Abstract This study aimed to evaluate the influence of temperature on torsional strength and angular deflection of two experimental NiTi rotary instruments manufactured from Blue and Gold thermal treatments and with identical cross-sections. A total of 40 experimental NiTi instruments 25.06 and with a triangular cross-section and manufactured from Blue and Gold thermal treatments were used (n=20). The torsional test was performed in the 3 mm from the tip of the instrument according to ISO 3630-1. The torsional test evaluated the torsional strength and angular deflection to failure at room temperature (21°C ± 1° C) and body temperature (36°C ±1°C). The fractured surface of each fragment was observed by using scanning electron microscopy (SEM). Data were analyzed using an unpaired t test for inter and intra-group comparison and the level of significance was set at 5%. The results showed that the body temperature did not affect the torsional strength and angular deflection of the instruments when compared with room temperature (P>0.05). However, at body temperature, the Blue NiTi instruments presented significantly lower angular deflection in comparison with Gold NiTi instruments (P<0.05). There was no significant difference regarding the torsional strength of the instruments at body temperature (P>0.05). The temperature did not affect the torsional strength of the instruments manufactured from Blue and Gold technology. However, the Blue NiTi instruments presented significantly lower angular deflection than Gold instruments at 36°C temperature.

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

Abstract Irrigation solutions might affect dentin surface characteristics and, consequently, endodontic sealers adhesion. Objective This study analyzed the effect of different final irrigation protocols on push-out bond strength (BS) of AH Plus to dentin seven days and 20 months after obturation. Scanning electron micrographs were obtained from the dentin surface of one sample/group after final irrigation. Methodology Canals of bovine incisors were instrumented and received final irrigation with (n=21): G1 – 2.5% sodium hypochlorite (NaOCl) + distilled water; G2 – 2.5% NaOCl + 17% EDTA; G3 – 2.5% NaOCl + 17% EDTA + 2.5% NaOCl; G4 – 2.5% NaOCl + 17% EDTA + 2% chlorhexidine (CHX); G5 – mixture 5% NaOCl + 18% etidronate (HEDP); and G6 – mixture 5% NaOCl + 10% tetrasodium EDTA (Na4EDTA). After irrigation, one root/group was split and images were obtained by scanning electron microscopy (SEM). The other 20 roots/group were filled with only AH Plus sealer. Three slices/root were used for push-out assessment seven days and 20 months after obturation. One-way analysis of variance and Tukey (α<0.05) were used to compare the results among experimental groups, and unpaired t-test (α<0.05) was used to compare the results of the same group over time. Results The photomicrographs showed that, excepting G1, all groups completely removed the smear layer from the samples. In G2 and G4, the opening of the dentin tubules enlarged. In G3, erosion was observed in the peritubular and intertubular dentin. Values of the BS in the seven days were G2=G3=G4=G5>G6=G1 and in the 20 months were G3=G5>G6=G4>G1=G2. G3, G5, and G6 presented values of BS in 20 months similar to the values of seven days (P>0.05). Conclusions The final irrigation protocols tested produced dentin surfaces with different characteristics. Only G3 and G5 presented high BS values that were stable over time.

