Root canal curvature influences uncontrolled removal of dentin and cleaning efficacy after ultrasonic activation

Abstract This study evaluated the correlation between root canal curvature and the effects of ultrasonic irrigation in the following parameters: volume of uncontrolled dentin removal (UDRVol), maximum depth of dentin defects, removal of accumulated hard tissue debris (AHTD), and canal transportation in prepared curved root canals. Twenty-four human permanent mandibular molars were divided into two groups according to root canal curvature: moderate curvature (MC: mean 25°); and severe curvature (SC: mean 48°). The specimens were scanned using an X-ray microcomputed scanner (Skyscan 1172) before and after cleaning and shaping and after the final irrigation protocol with ultrasonic irrigation. There was a moderate correlation between the degree of root canal curvature and the volume of remaining AHTD (p<0.05) and between the degree of root canal curvature and maximum depth of defects due to uncontrolled removal of dentin (p<0.05). The teeth in the SC group had a greater maximum depth of defects on the dentin wall in the apical third than the teeth in the MC group (p <0.05). Both groups had a significant reduction of AHTD in all canal thirds, but the amount of remaining AHTD in the middle and apical thirds and the whole canal was significantly greater in the SC than in the MC group (p <0.05). Canal transportation was not influenced by the canal curvature in all thirds (p >0.05). This study concluded that root canal curvature affects significantly the uncontrolled removal of dentin and remaining AHTD volume after the final irrigation protocol with ultrasonic irrigation.

Resumo Este estudo avaliou a correlação entre a curvatura do canal radicular e os efeitos da irrigação ultrassônica nos seguintes parâmetros: volume de remoção não controlada de dentina (UDRVol), profundidade máxima do desgaste de dentina, remoção de debris de tecido duro acumulado (AHTD) e transporte em canais radiculares curvos. Vinte e quatro molares inferiores humanos permanentes foram divididos em dois grupos de acordo com a curvatura do canal radicular: curvatura moderada (MC: média de 25°); e curvatura acentuada (SC: média de 48°). Os espécimes foram digitalizados usando um scanner microcomputador de raios X (Skyscan 1172) antes e depois da limpeza e modelagem e após a irrigação ultrassônica. Houve uma correlação moderada entre o grau de curvatura do canal radicular e o volume de AHTD remanescente (p<0,05) e entre o grau de curvatura do canal radicular e a profundidade máxima de defeitos devido à remoção descontrolada de dentina (p<0,05). Os dentes do grupo SC apresentaram maior profundidade máxima de defeitos na parede dentinária no terço apical do que os dentes do grupo MC (p<0,05). Ambos os grupos tiveram uma redução significativa de AHTD em todos os terços do canal, mas a quantidade de AHTD remanescente nos terços médio e apical e em todo o canal foi significativamente maior no grupo SC do que no grupo MC (p <0,05). O transporte do canal não foi influenciado pela curvatura do canal em todos os terços (p > 0,05). Este estudo concluiu que a curvatura do canal radicular afeta significativamente a remoção descontrolada de dentina e o volume remanescente de AHTD após a irrigação ultrassônica.

Tissue repair capacity of bioceramic endodontic sealers in rat subcutaneous tissue

Abstract This study aimed to evaluate the tissue repair capacity of four bioceramic endodontic sealers by quantifying type I and III collagen fibers. The following sealers were tested: EndoSequence BC Sealer (Brasseler, Brasseler, Savannah, USA), Bio C Sealer (Angelus, Londrina, Brazil), Bioroot RCS (Septodont, Santa Catarina, Brazil), and Sealer Plus BC (MKLife, Porto Alegre, Brazil). Polyethylene tubes 1.5 mm in diameter and 1 cm in length containing the endodontic sealers were implanted in the subcutaneous tissue of five rats (Rattus norvegicus albinus, Wistar lineage). After 14 days, the animals were euthanized, and collagen fibers were quantified from the histological tissue sections. Given a non-normal distribution of the data, a gamma regression with log link function was employed and implemented through the generalized linear models module, was used to test whether there was a significant difference between the sealers. The pairwise comparison was performed using Least significant difference. There were significant differences between the sealers for type I (p=0.001), type III (p=0.023), and total collagen (p=0.002). Overall, Bioroot sealer was statistically superior to the other sealers, except in the analysis of type III collagen, in which there was no difference between the Bioroot sealer and Bio C Sealer sealer and the control group (p>0.05). Bioroot RCS bioceramic endodontic sealer stimulates a greater production of collagen.

