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Whether ultrasonic activation of the adhesive system improves dentin tubule penetration and the bond strength of fiber posts to root dentin is unclear.The purpose of this in vitro study was to evaluate the effect of ultrasonic activation of 2 adhesive systems (etch-and-rinse and self-etch) and 1 glass ionomer cement on the dentin tubule penetration and pushout bond strength of fiber posts to root dentin.Sixty maxillary central incisors were endodontically treated and divided into 6 groups (n=10) as per the post cementation strategy: etch-and-rinse, etch-and-rinse and ultrasonic, self-etch, self-etch and ultrasonic, glass ionomer cement, and glass ionomer cement and ultrasonic. The primers, the adhesives, and the glass ionomer cement were activated for 20 seconds each, and the fiber posts were cemented with a resin cement. Dentin tubule penetration was evaluated by confocal laser scanning microscopy and the pushout bond strength measured at 3 post locations: cervical, middle, and apical. The failure patterns were also described after pushout testing.Self-etch and ultrasonic showed higher dentin tubule penetration than the other cementation strategies (P.05) and improved the bond strength values (P.05), which were higher than etch-and-rinse and ultrasonic and glass ionomer cement and ultrasonic (P.05). Adhesive failures at the cement and dentin interface were predominant in the etch-and-rinse, self-etch, and self-etch and ultrasonic groups.Ultrasonic activation improved the dentin tubule penetration of a self-etch adhesive system. The bond strength of fiber posts cemented with a self-etch adhesive system and a resin cement was improved after ultrasonic activation.

This study aimed to evaluate the effect of ultrasonic activation (UA) of endodontic sealers on dentin tubule penetration and the bond strength to root dentin.One hundred single-rooted teeth were prepared with 40.06 nickel-titanium instruments and divided into 2 groups: with or without UA. Three resin-based sealers (MTA Fillapex [Angelus Dental Solutions, Londrina, PR, Brazil], Sealer Plus [MK Life Medical and Dental Products, Porto Alegre, RS, Brazil], and AH Plus [Dentsply, DeTrey GmbH, Konstanz, Germany]; n = 20) and 2 calcium silicate-based sealers (Sealer Plus BC [MK Life Medical and Dental Products] and EndoSequence BC [Brasseler, Savannah, GA], n = 20) were used and subdivided (n = 10) according to the protocols. Fluo-3 (Thermo Fisher Scientific, Waltham, MA) and rhodamine B dyes were added to the calcium silicate- and resin-based sealers, respectively. In the UA groups, the activation was performed for 40 seconds followed by lateral compaction. Samples were transversely sectioned to evaluate the dentin tubule penetration and the bond strength to root dentin. The penetration data were analyzed with the Student t test, 1-factor analysis of variance, and Bonferroni tests. Bond strength was evaluated using the Student t test, Kruskal-Wallis, and Dunn post hoc test.Resin-based sealers showed the highest tubule penetration without UA (P.05). UA significantly enhanced MTA Fillapex and Endosequence BC dentin tubule penetration (P.05). AH Plus and Sealer Plus BC improved their bond strength to root dentin after UA (P.05). AH Plus/UA, Sealer Plus/UA, and Sealer Plus BC/UA presented the highest bond strength values (P.05). Adhesive failures were predominant in all groups regardless of the use of ultrasound.UA interferes with tubule penetration and the bond strength to root dentin of resin- and calcium silicate-based sealers.

Made available in DSpace on 2022-04-28T19:28:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-01 Introduction: The aim of this study was to evaluate the bleaching effect after aging simulation in teeth submitted to bonding and debonding of orthodontic brackets. Materials and methods: For this study, 90 human premolars were selected, and randomly divided into 6 groups: control, bleaching, and other 4 groups submitted to bleaching after bonding and debonding brackets using different methods. Color measurement of sample through the CIE L*a*b* system was performed in three moments: T1 – after brackets debonding, T2 – after staining cycling, and T3 – after bleaching. For evaluation of results among the components L*, a* and b*, the two criteria analysis of variance and the multiple comparison Tukey test (p < 0.05) were used. Results: Statistically significant difference was observed among the groups submitted to brackets bonding and debonding through self-conditioning adhesive system and tungsten drill, also the control and bleaching groups between the moments T1 e T2. Conclusion: Bonding and debonding brackets methods tested in this study showed influence on the sample color change, and after the tooth bleaching process, only the group without brackets previous bonding achieved the color value presented before the staining and aging of samples in the brackets absence. Postgraduate Program in Health Sciences University of Southern Santa Catarina, José Acácio Moreira, 787 Department of Social Dentistry School of Dentistry São Paulo State University, Humaitá, 1680 Department of Orthodontics and Public Health School of Dentistry University of São Paulo, Alameda Doutor Octávio Pinheiro Brisolla, 975 Postgraduate Program in Oral Science School of Dentistry Santa Maria Federal University, Roraima Av., 1000 Department of Conservative Dentistry School of Dentistry Federal University of Rio Grande do Sul, Paulo Gama Av., 110 Postgraduate Program in Health Sciences University of Southern Santa Catarina, José Acácio Moreira Tubarão, 787 Department of Social Dentistry School of Dentistry São Paulo State University, Humaitá, 1680

