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.

The effect of root canal preparation tapers on planktonic bacteria and biofilm reduction in the apical third: A correlative microtomography and microbiological laboratory study.

AIM: To evaluate the influence of different preparation tapers on the reduction in planktonic bacteria and biofilms of Enterococcus faecalis and Candida albicans in the apical third (4 mm) of the mesial roots of mandibular molars, correlating decontamination with canal shape. METHODOLOGY: After microtomography analysis for morphological standardization of the canals, 48 mandibular molar roots, each containing two canals (96 canals), were contaminated with E. faecalis and C. albicans and divided into four groups (n = 11) for canal instrumentation using ProDesign Logic 2 files with different tapers G (.03): # 25.03; G (.04): # 25.04; G (.05): # 25.05; and G (.06): # 25.06 and irrigation with 2.5% sodium hypochlorite. Four roots were examined under a scanning electron microscope (SEM) to qualitatively assess biofilm formation. Eight roots were used as the negative control group (samples were not contaminated). Bacteriological samples were taken exclusively from the apical third of the roots before and after chemical-mechanical preparation and bacterial counts were determined (CFU/mL). The final micro-CT scan was used to quantify the volume variation and unprepared canal area in the apical third. Statistical analysis was performed using the Kruskal-Wallis, Student-Newman-Keuls and Wilcoxon tests for analysis of microbiological data. anova and the Tukey or Games-Howell test were used for analysis of micro-CT data and Spearman's test for correlations (α = 5%). RESULTS: All groups showed a significant reduction in bacteria (p < .05), with no statistically significant difference between groups. There was no significant difference in per cent volume increase between groups. The unprepared area (Δ%) was affected by the file used (p = .026) and was significantly lower for G (.06) compared to G (.03). There was no statistically significant correlation among bacterial reduction, volume and unprepared area (p > .05). CONCLUSION: The different preparation tapers influenced root canal shaping in the apical third but did not improve decontamination in this region.

Effect of obturation technique on dentinal tubule penetration of two tricalcium silicate-based sealers: Ex vivo study.

The aim of this study was to assess by confocal laser microscope the depth of dentinal tubule penetration of two tricalcium silicate-based sealers promoted by two obturation techniques in curved canals compared with AHPlus. One hundred and twenty canals were divided into six groups (n = 20): BCSC-Bio-C Sealer (BC) and single-cone technique (SC); BCCW-BC and continuous condensation wave (CW); TFSC-Total Fill (TF) and SC; TFCW-TF and CW; AHSC-AH Plus (AH) and SC; AHCW-AH and CW. Data were analysed using the three-way ANOVA and Tukey's test (α = 5%). Penetration depth was significantly greater for TFCW than TFSC and greater for AHCW than AHSC (p < 0.05). There was no significant difference between BCCW and BCSC (p > 0.05). The penetration of TF was significantly greater (p < 0.05). The CW technique promoted greater intratubular penetration, except for the BC sealer.

Analysis of the penetration of NaOCl 5.25% into dentinal tubules using different irrigation protocols: An ex vivo study.

The objective of the study was to investigate the 5.25% sodium hypochlorite (NaOCl) penetration into the dentinal tubules after different irrigation methods. Seventy canines were stained with 1% crystal violet and divided into groups (n = 20): GEC-EasyClean; GPUI-E1 Irrisonic ultrasonic insert; GXP-XP-Endo finisher; GPC-conventional irrigation and GNC-stained tooth without irrigation. Axial sections (16×) were assessed and irrigant penetration was quantified as a bleaching halo on the surface of the apical, middle and coronal third. In the apical third, GPUI promoted greater NaOCl penetration (p < 0.05). GXP was better than GEC (p < 0.05), as was GPC (p > 0.05). The GPUI and GXP groups were similar in the middle and coronal third (p > 0.05). GPUI and GXP showed better results than GEC (p < 0.05). GPUI was more effective in the apical third and like GXP in the cervical and middle third.

Evaluation of the Ability of 3 Reciprocating Instruments to Remove Obturation Material: A Micro-Computed Tomography Study.

