the values for GA 10% group were similar to those of the control group (P = 0.093). No statistically significant difference was found among the groups for the flexural strength test (P = 0.1974). Fracture strength test showed that EDTA and GA 17% were statistically similar to each other (P = 0.7694) and statistically inferior to GA 10% (P = 0.0007 and P = 0.0004 respectively). It was concluded that 10% GA showed fewer negative effects on dentin mechanical properties.

To compare the design, metallurgy, mechanical performance, and canal preparation of 5 rotary systems.A total of 735 25-mm NiTi instruments (sizes 0.17[0.18]/.02v, 0.20/.04v, 0.20/.07v, 0.25/.08v, 0.30/.09v) from ProTaper Gold, ProTaper Universal, Premium Taper Gold, Go-Taper Flex, and U-File systems were compared regarding overall geometry and surface finishing (stereomicroscopy and scanning electron microscopy), nickel and titanium ratio (energy-dispersive spectroscopy), phase transformation temperatures (differential scanning calorimetry), mechanical performance (torsional and bending tests), and unprepared canal surface (micro-CT). One-way ANOVA and Mood's median tests were used for statistical comparisons with a significance level set at 5%.Stereomicroscopic analysis showed more spirals and high helical angles in the Premium Taper Gold system. All sets of instruments had symmetrical spirals, no radial lands, no major defects, and an almost equiatomic ratio between nickel and titanium elements, while differences were observed in their tips' geometry and surface finishing. At room temperature (20 °C), DSC test revealed martensitic characteristics for ProTaper Gold and Go-Taper Flex, and mixed austenite plus R-phase for the Premium Taper Gold, while ProTaper Universal and U-Files had full austenitic characteristics. Overall, larger instruments had higher torque resistance and bending load values than smaller ones, while a lack of consistency and mixed values were observed in the angle of rotation. The 0.25/.08v and 0.30/.09v instruments of ProTaper Universal and U-File had the highest maximum torques, the lowest angles of rotation, and the highest bending loads than other tested systems (P .05). No significant difference was noted regarding the untouched root canal walls after preparation with the tested systems (P .05).Although differences observed in the overall geometry and phase transformation temperatures have influenced the results of mechanical tests, unprepared canal surface areas were equivalent among systems.Root canal preparation systems with similar geometries might present different mechanical behaviors but equivalent shaping ability.

This study aims to compare the design, metallurgy, microhardness, and mechanical properties of 3 glide path nickel-titanium (NiTi) instruments.A total of 132 ProGlider (Dentsply Sirona, Ballaigues, Switzerland), Edge Glide Path (EdgeEndo, Johnson City, TN), and R-Pilot instruments (VDW, Munich, Germany) (44 per group) were selected. Design was assessed through stereomicroscopy (blades, helical angle, measuring lines, and deformation) and scanning electron microscopy (symmetry, cross section, tip, and surface finishing). NiTi ratios were measured by energy-dispersive X-ray spectroscopy and phase transformation temperatures by differential scanning calorimetry. Microhardness and mechanical performance (torsion, bending, and buckling resistance tests) were also evaluated. Statistical analyses were performed with the Mood median test with a significance set at 5%.The Edge Glide Path had the lowest number of blades and the R-Pilot the greatest helical angle. All instruments had an almost equiatomic NiTi ratio, while showing different cross sections and tip geometries. The Edge Glide Path had a smoother surface finishing. The R-Pilot showed martensitic characteristics at room temperature, whereas mixed austenite plus R-phase was observed in the other instruments. The R-Pilot had higher results on the microhardness (436.8 hardness Vickers number), maximum torsion (0.9 Ncm), and buckling load (0.7 N) tests (P .05), whereas the Edge Glide Path had a superior angle of rotation (683.5°) and the ProGlider was more flexible (144.1 gf) (P .05).Differences in the design of the instruments and the phase transformation temperatures accounted for their mechanical behavior. The R-Pilot showed the highest torque, buckling, and microhardness, whereas the ProGlider instrument was the most flexible.