This study aimed to evaluate the influence of endodontic sealer inside dentinal tubules on the retention of fibreglass posts. One hundred eighty extracted teeth were instrumented with rotary instruments and divided into two groups (n = 90) according to their filling technique: (LC) lateral condensation and (CT) controlled technique, and subdivided into three subgroups according to the endodontic sealer used: (A) epoxy resin sealer, (B) zinc-oxide and eugenol sealer, and (C) bioceramic endodontic sealer. After root preparation, each subgroup received a fibreglass posts cemented with (1) adhesive resin cement, (2) self-adhesive resin cement, and (3) glass ionomer cement. After stored for 15 days at 37 °C and 100% humidity, the teeth were sectioned transversely into 1-mm thick slices and subjected to laser confocal scanning microscopy and push-out test. The failure mode was analyzed by stereo microscope, and scanning electron microscopy images of representative fractures were made. Although there were no significant differences in the dislocation resistance among the filling techniques (p > 0.05), the type of sealer used affected bond strengths on the cervical and middle thirds. Fibreglass posts cemented with glass ionomer cement presented higher values for the push-out test than those cemented with resin cements (p

This study investigated the cyclic fatigue, bending, torsional resistance and angular deflection of Pro-R 25.08, Logic RT 25.08, MK Retreatment 25.08 (MK RT) and ProTaper Retreatment D2 instruments. Cyclic fatigue test was performed until fracture in a custom stainless-steel device with water bath equipment to simulate body temperature. Fracture time was recorded. A number of cycles were calculated. Resistance to bending at 45°, torsional resistance and angular deflection were evaluated. The fracture surfaces were examined by scanning electron microscopy. Statistical analysis was performed with one-way ANOVA and Tukey and Kruskal-Wallis and Dunn tests. Pro-R and Logic RT presented the highest cyclic fatigue (P 0.05). D2 had higher strength to bend than Pro-R and Logic RT (P 0.05). Logic RT showed the highest torque and angular deflection (P 0.05), without differences when compared to D2 (P 0.05). Instrument performances were dependent on their geometrical features and heat treatments.

Background: The aim of this study was to evaluate the bending and torsional resistance of the following instruments: Mtwo 25.07, Navigator W-XN, ProTaper SX, MK Orifice Shapper and MK Sequence 17.12. Methods: One hundred instruments were used (n=20). Resistance to bending (n=10), torque and angular deflection (n=10) at the failure of new instruments were measured according to ISO 3630-1. The fractured surface of each fragment was examined by scanning electron microscopy (SEM). Data were analyzed using 1-way analysis of variance and Tukey tests. Results: Torsional resistance values of MK Sequence were higher than the other groups (P.05) and ProTaper SX, which presented the lowest values (P.05). ProTaper SX and MK Orifice Shapper also showed no significant differences (P>.05). MK Sequence 17.12 instruments had the lowest angular deflection values (PConclusions: In conclusion MK Sequence 17.12 had the highest torsional fracture resistance. Mtwo 25.07 showed higher angular deflection capacity, and ProTaper SX the lower bending stiffness.

This study aimed to evaluate penetrability on dentinal tubule of a new bioceramic sealer through confocal laser scanning microscopy (CLSM). A specific fluorophore (Fluo-3) was mixed with the sealer. Forty distobuccal roots from maxillary molars were selected, and root canal preparation was carried out with Wave One Gold # 35.06 instruments. Roots were randomly assigned to 4 groups according to the filling procedures: Bioceramic/Lentulo (Sealer Plus BC); Bioceramic/EasyClean group, three activation of the sealer (3x20 s) with Easy Clean instrument; Bioceramic/Irrisonic: ultrasonic activation for 30 s; and AHplus/Lentulo: epoxy resin based sealer (AH Plus) was utilized with the same protocol as the BC/LE group. After 72 h, specimens were transversally sectioned at 2 and 7 mm from root apex and then analyzed through CLSM. Sealer penetration area on dentinal tubule was measured by Adobe Photoshop CC2018. Kruskal Wallis and Wilcoxon T tests were carried out. Penetrability results were similar for both sealers regardless of which technique was performed to activate them inside the root canal (p>0.05). It is reasonable to conclude that penetration of bioceramic and epoxy resin based sealers occurred unimpressively. The type of instrument used to activate bioceramic sealer did not affect penetrability. Fluo 3 should be recommended as the fluorophore to evaluate dentinal tubule penetration of bioceramic sealers. Resumo Este estudo objetivou avaliar a penetração nos túbulos dentinários de um novo cimento biocerâmico utilizando microscopia confocal de varredura a laser (MCVL). Um fluoróforo específico (Fluo-3) foi misturado com o cimento. Quarenta raízes distovestibulares de molares superiores foram selecionados e o preparo do canal radicular foi realizado com instrumentos Wave One Gold #35.06. As raízes foram divididas randomicamente em quatro grupos de acordo com os procedimentos obturadores: Bioceramic/Lentulo: cimento biocerâmico (Sealer Plus BC); Bioceramic/EasyClean: três ativações do cimento com instrumento Easy Clean (3 x 20 s); Bioceramic/Irrisonic: ativação ultrassônica do cimento por 30 s e AHplus/Lentulo: cimento à base de resina epóxica (AH Plus) foi utilizado com o mesmo protocolo que o grupo Bioceramic/Lentulo. Após 72h, os espécimes foram seccionados transversalmente em 2 e 7 mm do ápice radicular e analisados com MCVL. A área de penetração nos túbulos dentinários foi mensurada com Adobe Photoshop CC2018. O teste de Kruskal Wallis e T de Wilcoxon foram realizados. Os resultados de penetração foram similares para ambos os cimentos independentemente de qual técnica foi utilizada para ativá-los no interior do canal radicular (p>0,05). É razoável concluir que a penetração de cimentos biocerâmicos e à base de resina epóxica ocorreram de forma pouco expressiva. O tipo de ativação do cimento biocerâmcio não afeta sua penetrabilidade nos túbulos dentinários. Fluo 3 deve ser recomendado como o fluoróforo para avaliar a penetração intratubular de cimentos biocerâmicos.