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

Resumo A proposição deste estudo foi avaliar o pH, solubilidade e ação antimicrobiana da pasta de Hidróxido de Cálcio (HC), Pasta Diantibiótica (metronidazol+ciprofloxacina-DAP), Hidróxido de Cálcio adicionado a DAP (HC/DAP) e pasta Triantibiótica (metronidazol + ciprofloxacina + miociclina - TAP). a medição do pH e liberação de íons cálcio (n=10) foram avaliadas através de peagômetro e espectofotômetro de absorção atômica. Canais de dentes de acrílico (n=10) foram preenchidos com as medicações de canal mencionadas, imersos em água ultrapura e a solubilidade foi aferida pela diferença entre o volume inicial e final (7,15 e 30 dias) usando micro tomografia computadorizada. O biofilme de Enterococcus faecalis foi induzido em blocos de dentina bovina (n=20) e tratados com as pastas em questão por 7 dias. A porcentagem de bactérias vivas foi verificada usando o microscópio confocal com corante LIVE/DEAD. HC e HC/DAP apresentaram os maiores valores de pH e liberação de íons cálcio. A respeito da solubilidade, depois de 7 dias, os grupos com pastas antibióticas apresentaram perda de volume significante. HC e HC/DAP não tiveram diferenças estatísticas com o grupo controle na ação antimicrobiana contra biofilme. No entanto, a TAP e a DAP mostraram porcentagem significante de redução bacteriana. Conclusões: Devido à alta solubilidade das pastas, renovar as medicações antibióticas a cada 7 dias ou usa-las por esse período em protocolos regenerativos é recomendado. DAP é indicada para matar E. faecalis na forma de biofilme porque tem ação antimicrobiana similar a TAP. A adição do CH à DAP reduz significantemente sua ação antimicrobiana. Apesar da baixa solubilidade e altos valores de pH, a pasta de CH apresenta baixa ação antimicrobiana contra E. faecalis em biofilme.

Abstract: The purpose of this study was to evaluate the pH, solubility and antimicrobial action of Calcium Hydroxide Paste (CH), Double Antibiotic Paste (metronidazole+ciprofloxacin-DAP), calcium hydroxide added to DAP (CH/DAP) and Triple Antibiotic Paste (metronidazole + ciprofloxacin+minocycline-TAP). pH (n=10) were measured by pHmeter. Root canals of acrylic teeth (n=10) were filled with the above-mentioned intracanal-dressings, immersed in ultrapure water, and solubility was measured by the difference between the initial and final volume (7,15 and 30 days) by using micro-computed tomography. Enterococcus faecalis biofilm was induced on bovine dentin disc surfaces (n=20), and treated with the pastes for 7 days. Percentage bacterial viability was verified by confocal microscope, with LIVE/DEAD dye. CH and CH/DAP presented the highest pH values. Regarding solubility, after 7 days, antibiotic groups presented significant volume loss. CH and CH/DAP showed no statistical difference compared with the Control in antimicrobial action against E. faecalis biofilm. However, TAP and DAP presented a significant percentage reduction in bacterial population. Due to high solubility of the pastes, renewing antibiotic dressings every 7 days, or using the medications for this period in regeneration protocols is recommended. DAP is indicated for killing E. faecalis in biofilm because it has antimicrobial action similar to TAP. Adding Calcium Hydroxide to DAP significantly decreased its antimicrobial action. In spite of its the low solubility and high pH values, the CH paste showed a low level of antimicrobial action against E. faecalis in biofilm.

Abstract Objective This study aimed to analyze the following physicochemical properties: radiopacity, final setting time, calcium release, pH change, solubility, water sorption, porosity, surface morphology, and apatite-forming ability of two calcium silicate-based materials. Material and methods We tested MTA Repair HP and MTA Vitalcem in comparison with conventional MTA, analyzing radiopacity and final setting time. Water absorption, interconnected pores and apparent porosity were measured after 24-h immersion in deionized water at 37°C. Calcium and pH were tested up to 28 d in deionized water. We analyzed data using two-way ANOVA with Student-Newman-Keuls tests (p<0.05). We performed morphological and chemical analyses of the material surfaces using ESEM/EDX after 28 d in HBSS. Results MTA Repair HP showed similar radiopacity to that of conventional MTA. All materials showed a marked alkalinizing activity within 3 h, which continued for 28 d. MTA Repair HP showed the highest calcium release at 28 d (p<0.05). MTA Vitalcem showed statistically higher water sorption and solubility values (p<0.05). All materials showed the ability to nucleate calcium phosphate on their surface after 28 d in HBSS. Conclusions MTA Repair HP and MTA Vitalcem had extended alkalinizing activity and calcium release that favored calcium phosphate nucleation. The presence of the plasticizer in MTA HP might increase its solubility and porosity. The radiopacifier calcium tungstate can be used to replace bismuth oxide.

