Abstract The aim of this study was evaluate the influence of ultrasonic activation (UA) of AH Plus to improve canal and isthmus filing, and analyse the antimicrobial effect against Enterococcus faecalis within dentinal tubules. Material and Methods: Thirty mesial roots of mandibular first molars were selected and divided into 2 groups (n = 15): with and without UA of the sealer. Then the root canals were filled by using the single cone technique, and the specimens were sectioned at 2, 4 and 6 mm from the apex for stereomicroscope and confocal laser scanner microscopy (CLSM) analysis. In addition, 30 bovine incisors were contaminated with Enterococcus faecalis and divided into 3 groups (n = 10). The specimens were obturated by using the single cone technique with (G1) and without (G2) UA of the sealer and G3 as the control group. All were sectioned into 6 mm-long cylinders and stained with LIVE/DEAD to assess bacterial viability by CLSM. Results: The UA of the sealer significantly reduced the presence of unfilled areas in the canal and isthmus area in all sections (p<0.05), and there was a significant increase in sealer penetration in both canals and isthmuses (p<0.05). As regards gaps, a significant reduction was found at 2 and 6 mm in the isthmus area of the UA group (p<0.05). Moreover, UA of the sealer significantly reduced bacterial viability in the superficial dentine when compared with the other groups (p<0.05). Conclusion: Ultrasonic activation of the AH Plus sealer promoted a better quality of root canal filling and increased the intratubular penetration of sealer, especially in the isthmus area. Additionally, ultrasonic activation of the sealer increased the intradentinal antimicrobial action against Enterococcus faecalis, mainly in the superficial dentine of the root canal.

Resumo O objetivo deste estudo foi avaliar a influência de diferentes protocolos de irrigação ultrassônica passiva na remoção de detritos em sulcos artificialmente criados nos terços radiculares cervical, médio e apical. Quarenta raízes de incisivos bovinos extraídos foram instrumentadas a 1 mm do ápice radicular com um instrumento R50 Reciproc e irrigadas com hipoclorito de sódio a 2,5%. As raízes foram então inseridas numa mufla e clivadas em duas hemisecções. Sulcos (3 mm de comprimento) foram feitos a 2, 7 e 12 mm do ápice radicular em uma hemisecção e preenchidos com detritos dentinários. As hemisecções foram reagrupadas na mufla e divididas em 4 grupos (n = 10) de acordo com o protocolo de irrigação final: Grupo controle: 3x20 s usando agulha de calibre #30 sem agitação da solução irrigadora; Grupo PUI-s (static passive ultrasonic irrigation): 3x20 s de irrigação ultra-sônica passiva com a ponta do inserto mantida estática no terço apical; Grupo PUI-t (Irrigação ultrassônica passiva por terço): 20 s de PUI em cada terço; Grupo PUI-d (Irrigação ultrassônica dinâmica): 3x20 s de PUI movendo dinamicamente o inserto em toda extensão do canal radicular. Em todos os grupos, foi utilizado um total de 6 mL de hipoclorito de sódio a 2,5% como irrigante. Após estes procedimentos, os sulcos foram analisadas com um estereomicroscópio e pontuações foram atribuídas quanto à remoção dos detritos. Os dados foram analisados estatisticamente (a=0.05). Os resultados mostraram uma melhor limpeza em todos os grupos onde a solução de irrigação foi agitada com dispositivo ultrassônico do que no grupo controle (p<0,05). No terço apical, o PUI-d e o PUI-s apresentaram performance semelhantes (p>0,05) e melhor limpeza do que o PUI-t (p<0,05). Os métodos dinâmico e estático de agitação da solução de irrigação proporcionaram uma limpeza mais eficaz. O PUID promoveu os sulcos mais completamente limpos sugerindo que seu uso é o mais adequado em casos de dentes com anatomia de canal complexa.

