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OBJECTIVE: To evaluate the cleaning potential of 95% ethanol, acetone, and amyl acetate solutions used solely or in association, to remove epoxy resin-based sealer residues from pulp chamber dentin and their microstructural effects. MATERIALS AND METHODS: One hundred and eighty bovine incisor specimens were divided into nine groups according to the cleaning protocol: ET (ethanol); AC (acetone); AA (amyl acetate); E1: AA+AC; E2: AA+ET; E3: AC+ET; E4: AA+AC+ET; PC (positive control), and NC (negative control). All groups were impregnated with epoxy resin-sealer, except NC. Ninety specimens were divided into groups (n = 10) for evaluation of persistence of residues and amount of open dentinal tubules by SEM analysis and evaluation of chemical compounds on the dentin surface after cleaning with electron dispersive spectroscopy. The others 90 specimens were submitted to Knoop microhardness evaluation. Persistence of residues data were submitted to the Kruskal Wallis and Dunn tests (α = 0.05). Open dentinal tubules and microhardness data were submitted to one-way ANOVA and Mann Whitney tests (α = 0.05). RESULTS: AA and E4 protocols showed the lowest persistence of residues. E4 group had the highest incidence of open dentinal tubules. E3 and E4 groups showed no changes in the atomic ratio Ca/P, which was similar to NC group. E4 group did not present W, an element presents in all the other groups. ET and E4 protocols showed the smallest reduction in dentin microhardness. CONCLUSIONS: The combination of amyl acetate, acetone and ethanol is the most effective and safe protocol to remove epoxy sealer residues on pulp chamber dentin. Moreover, it has the lowest microhardness reduction. CLINICAL SIGNIFICANCE: The combined use of amyl acetate, acetone, and ethanol enhanced the cleaning of pulp chamber dentin with minimal microstructural damage.

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This study evaluated the effect of irrigation protocols using 95% ethanol (ET) or 1% peracetic acid (PA) prior the use of 2% chlorhexidine (CHX) compared to distilled water (DW) on the chemical smear layer (CSL) formation and incidence of open dentin tubules at the apical, medium, and cervical third of the post-space dentin. Scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) images were used. Forty bovine roots were endodontically treated. After, post-space preparation was performed and the roots were randomized in four groups (n = 10) according to the irrigation protocol: DW, CHX, CHX-ET and CHX-PA. The chemical composition of CSL and the incidence of open dentin tubules at the post-space thirds were evaluated by EDS (500× magnification) and SEM (2000× magnification) images, respectively. Data from chemical composition of CSL were descriptively analyzed, while the incidence of open dentin tubules was evaluated by scores and submitted to Kruskal-Wallis and Dunn test (p = .05). Cl, Bi, and Si were the chemical elements most found over the dentin after the irrigation with CHX and CHX-ET. Moreover, CHX and CHX-ET showed the highest incidence of CSL (p < .05), but without difference between them (p > .05), regardless of the post-space third. DW and CHX-PA showed similar incidence of CSL (p > .05). No difference on the incidence of open dentin tubules was found for any irrigation protocol and post-space third (p > .05). The use of 1% PA prior the post-space irrigation with CHX decrease the incidence of CSL. RESEARCH HIGHLIGHTS: The post-space irrigation with chlorhexidine results in the formation of chemical smear layer. Ethanol is not capable to remove the chemical smear layer. Peracetic acid is more effective to remove the chemical smear layer.