RESUMO Objetivo: Avaliar a influência do preparo cervical utilizando a broca LA-Axxess nº 1 (SybronEndo, Glendora, EUA) ou os instrumentos ProTaper S1 e SX (Dentsply Maillefer, Ballaigues, Suíça) na precisão dos Localizadores Apicais Eletrônicos (LAEs): Root ZX mini (J. Morita Corporation, Tóquio, Japão) e Joypex 5 (Denjoy, Changsha, China). Métodos: Trinta incisivos inferiores foram acessados e o comprimento do canal radicular (CCR) determinado com uma lima K #15 com o auxílio de um estereomicroscópio. Em seguida, os dentes foram distribuídos em dois grupos (n=15) referentes ao preparo cervical com LA-Axxess ou instrumentos ProTaper. Os dentes foram incluídos em alginato e o CCR determinado pelos LAEs antes e após o preparo cervical. Os dados foram classificados em: precisos, se a diferença na medida do CCR era ≤ 0,05 mm; e imprecisos, se a diferença era >0,5 mm ou estava além do CCR. Resultados: O teste de McNemar (α<0.05) foi utilizado para detectar diferenças na precisão dos LAEs antes e após o preparo com os diversos instrumentos, e para detectar diferenças na precisão entre os aparelhos. Não foram identificadas diferenças na precisão entre os dois LAEs (P>0,05) após o preparo cervical, indiferente do instrumento utilizado. Conclusão: O preparo cervical aumentou o número de medições precisas dos LAEs, com diferença estatística para Joypex 5 após o uso da LA-Axxess, contudo os aparelhos apresentaram precisão similar após o preparo cervical, indiferente do instrumento utilizado.

ABSTRACT Objective: This study was aimed at evaluating the influence of cervical preflaring using LA-Axxes No. 1 bur (SybronEndo, Glendora, USA) or S1 and SX ProTaper files (Dentsply Maillefer, Ballaigues, Switzerland) on the accuracy of the Electronic Apex Locators (EALs): Root ZX mini (J. Morita Corporation, Tokyo, Japan), and Joypex 5 (Denjoy, Changsha, China). Methods: Thirty mandibular incisors were accessed, and the root canal length (RCL) was determined with a K-file #15, with the aid of a stereo microscope. Afterwards, the specimens were divided into 2 groups (n = 15) referring to the cervical preflaring with LA-Axxess or ProTaper files. The teeth were embedded in alginate and the RCL was determined by the EALs before and after preflaring. Data were classified into: accurate, if the difference in RCL measurement were ≤0.05 mm; and inaccurate, if the difference were >0.5 mm or beyond the RCL. Results: McNemar's test (α<0.05) was used to detect differences in the accuracy of the EALs before and after each preflaring with different instruments, and to detect difference in accuracy among devices. No differences were found concerning the accuracy of the EALs (P > 0.05) after the cervical preflaring, regardless of the used instrument. Conclusion: The preflaring procedure increased the number of accurate measurements for both EALs, with statistical difference for Joypex 5 when the preflaring was performed with LA-Axxess. However, after the cervical preflaring, the EALs showed similar accuracy, regardless of the used instrument.