Resumo Este estudo visou avaliar a capacidade de reparação de tecidos de quatro cimentos endodônticos biocerâmicos através da quantificação de fibras colágenas de tipo I e III. Foram testados os seguintes cimentos: EndoSequence BC Sealer (Brasseler, Brasseler, Savannah, EUA), Bio C Sealer (Angelus, Londrina, Brasil), Bioroot RCS (Septodont, Santa Catarina, Brasil), e Sealer Plus BC (MKLife, Porto Alegre, Brasil). Foram implantados tubos de polietileno de 1,5 mm de diâmetro e 1 cm de comprimento contendo os cimentos endodônticos no tecido subcutâneo de cinco ratos (Rattus norvegicus albinus, linhagem Wistar). Após 14 dias, os animais foram eutanasiados e as fibras colágenas foram quantificadas a partir de cortes histológicos do tecido. Diante de uma distribuição não-normal dos dados, uma regressão gama com função de ligação log, implementada por meio do módulo de modelos lineares generalizados, foi empregada para testar se havia diferença significativa entre os cimentos. A comparação dois a dois foi realizada utilizando Least significant difference. Houve diferença significativa entre os cimentos para os colágenos tipo I (p=0,001), tipo III (p=0,023) e colágeno total (p=0,002). No geral, o cimento Bioroot foi estatisticamente superior aos demais cimentos, com exceção na análise do colágeno tipo III na qual não houve diferença entre o cimento Bioroot e o cimento Bio C Sealer e o grupo controle (p>0,05). O cimento endodôntico biocerâmico Bioroot RCS foi capaz de estimular uma maior produção de colágeno.

Resistência à fadiga cíclica dos instrumentos Reciproc e Mtwo nos movimentos rotatório e reciprocante / Resistance to cyclic fatigue of Reciproc and Mwto files on continuous rotation and reciprocating movements

Objetivo: O objetivo do presente estudo foi avaliar a influência da liga (NiTi convencional e M-Wire) e do movimento (reciprocante e rotação contínua) na resistência à fadiga cíclica. Métodos: Quinze limas Reciproc R25 (VDW GmbH, Munique, Alemanha) foram usadas em movimento reciprocante (MR), enquanto trinta limas Mtwo 25.07 (VDW GmbH, Munique, Alemanha) foram usadas em MR (n=15) ou em rotação contínua (RC) (n=15). Os instrumentos foram submetidos a ensaios dinâmicos movidos por motor elétrico, que permitiram reproduzir o movimento de pecking motion, a 300rpm de velocidade. Os instrumentos simularam a instrumentação de um canal radicular curvo com 40o e 5mm de raio de curvatura. A fratura dos instrumentos foi detectada por um sensor digital, e o tempo e o número de ciclos foram registrados. Os dados foram analisados estatisticamente pelos testes ANOVA e de Tukey (p<0,05). Resultados: Os instrumentos Reciproc R25 movidos por MR alcançaram número significativamente maior (p<0,05) de ciclos antes da fratura (1.777,68±334,2 ciclos), quando comparados aos instrumentos MT 25.07 movidos por MR (610,67±126,3 ciclos) ou RC (432,23±183,2 ciclos). Conclusões: O movimento reciprocante mostrou resistência à fadiga cíclica significativamente maior, e os instrumentos de NiTi M-Wire apresentaram maior resistência à fadiga cíclica do que os instrumentos rotatórios de NiTi convencional (AU).

Objective: The aim of present study was to evaluate the influence of alloy (conventional NiTi and M-Wire NiTi) and movement (reciprocating movement and continuous rotation) on resistance to cyclic fatigue. Methods: Fifteen Reciproc R25 files (VDW GmbH, Munich, Germany) were used in reciprocation motion (RM), while thirty MTwo 25/.07 files (VDW GmbH, Munich, Germany) were used either in RM (n=15) or in continuous rotation (CR) (n=15). The files were submitted to dynamic assays device moved by electric engine that allowed the reproduction of pecking motion under 300 rpm of speed. The files act simulating the instrumentation of a curved root canal with 40º and 5-mm of curvature radius. The fracture was detected by the device sensor and the time and number of cycles were obtained. Data were statistically analyzed by ANOVA and Tukeys tests (p<0.05). Results: The Reciproc R25 instruments moved by RM reached significantly higher number (p<0.05) of cycles before fracture (1777.68 ± 334.2 cycles) when compared with MTwo 25/.07 instruments moved by RM (610.67 ± 126.3 cycles) or CR (432.23 ± 183.2 cycles). Conclusions: The reciprocation motion showed significantly greater cyclic fatigue resistance and the M-Wire NiTi files showed higher cyclic fatigue resistance than conventional NiTi rotary files (AU).

Avaliação ex vivo da durabilidade de sistemas de instrumentação de NiTi tratados termicamente / Ex-vivo evaluation of the durability of thermally treated NiTi endodontic files

Objetivo: O presente estudo teve como objetivo comparar três sistemas de instrumentação de NiTi, tratados termicamente, quanto ao número de condutos instrumentados até a fratura. Métodos: Foram utilizados 210 molares humanos inferiores e superiores com curvaturas leves a moderadas, comprimentos reais entre 19 e 21 mm e forames apicais até 200µm. Esses foram randomicamente divididos em três grupos de acordo com o sistema de instrumentação utilizado: Reciproc (REC; R25), ProDesign Duo Híbrido (PDH; #25/.01 e #25/.08) e TF Adaptive (TFA; #25/.08). Foram utilizados 5 instrumentos/kits de cada sistema. Registrou-se, então, o número de condutos instrumenta- dos até a fratura e o número de reinserções necessárias até o alcance do comprimento de trabalho. Resultados: A análise estatística apontou diferenças significativas quando comparada a durabilidade dos sistemas, tendo os instrumentos do grupo PDH oferecido os maiores valores (29,2), seguido de REC (21,6) e TFA (15,4) (p<0,05). Quanto ao número de reinserções, o sistema TFA foi o que necessitou do menor número de reinserções (p<0,05). Conclusão: Nas condições do estudo, pode-se concluir que o sistema ProDesign Duo Híbrido foi o mais durável; ainda que o sistema TF Adaptive tenha alcançado o comprimento de trabalho com maior facilidade