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OBJECTIVE: The aim of this study was to evaluate the effectiveness of cleansing protocols to remove sealer residues using different cleaning strategies and the effect of bond strength of two universal adhesives to dentin impregnated with epoxy resin-based sealer. MATERIALS AND METHODS: Fifty bovine dentin specimens were impregnated with epoxy resin-based sealer containing calcium hydroxide (Sealer Plus) and submitted to cleansing protocols (n = 10): negative control (NC), positive control (PC), 95% ethanol (ET), xylol (XI), and amyl acetate (AA). Specimens were evaluated by scanning electron microscope (SEM). Other 100 specimens were submitted to the same protocols (n = 20). Each protocol was divided into subgroups (n = 10) according to the universal adhesive system used: Scotchbond Universal (SU); Ambar Universal (AU). Bond strength was evaluated by micro-shear bond test (µSBT). Persistence of residues data were assessed with Kruskal-Wallis and Dunn's tests. µSBT data were analyzed with two-way ANOVA (α = 5%). RESULTS: ET presented higher persistence of residues compared to AA and XI (p < 0.05). AA and XI were similar from each other (p > 0.05). AU and SU presented similar µSBT values, regardless of the cleansing solution (p > 0.05). SU-NC presented the highest µSBT among all conditions (p < 0.05). CONCLUSION: The bond strength of universal adhesives was not affected by different amounts of sealer residues after different cleaning protocols. CLINICAL SIGNIFICANCE: Non-polar substances such as amyl acetate and xylol are effective for removing residues from epoxy resin-based endodontic sealers.

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O presente artigo descreve um caso incomum de canino superior direito com duas raízes. Esse é o quarto caso relatado na literatura. Paciente do sexo feminino, 66 anos de idade, foi encaminhada para tratamento endodôntico do dente #13. A avaliação clínica mostrou que o dente #13 não apresentava resposta após o teste de vitalidade. Radiografias foram realizadas e revelaram que o dente #13 apresentava duas raízes. Em seguida, a paciente foi submetida a tratamento endodôntico. Esse relato de caso é relevante porque descreve uma variação anatômica rara, mas que pode se apresentar na clínica. Por tal motivo, o dentista precisa ter domínio da anatomia normal dos dentes para realizar corretamente o tratamento endodôntico, assim como conhecer as possíveis variações anatômicas, e analisar minuciosamente a radiografia de diagnóstico para ter uma noção individualizada da anatomia do dente a tratar (AU).

This paper describes an unusual case of right maxillary canine with two roots. This is the fourth finding that has been reported in the literature. A 66-year-old female patient was referred to endodontic treatment in the tooth #13. Clinical evaluation showed that tooth #13 presented no response after the vitality test. Radiographs were taken and revealed that the tooth #13 presented two roots. Then, the patient was submitted to endodontic treatment. This case report is relevant because it describes an atypical anatomical variation, but with possible occurrence in endodontic clinical. For this reason, the dentist needs to have knowledge of the normal anatomy of the teeth to correctly perform the endodontic treatment, as well as to know the possible anatomical variations, and to thoroughly analyze the diagnostic radiography to have an individualized notion of the anatomy of the tooth to be treated (AU).

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Objetivo: esse estudo avaliou a incidência de resíduos (debris) na dentina, no espaço preparado para pino de fibra, submetida a um dos seguintes protocolos de irrigação: água destilada (AD); hipoclorito de sódio a 2,5% (HS); hipoclorito de sódio a 2,5% mais EDTA a 17% (HSE); hipoclorito de sódio a 2,5% agitado com irrigação ultrassônica passiva (HSUS). Métodos: os canais radiculares de quarenta incisivos bovinos, com comprimento radicular de 17,0 mm, foram obturados pela técnica do cone único. Após sete dias, um espaço para o pino de fibra foi preparado com brocas de Largo #1 e #2 e broca DC2 (White Post; FGM). Os espécimes foram aleatoriamente distribuídos em quatro grupos (n = 10), de acordo com o protocolo de irrigação usado: AD; HS, HSE ou HSUS. As raízes foram clivadas longitudinalmente e obtidas imagens, em microscopia eletrônica de varredura (500X), da superfície dentinária dos segmentos radiculares cervical e apical do espaço preparado para pino de fibra. Escores foram atribuídos de acordo com a presença de debris. Resultados: no segmento cervical, HSE e HSUS apresentaram menor incidência de debris do que AD e HS (p < 0,05). No segmento apical, HSUS proporcionou a menor incidência de debris na dentina radicular (p < 0,05). Não houve diferença entre os demais protocolos de irrigação, tanto no segmento cervical quanto no apical (p > 0,05). Conclusões: o protocolo HSUS proporcionou menor incidência de debris sobre a superfície dentinária do espaço preparado para pino de fibra (AU).

