In vitro study of structural and chemical changes in two reciprocating files after multiple reuses and sterilisation.

To use scanning electron microscopy and energy dispersive X-ray spectroscopy to evaluate the metallurgical-chemical changes of WaveOne Gold (WOG) and R-Motion (RM), after multiple uses. The instruments were divided into groups (n = 8): WOG and RM-control groups, new instruments; WOG1 and RM1; WOG2 and RM2; WOG3 and RM3 after instrumentation of 1, 2 or 3 molars, respectively. Burrs occurred mainly in the control group and after the first use. The RM files were found to have a higher nickel content, which increased during reuse, and a decrease in oxygen content with increasing reuse, in addition to calcium impregnation, which occurred in greater amounts in the corrosion areas in the WOG files. The presence of topographic and chemical changes was demonstrated, indicating that caution should be taken when reusing endodontic instruments to avoid fractures.

Comparative in vitro analysis of the antifungal activity of different calcium silicate-based endodontic sealers

Aim: This study aimed to perform an in vitro comparative analysis of the antifungal activity of different calcium silicate-based endodontic sealers against three fungal species. Methods: The antifungal properties of three calcium silicate-based sealers were tested: Bio-C Sealer, Cambiar a Sealer Plus BC, and MTA-Fillapex. Two commonly used sealers were used as controls: AH Plus and Endomethasone. An agar diffusion test was performed to analyze the antifungal activity of the sealers against Candida albicans, Candida glabrata, Candida tropicalis, and a mixed microbial culture medium. The results were analyzed using ANOVA (p <0.05). Results: Endomethasone exhibited the highest inhibition against all strains examined, maintaining a consistent level of inhibition throughout 7 days. MTA-Fillapex demonstrated the best performance among the calcium silicate-based sealers for the three fungal species (p < 0.05), maintaining stable values over the 7 days, surpassing that of Endomethasone. Nevertheless, MTA-Fillapex only exhibited antimicrobial effect against the mixed culture for the first 24 hours, and no antimicrobial activity was observed at 48 hours, being surpassed by all tested sealers (p < 0.05). Conclusion: Of all silicate-based sealers tested, only MTA-Fillapex exhibited promising antifungal activity. Nevertheless, care must be taken when extrapolating these results, as MTA-Fillapex exhibited poor antimicrobial activity when tested in mixed microbial cultures

Evaluation of the apical sealing of an eggshell hydroxyapatite-based sealer.

Background: The success of endodontic treatment can be influenced by the type of endodontic sealer used, as certain sealers may be prone to apical microleakage, leading to treatment failure. The limitations of currently available sealers necessitate the development of new materials to improve the success rate of endodontic treatment. Therefore, the objective of this study was to assess the apical microleakage of newly developed hydroxyapatite-based endodontic sealers, including one derived from eggshells, and compare them with other commercially available sealers. Material and Methods: Eighty-five extracted human upper anterior teeth were selected for this study. The teeth were divided into 5 experimental groups and 2 control groups. The experimental groups were designated as follows: (1) HPSINT - obturated with gutta-percha cone and synthetic hydroxyapatite-based sealer, (2) BIOC - obturated with gutta-percha cone and Bio C-Sealer sealer, (3) AHPLUS-BC - obturated with gutta-percha cone and AHPLUS Bioceramic sealer, (4) AHP - obturated with gutta-percha cone and AHPLUS sealer, and (5) HPO - obturated with gutta-percha cone and sealer based on hydroxyapatite extracted from eggshells. Additionally, there were positive and negative control groups consisting of instrumented teeth filled with gutta-percha cones without any sealer and instrumented teeth without any filling, respectively. Methylene blue dye penetration was used to assess apical microleakage. Descriptive statistical analysis and Shapiro-Wilk normality test were applied to the observed results. As the samples followed a normal distribution, the ANOVA test was applied. Results: The control groups confirmed the validity of the experimental method, while the experimental groups showed varying degrees of dye penetration. The group obturated with Bio C-Sealer exhibited the highest mean apical microleakage, while AHPLUS Bioceramic sealer demonstrated lower mean than AHPLUS sealer and sealer based on hydroxyapatite extracted from eggshells (p<0.05). Finally, there was no difference between the synthetic hydroxyapatite-based sealer and AHPLUS Bioceramic sealer, AHPLUS sealer and sealer based on hydroxyapatite extracted from eggshells (p>0.05). No significant difference was observed between the hydroxyapatite-based sealers and the AHPLUS-BC sealer. Conclusions: The results of this study suggest that the newly developed hydroxyapatite-based endodontic sealers, including the one derived from eggshells, may have a lower risk of apical microleakage compared to other commercially available sealers. These findings highlight the potential of hydroxyapatite-based sealers to improve the success rate of endodontic treatment. Further research and clinical studies are warranted to validate these results and explore the long-term effects of these novel sealers. Key words:Endodontic treatment, apical microleakage, endodontic sealer, hydroxyapatite, eggshell-derived sealer.