Objective: The present study compared three systems of thermally treated NiTi endodontic files regarding their achieved number of prepared root canals before fracture. Methods: Two hundred and ten slightly and moderately curved upper and lower molars with actual length ranging from 19 to 21 mm and apex foramens diameters up to 200 µm were used. The sample was allotted to three groups according to the instrumentation system in use: Reciproc (REC; R25), ProDesign Duo Hybrid (PDH; #25/.01 and #25/.08), and TF Adaptive (TFA; #25/.08). Five instruments/kits of each system were used. Then, it was registered the number of root canals prepared until the instrument fractured and the number of reinsertions needed until the working length was achieved. Results: The statistical analysis showed significant differences among the durability of the three systems, being the instruments of group PDH the ones that yielded higher reuses (29.2) followed by groups REC (21.6), and TFA (15.4) (P < .05). Regarding the number of insertions, the TFA system was the one that needed the lowest number of reinsertions (P < .05). Conclusion: Under this study conditions, ProDesign Duo Hybrid was the most durable system, whereas TF Adaptive system was the one that most easily achieved the working length.

Knowledge about Coronavirus disease 19 (COVID-19) and its professional repercussions among Brazilian endodontists

Abstract The aim of this study was to assess Brazilian endodontists' level of knowledge about the coronavirus disease (COVID-19) and examine its professional repercussions. The link to the online survey that was created for this study was shared with Brazilian endodontists through social networking applications. The questionnaire contained questions that pertained to COVID-19 and its impact on dental practice. The collected data were analyzed using t-test, chi-square analysis, and analysis of variance, and the level of significance was set at 0.05. A total of 2,135 participants responded to the questionnaire, and all five Brazilian regions were represented in the sample. A total of 98.50% of endodontists reported that dental procedures can transmit COVID-19. Complete social distancing was practiced by 96.68% of the participants, and approximately 25% knew someone who had COVID-19. Moreover, in their daily practice, 72.13% of them implemented biosecurity measures that are ineffective in preventing COVID-19. Furthermore, 91.7% of them reportedly suspended elective dental procedures. Only 55.69% of them reported that they performed only emergency procedures in their workplaces. Those who believed that COVID-19 cannot be transmitted during dental procedures were less knowledgeable about the symptoms of COVID-19 (p = 0.0095). Endodontists who believed that personal protective equipment cannot prevent contamination were more knowledgeable about the symptoms of COVID-19 than their counterparts (p = 0.0003). The participating Brazilian endodontists demonstrated adequate knowledge about the risk of contamination during dental procedures and the main symptoms of COVID-19. Only some professionals reported providing emergency dental care during the pandemic.

Influência de soluções irrigadoras e de materiais obturadores na infiltração apical ­ análise pelo método de filtração de fluidos / Influence of irrigating solutions and of root filling materials on apical leakage ­ Fluid filtration method analysis

Objetivo: avaliar, por meio do método de filtração de fluidos, a influência da solução irrigadora e diferentes associações de materiais obturadores na infiltração apical. Métodos: foram utilizados 112 pré-molares inferiores extraídos, divididos em dois grupos controle (n=8) e oito grupos experimentais (n=12), de acordo com a solução irrigante: hipoclorito de sódio (H), vinagre de maçã (V), e, de acordo com o material obturador, guta-percha/AH Plus (GA), Resilon/Epiphany (RE), guta-percha/Epiphany (GE) e Resilon/AH Plus (RA). Os canais radiculares foram instrumentados e obturados pela técnica híbrida de Tagger. Em seguida, os canais foram desobturados nos terços médio e cervical, permanecendo apenas 4 mm do terço apical para a análise da infiltração pelo método de filtração de fluidos. Os dados foram analisados, estatisticamente, pelo teste de Kruskal-Wallis, sendo considerado significante quando P<0,05. Resultados: as médias obtidas de infiltração apical (µL/min) nos grupos foram: H/GA (0,03 ± 0,09), V/GA (0,04 ± 0,05), H/RE (0,06 ± 0,13), V/RE (0,10 ± 0,20), H/GE (0,08 ± 0,18), H/GE (0,16 ± 0,21), H/RA (0,40 ± 0,63) e V/RA (0,57 ± 1,13). Não foi observada diferença estatística quanto às soluções de irrigação aplicadas (P>0,05). No entanto, em relação aos materiais obturadores, verificou-se que os grupos obturados com a associação Resilon/AH Plus apresentaram, significativamente, maior infiltração que os demais grupos (P<0,05). Conclusões: a infiltração apical foi influenciada apenas pelos materiais obturadores, independentemente da solução de irrigadora.