ABSTRACT The knowledge of the internal anatomy of three-rooted mandibular molars may help clinicians to diagnose and plan the root canal treatment in order to provide adequate therapy when this variation is present. Objectives: To determine the prevalence of three-rooted mandibular molars in a Brazilian population using cone beam computed tomography (CBCT) and to analyze the anatomy of mandibular first molars with three roots through micro-CT. Material and Methods: CBCT images of 116 patients were reviewed to determine the prevalence of three-rooted first mandibular molars in a Brazilian subpopulation. Furthermore, with the use of micro-CT, 55 extracted three-rooted mandibular first molars were scanned and reconstructed to assess root length, distance between canal orifices, apical diameter, Vertucci's classification, presence of apical delta, number of foramina and furcations, lateral and accessory canals. The distance between the orifice on the pulp chamber floor and the beginning of the curvature and the angle of canal curvature were analyzed in the distolingual root. Data were compared using the Kruskal-Wallis test (α=0.05). Results: The prevalence of three-rooted mandibular first molars was of 2.58%. Mesial roots showed complex distribution of the root canal system in comparison to the distal roots. The median of major diameters of mesiobuccal, mesiolingual and single mesial canals were: 0.34, 0.41 and 0.60 mm, respectively. The higher values of major diameters were found in the distobuccal canals (0.56 mm) and the lower diameters in the distolingual canals (0.29 mm). The lowest orifice distance was found between the mesial canals (MB-ML) and the highest distance between the distal root canals (DB-DL). Almost all distal roots had one root canal and one apical foramen with few accessory canals. Conclusions: Distolingual root generally has short length, severe curvature and a single root canal with low apical diameter.

ABSTRACT Sodium hypochlorite (NaOCl) remains the most used irrigation solution during root canal preparation because of characteristics such as wide-spectrum antimicrobial activity and organic tissue dissolution capacity. However, these solutions can alter dentin composition and there is no consensus on the optimal concentration of NaOCl to be used. Objectives To determine the organic matter dissolution and changes in dentin chemical composition promoted by different concentrations of NaOCl over time. Material and Methods: Fragments of bovine muscle tissue were weighed before and after 5, 10, and 15 min of immersion in the groups (n=10): G1- 0.9% saline solution; G2- 1% NaOCl; G3- 2.5% NaOCl; and G4- 5% NaOCl. Bovine dentin fragments were subjected to the same irrigants and absorption spectra were collected by Attenuated Total Reflectance of Fourier Transform Infrared Spectroscopy (ATR-FTIR) before and after 0,5, 1, 2, 3, 5, 8, and 10 min of immersion in the solutions. The ratios of the amide III/phosphate and carbonate/phosphate absorption bands were determined. The tissue dissolution and carbonate/phosphate ratios were submitted to the two-way analysis of variance (ANOVA) with Tukey’s multiple-comparison test (α<0.05) and to the one-way analysis of variance with Tukey’s (α<0.05). The amide III/phosphate ratio was analyzed by Friedman test (α<0.05) and the Kruskal-Wallis test with Dunn’s post-hoc (α<0.05). Results The increase in NaOCl concentration and contact time intensified the dissolution of organic matter and dentin collagen with reduction in the amide III/phosphate ratio. Significant differences between all groups (p<0.05) were observed in the dissolution of organic matter at 10 min and in the amide III/phosphate ratio between the saline solution and 5% NaOCl at 5 min. The carbonate/phosphate ratio decreased significantly in G2, G3, and G4 after 0,5 min of immersion (p<0.05), but more alterations did not occur in the subsequent periods (p>0.05). Intergroup differences were not observed in this ratio (p>0.05). Conclusions The increase in the exposure time and in the concentration of NaOCl solution lead to an increase in the tissue dissolution and dentin collagen deproteination. Furthermore, some carbonate ions are removed from the dentin inorganic phase by the NaOCl.

ABSTRACT Objectives To evaluate the sealing ability of three root-end filling materials (white MTA, CPM, and MBPc) using an Enterococcus faecalis leakage model. Material and Methods Seventy single-root extracted human teeth were instrumented and root-ends were resected to prepare 3 mm depth cavities. Root-end preparations were filled with white MTA, CPM, and MBPc cements. Enterococcus faecalis was coronally introduced and the apical portion was immersed in BHI culture medium with phenol red indicator. The bacterial leakage was monitored every 24 h for 4 weeks. The statistical analysis was performed using the Wilcoxon-Gehan test (p<0.05). Results All cements showed bacterial leakage after 24 hours, except for the negative control group. The MBPc showed significantly less bacterial leakage compared with the MTA group (p<0.05). No significant differences were found between the CPM and the other groups. Conclusions The epoxy resin-based cement MBPc had lower bacterial leakage compared with the calcium silicate-based cements MTA and CPM.