Objetivo: O objetivo do presente estudo foi avaliar a influência do pré-alargamento coronário na resistência à fadiga cíclica de dois instrumentos reciprocantes tratados termicamente. Métodos: 20 instrumentos Reciproc Blue (R25 Blue) e 20 instrumentos X1 Blue (X1) foram utilizados para instrumentar blocos de resina simulando um molar superior com três canais radiculares. Os dentes foram divididos em quatro grupos (n=10), de acordo com o instrumento e com a técnica de instrumentação utilizada: grupos R25 e X1 - instrumentação com R25 Blue (25/0.08) ou X1 Blue (25/0.06), respectivamente, sem alargamento prévio; e grupos R25 ou X1 + pré-alargamento cervical - pré-alargamento com os instrumentos ProTaper Universal SX e S1 antes da instrumentação com R25 Blue ou X1. Os instrumentos foram testados com relação à fadiga cíclica utilizando-se um canal simulado de aço inoxidável com ângulo de curvatura de 86 graus e raio de curvatura de 6 mm. Os instrumentos foram acionados utilizando-se o movimento “RECIPROC ALL” do motor endodôntico (VDW) e o tempo de instrumentação até a fratura do instrumento foi contabilizado. Os resultados foram analisados pelo teste t de Student (p0,05). Conclusão: O instrumento X1 Blue apresentou maior resistência à fadiga cíclica do que o Reciproc Blue. O pré-alargamento coronário não foi capaz de aumentar a resistência à fratura por fadiga cíclica dos instrumentos testados.

The purpose of this narrative review was to discuss the scientific milestones that led to the current understanding of the root dentinal microcrack phenomenon based on the interplay between the usage of micro-computed tomography (micro-CT) as an analytical tool alongside a close-to-mouth experimental model. In 2009, reports on the development of dentinal microcracks in extracted teeth after root canal preparation triggered an awareness of the potential for vertical root fractures (VRFs) of endodontically treated teeth could be developed from defects created by the mechanical stress of nickel-titanium preparation systems on dentine. This assumption was taken for granted, even though no cause-effect relationship had been scientifically demonstrated. Since then, several studies using the sectioning method with extracted teeth have been published and the large discrepancy amongst their outcomes soon become evident. Moreover, the high frequency of reported dentinal microcracks largely contrasted with the clinical incidence of VRFs, raising doubts on their methodological reliability. Using micro-CT technology, it was demonstrated by several studies that, in extracted teeth, dentinal defects already existed before the endodontic procedures, indicating that the initial reports framed a non-existing cause-effect relationship between canal preparation and dentinal microcracks. Although these new findings contributed to a better comprehension of this phenomenon, the misconception that microcracks were the starting point for VRFs was only surpassed with a new in situ approach using fresh cadavers. Surprisingly, microcracks were not identified in sound teeth. As a conclusion, dentinal microcracks in extracted teeth can be considered a non-natural occurrence observed only in a laboratory set-up as a consequence of dehydration and storage conditions. Thus, dentinal microcracks shall not be considered as the starting point for VRFs as they do not manifest in non-extracted teeth. Identifying dentinal microcracks as a laboratory phenomenon highlights the impact of recent scientific developments to disclaim the clinical relevance of laboratory-obtained outcomes.

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.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%).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.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.

This systematic review assessed the clinical influence of centric and eccentric engine-driven instrument design for reduction in microbial load in infected root canal system. The literature search was conducted in electronic databases (PubMed, Cochrane Library, Scopus, Lilacs and Google Scholar) and grey literature till June 2022. The search strategy followed the PRISMA 2020 guidelines. Qualitative and quantitative synthesis was conducted based on the guidelines of the Cochrane Handbook. The risk of bias was assessed using the revised Cochrane criteria and quality of evidence was conducted using the Grading of Recommendation Assessment, Development and Evaluation tool. Out of 28 papers, only five papers met the inclusion criteria of this review. Studies showed reduction in microbial load after instrumentation using centric or eccentric instruments with no statistically significant difference in the meta-analysis. In conclusion, there is low-grade evidence suggesting that microbial reduction is similar using centric and eccentric instruments.

A fístula cutânea de origem odontogênica é decorrente da infecção crônica que pode comprometer a estética do paciente e quando mal disgnóstica, por médicos e/ou cirurgiões-dentistas, pode ocasionar alteração estética e transtornos psicológicos ao paciente. O presente relato de caso descreve o correto diagnóstico e o tratamento de uma paciente que foi anteriormente encaminhada a diferentes profissionais de saúde, sendo inclusive submetida a biopsia após hipóteses diagnósticas incorretas. Após avaliação clínica e de exames radiográficos periapicais e tomografia computadorizada de feixe cônico, solicitados por um endodontista, o caso foi diagnosticado de maneira adequada e um plano de tratamento foi proposto. O tratamento endodôntico não-cirúrgico foi realizado, proporcionando a resolução da fístula em curto período de tempo. O presente caso clínico reforça a necessidade de se realizar o diagnóstico diferencial de patologias associadas as fístulas cutâneas ocorridas na região facial ou cervical, e da importância da colaboração interprofissional, inclusive considerando a etiologia odontogênica.