Ex Vivo Evaluation of the Efficacy of Photodynamic Therapy in Eliminating Enterococcus faecalis from Dentinal Tubules by Confocal Laser Scanning Microscopy.

INTRODUCTION: The aim of the present study was to investigate ex vivo by confocal laser scanning microscopy the antibacterial effect of photodynamic therapy (PDT) on dentinal tubules in the apical 5 mm of human mandibular premolars contaminated with Enterococcus faecalis. METHODS: Thirty-four teeth were standardized to 20 mm and foraminal anatomic diameters using a #20 K-file (Dentsply Maillefer). Samples were contaminated for 21 days and divided into the following 3 experimental groups (n = 10): the PDT group (instrumented canals and PDT), the passive ultrasonic irrigation (PUI) group (instrumented canals and PUI), and the PUI-PDT group (instrumented canals, PUI, and PDT), along with a control group (n = 4) (noninstrumented canals). The canals in the experimental groups were instrumented with ProTaper Next (Dentsply Maillefer) up to X3 and rinsed with EDTA and sodium hypochlorite. The photosensitizer used was 0.01% methylene blue with a preirradiation time of 5 minutes and a diode laser with 4 J energy and a 660-nm wavelength. Cross sections were made 5 mm from the apex of all samples, which were analyzed using confocal laser scanning microscopy. The results were analyzed using the Shapiro-Wilk and Kruskal-Wallis (Dunn) tests. RESULTS: There was a lower percentage of live bacteria in the PUI-PDT group, with a statistical difference compared with the control and PDT groups (P < .05). There was no statistical difference in the percentage of live bacteria between PUI-PDT and PUI (P > .05). CONCLUSIONS: It was concluded that the PUI-PDT association was most effective in disinfecting root canals compared with the control group and PDT.

Micro- CT evaluation of sealers removal by reciprocal instrumentation followed by continuous ultrasonic irrigation in teeth with oval root canals.

Background: The ability of the Reciproc system (R40) followed by continuous ultrasonic irrigation (CUI) to remove filling material from oval root canals of mandibular premolars filled with gutta-percha and AH Plus or Bio-C Sealer was evaluated by microtomography (micro-CT). Material and Methods: The straight and oval root canals of 42 mandibular premolars were prepared with the ProDesign R 35.05 reciprocal file and randomly divided into two groups according to the material used to fill the canals (n=21): Group AH - Master Cone and AH Plus; Group BC - Master Cone and Bio-C Sealer. After filling and provisional sealing, the teeth were stored at 100% relative humidity and a temperature of 37°C for 30 days. The filling material was then removed with an R40 file. The material was considered completely removed when the R40 file reached the working length (WL), and no remaining filling material was visible on the canal walls. CUI was then performed. The teeth were scanned by micro- CT before and after removal of the filling material. The remaining filling material was measured in mm in the last apical 5 mm. The data were analyzed with the nonparametric Friedman test and subsequently with the Dunn test. The Mann-Whitney U test was also performed. Statistical significance was accepted at the 5% level. Results: After instrumentation with the Reciproc R40, the volume of residual filling material was significantly greater in the BC group than in the AH group (P = 0.035). After CUI, there was no difference in the volume of residual material between the two groups (P = 0.705). Conclusions: Bio-C sealer was more difficult to remove with the Reciproc file than AH Plus. CUI improved the removal of residual filling material regardless of sealer type. However, no technique was able to completely clear the canals of filling material. Key words:Bioceramic cement, CUI, micro-CT, reciproc, retreatment.

In Vivo Evaluation of Painful Symptomatology after Endodontic Treatment Performed Using Two Different Irrigation Needle Insertion Depths.

OBJECTIVE: The main purpose of this study was to evaluate pain symptoms in patients after endodontic treatment performed in a single session in teeth with vitality or pulp necrosis, comparing two depths of insertion of the NaviTip irrigation needle. MATERIALS AND METHODS: One-hundred upper uniradicular teeth were selected and divided into four groups (n = 25), namely Bio group 1 (live pulp/1 mm from the foramen), Bio group 3 (live pulp/3 mm from the foramen), Necro group 1 (pulp necrosis/1 mm from the foramen), and Necro group 3 (pulp necrosis/3 mm from the foramen). All canals were instrumented with Wave One Gold System. Irrigation was performed using 2.5% NaOCl. The teeth were filled using the single-cone technique with AH Plus sealer using a McSpadden compactor. After treatment, patients answered a questionnaire with a visual analog scale scored from 0 to 10 at 1, 3, and 7 days after treatment. STATISTICAL ANALYSIS: Data were analyzed using Mann-Whitney U, Wilcoxon, and Friedman tests. RESULTS: There was a decrease in average pain levels at the three time points for both vital and necrotic teeth (p < 0.05). There were no significant differences in postoperative pain levels comparing needle depth, or vitality and pulp necrosis (p > 0.05). The percentage of mild pain increased over time and moderate pain decreased, regardless of pulp condition. There was no incidence of acute pain at any time. CONCLUSIONS: Post-treatment endodontic pain levels in upper uniradicular teeth with or without pulp vitality resulted in similar pain scores, regardless of the depth of insertion of the irrigation needle in relation to the apical foramen.