Objective: To evaluate the response of rat subcutaneous tissue in implanted polyethylene tubes that were filled with GMTA Angelus and Portland cements containing different arsenic concentrations. Material and Methods: Atomic absorption spectrophotometry was utilized to obtain the values of the arsenic concentration in the materials. Thirty-six rats were divided into 3 groups of 12 animals for each experimental period. Each animal received two implants of polyethylene tubes filled with different test cements and the lateral of the tubes was used as a control group. After 15, 30 and 60 days of implantation, the animals were killed and the specimens were prepared for descriptive and morphometric analysis considering: inflammatory cells, collagen fibers, fibroblasts, blood vessels and other components. The results were analyzed utilizing the Kuskal-Wallis test and the Dunn's Multiple test for comparison (p<0.05). Results: The materials showed, according to atomic absorption spectrophotometry, the following doses of arsenic: GMTA Angelus: 5.01 mg/kg, WPC Irajazinho: 0.69 mg/kg, GPC Minetti: 18.46 mg/kg and GPC Votoran: 10.76 mg/kg. In a 60-day periods, all specimens displayed a neoformation of connective tissue with a structure of fibrocellular aspect (capsule). Control groups and MTA Angelus produced the lower amount of inflammatory reaction and GPC Minetti, the highest reaction. Conclusions: There was no direct relationship between the concentration of arsenic present in the composition of the materials and the intensity of the inflammatory reactions. Higher values, as 18.46 mg/kg of arsenic in the cement, produce characteristics of severe inflammation reaction at the 60-day period. The best results were found in MTA angelus.

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

Objective To evaluate the biocompatibility and the setting time of Portland cement clinker with or without 2% or 5% calcium sulfate and MTA-CPM. Material and Methods Twenty-four mice (Rattus norvegicus) received subcutaneously polyethylene tubes filled with Portland cement clinker with or without 2% or 5% calcium sulfate and MTA. After 15, 30 and 60 days of implantation, the animals were killed and specimens were prepared for microscopic analysis. For evaluation of the setting time, each material was analyzed using Gilmore needles weighing 113.5 g and 456.5 g, according to the ASTM specification Number C266-08 guideline. Data were analyzed by ANOVA and Tukey's test for setting time and Kruskal-Wallis and Dunn test for biocompatibility at 5% significance level. Results Histologic observation showed no statistically significant difference of biocompatibility (p>0.05) among the materials in the subcutaneous tissues. For the setting time, clinker without calcium sulfate showed the shortest initial and final setting times (6.18 s/21.48 s), followed by clinker with 2% calcium sulfate (9.22 s/25.33 s), clinker with 5% calcium sulfate (10.06 s/42.46 s) and MTA (15.01 s/42.46 s). Conclusions All the tested materials showed biocompatibility and the calcium sulfate absence shortened the initial and final setting times of the white Portland cement clinker.

OBJECTIVES: To compare, in vivo, the accuracy of conventional and digital radiographic methods in determining root canal working length. MATERIAL AND METHODS: Twenty-five maxillary incisor or canine teeth from 22 patients were used in this study. Considering the preoperative radiographs as the baseline, a 25 K file was inserted into the root canal to the point where the Root ZX electronic apex locator indicated the APEX measurement in the screen. From this measurement, 1 mm was subtracted for positioning the file. The radiographic measurements were made using a digital sensor (Digora 1.51) or conventional type-E films, size 2, following the paralleling technique, to determine the distance of the file tip and the radiographic apex. RESULTS: The Student "t" test indicated mean distances of 1.11 mm to conventional and 1.20 mm for the digital method and indicated a significant statistical difference (p<0.05). CONCLUSIONS: The conventional radiographic method was found to be superior to the digital one in determining the working length of the root canal.