INTRODUCTION: The purpose of this study was to evaluate the ability of the Reciproc, Reciproc Blue, and WaveOne Gold systems to remove filling material during endodontic retreatment of extracted human mandibular premolars. METHODS: Thirty-nine teeth were instrumented with the Protaper Universal System to the F3 file and filled with the Tagger hybrid technique using an F3 gutta-percha cone and AH Plus cement. At the end of this period, the teeth were scanned with micro-computed tomography before and after removal of the filling material from the root canals. The teeth were divided into 3 groups (n = 13) based on the apical volume, depending on the systems used to remove the filling material. Group GR: Reciproc 40/.06; Group GRB: Reciproc Blue 40/.06; and Group GWG: WaveOne Gold 35/.06. The results were statistically analyzed using the tests of Kruskal-Wallis, Duncan, and analysis of variance at a significance level of 5%. RESULTS: The results showed that there were no significant differences between the amounts of filling material removed, either for the apical and middle regions alone or in the overall evaluation for the 3 groups (P = .97). The time evaluation statistically showed that the GR and GWG groups required less time to clean the root canals than the GRB group. CONCLUSIONS: Reciproc R40 files and WaveOne Gold Medium files required less time for endodontic treatment than Reciproc Blue R40 files. There was no difference in the ability to remove obturation material between the 3 instruments. No instrument was able to completely remove the filling material from the root canals.

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.

Internal morphology of distal roots of mandibular first molars revealed by computed microtomography.

To evaluate the internal morphology of 100 distal roots of mandibular first molars using micro-CT. Teeth were scanned to characterise: Vertucci type, root length, canal shape, presence and location of accessory canals, and the number of foramina at 4 mm from the apex, presence of root isthmus and the length from the primary canal to the apical foramen. Vertucci type I was found in 57% of cases, followed by V (27%). The most common cross-section 1 mm from the apex was oval (49%) and circular (38%). The average root length was 16.06 mm (16.61-19.02 mm). The mean foramen size was 0.32 and 0.53 mm for the minor and major diameters, respectively. The volume, surface area and SMI were 7.84 mm3 , 68.87 mm2 and 1.52 mm, respectively. Root isthmi were found in 47% of the samples, and the length mean from the primary canal to the apical foramen was 2,03 mm. The internal morphology of the distal roots of mandibular first molars may be complex and shows variations.

Evaluation of antimicrobial activity against Enterococcus faecalis of activated chelating agents in different final rinse protocols: An ex vivo study.

Background: To evaluate the antimicrobial activity of the following chelating agents against Enterococcus faecalis using quantitative polymerase chain reaction (qPCR) analysis: 1% peracetic acid (PA), 1% peracetic acid with 0.1% cetrimide (PAC), and 17% ethylenediaminetetraacetic acid (EDTA) activated by passive ultrasonic irrigation (PUI) or with Easy Clean (EC), all followed by 2.5% sodium hypochlorite (NaOCl). Material and Methods: A total of 80 permanent human mandibular premolars were randomly divided into eight experimental groups according to the chemical solution and agitation protocol used: Group PA + PUI; Group PA + EC; Group PAC + PUI; PAC + EC; group EDTA + PUI; EDTA + EC, all followed by 2.5% NaOCl; and two control groups with saline solution(NaCl): NaCl + PUI and NaCl + EC. Microbial samples were collected before (S1) and after the irrigation protocol (S2). Intracanal E. faecalis reduction analysis was performed by qPCR. Intragroup analysis was performed using the Wilcoxon signed-rank test for paired data, and intergroup analysis was performed using the Wilcoxon Mann-Whitney U test for independent samples. The significance level was set at p< 0.05. Results: A significant difference was found between S1 and S2 in all groups except NaCl+ EC (p = 0.1602). Comparison between groups showed that PAC + PUI was significantly different from PA +EC (p = 0.0448). Conclusions: The activated chelating agents were effective against E. faecalis, with significant results compared to the control groups. The peracetic acid with cetrimide activated by PUI showed better results than peracetic acid with EC. Key words:Easy clean, Final irrigation protocols, Passive ultrasonic irrigation, Peracetic acid.