Effect of immersion in sodium hypochlorite on the cyclic fatigue resistance of three rotary instruments.

CONTEXT: It is essential to know if the immersion in sodium hypochlorite (NaOCl) influences the cyclic fatigue resistance of nickel-titaniumm (NiTi) files. AIM: This study was aimed to evaluate the resistance to the cyclic fatigue of three NiTi systems, as well as the influence of 5.25% NaOCl on their resistance. METHODS: Files from the Sequence Rotary File (MK life, Porto Alegre, Brazil), ProTaper Next (PTN) (Dentsply, Maillefer, Baillagues, Switzerland), and HyFlex EDM (Coltène Whaledent, Allstatten, Switzerland) systems were tested and separated into Group 1)-without immersion in NaOCl solution and Group 2 and Group 3-immersed in 5.25% NaOCl solution, for 1 min, and 5 min, respectively. All instruments were submitted to the cyclic fatigue test. Images of the instruments were observed by scanning electron microscopy, to evaluate the type of defect presented on the fractured surface. The test performed for the analysis of two independent factors was a two-way analysis of variance. RESULTS: HyFlex EDM presented a greater number of cycles until fracture when compared to others (P < 0.001). The control group showed a greater number of cycles until fracture than the same instruments submitted to NaOCl (P < 0.001). Sequence instruments showed the lowest values of cycles until fracture (P < 0.001). There was no statistically significant difference between treatments (P = 0.998). PTN, showed intermediate values of fracture resistance when compared to the HyFlex EDM and sequence instruments (P < 0.001), but without intragroup differences (P = 0.437). CONCLUSIONS: Hyflex EDM instruments were the most resistant to cyclic fatigue.

Root Fracture Resistance of Maxillary Premolars Obturated with Three Root Canal Sealers after Passive Utrasonic Irrigation: An in Vitro study.

Introduction: Maxillary premolars, may be more susceptible to fracture due to their anatomy; especially when there is loss of tooth structure. Therefore, it is necessary to evaluate materials and techniques that may increase fracture resistance during and post root canal treatment. This in vitro study aimed to evaluate root fracture resistance of maxillary premolars when filled with three root canal sealers as well as whether this resistance would be increased by passive ultrasonic irrigation (PUI). Methods and Materials: Sixty-four maxillary premolars with two roots were randomly divided into one negative control group (intact canals; n = 8), one positive control group (instrumented, unsealed canals; n = 8), and six experimental groups (n = 8), which were instrumented with ProTaper Next rotary system up to X2 file and subdivided according to final irrigation (with or without PUI) and type of sealer used (AH-Plus [AH], MTA Fillapex [MTA], or EndoSequence BC Sealer [ES]). The specimens were subjected to fracture strength test in a universal testing machine at a speed of 1 mm/min until fracture. The maximum force required to induce fracture was recorded (N). The Kruskal-Wallis test and DUNN test were used for analysis. Results: The lowest force required to cause root fracture was observed in the positive control group (310.48 ± 54.08 N); this was significantly different from the other groups (P < 0.05). There was no significant difference between experimental groups obturated with the same sealer, whether with or without PUI (AH with PUI: 558.80 ± 87.12 N; AH without PUI: 508.75 ± 97.55 N; MTA with PUI: 507.27 ± 174.55 N; MTA without PUI: 516.69 ± 96.56 N; ES with PUI: 526.76 ± 143.97 N; ES without PUI: 628.40 ± 94.74 N) (P > 0.05). There was also no significant difference between the experimental groups and the negative control group (P > 0.05). Conclusions: In this in vitro study PUI did not increase the fracture resistance of maxillary premolars, while AH Plus, MTA Fillapex, EndoSequence sealers increased fracture resistance of instrumented root canals.

Assessment of Extrusion and Postoperative Pain of a Bioceramic and Resin-Based Root Canal Sealer.