SUMMARY Objective: The aim of this study was to evaluate the effect of five intracanal irrigants on bond strength of fiber posts cemented with newer self-adhesive resin cement. Methods: A total of 60 extracted, single-rooted human premolars, sectioned at 14 mm, were prepared with the ProTaper Universal system with a size F3 instrument and filled with an F3 master cone and AH Plus. The root canal filling was partially removed, leaving 4 mm of apical gutta-percha. Specimens were randomly assigned to five groups (n=12), according to the solution used for dentin surface treatment before fiber post cementation, as follows: EDTA 17% (EDTA); QMix (QM); SmearClear (SC); 2.5% sodium hypochlorite (NaOCl), and 0.9% saline solution (SS). Ultrasonic activation was performed (three times, 20 seconds each), and root canals were dried with paper points. Fiber posts were cemented with RelyX U200. In one specimen per group, rhodamine B dye was mixed with RelyX U200 to provide adequate fluorescence for confocal laser scanning microscopy (CLSM) assessment. Specimens were transversally sectioned and three slices were obtained, one for each root third. Next, a push-out test was performed. A stereomicroscope and CLSM were used to analyze the failure modes and to illustrate the pattern of infiltration of RelyX U200 into dentinal tubules, respectively. Bond strength means were calculated, and analysis of variance and Bonferroni tests were used for statistical analysis. Results: SS showed the highest mean bond strength values (11.5±5.3), superior to QM (5.1±3.1) and SC (5.1±3.3). NaOCl presented intermediary bond strength values (9.7±5.0), similar to EDTA (7.7±2.9) and SS. QM and SC showed the lowest mean bond strength (p Conclusion: SS and NaOCl associated with ultrasonic activation seem to be adequate solutions for root canal cleaning before fiber post cementation with self-adhesive resin cement, whereas chelating solutions, such as EDTA, QM, and SC, cause a decrease in bond strength.

The aim of this study was to quantify the residual filling material after filling removal, re-preparation with rotary or reciprocating files and passive ultrasonic irrigation (PUI). Twenty maxillary molars were prepared using ProTaper instruments up to F1. The teeth were filled with AH Plus and ProTaper gutta-percha points using the single-cone technique. Thereafter, the specimens were scanned using a micro-computed tomography system (Micro-CT #1). Then, the root canal filling was removed using ProTaper Retreatment files, and a new scan was performed (Micro-CT #2). The specimens were divided into two groups according to the instrument used for re-preparation: ProTaper rotary or WaveOne reciprocating files (Micro-CT #3). Finally, PUI was performed, and a new micro-CT scan was performed (Micro-CT #4). Intragroup and intergroup analyses were performed using Friedman and Dunn's post hoc test and the Kruskal-Wallis and Dunn post hoc tests, respectively. Palatal canal presented the highest volume of residual filling material in all stages of endodontic retreatment (p0.05). Rotary and reciprocating files achieved similar removal of the root canal filling (p>0.05). The greatest reduction in filling material was achieved after using ProTaper Retreatment files. Rotary and reciprocating instruments and PUI did not improve the removal of root canal filling materials. Resumo O objetivo dente estudo foi quantificar o material obturador residual após remoção da obturação, repreparo do canal com instrumentos de rotação contínua e reciprocantes e após irrigação ultrassônica passiva (IUP). Vinte molares superiores foram preparados usando instrumentos ProTaper sequencialmente até F1. Os dentes foram obturados com AH Plus e cones de guta percha ProTaper utilizando a técnica de cone único. Em seguida, os espécimes foram submetidos à microtomografia computadorizada (Micro-CT #1). Então, o material obturador foi removido utilizando instrumentos ProTaper Retratamento e novo escaneamento foi realizado (Micro-CT #2). Os espécimes foram divididos em dois grupos de acordo com o instrumento usado para o repreparo: de rotação contínua (ProTaper) ou reciprocante (WaveOne) (Micro-CT #3). Finalmente, IUP foi realizada e nova micro-CT foi conduzida (Micro-CT #4). As análises intra-grupo e inter-grupos foram realizadas utilizando os testes de Friedman e de Dunn e o teste de Kruskal-Wallis e Dunn, respectivamente. O canal palatino apresentou o maior volume de material obturador remanescente em todos os estágios do tratamento endodôntico (p0,05). Instrumentos de rotação contínua e reciprocantes proporcionaram similar remoção de material obturador (p>0,05). A maior redução do volume de material obturador foi obtida após utilizar os instrumentos ProTaper Retratamento. Instrumentos de rotação contínua e reciprocantes, assim como a IUP, não reduzíram o volume de material obturador remanescente.