Objective: The present study evaluated the residues (debris) incidence in dentin fiber post space submitted to irrigation protocols using distilled water (DW), 2.5% sodium hypochlorite (HS), 2.5 % sodium hypochlorite and 17% EDTA (HSE), or 2.5% sodium hypochlorite energized bypassive ultrasonic irrigation (HSUS). Methods: Forty bovine incisors root canals with standardized root length (17.0mm) were obturated using single cone technique and epoxyresin sealer. After 7 days, the fiber post space was prepared using # 1 and # 2 Largo burs, and DC2 (White Post; FGM).The specimens were randomly divided into four groups (n= 10), according to the irrigation protocol: AD; HS, HSE or HSUS. After 48 hours, the roots were sectioned. Cervical and apical segment images were obtained using scanning electron microscopy (500X). Scores were assessed according to debris presence. Results: In cervical segment, HSE and HSUS presented debris incidence lower than DW and HS (P <0.05). DW and HS or HSE and HSUS were similar to each other (P > 0.05). Conclusions: HSUS provided the lower debris incidence in dentin surface of the fiber post space (P < 0.05) (AU).

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AIM: This study aimed to evaluate the cleaning protocol of dentin impregnated with epoxy resin-based sealer (AH Plus) and the effects on the adhesive interface using 95% ethanol (E) or formamide solution (F) associated with microabrasion with glass microparticles (M). METHODOLOGY: Forty dentin specimens were impregnated with sealer (AH Plus). Specimens were cleansed according to the following protocols (n = 10): G1 (E); G2 (F); G3 (E = M); and G4 (F = M). No treatment was performed in G5 (control). Specimens were subjected to standard error of the mean to evaluate the residues persistence (×500) and open dentinal tubules counting (×2000). Another fifty specimens were subjected to similar procedures and cleaning protocols. Seven days later, composite-resin-made specimens were performed on dentin using etch-and-rinse adhesive system, then submitted to microshear test. RESULTS: G2 and G4 showed higher residues' persistence and lower incidence of open dentinal tubules than G1 and G3 (P < 0.05). No difference was found between G1 and G3 or G2 and G4 (P > 0.05). Adhesive system bond strength was similar in all groups (P > 0.05). CONCLUSIONS: Microabrasion negatively affected the epoxy resin-based sealer residues' removal protocols' action; all groups presented residues on the dentin surface. However, 7 days later, the protocols did not affect the bond strength of adhesive system to sealer-impregnated dentin.

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OBJECTIVES: To evaluate the effect of desensitizing agent containing calcium phosphate nanoparticles on the bond strength of etch-and-rinse adhesive system (Scotchbond Multi-Purpose), presence of precipitate, dentinal tubule obliteration and hybrid layer formation in dentin in comparison with potassium nitrate plus sodium fluoride or strontium chloride compounds. METHODS: 150 bovine incisors were treated with (n = 10): G1, Desensibilize Nano P (Ca3(PO4)2+5%KNO3+0.9%NaF); G2, Desensibilize (10%SrCl2+5%KNO3); G3, Desensibilize KF2% (5%KNO3+0.2%NaF); G4, Ultra EZ (3%KNO3+0.25%NaF) and G5, no treated (control). Scanning electron microscopy was used to assess the incidence of precipitates (500×) and obliterated dentinal tubule counts (1.000×). The adhesive system was used after all desensitization treatments. The bond strength (n = 40) and the fracture pattern were evaluated. Confocal laser microscopy was used to quantify the hybrid layer formation in dentin. RESULTS: G1 and G2 presented higher adhesive system bond strength (MPa) than G4 and G5, however no significant differences were observed in comparison with G3. Cohesive fracture was frequently found: G1 (58.5%), G2 (51.3%) and G3 (43.8%). G1 showed the highest incidence of precipitates and the highest number of blocked dentinal tubules. G1 and G2 presented similar hybrid layer formation and the highest hybrid layer formation values. CONCLUSIONS: Desensibilize Nano P (G1) favored the bond strength of the adhesive system to dentin, increased the precipitation of residues, obliteration of dentinal tubules, and hybrid layer formation in comparison with other agents. CLINICAL RELEVANCE: Desensitizers promote dentin obliteration, however, may affect dentin bonding.