OBJECTIVES: The objective of this study was to compare a bioceramic and a resin-based endodontic sealer with regard to extrusion and postoperative pain. MATERIALS AND METHODS: Sixty-four patients requiring endodontic treatment of single-rooted maxillary teeth with necrotic pulps were included in this study. The root canal treatments were performed in a single visit using a size 40.06 single-file reciprocating system under 2.5% NaOCl irrigation. After irrigation with 17% ethylenediaminetetraacetic acid (EDTA) and 2.5% NaOCl, the canals were dried and randomly divided into two different groups (n = 32) depending on the sealer used: resin-based group (RG) in which the canals were filled with the AH Plus, and the bioceramic group (BG) in which the canals were filled with the Sealer Plus BC. Ibuprofen (600 mg) was prescribed every 6 hours if the volunteers experienced pain. The patients registered their pain sensation in a visual analog scale (VAS) card, ranging from 0 to 10 at 24-hour, 48-hour, 72-hour, and 1-week intervals. STATISTICAL ANALYSIS: For statistical analysis, the level of significance was set at p < 0.05. RESULTS: Sealer extrusion occurred in nine patients of the RG and in 19 patients of the BG (p < 0.05). The average pain level at 24-hour and 48-hour intervals was, respectively, 1.46 ± 1.96 and 0.44 ± 0.86 for RG, and 1.21 ± 2.09 and 0.09 ± 0.38 for BG. There was no report of pain after 48 hours. The mean number of tablets taken for pain relief was 0.03 ± 0.17 for RG and 0.06 ± 0.24 for BG. No statistically significant difference was found with regard to pain level and intake of pain killer tablets (p > 0.05). CONCLUSIONS: The BG sealer presented significantly more extrusion than the RG sealer. Sealer extrusion was not associated with pain. The average pain level and the mean number of tablets taken for pain relief were similar in both groups.

Ex-vivo Smear Layer Removal Efficacy of Two Activated Irrigation Techniques After Reciprocating Instrumentation in Curved Canals.

INTRODUCTION: This study aimed to compare the effectiveness of two activated irrigation techniques in removing the smear layer after single-file reciprocating instrumentation in curved canals. MATERIALS AND METHODS: Sixty distobuccal roots of maxillary molars were standardized to create a closed system, and then instrumented using WaveOne Primary (Dentsply Maillefer, Ballaigues, Switzerland) instruments. Fifty-four specimens were randomly distributed into 3 groups for final irrigation: Non-activated irrigation, passive ultrasonic irrigation (PUI), and EndoActivator (EA;Dentsply Maillefer, Tulsa, USA) irrigation. All specimens received 3 mL of 17% EDTA for 1 minute, followed by irrigation with 6 mL of 2.5% NaOCl. The apical, middle and cervical thirds of the specimens were analyzed using scanning electronic microscopy (SEM), and the amount of remaining smear layer on the canal walls was rated by three examiners using a five-category scoring system. Kendall's concordance coefficient was used to assess inter-rater agreement. Kruskal-Wallis and Mann-Whitney (Bonferroni) tests were used to compare the scores. RESULTS: Kendall's concordance coefficient was ≥ 0.7, indicating an excellent level of agreement between the raters. No statistically significant difference in irrigation techniques efficacy for removal of the smear layer (p=0.061) was found for the apical third. The scores attributed to the specimens irrigated with the EA system were significantly lower than those of the other groups in the cervical and middle thirds (p< 0.05). CONCLUSIONS: The efficacy of the EA system in removing the smear layer in the cervical and middle thirds of root canals instrumented with reciprocating motion was significantly higher than that of either PUI or non-activated irrigation. Both EA and PUI performed similarly in apical third.

In vivo assessment of accuracy of Propex II, Root ZX II, and radiographic measurements for location of the major foramen.

OBJECTIVES: The aim of this in vivo study was to assess the accuracy of 2 third-generation electronic apex locators (EALs), Propex II (Dentsply Maillefer) and Root ZX II (J. Morita), and radiographic technique for locating the major foramen (MF). MATERIALS AND METHODS: Thirty-two premolars with single canals that required extraction were included. Following anesthesia, access, and initial canal preparation with size 10 and 15 K-flex files and SX and S1 rotary ProTaper files, the canals were irrigated with 2.5% sodium hypochlorite. The length of the root canal was verified 3 times for each tooth using the 2 apex locators and once using the radiographic technique. Teeth were extracted and the actual WL was determined using size 15 K-files under a × 25 magnification. The Biostat 4.0 program (AnalystSoft Inc.) was used for comparing the direct measurements with those obtained using radiographic technique and the apex locators. Pearson's correlation analysis and analysis of variance (ANOVA) were used for statistical analyses. RESULTS: The measurements obtained using the visual method exhibited the strongest correlation with Root ZX II (r = 0.94), followed by Propex II (r = 0.90) and Ingle's technique (r = 0.81; p < 0.001). Descriptive statistics using ANOVA (Tukey's post hoc test) revealed significant differences between the radiographic measurements and both EALs measurements (p < 0.05). CONCLUSIONS: Both EALs presented similar accuracy that was higher than that of the radiographic measurements obtained with Ingle's technique. Our results suggest that the use of these EALs for MF location is more accurate than the use of radiographic measurements.

Fracture Incidence of WaveOne and Reciproc Files during Root Canal Preparation of up to 3 Posterior Teeth: A Prospective Clinical Study.