The purpose of this study was to quantify the presence of nickel (Ni) and titanium (Ti) on dentin walls of prepared root canals using Endosequence (ES) and Wave One (WO) systems, the deformation, and fracture of these instruments. Thirty extracted human premolar teeth were selected and prepared with WO, ES, and manually (control group-CG). Each instrument was used in four root canals. The root canals were irrigated with 2.5% sodium hypochlorite solution. After preparation, roots were sectioned longitudinally and the apical third was analyzed by scanning electron microscopy with X-ray microanalysis (SEM-EDS). The percentage of Ni and Ti found on dentin walls was compared using Kruskal-Wallis test and post hoc Dunn. The instruments deformation and fracture was evaluate by SEM before and after use. Spiral distortion, fractures, and surface wear were compared using Mann-Whitney test. The level of significance was set at 5%. Ni and Ti were found on the dentin walls of the apical root canal for ES and WO systems (p > .05). No distortion in the spirals and no instrument fracture were observed. Regarding to surface wear, most of the instruments scored as moderate wear (p > .05). This study concluded the WO and ES presented Ni and Ti loss. In addition, the preparation of four root canals did not caused irreversible deformation in WO and ES instruments.

This study aimed to evaluate the penetration of a new endodontic sealer into the dentinal tubules. Twenty single-rooted teeth were selected. The crown was sectioned, and the canals were instrumented with a reciprocating system. Irrigation was performed with 2 mL of 2.5% sodium hypochlorite between each file change. After instrumentation, the root canals were irrigated with 2 mL of17% EDTA for 3 min followed by saline solution. The specimens were randomized into two groups (n =10) according to the endodontic sealer: AH Plus (AP) or Sealer Plus (SP). All specimens were filled using the lateral compaction technique. Rhodamine B dye (red) was incorporated to the sealers to provide the fluorescence which will enable confocal laser scanning microscopy (CLSM) assessment. The roots were sectioned 2, 4, and 6 mm from the apex and assessed by CLSM. The root canal level affected the penetration of the sealer, but no statistical significant differences were found between the two experimental groups (p > .05). SP presented similar dentinal penetration and perimeter integrity to the gold standard (AP). RESEARCH HIGHLIGHTS: Sealer Plus presents dentinal penetrability and perimeter integrity similar to the gold standard sealer (AH Plus), demonstrating excellent ability of filling areas of difficult access.

The aim of this study was to assess the effect of calcium hydroxide on bond strength of two bioactive cements. One-mm thick longitudinal slabs of root dentin were obtained from freshly extracted human monorradicular teeth (n = 60). Simulated root perforations (1 mm in diameter) were prepared in radicular dentin. Thereafter, the specimens were randomly divided into two groups (n = 30), according to the repair material: MTA (n = 30) and Biodentine (BD) (n = 30). Next, the specimens in each group were further randomly divided into 4 equal subgroups (n = 15) according to the prior use of Ca(OH)2: MTA/Ca(OH)2 and BD/Ca(OH)2 groups: perforations were filled with calcium hydroxide [Ca(OH)2] and after 7 days, it was removed, and MTA and BD groups: calcium hydroxide dressing were not used. Push-out test was performed at a crosshead speed of 1 mm/min. Bond strength values were compared statistically using Kruskal-Wallis test and Dunn's post-test at a significance level of 5%. The failure analysis was performed using a stereoscopic and classified as adhesive, cohesive and mixed. The push-out bond strength of MTA and BD was not affected by the prior use of Ca(OH)2 (p > 0.05). BD yielded higher push-out bond strength values compared with those of MTA, regardless of the use of Ca(OH)2 (p

The aim of the study was to assess the penetrability of two endodontic sealers (AH Plus and MTA Fillapex) into dentinal tubules, submitted to endodontic treatment and subsequently to endodontic retreatment. Thirty ex vivo incisors were prepared using ProTaper rotary system up to F3 instrument and divided in three groups according to the endodontic sealer used for root canal filling: AH Plus (AHP), MTA Fillapex (MTAF), and control group (CG) without using EDTA previously to the root canal filling. Rhodamine B dye (red) was incorporated to the sealers in order to provide the fluorescence which will enable confocal laser scanning microscopy (CLSM) assessment. All specimens were filled with gutta-percha cones using the lateral compaction technique. The specimens were submitted to endodontic retreatment using ProTaper Retreatment system, re-prepared up to F5 instruments and filled with gutta-percha cones and the same sealer used during endodontic retreatment. Fluorescein dye (green) was incorporated to the sealer in order to distinguish from the first filling. The roots were sectioned 2 mm from the apex and assessed by CLSM. No difference was found between the two experimental groups (P > 0.05). On the other hand, in the control group the sealers were not capable to penetrate into dentinal tubules after endodontic treatment (P > 0.05). In retreatment cases, none of the sealers were able to penetrate into dentin tubules. It can be concluded that sealer penetrability is high during endodontic treatment. However, MTA Fillapex and AH Plus do not penetrate into dentinal tubules after endodontic retreatment.