Effect of obturation technique on penetration of calcium silicate-based sealer into dentinal tubules after endodontic retreatment of mandibular premolars.

OBJECTIVE: Confocal laser scanning microscopy (CLSM) was used to investigate the penetration of endodontic sealers into the dentinal tubules after retreatment using two different obturation techniques. MATERIALS AND METHODS: Thirty mandibular premolars were prepared up to instrument F3 (ProTaper Universal, Dentsply) and filled with Endofill using the single cone technique. The canals were retreated using Mtwo instruments. Reobturation was performed with the Bio-C sealer mixed with a fluorophore dye (Fluo-3) using either the lateral condensation technique (group LC) or the single cone technique (group SC) (n = 15). Teeth were sectioned 2, 4, and 6 mm from the apex and analyzed with CLSM to assess the penetration of the sealer into the canal perimeter and the maximum depth of penetration of the sealer into the dentinal tubules. Data were analyzed using ANOVA and the Student-t and Holm-Sidak tests. RESULTS: In the apical segment, the penetrated perimeter was significantly higher in the LC group than in the SC group (p < 0.05); no significant difference was found in the middle and cervical segments (p > 0.05). In terms of penetration depth, no significant differences were found for any of the segments studied (p > 0.05). CONCLUSION: The LC technique promoted a higher percentage of canal circumference penetrated by the sealer than the SC technique in the apical segment after endodontic retreatment. CLINICAL RELEVANCE: CLSM demonstrated that the LC technique promoted a higher percentage of canal perimeter penetrated by the Bio-C sealer than the SC technique in the apical segment of mandibular premolars after retreatment.

Influence of Sodium Hypochlorite and Chlorhexidine on the Dynamic Cyclic Fatigue Resistance of XP Endo Shaper Instruments.

OBJECTIVE: This study evaluated the dynamic cyclic fatigue resistance of the XP-Endo Shaper (XPS), associated with chlorhexidine digluconate (CHX) or sodium hypochlorite (NaOCl) in two different formulations: gel (G) or liquid (L). MATERIALS AND METHODS: Sixty XPS were used in an artificial stainless-steel canal, and the files were fully immersed in the irrigating solution throughout the experiment until the fracture. The files were divided into six groups (n = 10) based on the irrigation solution used: NaOCl(L), NaOCl(G), CHX(L), CHX(G), natrosol gel (NAT) (control), and lubricating oil (LO) (control). The artificial canal was manufactured 1.5 mm wide, 20 mm long, and, 3.5 mm deep with a straight cervical segment measuring 14.29 mm; an apical segment of 4.71 mm with 3 mm radius; and 90 degrees of curvature apical 1 mm long straight segment. Resistance to cyclic fatigue was determined by recording the number of cycles to fracture (NCF). RESULTS: The CHX(G), CHX(L), and OIL (LO) groups showed no significant difference between them and presented longer time to fracture (p > 0.05). NaOCl(L) shows the lowest NCF without significant differences between NaOCl(G) and NAT. The NCF of the NaOCl(G) was statistically similar to the CHX(L) and statistically lower than the CHX(G) and OIL groups. NAT did not present a statistical difference of the NaOCl(L), NaOCl(G), and presented a significantly lower NCF than the CHX(G) (p < 0.01). CONCLUSION: The use of CHX(G) resulted in increased cyclic fatigue resistance of the XPS instruments compared to NaOCl or LO.

The Effectiveness of Three Irrigation Systems in the Enterococcus faecalis Reduction after Instrumentation with a Reciprocating Instrument.