INTRODUCTION: Reciprocating instruments were developed to improve and simplify the preparation of the root canal system by allowing greater centralization of the canal and requiring a shorter learning curve. Despite the risk of instrument separation, using a reciprocating instrument in more than 1 case is a relatively common clinical practice. The aim of this study was to evaluate the fracture resistance of Reciproc (R25; VDW, Munich, Germany) and WaveOne (Primary; Dentsply Maillefer, Ballaigues, Switzerland) instruments according to the number of uses during the preparation of root canals in up to 3 posterior teeth. METHODS: A prospective clinical study was conducted by 3 experienced specialists who performed treatment of 358 posterior teeth (1130 canals) over a period of 12 months using 120 reciprocating instruments, 60 of which were Reciproc R25 and 60 were WaveOne Primary. The motion used during instrumentation followed the recommendations of the respective manufacturers. After each use, the instruments were observed under a dental operating microscope at 8× magnification. In the case of fracture or deformation, the instrument was discarded. RESULTS: None of the instruments showed any signs of deformation, but 3 instruments fractured (0.26% of the number of canals and 0.84% of the number of teeth). All fractures occurred in mandibular molars (1 WaveOne Primary file during the third use and 2 Reciproc R25 files, 1 during the first use and the other during the third use). CONCLUSIONS: There was a low incidence of fracture when reciprocating files were used in up to 3 cases of endodontic treatment in posterior teeth.

Avaliação da acurácia de quatro localizadores apicais durante o retratamento endodôntico / Evaluate the accuracy of four electronic apex locators during endodontic retreatment

Este estudo teve como objetivo avaliar a acurácia de quatro localizadores apicais eletrônicos durante o retratamento endodôntico. Quarenta pré-molares unirradiculares com apenas um canal, ápice completamente formado, foram divididos em quatro grupos e analisados: Grupo 1: Root ZX ll. Grupo 2: Mini Root. Grupo 3: Propex ll e Grupo 4: Mini Apex. Todos os elementos foram padronizados no comprimento de 22 mm, instrumentados com limas Wave One Primary (25.08), obturados e armazenados. Após um mês, foram desobturados com limas reciprocantes Wave One Primary (25.08) e, em seguida, montados em blocos de esponja vegetal, embebida em solução de cloreto de sódio a 0,9%. A acurácia eletrônica de cada elemento foi realizada, utilizando-se uma lima manual do tipo K#20, até que a mesma fosse ultrapassada pelo forame e recuada até o comprimento real do dente, onde, então, as medidas de cada elemento eram anotadas. Todas as medidas obtidas de cada grupo passaram por análise estatística. Não houve diferença estatisticamente significante entre os localizadores apicais eletrônicos analisados, quando utilizados durante o retratamento endodôntico, sendo possível concluir que, os quatro modelos de localizadores apicais analisados mostraram-se eficientes durante o retratamento endodôntico, dentro dos limites estabelecidos, não havendo diferença entre eles.

This study aimed to evaluate the accuracy of four electronic apex locators during endodontic retreatment. Forty single-rooted premolars, with a root canal, with fully formed apex, were divided into four groups and analyzed: Group 1: Root ZX II. Group 2: Mini Root. Group 3: Propex II and Group 4: Mini Apex. All elements have been standardized in the length of 22 mm, instrumented with Wave One Primary (25.08) files, sealed and stored. After a month, the desobturation with reciprocating Wave One Primaty (25.08) files off and then assembled into blocks vegetable sponge, soaked in 0.9% sodium chloride solution. Electronic accuracy of each element was performed using a manual file type K#20, until it was overtaken by the foramen and retracted to the actual length of the tooth, which then measures each element were noted. All measurements obtained from each group passed by statistical analysis. There was no statistically significant difference between the electronic apex locators analyzed when used during endodontic retreatment it is possible to conclude that the four models analyzed apex locators were effective during endodontic retreatment wirhin the established timits, there is no difference between them.

Comparative Analysis of Dentinal Erosion after Passive Ultrasonic Irrigation versus Irrigation with Reciprocating Activation: An Environmental Scanning Electron Study.

INTRODUCTION: The aim of this study was to assess ex vivo the erosive effects of passive ultrasonic irrigation versus irrigation with reciprocating activation on the dentinal surface of the root canal at 3 predetermined levels using environmental scanning electron microscopy. METHODS: Ten roots of mandibular premolars were prepared using the ProTaper Universal system (Dentsply Maillefer, Ballaigues, Switzerland). The specimens were embedded in flasks cleaved longitudinally, and indentations were made 3.0, 6.0, and 9.0 mm from the apex. The specimens in the control group (n = 10) were cleaned in an ultrasonic bath containing 2.5% sodium hypochlorite and 17% EDTA and then dried. Then, environmental scanning electron microscopic images were obtained at magnification × 800. The specimens were then reassembled in their flasks, and the NaOCl and EDTA solutions were activated according to the conditions established for the experimental groups (ie, the passive ultrasonic irrigation group [n = 5] and the EasyClean (Easy Equipamentos Odontológicos, Belo Horizonte, MG, Brazil) group, irrigation with reciprocating activation with the EasyClean instrument [n = 5]). The specimens of both experimental groups were analyzed in the same manner as in the control group. Analysis of the dentinal surface topography was conducted using the 3D Roughness Reconstruction program (Phenom-World BV, Eindhoven, the Netherlands) as a means for assessing erosion. The data were evaluated by means of the Kruskal-Wallis, Student-Newman-Keuls, and Mann-Whitney tests. RESULTS: In the EasyClean group, the degree of dentinal erosion at 3.0 mm was significantly higher than at 9.0 mm. In the other comparisons, there was no statistically significant difference (P < .05). CONCLUSIONS: The final irrigation techniques tested were equivalent in relation to the degree of erosion caused to the dentinal surface.