Summary The aim of this ex vivo study was to evaluate, by scanning electron microscopy (SEM), the presence of gaps at the interface between filling material and three root-end filling materials. Thirty human upper molars disto-buccal roots were instrumented and filled with gutta-percha and eugenol-based sealer. The apicoectomy was performed 2 mm from the apex and retrograde cavities were prepared with ultrasonic points (3 mm in deep). The samples were divided into three experimental groups (n = 10): Group I—white mineral trioxide aggregate (MTA); Group II—Super EBA; and Group III—Portland cement. The root-end filling materials were inserted into the retocavities using a MTA carrier. After 48 h, the roots were transversally sectioned in order to obtain the apical 5 mm. Next, each specimen was prepared longitudinally with crescent granulation of abrasives water-wet sandpapers in order to expose the filling and root-end filling materials. Then, the specimens were subjected to slow dehydration with silica gel, mounted onto specific stubs and coated with paladium coverage for SEM analysis of the interface between filling and root-end filling materials. The percentage of gaps at the interfacial area was calculated by using Image Tool 3.0 software. Super EBA presented the higher percentage of gaps (1.5 ± 0.67%), whereas MTA presented the lowest values (0.33 ± 0.20%; p = 0.0004). Despite the statistical differences observed between Super EBA and MTA, all the root-end filling materials presented great adaptation to the filling material, presenting small amount of gaps. SCANNING 36:252–257, 2014. © 2013 Wiley Periodicals, Inc.

Introduction The aim of this study was to evaluate the ex vivo effects of root canal preparation, filling techniques, and mechanical cycling (MC) on the incidence of dentin defects and vertical root fractures (VRFs). Methods Seventy extracted single-rooted teeth were divided into 6 groups. The first 2 groups were the unprepared and unprepared/MC groups. The other groups were prepared by using Gates Glidden drills and ProTaper Universal files up to F3 and were grouped according to the following: prepared teeth and the absence of root canal filling, passive technique, lateral compaction, and Tagger's hybrid technique. All of the groups except the unprepared group were subjected to MC (1,000,000 cycles, 90 N, 4 Hz, 37°C). The roots were then sectioned horizontally at 3, 6, and 9 mm from the apex and observed under a ×10 stereomicroscope. The defects were categorized as no defect, vertical root fracture, and other defects. The differences between the groups were analyzed by using the Fisher exact and χ 2 tests. Results MC by itself did not influence the incidence of dentinal defects ( P > .05, between the unprepared and unprepared/MC groups). The filled groups presented a similar incidence of other defects ( P > .05), although VRFs were observed only when the MC was associated with pressure filling techniques (the lateral compaction and Tagger's hybrid groups). Conclusions MC by itself did not induce VRF. When associated with apical pressure filling techniques, however, VRF occurred in 13.3% (lateral compaction) and 33.3% (Tagger's hybrid) of the cases.

The aim of this study was to evaluate the penetration of endodontic sealer into the dentin tubules, the integrity of the sealer layer perimeter, and the sealer area at the apical third after different filling techniques by confocal laser scanning microscopy (CLSM). Forty-five mandibular premolars were mechanically prepared with ProTaper files, until F5 file. Thereafter, they were filled with an epoxy-resin sealer (AH Plus) mixed with Rhodamine B dye (0.1% proportion) and allocated in three groups: Group 1, single master cone; Group 2, cold lateral compaction; and Group 3, Thermafil. For confocal laser scanning microscopy analysis, the specimens were transversely sectioned at 4 mm from the apex. The images at ×10 and ×40 were analyzed by Imagetool 3.0 software. Significant differences were not found among the three experimental groups according the dentin-impregnate area by the sealer (P = 0.68) and between the sealer and root canal perimeter (P = 0.18). However, root canal filling techniques were significantly different when apical sealer areas were compared (P = 0.001). Thermafil group showed smaller sealer areas (8.09%) while cold lateral compaction and gutta-percha master cone showed similar areas (17.37 and 21.18%, respectively). The dentin-impregnated area was not dependent on the root canal filling technique. Single master cone, cold lateral condensation and Thermafil techniques presented integrity of the sealer perimeter close to 100% and Thermafil resulted in a significantly thinner sealer layer.