This systematic review (PROSPERO - CRD42020150722) was performed to answer the following question: Does the use of chelating agents affect the dislodgment resistance of epoxy resin-based root canal sealers? A search was conducted in PubMed, EMBASE, Scopus, LILACS and Web of Science, hand searching of two endodontic journals and grey literature until September 2020. Extracted data included: teeth used, sample size, root canal preparation, irrigant, chelating solution, neutralisation solution, type of resin-based sealer and obturation approach, storage method and duration, root third and slice thickness, plunger dimension and loading direction and the push-out testing parameters and values. The search retrieved a total of 2.389 studies. After analysis, 12 studies fulfilled the eligibility criteria and were included. Most of the final irrigation protocols with chelating agents had a positive impact and promoted an improvement in the dislodgment resistance of epoxy resin-based sealers to the root dentin.

To compare six reciprocating instruments regarding their geometric design, metallurgical characteristics, mechanical behaviour and ability to prepare root canals.A total of 246 new 25-mm NiTi instruments (41 per group) from six reciprocating systems (Reciproc, Reciproc Blue, One Files, One Files Blue, Reverso Silver, and WaveOne Gold) were evaluated throughout a multimethod approach regarding their design using stereomicroscopy (number of blades and helix angle) and scanning electron microscopy (blades symmetry, cross section and surface finishing), nickel-titanium composition, phase transformation temperatures, mechanical performance (cyclic fatigue, torsional and bending resistance) and unprepared canal surface area on anatomically matched mandibular molars assessed by micro-CT. One-way ANOVA and post hoc Tukey's or Mood's median tests were selected depending on sample distribution with significance level set at 5%.The instruments had similarities regarding their metal composition and unprepared canal area, whilst differences in phase transformation temperatures and geometric design (number of blades, surface finishing and tip geometry) were observed. Overall, no difference was observed regarding the maximum torque values (P 0.05), whilst One Files (72 s) and One Files Blue (414 s) had the shortest and longest times to fracture, respectively (P 0.05). Similar angles of rotation were observed in Reciproc (310°), One Files (285°) and Reverso Silver (318°) instruments (P 0.05), which were significantly lower than Reciproc Blue (492°), One Files Blue (456°) and WaveOne Gold (492°; P 0.05). Maximum bending load demonstrated that Reciproc Blue (201.3 gf) was significantly more flexible that the other instruments (P 0.05).Although there were similarities in metal composition and percentage of unprepared canal surface, the instruments had differences in the overall geometric design, phase transformation temperatures and in the four mechanical resistance parameters (time to fracture, maximum torque, angle of rotation and maximum bending load).

Objective The aim of this study was to evaluate the influence of the incorporation of chlorhexidine-hexametaphosphate nanoparticles (CHX-HMP NPs) on antibacterial, cytotoxic and physicochemical properties of AH Plus (AH), MTA Fillapex (MTA) and Pulp Canal Sealer (PCS). Methods The NPs were synthesized and characterized by Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), zeta potential, Atomic Force Microscopy (AFM) and Energy-Dispersive X-ray Spectroscopy (EDS). The incorporation was made by weight, 2% and 5% of NPs. The antimicrobial activity, cytotoxicity, flow, radiopacity, setting time, solubility and pH were evaluated. The statistical analysis was performed by two-way analysis of variance test and Tukey post hoc test (P Results SEM analysis showed the tendency for CHX-HMP NPs to cluster, the effective mean diameter measured by DLS: 169.39 nm and the zeta potential: -10.18 mV. The NPs were individually measured by AFM: 22.99–52.75 nm. EDS analysis identified the presence of C, N, O, Na, P, Cl. After incorporation: The Direct Contact Test showed an increase in the antimicrobial action of AH, PCS and MTA; the sealers showed a decrease in flow and at 24 h of immersion also an increase in solubility, but did not affect the radiopacity of the samples; AH setting time increased and MTA did not reach setting under any of the conditions tested. All samples showed a decrease in pH value as the immersion time progressed. Significance The incorporation of NPs can improve the antimicrobial performance of endodontic sealers without impairing other biological and physicochemical properties.