Estudo comparativo da radiopacidade de cimentos endodônticos avaliado por meio de sistema radiográfico digital / Evaluation of the radiopacity of endodontic cements using digital radiograph system: comparative study

A radiopacidade e especificação foram avaliadas de acordo com a norma padrão ISO6876/2001. Para a análise da radiopacidade, 10 placas acrílicas foram confeccionadas com seis furos, cada um com 10,0 mm de diâmetro e 2,0 mm de espessura, e preenchidos com cinco cimentos estudados: AH Plus, Endofill, EndoREZ, Sealapex e MTA Fillapex, e como controle foi utilizada guta-percha. Imagens radiográficas digitais dos espécimes foram importadas do software Digora 1.51. Um densitômetro de alumínio foi utilizado como um instrumento de medição da densidade radiográfica na comparação das amostras, e o valor da radiopacidade foi determinado de acordo com essa densidade radiográfica (mmAl). Os resultados foram analisados estatisticamente por Kruskal-Wallis e complementados por StudentNewman-Keuls. Os cimentos testados apresentaram diferenças estatisticamente significativas entre eles (p<0,05). Os valores da radiopacidade dos cimentos em ordem decrescente em escala de alumínio foram os seguintes: AH Plus (14.86), Sealapex (13.50), Endofill (12.87), MTA Fillapex (11.90) e EndoREZ (10.27). Concluiu-se que a maior radiopacidade ocorreu no cimento AH Plus, porém, todos os materiais testados preencheram os requisitos das normas ISO 6876/2001 (AU).

Specification and radiopacity were evaluated according to standard ISO 6876/2001. For the analysis of radiopacity, 10 acrylic plates were made with six holes, each with 10.0 mm diameter and 2.0 mm thick, and filled with the five studied cements: AH Plus, Endofill, EndoREZ, Sealapex, MTAFillapex, and a control guta-percha was used. Digital radiographic images of the specimens were imported from Digora software version 1.51. An aluminum densitometer was used as an instrument for measure the radiographic density in the comparison sample, and the value of optical density was determined in accordance with this radiographic density (mm Al). The results were statistically analyzed using Kruskal-Wallis test and complemented by Student-Newman-Keuls test. The tested cements showed significant statistically differences between them (p < 0.05). The values of the radiopacity of the cement in decreasing scale aluminum were the following: AH Plus (14.86), Sealapex (13.50), Endofill (12.87), MTA Fillapex (11.90), and EndoREZ (10.27). It was concluded that most radiopacity occurred in AH Plus cement, however, all materials tested met the requirements of ISO 6876/2001 standards (AU).

The Effect of Foraminal Enlargement of Necrotic Teeth with the Reciproc System on Postoperative Pain: A Prospective and Randomized Clinical Trial.

INTRODUCTION: The aim of this prospective study was to evaluate the postoperative pain that followed root canal treatments performed with a single-file reciprocating system on asymptomatic uniradicular necrotic teeth with and without foraminal enlargements (FEs). METHODS: Forty-six volunteers were randomly divided into 2 groups according to the established working lengths. The FE group had a working length of 0.0 mm from the apex, and the control group had a working length of 1.0 mm short of the apex. The treatments of both groups were performed with a Reciproc R40 (VDW, Munich, Germany) instrument. Both groups underwent the same treatment protocol with the exception of the established working length. The volunteers were instructed to record their pain (none, mild, moderate, or severe) on a visual analog scale at 24 hours, 72 hours, and 1 week after the procedures. The Kruskal-Wallis test was used to identify significant differences. RESULTS: Overall, 82.22% of the patients indicated no pain or mild pain. A greater proportion of the patients in the FE group reported mild pain compared with patients in the control group in the first 24 hours (P < .05). At 72 hours and 1 week, there were no statistically significant differences between the groups (P > .05). CONCLUSIONS: FEs during endodontic treatments of asymptomatic necrotic, uniradicular teeth that were performed in single visits using the Reciproc R40 reciprocating file resulted in a low incidence of pain. After 24 hours, the FEs resulted in more patients reporting mild pain compared with the control group, but no differences were observed at 72 hours or 1 week.

Effective analysis of the use of peracetic acid after instrumentation of root canals contaminated with Enterococcus faecalis.