Purpose: To simulate soft and hard tissues to assess radiopacity of three root canal sealers (Endofill, AH Plus and Sealer 26). Methods: Five circular specimens (10x1 mm) were made and three experimental conditions were created. Situation #1: an aluminum step wedge allowed specimen being submitted to three digital radiographs. Situation #2: a retromolar mandibular segment containing the specimen was positioned between the phosphor plate and X-ray machine. Situation #3: a soft tissue simulating material (utility wax – 30 mm) was associated with the mandibular segment. Mean gray values were measured using ImageTool 3.0 software. Two-way ANOVA and Tukey’s test (alpha=0.05) was performed. Results: Radiopacity increased when bone tissue was used (P < 0.05), except for AH Plus. Situation #3 provided greater radiopacity (P < 0.05). Radiopacity between most and least sealers decreased 44% when Situation #1 and #3 were compared. Conclusion: Simulated soft and hard tissues influenced the radiopacity of root canal sealers. Objetivo: Simular tecidos moles e duros para avaliar a radiopacidade de três cimentos endodônticos. Metodologia: Cinco espécimes circulares (10x1 mm) foram confeccionados e três situações experimentais foram criadas. Situação #1: espécime e uma escala de alumínio foram submetidos a 3 tomadas radiográficas digitais. Situação #2: um segmento retromolar de uma mandibula humana contendo o espécime foi posicionada entre o aparelho de raio X e o sensor digital. Situação #3: um simulador de tecido mole (cera utilidade – 30 mm) foi associado ao segmento mandibular. A média dos valores de cinza foi medida através do programa ImageTool 3.0. Análise de variância de dois critérios e Teste de Tukey (alfa=0.05) foram realizados para análise estatística. Resultados: A radiopacidade aumentou quando tecido ósseo foi usado (P < 0.05), exceto para o Ah Plus. A Situação #3 proporcionou os maiores valores de radiopacidade (P < 0.05). Os valores de radiopacidade entre o cimento mais e o menos radiopaco diminuiu 44% quando as situações #1 e #3 foram comparadas. Conclusão: A simulação de tecidos moles e duros influencia a radiopacidade de cimentos endodônticos.

Objectives The aim of this study was to evaluate the volume of remaining filling material after passive ultrasonic irrigation (PUI) of sodium hypochlorite (NaOCl) and orange oil in mesial canals of mandibular molars, with and without isthmus. Material and Methods Thirty mesial roots of mandibular molars were divided according to the presence or absence of isthmus. Canals were prepared and filled (Micro-CT #1). Filling was removed using rotary instruments, and specimens were sub-divided into three groups according to the irrigation procedures: Conventional – conventional irrigation with NaOCl, PUI/NaOCl – PUI of NaOCl (three activations, 20 seconds each), and PUI/orange oil – PUI of orange oil (Micro-CT#2). Specimens were enlarged using the X2 and X3 ProTaper Next instruments and submitted to the same irrigation protocols (Micro-CT #3). Results No differences were found between the experimental groups in each stage of assessment (P>0.05). The volume of residual filling material was similar to those in Micro-CT #2 and Micro-CT #3, but lower than those observed in Micro-CT #1 (P

Made available in DSpace on 2015-08-06T16:14:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-10-01. Added 1 bitstream(s) on 2015-08-06T16:44:21Z : No. of bitstreams: 1 S1678-77572014000500390.pdf: 2186068 bytes, checksum: 2a282f09bce82454a2c89a135ac0f0f8 (MD5) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) OBJECTIVE: The purpose of this study was to assess the push-out bond strength of glass fiber posts to root dentin after cementation with glass ionomer (GICs) and resinmodified glass ionomer cements (RMGICs). MATERIAL AND METHODS: Fifty human maxillary canines were transversally sectioned at 15 mm from the apex. Canals were prepared with a step back technique until the application of a #55 K-file and filled. Post spaces were prepared and specimens were divided into five groups according to the cement used for post cementation: Luting & Lining Cement; Fuji II LC Improved; RelyX Luting; Ketac Cem; and Ionoseal. After cementation of the glass fiber posts, all roots were stored at 100% humidity until testing. For push-out test, 1-mm thick slices were produced. The push-out test was performed in a universal testing machine at a crosshead speed of 0.5 mm/minute and the values (MPa) were analyzed by Kolmogorov-Smirnov and Levene's tests and by two-way ANOVA and Tukey's post hoc test at a significance level of 5%. RESULTS: Fiber posts cemented using Luting & Lining Cement, Fuji II LC Improved, and Ketac Cem presented the highest bond strength to root dentin, followed by RelyX Luting. Ionoseal presented the lowest bond strength values (P>0.05). The post level did not influence the bond strength of fiber posts to root dentin (P=0.148). The major cause of failure was cohesive at the cement for all GICs and RMGICs. CONCLUSIONS: Except for Ionoseal, all cements provided satisfactory bond strength values. Dental School Dental School Department of Prosthodontics Department of Prosthodontics University of Southern Santa Catarina Federal University of Rio Grande do Sul Department of Conservative Dentistry Univ. Estadual Paulista School of Dentistry Department of Endodontics University of São Paulo Bauru School of Dentistry Department of Pediatric Dentistry, Orthodontics and Community Health University of São Paulo Bauru School of Dentistry Department of Prosthodontics