Background Orthodontic tooth movements are performed by applying forces on teeth, which may cause alterations within the dental pulp. Previously published systematic reviews on the subject only included a small number of studies that assessed pulp status through reliable diagnostic methods. Since then, new evidence has been published, and a further systematic review on the subject is necessary. Objectives To evaluate whether there is scientific evidence to support the possibility that orthodontic tooth movements could induce pulp necrosis. Methods A systematic search of articles published until June 2020 was performed using MeSH and free terms in the PubMed, Cochrane Library, LILACS, SciELO, Web of Science, EMBASE, Open Grey and Grey Literature databases. Randomized clinical trials (RCTs), nonrandomized clinical trials (nRCTs) and longitudinal (prospective or retrospective) studies that evaluated the pulp status of teeth subjected to orthodontic movements using laser Doppler flowmetry or pulse oximetry were included. The revised Cochrane risk of bias tools for randomized trials (RoB 2) and nonrandomized interventions (ROBINS-I) were used to assess the quality of the included studies. Relevant findings were summarized and evaluated. The overall quality of evidence was assessed through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool. Results Initial screening of databases resulted in 353 studies. In total, 285 studies were excluded because they were duplicates. Of 68 eligible papers, fourteen met the inclusion criteria and were selected for full-text reading. Two studies were excluded due to the methods used to evaluate pulp status. Twelve studies (five RCTs, one nRCT and six prospective) were included. Four RCTs were classified as having an unclear risk of bias and one as having a high risk of bias. The nRCT was classified as having a low risk of bias. Two prospective studies were classified as having a moderate risk of bias and four as having a serious risk of bias. The GRADE analysis demonstrated a low to very low quality of evidence. Discussion Significant limitations regarding the randomization processes within the included RCTs and a lack of control of confounders on most nonrandomized and longitudinal studies were verified. Conclusions This systematic review indicates that orthodontic movements do not induce loss of pulp vitality with low to very low certainty of evidence.

Objetivo: Testar a hipótese nula de que a orientação das ranhuras superficiais não influencia na vida em fadiga de fios de níquel-titânio (NiTi). Material e Métodos: Segmentos de fio de NiTi (Moreli, Sorocaba/SP, Brasil) medindo 30mm e com diâmetro de 0,40mm fo- ram utilizados. As ranhuras foram criadas em relação à direção longitudinal, em 45 e 90 graus. O fio foi analisado sob microscopia eletrônica de varredura e a rugosidade, quantificada por interferometria. O número de ciclos para a fratura (NCF) foi determinado pelo teste de flexão rotativa. Resultados: A rugosidade entre os grupos de 45 e 90 graus apresentou diferenças estatisticamente significativas (p

This study evaluated the ability of reciprocating glide path instruments to reach the full working length (RFWL). Thirty mesial roots of mandibular molars were matched into 2 groups (n = 15 teeth, 30 root canals), according to the system used for glide path: WaveOne Gold Glider (WOGG) and R-Pilot. The samples with fractured instruments or when it was not possible to RFWL were scanned using micro-computed tomography. Fractured instruments were also visualised through a scanning electron microscopy to verify the type of fracture. The parameters were compared statistically by Fisher's and chi-square tests (P 0.05). No instrument fractures were observed in the R-pilot, while 2 fractures occurred in the WOGG group (P 0.05). RFLW was achieved in 29 canals (96.66%) and 28 canals (93.33%) with R-pilot and WOGG instruments, respectively (P 0.05). The instruments are able to RFWL in mesial canals of mandibular molars. WOGG showed two fractures while no R-Pilot instruments fractured.

This study aimed to evaluate the efficacy of supplementary methods to remove the remaining root filling material from root canals. Twenty mandibular single-rooted teeth were instrumented with Reciproc 25/0.08 and filled with gutta-percha and AH-Plus sealer, followed by a micro-CT scanning. The retreatment procedures were performed, the samples were rescanned and divided into two groups (n = 10) according to the supplementary method: XP-endo Finisher R and Clearsonic tip. The samples were rescanned and the volume of remaining root filling material was quantified. Data were analysed statistically (P < 0.05). The amount of filling material removed after supplementary methods was higher compared with retreatment procedure (P < 0.05). XP-endo Finisher R promoted a greater percentage of filling materials reduction in the entire root canal and apical third compared with Clearsonic tip (P < 0.05). Supplementary methods were effective in the reduction of root filling materials. XP-endo Finisher R removed more root filling material than Clearsonic tip.