Objective: to evaluate by fluid filtration method, the influence of the irrigating solution and different root filling materials associations in the apical leakage. Methods: One hundred-twelve lower premolars extracted were divided in 2 control groups (n=8) and 8 experimental groups (n=12), according to the irrigation solution; sodium hypochlorite (H), apple vinegar (V), and according to the root canal filling material, gutta-percha/AH Plus (GA), Resilon/Epiphany (RE), gutta-percha/Epiphany (GE), Resilon/AH Plus (RA). The roots canals were instrumented and filled by Tagger's hybrid technique being removed from the filling material, having remained only 4 mm of apical root third to analyze the leakage through fluid filtration method. Data were analyzed by Kruskal-Wallis test and P<0.05 was considered significant. Results: The apical leakage means (µL/min) observed in the groups were, H/GA (0.03 ± 0.09), V/GA (0.04 ± 0.05), H/RE (0.06 ± 0.13), V/RE (0.10 ± 0.20), H/GE (0.08 ± 0.18), H/GE (0.16 ± 0.21), H/RA (0.40 ± 0.63) e V/RA (0.57 ± 1.13). It was observed no statistical difference regarding the irrigation solutions applied (P>0.05), although the groups irrigated with sodium hypochlorite showed the best results. However, regarding the root canal filling material used, it was verified that the groups filled with Resilon/AH Plus association (H/RA e V/RA) have shown leakage higher significantly than other groups (P<0.05). Conclusion The apical leakage was influenced only by the root filling materials, regardless the irrigation solution.

Penetration of bioceramic and epoxy-resin endodontic cements into lateral canals

Abstract: The aim of the present study was to assess the penetration capacity of two endodontic cements, Endosequence BC Sealer and AH Plus, in artificial lateral canals. Twenty-six two-rooted, maxillary first premolars were instrumented to size 40.06 using K3 files. In each root, six lateral canals of two diameters (0.06 and 0.10 mm) were created with a working length of 2, 4, and 6 mm. The specimens were randomly divided into two groups according to the endodontic cement to be used (Endosequence BC Sealer and AH Plus) and obturated by the single-cone technique. The specimens were imaged by digital periapical radiography and scores from 0 to 4 were attributed according to the degree of penetration by sealers into the lateral canals. Data were analyzed statistically by Kruskal-Wallis and Student-Newman-Keuls tests, and a significance level of p < 0.05 was adopted. No significant difference was observed between the two endodontic cements used to fill the simulated lateral canals (p > 0.05). The diameter of lateral canals only influenced the capacity of the Endosequence BC Sealer in filling the canals, and presented greater penetration in the lateral canals of diameter 0.10 mm (p < 0.05). We concluded that the bioceramic endodontic cement Endosequence BC Sealer presented similar ability as AH Plus to fill simulated lateral canals.

Internal configuration of maxillary molars in a subpopulation of Brazil's Northeast region: A CBCT analysis

Abstract The present study aimed to evaluate the internal configuration of the maxillary molars of a population from the Northeast region of Brazil. Cone-beam computed tomography (CBCT) exams from 512 patients (1501 teeth) were evaluated regarding the anatomical configuration of the root canal system, according to Vertucci's classification. The images were obtained using a Prexion 3D scanner operating at 90 kVp and 4 mA. The voxel size was 0.125 mm and the cut thickness was 1 mm. The images were then analyzed in the Prexion 3D Viewer software. The data were analyzed statistically by Pearson's chi-square test, with 5% of significance. The first and second molars presented three roots in 99.14% and 87.27% of the cases, respectively. In relation to the number of canals, the first and second molars had a significantly higher frequency of three and four root canals respectively, presenting a higher prevalence of types I and II (p < 0.001). The second mesiobuccal canal (MB2) was observed in 48.21% and 22.72% of the first and second molars, respectively (p < 0.001). The identification of the MB2 canal was greater in young and adult patients (p < 0.001), presenting a higher prevalence in male patients (p < 0.001). The internal configuration of the MB root was influenced by gender and by age, presenting a higher prevalence of the MB2 in male patients younger than 50 years of age.

Influence of cross-section and number of use in cyclic fatigue resistance of rotary instruments

Aim: The aim of present study was to evaluate if the cross-section and the number of use have influence in cyclic fatigue resistance of rotary files. Methods: K3 Endo (group K) and EndoSequence (group E) files, 25/.04, 25 mm, were subdivided into 3 subgroups (n=12) according to the number of uses, 1, 3 and 5 uses, totalizing 72 files. The files were submitted to dynamic assays device moved by an electric engine, using 300 rpm of speed that permitted the reproduction of pecking motion. The files run within a temperate steel ring's groove, simulating an instrumentation of a curved root canal with 40-degrees and 5-mm of curvature radius. The fracture of file was detected by sensor of device and the time and the number of cycles was acquired. The data were analyzed statistically by two-way ANOVA (p<0.05). Results: There were no statistical significant differences in regard to the number of uses (p>0.05). K3 Endo files showed greater resistance to cyclic fatigue than EndoSequence instruments (p<0.01). Conclusion: It may be concluded that the cross-section of instruments presented significant influence in cyclic fatigue resistance and the number of uses up to 5 times had no influence in cyclic fatigue resistance in both NiTi rotation systems evaluated

Effect of different torques in cyclic fatigue resistance of K3 rotary instruments

Aim: To assess the effect of different torque values on cyclic fatigue resistance of K3 rotary nickel-titanium (NiTi) files. Methods: Eighty K3 files, size 25 mm, taper 0.04 were divided in 4 groups according to different torques (0.5, 1, 2 and 6 Ncm) and were submitted to a cyclic fatigue test. This test was performed with a device that allowed the file to rotate inside a stainless steel artificial curved canal, simulating the pecking motion. Files rotated until fracture occurred and time to failure was recorded in seconds with a stopwatch. Data were analyzed by ANOVA and Tukey tests (p<0.05). Results: All groups were compared and only the group of 6 N.cm showed statistically significant difference (p=0.0002). Conclusions: For #25.04 K3 files, the evaluated torques up to 2 N.cm had no influence on cyclic fatigue resistance. Using 6 N.cm torque value resulted in lower resistance to cyclic fatigue.