OBJECTIVE: This study compared the influence of three epoxy resin-based sealers with distinct radiopacities on the observers' ability to detect root canal filling voids during radiographic analysis. MATERIAL AND METHODS: The root canals of 48 extracted maxillary canines were prepared and divided into three groups. Each group was laterally condensed with one sealer (AH Plus®, Acroseal® or a non-radiopaque sealer), and a longitudinal void was simulated in half of the specimens from each group (n=8). Buccolingual radiographs were obtained and randomly interpreted for voids by a radiologist and an endodontist in a blinded fashion. Teeth were cut and inspected under a microscope to confirm the position of void. Differences in sensitivity and specificity between groups and examiners were compared using the Fisher's Exact and McNemar tests, respectively (α=0.05). RESULTS: Significantly lower sensitivity levels (p<0.05) were observed in the coronal portion of fillings performed with both radiopaque sealers. Specificity values for Acroseal® were significantly higher (p<0.05) in the coronal and apical portions of fillings. CONCLUSIONS: The type of root canal sealer can affect the observers' ability to detect root canal filling voids during radiographic analysis of upper single-rooted teeth.

O objetivo deste estudo laboratorial foi avaliar comparativamente a adaptação na interface obturação/dentina em canais mesiais de molares inferiores obturados com System B, tanto com guta percha/ThermaSeal Plus como com Resilon/Real Seal SE. Os canais mesiais de 60 molares inferiores foram modelados utilizando o sistema rotatório K3, realizando o batente apical com o instrumento 35,04. Em seguida os canais foram obturados com guta percha/ThermaSeal Plus (n=15) e com Resilon/Real Seal SE (n=15) por meio do System B. Obturações com a técnica do cone único utilizando os dois materiais foram empregadas como controle. Os cimentos foram corados com Rodamina B e os dentes obturados foram seccionados a 2, 4 e 6 mm do ápice. A adaptação da interface marginal foi avaliada utilizando a microscopia confocal. A análise estatística foi realizada empregando o teste Kruskall-Wallis (p<0,05). De modo geral, a análise microscópica mostrou um padrão regular na distribuição de fendas na interface cimento-dentina, principalmente para os dois grupos com cimento Real Seal SE. Sendo que os outros dois grupos (com ThermaSeal Plus), apresentaram uma quantidade significativamente menor de áreas com fendas, independentemente da técnica de obturação (p<0,05). A melhor adaptação marginal foi observada quando se utilizou guta percha e o cimento à base de resina epóxica, tanto com o System B como com cone único.

The aim of this laboratory study was to compare the interfacial adaptation of an epoxy-resin and a self-etch sealer in mesial root canals of mandibular molars filled using the System-B/Elements Obturation Unit. Sixty mesial root canals of mandibular molars were prepared using the K3 rotary system up to 35.04 instrument and then filled with the aid of the System-B/Elements Obturation Unit using either gutta-percha/ThermaSeal Plus (n=15) or Resilon/Real Seal SE (n=15). The single cone technique using both materials was used as control. The sealers were stained with Rhodamine B dye and the teeth were filled and sectioned at 2, 4 and 6 mm from the apex. The interfacial marginal adaptation of sealers was evaluated using confocal microscopy. Statistical analyses were performed by the Kruskall-Wallis test (α=0.05). In general, microscopic analysis showed a quite regular gap distribution pattern at sealer-dentin interfaces, mainly for the two groups filled with Real Seal SE. This means that both nonbonding root-filling groups (ThermaSeal Plus) showed significantly higher amount of gap-free regions regardless of the filling technique (p<0.05). Better marginal adaptation was obtained with gutta-percha and epoxy resin-based sealer using either the system B or the single cone technique.