INTRODUCTION: The aim of this study was to evaluate the effectiveness of peracetic acid (PAA) in cleaning root canals contaminated with Enterococcus faecalis. METHODS: Sixty first and second mandibular molars were used. Their mesiobuccal canals were prepared with the Reciproc System (VDW, Munich, Germany). The canals were irrigated with 10 mL saline during instrumentation. The teeth were randomly divided into 3 groups (n = 20), according to the irrigation solution to be used after instrumentation: group PAA (5 mL 1% PAA), group EDTA/sodium hypochlorite (NaOCl) (5 mL 17% EDTA followed by 5 mL 2.5% sodium hypochlorite), and group S (5 mL saline). Microbiological samples were collected before instrumentation and after final irrigation. Bacterial quantification was performed by counting the number of colony-forming units (CFUs/mL). The results were analyzed by the nonparametric Wilcoxon and Kruskal-Wallis tests. RESULTS: The 3 groups showed a significant reduction (P < .05) in CFUs/mL after final irrigation. PAA and NaOCl associated with EDTA produced a significantly higher reduction in CFUs/mL (P < .05) compared with saline. There was no statistically significant difference between PAA and EDTA + 2.5% NaOCl (P > .05). CONCLUSIONS: According to the results of the present study, the effectiveness of 1% PAA was similar to that of 17% EDTA + 2.5% NaOCl in cleaning curved root canals contaminated with E. faecalis.

Comparison of the ability to preserve the central axis of a canal after instrumentation using the ProTaper Universal© and EndoWave systems / Comparação da habilidade em preservar o eixo central do canal após instrumentação utilizando os sistemas ProTaper Universal© e EndoWave

O objetivo deste estudo foi comparar ex vivo a capacidade de manutenção do eixo central do canal após a instrumentação com dois sistemas rotatórios de n¡quel titânio: sistema ProTaper Universal© e sistema EndoWave©. Para tanto, foram utilizados para o estudo 20 raízes mesiais de molares inferiores que possuíam canais mesiais separados em todo o eixo longitudinal que foi avaliado antes e depois da instrumentação, usando-se a metodologia de avaliação de imagens transversais das raízes pré e pós-instrumentação proposta por Bramante4 (1987) e modificada por Kuttler14 (2001). Foram realizados os acessos, e os comprimentos de trabalho (CT) foram padronizados em 18.00 mm. As amostras foram incluídas em resina acrílica dentro da mufla. Os dentes foram seccionados a 3, 6 e 9 milímetros do  pice radicular e imagens pré-instrumentação foram obtidas dos cortes transversais através de método fotográfico. As amostras foram remontadas no cubo endodôntico e posteriormente 20 canais foram preparados com o sistema ProTaper Universal© e 20 canais foram preparados com o sistema EndoWave©. Foram realizadas novas imagens pós-instrumentação, que foram sobrepostas e avaliadas por meio do programa AutoCad© para determinar o desvio do eixo central do canal após o preparo endodêntico. Os dados obtidos foram submetidos … análise estatística, através do teste Two-Way ANOVA. O nível de significância foi de 5%. Os canais vestibulares e linguais das seções a 3, 6 e 9 mm do  pice mostraram um leve desvio do eixo central do canal após a instrumentação (0.109 mm para o sistema Protaper Universal© e 0.112 mm para o sistema EndoWave©), porém não houve diferenças estatisticamente significativas no desvio entre os dois sistemas em nenhum nível da raiz. Desta forma, a instrumentação com qualquer um dos dois sistemas pesquisados propiciou a manutenção do eixo central dos canais sem alterações significativas.

The aim of this study was to compare ex vivo the ability to preserve the central axis of a canal after instrumentation with two nickel-titanium rotary systems: ProTaper Universal© and EndoWave©. Twenty mesial roots of mandibular molars with separated mesial roots all along the longitudinal axis were assessed before and after instrumentation using a cross-sectional image assessment methodology for pre and post-instrumentation roots, as proposed by Bramante4 (1987) and modified by Kuttler14 (2001). Accesses were performed, the working length (WL) was standardized to 18.00 mm, and samples were embedded in acrylic resin inside a muffle. The teeth were cut at 3, 6, and 9 mm from the apex and pre-instrumentation images were obtained from cross sections through a photographic method. Samples were reassembled in the endodontic cube and subsequently prepared; 20 canals were prepared with the ProTaper Universal© system, and 20 canals were prepared with the EndoWave© system. New images were taken after instrumentation, which were overlapped and evaluated with AutoCad©, a computer graphics program to determine the deviation from the central axis of the canal after endodontic preparation. Data gathered underwent statistical analysis through the Two-Way ANOVA test. The significance level was 5%. Buccal and lingual canals for those sections at 3, 6, and 9 mm from the apex showed a slight deviation from the central axis of the canal after instrumentation (0.109 mm for the ProTaper Universal© and 0.112 mm for the EndoWave©), but there was no statistically significant differences in deviation between the two systems at any level of the root. Thus, instrumentation with any of the two systems under investigation provided for preservation of the central axis of the canals with no significant changes