Ex vivo evaluation of three instrumentation techniques on E. faecalis biofilm within oval shaped root canals

The objective of the present study was to assess the effectiveness of reciprocating instrumentation in disinfecting oval-shaped root canals infected with Enterococcus faecalis. Forty-five human lower premolars were infected with a culture of E. faecalis (ATCC 29212) for 28 days. Five other teeth that were neither contaminated nor instrumented were used as controls. The 45 specimens were divided into three experimental groups (n = 15) based on the root canal preparation technique used: manual (K-type, Dentsply Maillefer, Ballaigues, Switzerland); rotary (MTwo, VDW GmbH, Munich, Germany); and reciprocating (Reciproc R50, VDW GmbH, Munich, Germany) instruments. During chemomechanical preparation, 21 mL of 2.5% NaOCl was used as the irrigating solution. Microbiological sampling was performed before (S1) and immediately after (S2) the chemomechanical preparation using sterilized paper points. Specimens were then cleaved, and 0.02 g of dentine chips was collected from the root thirds to verify the presence of microorganisms in dentinal tubules. All three preparation techniques reduced the number of microorganisms in the root canal lumen and dentine chips from the root thirds, but no significant differences were observed between the three groups (p > 0.05). Reciprocating instrumentation with Reciproc R50 was effective in reducing the number of microorganisms within the root canal system. Although this technique involves the use of only one file to perform the root canal therapy, it is as effective as conventional rotary instrumentation in reducing theE. faecalis biofilm from the root canal system. However, further clinical investigations are warranted in order to ratify these results.

Avaliação da radiopacidade, escoamento, pH e da liberação de íons cálcio de um cimento endodôntico biocerâmico / Evaluation of Radiopacity, flow, pH and release of calcium ions of a bioceramic root canal sealer

O objetivo do presente trabalho foi avaliar as propriedades físico-químicas de um cimento endodôntico biocerâmico, Endosequence BC Sealer (Brasseler USA, Savannah, GA, EUA). Radiopacidade, escoamento, pH e liberação de íons cálcio (Ca2+) foram analisadas e os resultados foram comparados aos do cimento AH Plus (Dentsply De Trey Gmbh, Konstanz, Alemanha). A radiopacidade e o escoamento foram avaliados de acordo com as normas ISO 6876/2001. Para o teste de radiopacidade, anéis metálicos com 10 mm de diâmetro e 1 mm de altura foram preenchidos com os cimentos. O valor da radiopacidade foi determinado de acordo com a densidade radiográfica, representada em mm Al. A análise do escoamento foi feita com 0,05 mL de cada cimento colocados sobre uma placa de vidro. Outra placa de vidro, com 20 g, foi cuidadosamente colocada sobre o cimento e sobre esta um peso de 100 g, totalizando 120 g, que permaneceram por 7 minutos. Em seguida, foram medidos os diâmetros maiores e menores dos discos formados, sendo esta feita com um paquímetro digital. A liberação de íons cálcio (Ca2+) e o pH foram medidos nos períodos de 3, 24, 72, 168 e 240 horas, com o auxílio de um espectrofotômetro e pHmetro, respectivamente. Os resultados foram analisados estatisticamente pelos testes ANOVA e Tukey, sendo considerado significante quando p<0,05. O cimento biocerâmico analisado apresentou radiopacidade (3,84 mm Al) significantemente menor do que o AH Plus (6,90 mm Al). Foi observado que o cimentos Endosequence BC Sealer e o AH Plus apresentaram escoamentos de 26,96 mm e 21,17 mm, respectivamente (p<0,05). O cimento biocerâmico apresentou maior pH e maior liberação de íons cálcio (Ca2+) do que o cimento AH Plus (p<0,05). Concluiu-se que o cimento Endosequence BC Sealer apresentou valores de radiopacidade e de escoamento em concordância com as norma ISO 6876/2001. Os valores de pH e de liberação de íons cálcio (Ca2+) foram favoráveis para um cimento endodôntico.

The aim of the present study was to evaluate the physicochemical properties of a bioceramic root canal sealer, Endosequence BC Sealer. Radiopacity, pH, release of calcium ions (Ca2+) and flow were analyzed and the results were compared with AH Plus cement. Radiopacity and flow were evaluated according to ISO 6876/2001 standards. For the radiopacity analysis, metallic rings with 10 mm in diameter and 1 mm of thickness were filled with cements. The radiopacity value was determined according to radiographic density (mm Al). The flow test was performed with 0.05 mL of cement placed on a glass plate. A 120-g weight was carefully placed over the cement. The largest and smallest diameters of the disks formed were measured using a digital caliper. The release of Ca2+ and pH were measured at periods of 3, 24, 72, 168 and 240 hours, with spectrophotometer and pHmeter, respectively. Data were analyzed by ANOVA and Tukeys test (p<0.05). The bioceramic endodontic cement showed radiopacity (3.84 mm Al) significantly lower than that of AH Plus (6.90 mm Al). The pH analysis showed that Endosequence BC Sealer showed pH and release of Ca2+ greater than those of AH Plus (p<0.05), during the experimental periods. The flow test revealed that the BC Sealer and AH Plus presented flow 26.96 mm and 21.17 mm, respectively (p<0.05). Endosequence BC Sealer showed radiopacity and flow according to ISO 6876/2001 recommendations. The others physicochemical properties analyzed demonstrated favorable values for a root canal sealer.