O objetivo deste estudo foi avaliar a resistência à fratura de dentes amplamente destruídos após duas técnicas de preparo (limas manual e rotatória) e após duas técnicas obturadoras (compactação ativa e passiva). Sessenta e oito raízes de caninos superiores com diâmetro apical igual a uma lima K #25 foram embutidas em resina acrílica e o ligamento periodontal foi simulado utilizando um material de moldagem à base de poliéter. As raízes foram distribuídas aleatoriamente em quatro grupos (n=17): preparo manual e compactação ativa (MA), preparo manual e compactação passiva (MP), preparo rotatório e compactação ativa (RA) e preparo rotatório e compactação passiva (RP). Todas as raízes foram restauradas com pino de fibra de vidro e coroa metálica. Os espécimes foram ciclados mecanicamente (500.000 ciclos, 45°, 37°C, 133 N, 2 Hz) e depois submetidos ao teste de resistência à fratura. Um único examinador cego analisou a superfície externa das raízes e classificou o padrão de falha em favorável ou desfavorável. Os valores de resistência à fratura variaram entre 621,15 N (MP) e 785,71 N (MA). Entretanto, o teste de Kruskal-Wallis não revelou diferença nos valores de resistência à fratura entre os quatro grupos (p=0,247). Diante das condições testadas, as técnicas de preparo e de obturação do canal radicular não influenciam na resistência à fratura de dentes amplamente destruídos restaurados com pino de fibra de vidro e coroa metálica. The purpose of this study was to assess the fracture resistance of extensively damaged teeth after two root canal preparation techniques (hand and rotary files) and after two filling techniques (active and passive compaction). Sixty-eight maxillary canines roots with an apical diameter equal to that of a #25 K-file were embedded in acrylic resin and the periodontal ligament was simulated by using a polyether impression material. The roots were randomly distributed into four groups (n=17): hand preparation and active compaction (HA), hand preparation and passive compaction (HP), rotary preparation and active compaction (RA), and rotary preparation and passive compaction (RP). All roots were restored with glass fiber post and metallic crown. The specimens were mechanically cycled (500,000 cycles, 45°, 37°C, 133 N, 2 Hz) and then subjected to a fracture resistance test. A single blinded examiner analyzed the external root surface and classified the failure pattern as favorable or unfavorable. The fracture resistance values ranged between 621.15 N (HP) and 785.71 N (HA). However, the Kruskal-Wallis test did not reveal differences in the fracture resistance values among the four groups (p =0.247). Under the tested conditions, root canal preparation and filling techniques had no influence on the fracture resistance of extensively damaged teeth restored with fiber post and metallic crown.

Statement of problem Glass fiber posts are commonly used to provide adequate support and retention for the restoration of endodontically treated teeth, but their resistance to dislodgement depends on their adhesion to root dentin. Purpose The purpose of this study was to assess the effect of cement type on the pull-out bond strength of fiber posts. Material and methods Seventy maxillary canines were endodontically treated and then divided into 7 groups according to the cement used for fiber post cementation as follows (n=10): RelyX Unicem, BisCem, RelyX Luting 2, RelyX ARC, Panavia F, Enforce, and Allcem. The specimens were subjected to a pull-out bond strength test in a universal testing machine at a crosshead speed of 0.5 mm/min. The results, in newtons, were analyzed with 1-way ANOVA and the Tukey post hoc test (α=.05). Results RelyX Unicem (472.3 ±8.9 N), BisCem (506.6 ±9.2 N), RelyX ARC (498.0 ±8.2 N), Panavia F (502.3 ±7.0 N), and Allcem (470.0 ±11.3 N) presented significantly higher bond strength than RelyX Luting 2 (241.8 ±9.70 N) and Enforce (309.5 ±6.3 N) cements (mean ±SD; P Conclusions Except for Enforce, all resin cements produced pull-out bond strength values twice that of resin modified glass ionomer cement. However, all cements promoted adequate retention to fiber posts to withstand functional loads.

The aim of this in vitro study was to compare the effectiveness of saline, 2.5% sodium hypochlorite, and 2% chlorhexidine, with or without passive ultrasonic irrigation (PUI), in debris removal from simulated canal irregularities within prepared root canals.Ninety bovine lateral incisors were randomly divided into 3 main groups (n = 30) based on the irrigant and prepared with hand files attached to an oscillating handpiece (NSK, Tokyo, Japan) up to a size #80 K-file. Next, the teeth were split longitudinally, and a standardized groove was prepared into the apical third and filled with dentin debris. After the halves were reassembled, they were placed in a muffle. Each main group was randomly subdivided into 2 groups (n = 14) and was treated with different final irrigation protocols. In the sodium hypochlorite/PUI, chlorhexidine/PUI, and saline/PUI groups, the solution was ultrasonically activated 3 times for 20 seconds. In the remaining groups, PUI was not performed. Specimens were scored for debris removal and analyzed under a scanning electron microscope.An association was observed between the score of debris removal and protocols using PUI (P.05). No association was observed between the scores of debris removal and the irrigants (P = .87).Final irrigation protocols that used PUI were more effective in removing debris from simulated canal irregularities into the apical third than those that did not use it.