AIM To evaluate the correlation between the volume of dental hard tissues removed and the fracture resistance of mandibular molar teeth with ultraconservative (UltraAC) or traditional (TradAC) access cavity preparations. METHODOLOGY Sixty recently extracted and intact mandibular first molars were scanned in a microcomputed tomographic (micro-CT) device, anatomically matched and assigned at random to 2 groups (n = 30), according to the access cavity type: UltraAC or TradAC. After access preparation, mesial and distal canals were prepared using Reciproc instruments and a new scan was taken. The volumes of pulp chamber and dental hard tissues in each specimen were measured before and after the experimental procedures, and the percentage volume reduction of hard tissues calculated for the entire tooth and for the crown separately. Teeth were then root filled, restored and subjected to fracture resistance tests in an universal testing machine. The force required to fracture was recorded in Newtons (N). The adherence of the variables to a Gaussian curve was verified using a Shapiro-Wilk test. Skewed data were analysed with nonparametric Wilcoxon signed rank or Spearman correlation tests, whilst the normally distributed data were analysed with a dependent samples Student t-test. Level of significance was set at 5%. RESULTS Pre-operatively, no difference was observed between groups regarding the volume of pulp canal space or dental hard tissues (P > 0.05). After access preparation, volumes of the removed hard tissues from the entire tooth and from the crown were significantly greater in teeth prepared with TradAC than with UltraAC (P

This systematic review and meta-analysis evaluated whether epoxy resin-based root canal sealers present an increased solubility than calcium silicate-based root canal sealers. A systematic search was performed in the following databases: PubMed, Science Direct, Scopus, Web of Science and Open Grey. The inclusion criteria consisted of in vitro studies that compared the solubility of epoxy resin-based and calcium silicate-based sealers. The quality assessment and data extraction of the selected articles were performed. The meta-analysis of the pooled data and the subgroups according to the root thirds were carried out using the RevMan software (P

To compare the ProTaper Next (PTN) system with a replica-like and a counterfeit system regarding design, metallurgy, mechanical performance and shaping ability.Replica-like (X-File) and counterfeit (PTN-CF) instruments were compared to the PTN system regarding design (microscopy), phase transformation temperatures (differential scanning calorimetry), nickel-titanium ratio (energy-dispersive X-ray spectroscopy), cyclic fatigue, torsional resistance, bending strength, and untouched canal areas in extracted mandibular molars (micro-CT). anova, post hoc Tukey's and Kruskal-Wallis tests were used according to normality assessment (Shapiro-Wilk test) with the significance level set at 5%.Overall similarities in design and nickel-titanium (Ni/Ti) ratio were observed amongst instruments with the X-File having a smoother surface finish. PTN and PTN-CF had mixed austenite plus R-phase (R-phase start approximately at 45 ºC and near 30 ºC, respectively), whilst X-File instruments were austenitic (R-phase started at approximately at 17 ºC) at room temperature (20 ºC). PTN-CF had the greatest inconsistency in the phase transformation temperatures. Time to fracture of PTN-CF X2 and X3 was significantly shorter than PTN and X-File instruments (P 0.05), whilst no difference was noted in maximum torque to fracture amongst the tested systems (P 0.05). X-Files and PTN-CF had a stress-induced phase change during bending load. Mean unprepared surface areas of root canals were 25.8% (PTN), 31.1% (X-File) and 32.5% (PTN-CF) with no significant difference amongst groups (P 0.05).Similarities amongst the systems were noted in the Ni/Ti ratio and maximum torque to fracture, whilst differences were observed in the design, phase transformation temperatures and mechanical behaviour. The ProTaper Next counterfeit instruments could be considered as the less secure system considering its low-cyclic fatigue resistance. Apart from these differences, the unprepared canal surface areas, obtained with the tested systems, were similar.

The purpose of this study was to evaluate the cleanliness of root canal walls and dentinal tubules after attempting to remove the calcium hydroxide dressing with different irrigant solutions and the use of nonactivated irrigation or passive ultrasonic irrigation (PUI).After root canal instrumentation, 80 single-rooted teeth were filled with calcium hydroxide mixed with propylene glycol and 0.1% rhodamine B dye and inserted into canals with a Lentulo spiral. The calcium hydroxide dressing was initially removed with 10 mL saline solution and reinstrumentation with the master apical file. Then, the samples were randomly assigned into 8 experimental groups (n = 10) according to the irrigant solution with or without PUI: 2.5% sodium hypochlorite, 17% ethylenediaminetetraacetic acid + 1.25% sodium lauryl ether sulfate (EDTA-T), 37% phosphoric acid, or 70% ethanol. A final flush with 5 mL saline solution was performed. The percentage of clean root canal walls and the depth of clean dentinal tubules were measured with images of confocal laser scanning microscopy. The groups were compared using the 2-way analysis of variance test with the Bonferroni post hoc test for depth analysis and the Kruskal-Wallis with Dunn post hoc test for the perimeter analysis.Irrigation with 70% ethanol presented a significantly higher percentage of clean root canal walls and a higher depth of clean dentinal tubules when compared with irrigation with 2.5% sodium hypochlorite and 17% EDTA-T for both irrigation methods (P.05). No differences were observed between nonactivated irrigation or PUI protocols (P.05).Seventy percent ethanol enhanced calcium hydroxide removal from the apical root third compared with 2.5% sodium hypochlorite or 17% EDTA-T.