Fontes de financiamento em ensaios clínicos: análise crítica / Sources of funding in clinical trials: critical analysis

Os ensaios clínicos são de grande valor para a descoberta e confirmação de terapias contra diferentes patologias. A declaração CONSORT tem o objetivo de evitar erros metodológicos e de interpretação de resultados em ensaios clínicos. Este artigo faz uma análise crítica acerca do item 25 da declaração CONSORT 2010, sobre Fontes de Financiamento em ensaios clínicos randomizados, pois pode haver tendenciosidade na publicação de resultados de pesquisas patrocinadas por indústrias. Assim, verifica-se a necessidade de adequação das pesquisas clínicas, principalmente quanto ao registro e à transparência no financiamento, a fim de promover uma real melhoria destas pesquisas, promovendo o surgimento de novas terapias.

Clinical trials in the medical are of great value for the discovery and confirmation of therapies against different diseases. However, one senses a possible bias in scientific articles published from clinical trials sponsored by industry. The CONSORT statement aims to avoid methodological errors and interpretation of results in clinical trials. Thus, this article makes a critical analysis of item 25 of the 2010 update of the CONSORT statement on Sources of Funding in randomized clinical trials. Thus, there is a need for adequacy of clinical research, especially regarding the registration and ethics in finance in order to promote a real improvement of this research, fostering the emergence of new therapies.

A comparative scanning electron microscopy evaluation of smear layer removal with apple vinegar and sodium hypochlorite associated with EDTA

OBJECTIVE: The purpose of this study was to evaluate by scanning electron microscopy (SEM) the removal of smear layer from the middle and apical root thirds after use of different irrigating solutions. MATERIAL AND METHODS: Forty roots of permanent human teeth had their canals instrumented and were randomly assigned to 4 groups (n=10), according to the irrigating solution: apple vinegar (group A), apple vinegar finished with 17 percent ethylenediaminetetraacetic acid (EDTA) (group B), 1 percent sodium hypochlorite (NaOCl) finished with 17 percent EDTA (group C) and saline (group D - control). After chemomechanical preparation, the roots were cleaved longitudinally and their middle and apical thirds were examined by SEM at ×1,000 magnification. Two calibrated examiners (kappa=0.92) analyzed the SEM micrographs qualitatively attributing scores that indicated the efficacy of the solutions in removing the smear layer from the surface of the dentin tubules (1 - poor, 2 - good and 3 - excellent). Data from the control and experimental groups were analyzed by the Kruskal-Wallis and Dunn's test, while the Wilcoxon test was used to compare the middle and apical thirds of the canals within the same group (a=0.05). RESULTS: The middle third presented less amount of smear layer than the apical third, regardless of the irrigant. There was statistically significant difference (p=0.0402) among the groups in the middle third. In the apical third, the apple vinegar/EDTA group showed the greatest removal of smear layer (p=0.0373). CONCLUSION: Apple vinegar associated or not with EDTA was effective in removing smear layer when used as an endodontic irrigant.

Evaluation of apical leakage of white MTA associated with two different vehicles / Avaliação da infiltração apical do MTA branco associado a dois diferentes veículos

Objective - Compare ex vivo apical leakage of white Mineral Trioxide Aggregate (MTA) associated with distilled water or AH Plus endodontic sealer when used as retrofilling materials. Methods - Forty-four extracted human molars were randomly distributed into four groups. Their distal/palatine roots were sectioned and chemical-mechanical preparation was performed by the step technique up to instrument #55. The roots were filled with gutta-percha cones and endodontic sealer (Tagger's hybrid technique). The roots had the apex removed with a 90º angulation, and after sealing, ultrasonic retro preparations were performed (depth 3mm), following the long axis of the root. The retrograde cavities were retrofilled with White MTA powder associated with distilled water (Group I) or AH Plus endodontic sealer (Group II). In Group III (positive control) no retrofilling was performed and the specimens from Group IV (negative control) were completely covered with sealant.The roots were immersed in Indian ink and kept in an oven (37ºC, 48 hours). Longitudinal wear of the root apical portion was performed in the vestibular-palatine direction, in order to analyze leakage. Results - Among the experimental groups, Group II showed less leakage than Group I (p<0.05). Conclusion - The association MTA/AH Plus sealer showed less marginal leakage when compared with MTA/distilledwater.