OBJECTIVE: This study aimed to analyze the effectiveness of three irrigation systems: EndoActivator, passive ultrasonic irrigation (PUI), and Easy Clean in the reduction of Enterococcus faecalis, after instrumentation with the reciprocating system, through microbiological collection and culture method. MATERIALS AND METHODS: A total of 60 extracted human lower premolars were used and standardized at 16 mm in length. The teeth were accessed, contaminated with E. faecalis, and incubated for 21 days at 37°C. Initial collections (S1) were made with an absorbent paper cone to confirm the contamination; subsequently, instrumentation was performed with WaveOne Primary. The teeth were divided into four groups according to the final irrigation protocol (n = 15): group 1. EndoActivator; group 2, PUI; group 3, Easy Clean; and group 4, control group irrigated with saline solution sterile and without agitation. In the final irrigation, the agitation of the 17% ethylene amine tetra-acetic acid (EDTA) solutions was used, then 2.5% sodium hypochlorite (NaOCl); in both for this, three cycles of 20 seconds each. After the chemical-mechanical preparation and agitation of the irrigating solutions, the final collections (S2) for counting the colony-forming units (CFU/mL) occurred. RESULTS: The Kruskal-Wallis test revealed that all the agitation systems reduced by 100% and the control group by 65.7%. CONCLUSION: The control group presented a significantly higher amount of CFU/mL after the chemical-mechanical preparation than the other groups, which were similar to each other (p > 0.05).

Procedimento endodôntico regenerativo usando fibrina rica em plaquetas e leucócitos associada à cirurgia apical: relato de caso / Regenerative endodontic procedure using leukocyte- and platelet-rich fibrin associated with apical surgery: case report

ntrodução: A cirurgia parendodôntica é uma alternativa ao tratamento endodôntico convencional, principalmente em casos envolvendo lesões perirradiculares associadas a processos osteolíticos, em que a terapia endodôntica convencional ou seu retratamento não obtiveram sucesso. Novos métodos terapêuticos têm ganhado espaço na clínica odontológica para esse tipo de caso, entre os quais se destaca a fibrina rica em plaquetas e leucócitos, que, ao concentrar e permitir uma liberação mais prolongada dos fatores de crescimento, promove uma modulação do processo reparador. Esse processo é baseado na otimização da regeneração tecidual através da inserção da membrana de fibrina. Objetivo: O objetivo do presente trabalho é apresentar, por meio do relato de um caso clínico, a utilização de fibrina rica em plaquetas e leucócitos em cirurgia parendodôntica, com intuito de reparo ósseo. Resultados: O acompanhamento clínico e tomográfico foi realizado após 190 dias, momento no qual foi constatada ausência de sintomatologia, bem como completo reparo da lesão e restabelecimento do osso cortical vestibular, além de ausência de lesão detectável em tomografia. Conclusão: No caso clínico relatado, houve uma completa regeneração tecidual da área envolvida na lesão (AU).

Introduction: Parendodontic surgery is an alternative to conventional endodontic treatment, especially in cases involving periradicular lesions associated with osteolytic processes, in which conventional endodontic therapy or retreatment was not successful. New therapeutic methods for the treatment of these cases have ground in clinical dentistry . For example, leukocyteand platelet-rich fibrin which has a higher concentration and more prolonged release of growth factors, modulates the repair process. This process is based on the optimization of tissue regeneration through the insertion of fibrin membrane. Objective: The objective of this study is to report a case in which leukocyte- and platelet-rich fibrin associated with parendodontic surgery was used for bone repair. Results: Clinical and tomographic follow-up was performed after 72 days, which revealed absence of any symptoms, complete repair of the lesion, buccal cortical bone regeneration, and absence of detectable lesion on tomography. Conclusion: There was complete tissue regeneration at the lesion site(AU).

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.

In vivo evaluation of painful symptomatology after endodontic treatment with or without the use of photodynamic therapy.

CONTEXT: Postoperative pain control after endodontic treatment is important to maintain patient comfort. AIM: The aim of this prospective clinical study was to evaluate the postoperative symptomatology of endodontic treatments performed in a single session, with or without photodynamic therapy (PDT), using Reciproc #40 file in necrotic unirradicular anterior teeth. MATERIALS AND METHODS: In a prospective clinical study, 40 teeth indicated for endodontic treatment were treated by a single endodontist according to a preestablished protocol. The teeth were randomly divided into two groups (n = 20): control group (CG) and laser group (LG). After 24 h, 72 h, and 1 week of endodontic treatment, patients' pain symptomatology was evaluated through a Visual Analog Scale (VAS) ranging from 0 to 10, in which 0 corresponds to no pain and 10 indicates extreme pain. In both workgroups, similar protocols were used for instrumentation with the Reciproc system (R40), irrigation with 2.5% sodium hypochlorite, and filling by the gutta-percha plastification technique, in which the CG did not use PDT, and the LG used PDT after the instrumentation sequence. After the visit, the patients were given a prescription for ibuprofen 400 mg to be taken every 6 h if they experienced pain. RESULTS: The results of the study, analyzing the VAS, did not show any difference in pain symptoms between the groups at 24 h, 72 h, and 1 week (P > 0.05). CONCLUSIONS: It was concluded that there was no statistical difference between the groups.