ObjectivesThe purpose of this study was to evaluate the influence of endodontic access cavities design on the removal of calcium hydroxide medication of the apical third of mandibular incisor root canal walls and dentinal tubules with different cleaning protocols: EDDY sonic activation, Er,Cr:YSGG laser-activated irrigation, or conventional irrigation with IrriFlex.Materials and MethodsSeventy eight extracted human mandibular incisors were assigned to six experimental groups [n = 13] according to the endodontic access cavity and cleaning protocol for calcium hydroxide removal: traditional access cavity (TradAC)/EDDY; ultra-conservative access cavity performed in the incisal edge (UltraAC.Inc)/EDDY; TradAC/Er,Cr:YSGG; UltraAC.Inc/Er,Cr:YSGG; TradAC/IrriFlex; or UltraAC.Inc/IrriFlex. Confocal laser scanning microscopy images were used to measure the non-penetration percentage, maximum residual calcium hydroxide penetration depth, and penetration area at 2 and 4 mm from the apex. Data were statistically analyzed using Shapiro–Wilk and WRS2 package for two-way comparison of non-normally distributed parameters (depth of penetration, area of penetration, and percentage of non-penetration) according to cavity and cleaning protocol with the significance level set at 5%.ResultsThe effect of cavity and cleaning protocol interactions on penetration depth, penetration area and non-penetration percentage was not found statistically significant at 2 and 4 mm level (p > 0.05).ConclusionThe present study demonstrated that TradAC or UltraAC.Inc preparations with different cleaning protocols in extracted mandibular incisors did not influence the remaining calcium hydroxide at 2 and 4 mm from the apex.Clinical RelevanceThis study highlighted that TradAC or UltraAC.Inc, access cavities design and the different cleaning protocols have not influenced the remaining calcium hydroxide apical third of mandibular incisor.

This study evaluated the danger zone (DZ) in mesial roots of mandibular molars and the correlation between anatomical references of the DZ and some anatomical landmarks including tooth/root length, depth of mesial and distal grooves, and inter-canal orifices distance. Twenty-eight mesial roots of mandibular molars with 2 independent canals were scanned and divided into 2 groups according to root length. The anatomical landmarks were correlated (Pearson or Spearman coefficients) with root level, thickness, and position of the DZ and also compared (independent samples t or Mann-Whitney tests) between the 2 groups at α = 5%. No statistical difference was observed between groups regarding DZ parameters and depth of mesial and distal grooves (P > 0.05). Orifice distance in group 2 (4.49 ± 0.75 mm) was significantly greater than group 1 (3.76 ± 0.89 mm) (P < 0.05). Significant correlations (P < 0.05) were found between (i) DZ level and root/tooth length (r = 0.54 and 0.49, respectively), (ii) DZ thickness and distal groove depth (r = − 0.45), and orifice distance (r = 0.38), and (iii) DZ position and depth of mesial (r = 0.39) and distal (r = 0.40) grooves. Other variables such as root length and distal groove depth (r = 0.28), and orifice distance and mesial groove depth (r = 0.36) were also correlated (P < 0.05). The length of tooth/root, the distance of canal orifices, and the depth of mesial/distal grooves of mesial roots of mandibular molars might be predictive factors for the root level, position, and thickness of the DZ. The length, distance of mesial canal orifices, and the depth of mesial and distal grooves of the mesial roots of mandibular molars might be moderate predictive factors for the root level, position, and thickness of the DZ.

The aim of the present study was to compare the cyclic fatigue resistance of Reciproc R25 (R25) and Reciproc Blue R25 (R25B) instruments, after simulated clinical use in traditional (TradAC) and ultraconservative (UltraAC) endodontic access cavities.Forty mandibular molars were randomly assigned into the following groups, according to the type of access and instrument to be used: TradAC and R25, TradAC and R25B, UltraAC and R25, and UltraAC and R25B. Teeth were accessed accordingly, and the root canals were prepared using "RECIPROC ALL" kinematics. The cyclic fatigue resistance of the forty used instruments was obtained measuring the time to fracture in an artificial stainless-steel canal. Ten brand new R25 and R25B were used as control groups. The fracture surfaces and the side cutting edges of the instruments were examined with a scanning electron microscope. Data were statistically analyzed using one-way ANOVA and post hoc Tukey tests with a significance level of P0.05.R25B instruments showed significantly higher cyclic fatigue resistance than R25, regardless of the access cavity type (P0.05). No differences were observed in the cyclic fatigue resistance between instruments without simulated clinical use and used in TradAC (P0.05). R25 and R25B used in UltraAC showed significantly lower cyclic fatigue resistance compared with the instruments used in TradAC and without simulated clinical use (P0.05).R25B files showed improved cyclic fatigue resistance than R25. The use of R25B and R25 files in mandibular molars with UltraACs decreased their cyclic fatigue resistance, compared with TradAC.The use of Reciproc and Reciproc Blue files in mandibular molars with ultra-conservative endodontic access cavities reduced their cyclic fatigue resistance. Clinicians should be aware about the reduced cyclic fatigue resistance of these files when used in mandibular molars with UltraAC, due to the synergistic effect of access angulation and severe curvature induced in the endodontic files.