Objetivo - Comparar ex vivo a infiltração apical do Mineral Trióxido Agregado (MTA) associado à água destilada ou ao cimento endodôntico AH Plus quando usados materiais retro-obturadores. Métodos - Quarenta e quatro molares foram randomicamente distribuídos em quatro grupos. Os dentes tiveram as raízes distais ou palatinas seccionadas e o preparo químico-mecânico realizado pela técnica escalonada até o instrumento #55. As raízes foram obturadas com cones de guta-percha e cimento endodôntico (Técnica híbrida de Tagger). As raízes tiveram os ápices removidos com uma angulação de 90º e, após a impermeabilização externa, foram feitos retro-preparos ultrassônicos (3 mm de profundidade), seguindo o longo-eixo radicular. As cavidades retrógradas foram preenchidas com o pó do MTA branco associado à água destilada (Grupo I) ou ao cimento endodôntico AH Plus (Grupo II). No Grupo III (controle positivo), não houve o preenchimento das cavidades e, os espécimes do Grupo IV (controle negativo) foram completamente cobertos com o material impermeabilizante. As raízes foram imersas em tinta Nanquim, permanecendo por 48 horas a 37ºC. Cortes longitudinais foram feitos na porção apical no sentido vestíbulo-palatino, a fim de analisar-se a infiltração. Resultados - Entre os grupos experimentais, o Grupo II apresentou menores infiltrações do que o Grupo I (p<0,05). Conclusão - A associação entre o MTA branco e o cimento AH Plus apresentou menores infiltrações quando comparada ao MTA branco e a água destilada.

Análise comparativa da infiltração apical entre diferentes materiais retro-obturadores / Comparative analysis of apical leakage among four differents retrofilling materials

The aim of this study was to compare the apical sealing ability between the white MTA, gray MTA, Super EBA and Sealapex/Zinc Oxide association when used as root-end filling materials. Forty four maxillary central incisors extracted were distributed in four groups with 10 specimens each and two control groups with two specimens each. The teeth had their crowns sectioned and their canals instrumented by step-back technique to #60 file, using constant irrigation of 2.5% sodium hypochlorite. Roots were filled with gutta-percha and EndoFill sealer by Tagger's hybrid technique. The apical 3 mm of each root was resected, and 3-mm deep root-end cavity preparations were made. The root-end cavities were filled with white MTA, gray MTA, Super EBA and Sealapex/ZO. The roots were immersed in Rhodamine B and kept in an oven for 72 hours at 37ºC. A longitudinal section was performed to verify using Image Tool the dye penetration. Statistical analysis showed that the group sealed with Super EBA showed lower apical leakage than the other groups, showing significant difference (p <0.05) only in relation to white MTA and gray MTA. It was concluded that the Super EBA and the Sealapex/ZO association showed adequate apical seal in retro-fillings.

O objetivo deste trabalho foi comparar ex vivo a capacidade seladora apical entre o MTA branco, o MTA cinza, o Super EBA e a associação Sealapex/Óxido de Zinco quando usados como materiais retro-obturadores. Foram divididos 44 incisivos centrais superiores humanos extraídos em quatro grupos experimentais com 10 espécimes cada e dois grupos controles com 2 espécimes cada. Os dentes tiveram as coroas seccionadas e seus canais instrumentados pela técnica escalonada até o instrumento #60, usando irrigação constante com hipoclorito de sódio 2,5%. As raízes foram obturadas com cones de guta-percha e cimento endodôntico EndoFill, pela técnica híbrida de Tagger. Os 3 mm apicais de cada raiz foram seccionados e foram feitas cavidades apicais com 3 mm de profundidade. As cavidades apicais foram preenchidas com os materiais MTA branco, MTA cinza, Super EBA e Sealapex/OZ. As raízes foram imersas no corante Rodamina B e mantidas numa estufa por 72 horas, à temperatura de 37ºC. Uma secção longitudinal foi realizada, a fim de verificar usando o programa Image Tool a penetração do corante. A análise estatística mostrou que o grupo selado com o Super EBA exibiu menores infiltrações apicais do que os demais grupos experimentais, apresentando diferença significante (p<0,05) apenas em relação ao MTA branco e o MTA cinza. Concluiu-se que o Super EBA e a associação Sealapex/OZ apresentaram selamento apical adequado em retro-obturações.

Tratamento cirúrgico em transmigração de canino inferior impactado: relato de caso / Surgical treatment of impacted lower canine transmigration: case report

The occurrence of impacted lower canine is not uncommon in daily clinical dental practice. Thus, several treatment modalities are proposed, with the main objective of trying to reposition the tooth to the dental arch and stabilize the occlusion, promoting an aesthetic and functional harmony. However, the orthodontic traction of teeth when present in the mandibular midline becomes difficult to be realized. The aim of this article was report the surgical treatment under local anesthesia and intra-oral access, an impacted lower canine on mentual region. Due to the horizontal position of the tooth and bone density site, orthodontic traction was discarded. With the aid of radiographic images, surgical planning was performed with great precision. It was concluded that the radiographic exams, especially the panoramic radiography, are important for planning and implementation of treatment in cases of lower canines with transmigration, is also crucial to the multidisciplinary approach involving the ortho-surgical planning.