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The aim of the study was to evaluate the effects when acid etching on the dentin surface was immediately performed (I) or 7 days (D) after calcium silicate-based sealer (MTA Fillapex) removal, using 95% ethanol (E) or xylol (X). First study, 60 bovine incisor dentin specimens were impregnated with sealer and divided into six groups (n = 10): (EI), E + I; (XI), X + I; (ED), E + D; (XD), X + D, (UN), untreated and (MR), mechanical removal of sealer. Scanning electron microscopy (SEM) images (500×) were obtained from each specimen and scores assessed the sealer residues persistence. Second study, 60 specimens were similarly treated; however, the specimens were restored with composite resin after the removal protocols. Hybrid layer formation was evaluated using confocal laser microscopy (1,024×). Third study, 60 specimens were similarly obtained and subjected to micro-shear test to evaluate the effects of removal protocols on the bond strength of etch-and- rinse adhesive system to dentin. XI showed the highest persistence of sealer residues (p < .05), similar to MR (p > .05). EI showed the greatest hybrid layer extension, except in relation to UN (p < .05). XI and MR presented the lowest bond strength adhesive system to dentin (p < .05). Acid etching immediately after calcium silicate-based endodontic sealer removal using xylol presented the highest residues persistence and negatively affected the adhesive interface between dentin and etch-and-rinse adhesive system.

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STATEMENT OF PROBLEM: The optimal irrigating solution with antimicrobial and dentin cleansing properties for post space preparation for fiber posts is unclear. Peracetic acid is one option but is available in various chemical formulations that require evaluation. PURPOSE: The purpose of this in vitro study was to evaluate dentin surface cleanliness based on the presence of a smear layer and the number of open dentin tubules. It also investigates the chemical composition of residues after canal irrigation with a 1% peracetic acid solution (PA) at low or high concentration of hydrogen peroxide during the preparation of intracanal fiber posts. MATERIAL AND METHODS: After filling the root canals of 40 mandibular incisors, a rotary instrument was used for intracanal preparation to place fiber posts. The teeth were divided into 4 groups (n=10) according to the post space irrigation protocol as follows: CG (control): distilled water; NA (NaOCl): 2.5% sodium hypochlorite; LH: PA with low concentration of hydrogen peroxide; and HH: PA with high concentrations of hydrogen peroxide. After irrigation, the teeth were sectioned, and the intracanal dentin surface was subjected to analysis using energy dispersive spectroscopy to evaluate chemical composition and to scanning electron microscopy (×500) to evaluate the presence of the smear layer. The number of open dentin tubules was measured by scanning electron microscopy analysis (×2000) using photo-editing software. ANOVA and the Tukey test (α=.05) were used to evaluate the data, except for the presence of a smear layer, for which the Kruskal-Wallis and Dunn tests were used (α=.05). RESULTS: The highest concentrations of oxygen in the dentin residues were detected in LH and HH (P<.05); CG and NA showed similar oxygen concentrations (P>.05). NA had a higher concentration of chlorine (P<.05), whereas LH had a lower amount of smear layer and a larger number of open dentin tubules than the other groups (P<.05). These were equivalent to each other (P>.05), except for HH, which also had a larger number of open dentin tubules than CG and NA (P<.05). CONCLUSIONS: PA 1% with a low concentration of hydrogen peroxide yielded a lower amount of smear layer and a larger number of open dentin tubules in the dentin of the post space when compared with PA 1% with a high concentration of hydrogen peroxide, despite maintaining a similar oxygen concentration in these dentin residues.

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