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.

Background To evaluate the physicochemical properties and cytotoxicity of AH Plus, MTA Fillapex and TotalFill BC Sealer. Volumetric changes were also evaluating using micro-computed tomography (micro-CT). Material and Methods Radiopacity and flow were evaluated in accordance with the ISO 6876, while setting time was evaluated in accordance with the ASTM- C266-08 specifications. The release of Ca2+ ions and pH were measured with spectrophotometer and pH meter, respectively, after different time intervals (1h, 3h, 24h, 72h, 168h, and 360h). Cytotoxicity was evaluated by MTT reduction assay to check 3T3 cells viability at 24, 48 and 72 hours. Volumetric change was evaluated by micro-CT, by using 30 acrylic teeth, filled with gutta-percha cones and the tested root canal sealer. The samples were evaluated after 168h, 360h and 720h of immersion in distilled water. Data were statistically analyzed by one-way ANOVA and Tukey test or by Kruskal-Wallis and Dunn tests (P

The aim of the present study was to evaluate the morphologic changes on the apical foramen and the formation of dentinal microcracks after foraminal enlargement in straight and curved root canals using scanning electron microscopic (SEM) and micro-computed tomographic (micro-CT) analyses.Sixty teeth were selected and divided into 2 experimental groups: GI (incisors/straight group, n = 30) and GM (molars/curved group, n = 30). Each group was divided into 2 subgroups (n = 15) according to the analysis performed: SEM or micro-CT analysis. The incisors and mesiobuccal canal of molars were instrumented with Reciproc Blue R25 instruments (VDW, Munich, Germany) using standardized shaping procedures in the apical foramen and 1 mm beyond. The occurrence of foraminal deformation was analyzed by scanning electron microscopy. The z test was used for statistical analysis (P.05). Micro-CT imaging was used to observe the presence of microcracks in the root apical third. Afterward, pre- and postoperative cross-sectional images were screened to identify the presence of dentinal defects.The curvature of the canal did not influence the occurrence of foraminal deformation either for instrumentation in the foramen or for instrumentation beyond the foramen (P.05). It was also observed that the increase in the working length did not influence the appearance of new deformations in the GI/SEM and GM-SEM groups (P.05). Qualitative micro-CT analysis showed the presence of dentinal defects in 0.8% (112) and 1.5% (208) of the cross sections of incisors and molars, respectively, from a total of 13,987 slices. All dentinal defects identified in the analysis of any postoperative scans were already present in the corresponding preoperative images. Therefore, no new microcracks were observed after root canal preparation.The preparation of straight and moderately curved root canals with Reciproc Blue, regardless of the working length, did not influence the occurrence of apical foramen deformations and did not cause the formation of dentinal microcracks.

This study aimed to compare the mechanical and metallurgical properties and shaping ability of different rotary systems using a multimethod approach.New NeoNiti A1 (Neolix SAS, Châtres-La-Forêt, France), HyFlex EDM One File (Coltène/Whaledent, Altstätten, Switzerland), ProTaper Gold F2 (Dentsply Maillefer, Ballaigues, Switzerland), and ProTaper Universal F2 (Dentsply Maillefer) rotary instruments were tested regarding cyclic fatigue, torsional resistance, design, and morphologic characteristics using scanning electron microscopy, metal alloy characterization using differential scanning calorimetry, and energy-dispersive X-ray spectroscopy. Additionally, their shaping ability on the preparation of 48 canals of maxillary molars was evaluated using micro-computed tomographic technology. Mechanical and metallurgical analyses were compared using analysis of variance post hoc Tukey tests, whereas the independent Student t test was used to compare the shaping ability of the ProTaper systems or the thermomechanically treated instruments. The significance level was set at 5%.The highest cyclic fatigue was observed with the NeoNiti and HyFlex EDM instruments (P.05), whereas HyFlex EDM had the highest angular rotation to fracture (P.05). Scanning electron microscopic/energy-dispersive X-ray spectroscopic analyses confirmed similarities in the instruments' design and an almost equiatomic composition of the systems. Differential scanning calorimetry showed that ProTaper Gold had higher transformation temperatures than ProTaper Universal, whereas a similar transformation was observed between NeoNiti and HyFlex. Micro-computed tomographic analysis revealed that, despite the fact that none of the systems was able to prepare all root canal walls, no statistical differences were observed in either ProTaper systems (P.05) or the thermomechanically treated instruments (P.05).Apart from differences in the mechanical tests and metallurgical characterization, systems with comparable instrument dimensions and preparation protocols showed a similar percentage of untouched surface areas in the root canal preparation of maxillary molars.