A ocorrência de caninos inferiores impactados não é incomum na prática clínica odontológica diária. Assim, diversas modalidades de tratamento são propostas, com o objetivo principal de tentar reposicionar o dente para o arco dentário, estabilizando a oclusão, promovendo uma harmonia estética e funcional. Entretanto, o tracionamento ortodôntico desses dentes quando presentes na linha média mandibular se torna difícil de ser realizado. O objetivo deste artigo foi fazer o relato do tratamento cirúrgico, sob anestesia local e acesso intra-oral, de um canino inferior impactado na região mentoniana. Devido à posição horizontal do dente e à densidade óssea local, o tracionamento ortodôntico foi descartado. Com o auxílio de imagens radiográficas, o planejamento cirúrgico foi realizado com grande precisão. Concluiu-se que os exames radiográficos, principalmente a radiografia panorâmica, são importantes para o planejamento e a execução do tratamento em casos de caninos inferiores com transmigração, sendo também de fundamental importância a abordagem multidisciplinar envolvendo o planejamento orto-cirúrgico.

Levantamento epidemiológico da posição dos terceiros molares na clínica de radiologia da Universidade Federal do Ceará / Epidemiological survey of wisdom teeth position in radiology clinic of the Federal University of Ceará

Impacted teeth are called who, once arriving at the normal time that would erupt, are closed partially or completely inside the bone, with no maintenance or pericoronal follicle. The etiology of the impaction is related mainly to the lack of available space in the region characteristic accentuated in the modern population, which appears to have lower bone growth. The aim of this study was to assess the prevalence of wisdom teeth and classify them according to their positioning. Based on patients' charts the Radiology Clinic of Dentistry College, Federal University of Ceará, from 2007 to 2008, 297 panoramic radiographs were examined. Eight hundred eighty seven teeth were observed, of which 442 upper molars and 445 lower molars. The frequency of the position of wisdom teeth was analyzed based on the Winter (1926) and Pell & Gregory (1933) classifications. The results, according to Winter’s classification, was a higher frequency of upper molars upright (64.26%) and lower molars in mesioangular position (54.36%). According to Pell & Gregory’s classification, the third molars were observed in Class II in 72.8% and in position A in 47.6% of cases.

Denominam-se dentes inclusos aqueles que, uma vez chegada à época normal em que deveriam irromper, ficam encerrados parcial ou totalmente no interior do osso, com manutenção ou não do folículo pericoronário. A etiologia da impacção está relacionada principalmente à falta de espaço disponível na região, característica acentuada na população moderna, que parece apresentar menor crescimento ósseo. O objetivo desse estudo foi verificar a prevalência de terceiros molares e classificá-los quanto a sua posição. Tomando como base os prontuários dos pacientes da Clínica de Radiologia da Faculdade de Odontologia da Universidade Federal do Ceará, no período de 2007 a 2008, foram examinadas 297 radiografias panorâmicas, sendo observados 887 dentes, dos quais 442 molares superiores e 445 inferiores. Foi analisada a freqüência da posição dos terceiros molares baseado na classificação de Winter e Pell & Gregory. Os resultados encontrados, de acordo com a classificação de Winter, foram uma maior freqüência dos molares superiores na posição vertical (64,26%) e dos molares inferiores na posição mesioangular (54,36%). De acordo com a classificação de Pell & Gregory, os 3º molares inferiores apresentaram-se em classe II em 72,8% e na posição A em 47,6% dos casos.

Ocorrência de molares supranumerários em pacientes da clínica de radiologia da Universidade Federal do Ceará / Occurrence of supernumerary molars in patients from the Radiology Clinic of Federal University of Ceará

Hyperdontia is a dental anomaly, very common and widely studied, caused by excessive teeth in the oral cavity. This disturb represents an abnormal formation of one or more teeth in both dental arch. The diagnosis is normally based on conventional radiography exams, mainly panoramic radiographies, and in some cases, a computed tomography. In the present study, 1.325 panoramic radiographies were evaluated, all from patients seen by the Radiology Clinic of Federal University of Ceará, residents in Fortaleza, over the period from October 2007 to December 2008. The aim was to evaluate the occurrence of supernumerary molars. Twenty five patients presented supernumerary molars, 13 men and 12 women. However, it was not observed differences statistically significant (p= 0,5264). The occurrence in the maxilla was more common compared to the mandible. A considerable occurrence of supernumerary molars in the examined population was reported, reinforcing the importance of a premature diagnosis in this dental anomaly, in order to perform the treatment if necessary.

A Hiperdontia é uma anomalia dentária muito comum e largamente estudada, causada por um número excessivo de dentes na cavidade oral. Esse distúrbio representa uma formação anormal de um ou mais dentes em ambos os arcos dentários. O diagnóstico normalmente é baseado em exames radiográficos convencionais, principalmente a radiografia panorâmica, e em alguns casos, a tomografia computadorizada. No presente estudo, 1325 radiografias panorâmicas foram avaliadas, todas de pacientes atendidos na clínica de Radiologia da Universidade Federal do Ceará, residentes em Fortaleza, no período de outubro de 2007 a dezembro de 2008. O objetivo foi avaliar a ocorrência de molares supranumerários. Vinte e cinco pacientes apresentaram molares supranumerários, sendo 13 homens e 12 mulheres. Entretanto, não foi observada nenhuma diferença estatisticamente significante (p= 0,5264). A ocorrência na maxila foi mais comum em comparação à mandíbula. Foi observada uma considerável ocorrência de molares supranumerários na população examinada, reforçando a importância do diagnóstico precoce dessa anomalia dentária, a fim de estabelecer um tratamento, se necessário.