This study aimed to assess the influence of the type of endodontic sealer (salicylate resin-based sealer vs. two endodontic sealers) and the time of fiber post cementation after root filling on the post adhesion to bovine root dentin. Sixty bovine roots were assigned to six groups (n=10), considering an experimental design with two factors (factorial 3x2): endodontic sealer factor in three levels [epoxy resin-based sealer (AH Plus), eugenol-based sealer (Endofill), and salicylate resin-based sealer plus mineral trioxide aggregate - MTA (MTA Fillapex)] and time for post cementation factor in two levels (immediate post cementation or 15 days after root canal filling). After post cementation, 2-mm-thick slices were produced and submitted to push-out test. The failure modes were analyzed under a 40× stereomicroscope and scored as: adhesive at cement/dentin interface; adhesive at cement/post interface; cement cohesive; post cohesive; dentin cohesive; or mixed. Data were analyzed using two-way ANOVA and Tukey's post-hoc tests (α=0.05). When the fiber posts were cemented immediately after the root canal filling, the bond strengths were similar, independent of the endodontic sealer type. However, after 15 days, the epoxy resin-based sealer presented higher bond strength than the other sealers (p

This study aimed to evaluate, ex vivo, the nanoleakage in dentinal tubules, the lin- ear infiltration of silver nitrate in the dentin wall/root-end filling material interface, and the pres- ence of gaps in this interface in root-end cavities filled with 4 filling materials. Forty-eight disto- buccal root canals of maxillary molars were instrumented and filled. Retrograde cavities were pre- pared with ultrasonic points (apical 2 mm). The samples were divided into 2 control groups (n 5 4) and 4 experimental groups (n 5 10): Group I - white mineral trioxide aggregate (MTA); Group II - Super EBA; Group III - Portland cement; and Group IV - Sealer 26. After 1 week, the specimens were subjected to silver nitrate and prepared for SEM (backscattered electrons). In the apical-api- cal segment, an area with significantly higher leakage was observed for Super EBA, followed by Portland cement, MTA, and Sealer 26 (P 5 0.0054). In the medium and cervical segments, all mate- rials showed the same leakage behavior (P 5 0.1815 and P 5 0.1723, respectively). The linear infil- tration at the dentin wall/root-end filling material interface was higher with Super EBA than the other groups. No differences in the percentage of gaps along the 3 mm of dentin wall/root-end fill- ing material interface between the 4 materials were evident (P > 0.05). Nanoleakage occurred mainly in the apical segment of the samples, and Super EBA showed the highest values. The area and linear leakage were lower in the middle and coronal segments, regardless of the root-end filling material. No material perfectly sealed the root-end cavities, which allowed for the leakage occur- rence. Microsc. Res. Tech. 75:796-800, 2012. V C 2011 Wiley Periodicals, Inc.

Made available in DSpace on 2015-08-06T16:13:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2014. Added 1 bitstream(s) on 2015-08-06T16:45:02Z : No. of bitstreams: 1 ISSN2317-5907-2014-02-05-388-397.pdf: 772890 bytes, checksum: c9b85a7e81e668202fb453e03e4995f0 (MD5) Aim: The aims of this study were to assess the penetration of two endodontic sealers (salicylate and epoxy resin-based sealers) into dentinal tubules using CLSM; and to evaluate the bacterial leakage of roots filled with the same sealers associated with gutta-percha. Material and Methods: For sealer penetrability assessment, thirty bovine roots were instrumented and divided into three groups: AHP: EDTA + filling with AH Plus and gutta-percha (n=10), MTAF: EDTA + filling with MTA Fillapex and gutta-percha (n=10), control group: canals were not irrigated with EDTA and were filled with gutta-percha and AH Plus (n=5) or MTA Fillapex (n=5). Rhodamine B was added to the sealers in order to provide adequate fluorescence. The roots were transversely sectioned 3mm from the apex to enable CLSM analysis. Leakage was evaluated for turbidity of the broth in a split chamber model system for 30 days, using Enterococcus faecalis as a microbial marker. Thirty roots were instrumented and divided in four grupos: AHP: filling with AH Plus and gutta-percha (n=10); MTAF: filling with MTA Fillapex and gutta-percha (n=10); positive control: filling with gutta-percha without sealer (n = 5); negative control: sealing with cyanoacrylate to test the seal of the system (n = 5). Results: The medians for dentinal tubule penetration were 6.8% (AHP) and 6.6% (MTAF) (P = 0.82). The average time for bacterial leakage was 8 days in both experimental groups (P = 0.79). Conclusion: MTA Fillapex and AH Plus presented similar behavior regarding dentinal tubule penetration and bacterial leakage. Universidade Federal do Rio Grande do Sul, Departamento de Odontologia Restauradora Universidade do Sul de Santa Catarina, Departamento de Próteses Universidade de São Paulo, Departamento de Odontopediatria, Ortodontia e Saúde Coletiva, Faculdade de Odontologia de Bauru Universidade Estadual Paulista Júlio de Mesquita Filho, Departamento de Odontologia Restauradora, Faculdade de Odontologia de Araraquara