Introdução: Pinos de fibra de vidro são bastante utilizados quando dentes tratados endodonticamente apresentam grande perda estrutural e necessitam de suporte para a sua reconstrução coronária. A completa adesão do pino à parede do canal radicular é fundamental para o sucesso dessa restauração. Resíduos de cimento endodôntico que permanecem nas paredes dentinárias, mesmo após o preparo para a cimentação, podem interferir negativamente na sua adesão e contribuir para o seu deslocamento. Objetivo: O objetivo da presente revisão de literatura foi avaliar o efeito de diferentes cimentos endodônticos e o tempo decorrido entre a obturação e a cimentação do pino na resistência de união entre o pino e a parede do canal radicular. Métodos: Essa revisão de literatura incluiu 21 estudos que analisaram a influência de cimentos endodônticos na adesão de pinos de fibra de vidro, entre os quais 9 acrescentaram a variável tempo na sua análise, com pinos cimentados logo após a obturação do canal radicular e dias após a obturação. Resultados: Os dentes obturados com cimentos à base de resina demonstraram maior resistência ao deslocamento dos pinos durante os testes. Parece haver uma predominância de menores valores de adesão quando os pinos são cimentados imediatamente após a obturação com cimentos contendo eugenol. Conclusões: Os tipos de cimento endodôntico e o período entre a obturação e a cimentação do pino podem afetar a força de ligação entre a parede do canal radicular e o pino de fibra de vidro.

In the last decade, several access cavity designs involveing minimal removal of tooth tissue have been described for gaining entry to pulp chambers during root canal treatment. The premise behind this concept assumes that maximum preservation of as much of the pulp chamber roof as possible during access preparation would maintain the fracture resistance of teeth following root canal treatment. However, the smaller the access cavity, the more difficult it may be to visualize and debride the pulp chamber as well as locate, shape, clean and fill the canals. At the same time, a small access cavity may increase the risk of iatrogenic complications as a result of poor visibility, which may have an impact on treatment outcome. This study aimed to critically analyse the literature on minimal access cavity preparations, propose new nomenclature based on self-explanatory abbreviations and highlight the areas in which more research is required. The search was conducted without restrictions using specifics terms and descriptors in four databases. A complementary screening of the references within the selected studies, as well as a manual search in the highest impact journals in endodontics, namely International Endodontic Journal and Journal of Endodontics, was also performed. The initial search retrieved 1831 publications. The titles and abstracts of these papers were reviewed, and the full text of 94 studies was assessed. Finally, a total of 28 studies were identified as evaluating the influence of minimally invasive access cavity designs on the fracture resistance of teeth and on the different stages of root canal treatment (orifice location, canal shaping, canal cleaning, canal filling and retreatment). Overall, the studies had major methodological drawbacks and reported inadequate and/or inconclusive results on the utility of minimally invasive access preparations. Furthermore, they offered limited scientific evidence to support the use of minimally invasive access cavities to improve the outcome of root canal treatment and retreatment; they also provided little evidence that they preserved the fracture resistance of root filled teeth to a greater extent than traditional access cavity preparations. It was concluded that at present, there is a lack of supporting evidence for the introduction of minimally invasive access cavity preparation into routine clinical practice and/or training of undergraduate and postgraduate students.

This study aimed to evaluate the antibacterial efficacy and discolouration potential of antibiotic pastes containing macrogol. Seventy single-rooted teeth were contaminated with a culture of Enterococcus faecalis for 30 days. Double (DAP) and triple antibiotic pastes (TAP) containing propylene glycol or macrogol as vehicles were applied. After 15 days, bacterial viability was compared. Change in teeth coronal colour was measured by a spectrophotometer. Statistical analysis was performed using anova and Tukey's test (P

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