Comparação entre os sistemas rotatórios Pathfile + Protaper Universal e Twisted Files quanto à preservação da morfologia e ao tempo de trabalho despendido na preparação de canais curvos / Comparison of preparation time and ability to maintain canal morphology in curved canals: Pathfile + Protaper Universal versus Twisted Files

Introdução: Instrumentos rotatórios em níquel-titânio (NiTi) reduzem erros processuais e o tempo requerido para a preparação do canal radicular. Objetivo: Comparar dois sistemas de instrumentação rotatória NiTi - Pathfile + ProTaper Universal e Twisted Files - quanto à capacidade de preservação da morfologia do canal e quanto ao tempo de trabalho necessário para a preparação de canais curvos. Material e Método: Os canais mesiais de 32 molares inferiores humanos (com ângulos de curvatura entre 20 e 40 graus) foram selecionados para o estudo. As amostras foram divididas aleatoriamente em dois grupos de 16 canais. Os preparos foram realizados por um Endodontista, utilizando-se a combinação dos instrumentos rotatórios Pathfile e ProTaper Universal (grupo PT) e os instrumentos rotatórios Twisted Files (grupo TF). Três Endodontistas analisaram imagens com a técnica da dupla radiografia digital, pré e pós-instrumentação, para avaliar se ocorreu transporte apical e/ou aberrações na morfologia dos canais. Por meio de uma análise computadorizada e com o auxílio de magnificação, as imagens inicial e final do canal radicular foram comparadas por meio de sua sobreposição. O teste de odds ratio foi utilizado para a comparação dos níveis de preservação da morfologia do canal, e ANOVA, complementada pelo teste de Tukey, foi utilizada para a comparação dos tempos de preparo. O nível de significância adotado foi de 5%. Resultado: Ocorreram desvios na trajetória do canal em ambos os grupos, mas a diferença entre estes não foi significativa. O tempo de trabalho requerido pela combinação dos sistemas Pathfile + ProTaper Universal foi significativamente maior do que o requerido pelo sistema Twisted Files. Conclusão: Os dois sistemas apresentaram performances semelhantes em relação à preservação da trajetória do canal; no entanto, o tempo de trabalho requerido pelo sistema Twisted Files foi menor.

Introduction: Nickel-titanium (NiTi) rotary instruments reduce procedural errors and the time required for root canal preparation. The aim of this study was to compare two rotary NiTi instrumentation systems-Pathfile + ProTaper Universal versus Twisted Files-as to their ability to maintain original canal morphology and the time they require to prepare curved root canals. Material and Method: The mesial canals of 32 human mandibular molars (with curvature angles between 20 and 40 degrees) were selected for the study, and divided at random into two groups of 16 canals each. The canals were prepared by an endodontist using either the combination of Pathfile and ProTaper Universal instruments (Group PT) or Twisted Files (Group TF). The double digital radiograph technique, pre- and post-instrumentation, was used by three endodontists to assess whether apical transportation and/or aberration in root canal morphology occurred. The initial and final images of the root canals were compared by superimposition through computerized analysis and with the aid of magnification. The odds ratio test was used to compare root canal morphology preservation, and ANOVA complemented by Tukey's test was used to compare preparation times. The significance level was set at 5%. Result: Deviation in root canal trajectory occurred in both groups, although the differences were not significant. The preparation time required by the Pathfile + ProTaper Universal combination was significantly longer than that required by the Twisted Files system. Conclusion: Both systems showed similar performances regarding the ability to maintain original root canal morphology; however, the preparation time required by the Twisted Files system was shorter.

Comparison of MTA Fillapex radiopacity with five root canal sealers

Introduction: The endodontic sealer is a filling material whose physicochemical properties are mandatory for the achievement of endodontic therapy final goal. An ideal endodontic sealer should have some properties, including radiopacity. Objective: This study compared MTA Fillapex™ radiopacity with the radiopacity of five others endodontic sealers: Endométhasone-N™, AH Plus™, Acroseal™, Epiphany SE™ and RoekoSeal™. Material and methods: Five cylindrical samples of each sealer were used, constructed with the aid of a matrix. On an occlusal film, a sample of each sealer was placed along with an aluminum stepwedge and five radiographic shots were taken. The radiographic images were digitized and each sample's gray scales were compared with each shade of the aluminum stepwedge, by using software. Results: The results, in decreasing order of radiopacity, were: AH Plus™ was statistically the most radiopaque sealer (9.4 mm Al), followed by Epiphany SE™ (7.8 mm Al), MTA Fillapex™ (6.5 mm Al), RoekoSeal™ (5.8 mm Al), Endométhasone-N™ (4.5 mm Al), and Acroseal™, the least statistically radiopaque (3.5 mm Al). Conclusion: It can be concluded that MTA Fillapex™ was the third most radiopaque sealer among all tested sealers. Also, MTA Fillapex™ has the radiopacity degree in agreement with ADA specification No. 57 (1983).