Efficacy of passive ultrasonic irrigation, continuous ultrasonic irrigation versus irrigation with reciprocating activation device in penetration into main and simulated lateral canals.

CONTEXT: The use of chemicals solutions and means of activation is of utmost importance in endodontic treatment. AIMS: This study compared three activation techniques used in the final irrigation of the endodontic treatment. SUBJECTS AND METHODS: Eighty uniradicular teeth were instrumented with the Protaper Universal system up to F4 file. After decalcification, the teeth had artificial lateral canals created at 2, 4.5 and 6 mm from working length (WL). The groups were randomly divided into four groups (n = 20): control group (C), passive ultrasonic irrigation (PUI) group, continuous ultrasonic irrigation (CUI) group, and easy clean (EC) group. The penetration of the irrigant into the samples was evaluated using image observation using the Image J program. STATISTICAL ANALYSIS USED: The level of agreement among the observers was determined by the Cronbach's alpha test. The likelihood ratio test was used to evaluate possible differences between the groups and the Kendall's W statistic test to verify possible differences between the irrigant penetration levels in the lateral canals. The Fisher's exact test was applied to verify differences by the studied group considering the WL variables and lateral canals. RESULTS: The results showed no statistical difference in the penetration of the irrigator in the main canal when compared to the C, PUI, CUI, and EC groups (P > 0.05). CONCLUSIONS: The method using a positive syringe and needle pressure was not able to effectively carry the irrigator to the artificially made lateral canals, whereas PUI, CUI, and EC were equally efficient in this regard (P < 0.01).

Estudo in vitro do nível de escoamento de cinco cimentos endodônticos: Endofill, AH Plus, MTA Fillapex, Sealer 26 e Pulp Canal Sealer EWT / In vitro study of the flow rate of five root canal sealers: Endofill, AH Plus, MTA Fillapex, Sealer 26 and Pulp Canal Sealer EWT

Objetivo: o objetivo desse trabalho foi estudar, in vitro, o nível de escoamento dos cimentos Endofill, AH Plus, MTA Fillapex, Sealer 26 e Pulp Canal Sealer EWT. Métodos: os cimentos foram manipulados de acordo com as recomendações dos fabricantes. A determinação do escoamento foi conseguida em conformidade com a especificação #57 da ADA (American Dental Association). Na comparação entre os grupos, foi realizada a ANOVA (análise de variância) e posterior teste de Tukey, com nível de confiança de 95%. Resultados: os resultados mostraram que o cimento MTA Fillapex apresentou o maior escoamento entre os cimentos estudados e o cimento AH Plus foi o único que apresentou escoamento estatisticamente significativo após 24 e 48 horas. Conclusão: concluiu-se que todos os cimentos avaliados estão em conformidade com a especificação #57 da ADA. No entanto, o cimento MTA Fillapex foi superior aos outros cimentos analisados, no que se refere ao poder de escoamento. O desempenho clínico do cimento obturador está diretamente relacionado à sua capacidade de penetrar nos túbulos dentinários e canais laterais; daí a importância do estudo do escoamento dos cimentos endodônticos.

Micro-Computed Tomographic Evaluation of 2 Nickel-Titanium Instrument Systems in Shaping Root Canals.

INTRODUCTION: Cleaning and shaping without making procedural errors have always been a challenge in endodontics, particularly when the root canals are curved. Several rotary instruments have been developed to minimize such errors. The purpose of this study was to compare the shaping ability of 2 rotary file systems, BioRace (BR; FKG, La Chaux-de-Fonds, Switzerland) and ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), during the preparation of curved root canals in extracted teeth using micro-computed tomographic imaging. METHODS: A total of 20 first and second human mandibular molars with 2 separate mesial canals were scanned before and after root canal preparations using the SkyScan 1176 X-ray microtomograph (Bruker microCT, Kontich, Belgium) at a resolution of 17.42 µm. Canals were prepared using the BR and PTN systems. The percentage of dentin removed after preparation, root canal volume increase, untreated canal walls, structure model index, degree of canal transportation, and centering ability were also measured. RESULTS: There were no significant differences between the 2 groups in the removed dentin after preparation and determination of the root canal volume, percentage of untreated canal walls, structure model index, degree of canal transportation, and centering ability (P > .05). CONCLUSIONS: In conclusion, within the limitations of this ex vivo study, instrumentation of moderately curved mesial roots with 2 independent root canals and foramina using the BR and PTN rotary file systems were equally effective. Both instrumentation systems caused negligible procedural errors with minimal apical transportation.

Revascularização pulpar: relato de caso clínico / Pulp revascularization: a clinical case report

A revascularização é uma abordagem alternativa para o tratamento de dentes com rizogênese incompleta e necrose pulpar, com bases biológicas. Ao contrário de técnicas de barreira apical artificial, a rizogênese permite a continuação do desenvolvimento radicular e o restabelecimento da vitalidade pulpar. Apresentar a importância do diagnóstico e do plano de tratamento, e um protocolo de tratamento que envolve o procedimento de revascularização pulpar, por meio de um caso clínico de dente com rizogênese incompleta e necrose pulpar. Depois da instrumentação passiva das paredes do canal e medicação com hidróxido de cálcio, foi realizada indução de sangramento, com posterior formação de coágulo e colocação de barreira de MTA. O selamento coronário foi realizado com resina composta. No controle clínico e radiográfico, observou-se que o dente apresentava-se assintomático e que a lesão tinha desaparecido. Concluiu-se que esse tratamento promove o espessamento das paredes dentinárias, evitando que o dente fique fragilizado.

Avaliação da infiltração marginal apical em dentes retro-obturados com MTA/água e MTA/FillApex: estudo em dentes avulsionados / Evaluation of apical marginal leakage in teeth retrofilled with MTA-water and MTA-Fillapex: a study in avulsed teeth

Introdução: como o sucesso da terapia cirúrgica periapical depende do adequado selamento apical, o MTA e a melhor indicação como material retro-obturador. Objetivo: avaliar se a manipulação do MTA com o cimento FillApex altera sua capacidade de selamento apical, por meio da infiltração apical com rodamina B a 1%. Métodos: usando o sistema rotatório Protaper, 50 raízes com canais retos foram preparadas ate o instrumento F5 e obturadas por meio de uma técnica de termoplastificação e cimento. Os espécimes foram divididos em quatro grupos: os Grupos I, II e III sofreram apicectomia e foram retropreparados com ponta de ultrassom; o Grupo IV não sofreu apicectomia, nem retropreparação, servindo como controle positivo. O Grupo I foi retro-obturado com MTA-água; Grupo II foi retro-obturado com MTA-FillApex; o Grupo III não foi retro-obturado, servindo como controle negativo. As raízes do Grupo IV foram revestidas com duas camadas de esmalte para unhas na cor vermelha; e as raízes dos Grupos I, II e III também foram revestidas, exceto na região apicectomizada, e imersas em 3 ml de solução de rodamina B a 1%,em recipientes padronizados e identificados, por 8 dias, em estufa, a temperatura de 37°C e 100% de umidade. Para avaliar o nível de corante infiltrado, os espécimes foram clivados no sentido longitudinal, fotografados e encaminhados a três mestres em Endodontia, que analisaram quatro níveis de infiltração: zero; 0 a 1 mm; 1 a 2 mm; 2 a 3 mm. Resultados: os resultados mostraram que associação MTA-FillApex teve menor infiltração marginal do que o MTA-água.