Abstract The aim of this study was to evaluate the influence of different passive ultrasonic irrigation protocols on the removal of debris in artificially created grooves in the cervical, middle and apical root thirds. Forty extracted bovine incisor roots were instrumented to 1 mm of the root apex with a R50 Reciproc instrument and irrigated with 2.5% sodium hypochlorite. The roots were then inserted in a muffle and cleaved into two hemisections. Grooves (3-mm long) were done at 2, 7 and 12 mm from the root apex in one hemisection and filled with dentinal debris. The hemisections were regrouped into the muffle and divided into 4 groups (n=10) according to the final irrigation protocol: Control group: 3x20 s using a #30 gauge needle without agitation of the irrigating solution; Group PUI-s (static passive ultrasonic irrigation): 3x20 s of passive ultrasonic irrigation with the tip of the insert maintained static on the apical third; Group PUI-t (passive ultrasonic irrigation per third): 20 s of PUI in each third; Group PUI-d (passive dynamic ultrasonic irrigation): 3x20 s of PUI dynamically moving the insert in the whole extent of the root canal. In all groups, was used a total of 6 mL of 2.5% sodium hypochlorite as irrigant. After these procedures, the grooves were analyzed with a stereomicroscope and assigned scores as regards removal of the debris. The data were analyzed statistically (a=0.05). The results showed a better cleaning in all the groups where the irrigating solution was agitated with ultrasonic device than in the control group (p<0.05). In the apical third, the PUI-d and PUI-s showed similar performance (p>0.05) and a better cleanness than PUI-t (p<0.05). The dynamic and static methods of agitation of the irrigating solution provided more effective cleaning. PUI-d provided the most completely clean grooves suggesting that its use is the most adequate in cases of teeth with complex canal anatomy.

OBJECTIVES: To evaluate the sealing ability of five root canal sealers, including two experimental cements (MBP and MTA-Obtura) using the fluid filtration method. MATERIAL AND METHODS: Teeth were divided into 5 study groups: G1-AH Plus; G2-Acroseal; G3Sealapex; G4-MBP; G5-MTA-Obtura; and two controls. Chemical-mechanical preparation was performed with ProFile rotary nickel-titanium instruments 1 mm short of the apical foramen. The sealing ability was evaluated by fluid filtration at 15, 30, and 60 days. RESULTS: The statistical analysis showed significant difference between the materials at different periods (p<0.05). AH Plus and MBP had similar leakage values at 15 and 60 days, alternating with significant reduction at 30 days, while the other materials showed progressive increase in leakage values. Acroseal and Sealapex presented the best results at 15 days and the worst at 60 days. CONCLUSIONS: All sealers evaluated presented fluid leakage, with AH Plus and MBP showing the best results at the end of the experimental period. Acroseal, Sealapex, and MTA-Obtura presented increase in leakage values at longer observation periods.

This ex vivo study evaluated the quality of digital radiographic images obtained with the photostimulable phosphor plate system (Digora) according to the processing delay and maintenance of optical plates in either opaque (supplied with the system) or transparent protective plastic cases during this period. Five radiographs were obtained from the mandibular molar region of a dry human mandible using optical plates. These plates were placed in the protective plastic cases before obtaining the radiographs and were processed immediately or after processing delays of 5, 60 and 120 min, when the case was removed. The results revealed a reduction in image quality when processing was delay 120 min compared to the other times. The opaque case provided better protection to the sensor than the transparent case. In conclusion, a 120-min processing delay for the Digora system caused a reduction in image quality, yet without interfering with the quality of diagnosis. The opaque case supplied by the system's manufacturer provided better protection to the optical plate than the transparent case.

The aims of this study were to evaluate the quality of indirect digitized radiographic images taken during endodontic procedures and to compare the measurements recorded with this technique to those obtained from conventional radiographs. Two-hundred conventional periapical radiographs taken at the undergraduate Endodontics Clinic of the Dental School of Bauru were digitized. The conventional and indirect digitized images were compared by three examiners as to the quality and accuracy of the measurements recorded during endodontic treatment, in canal length determination, gutta-percha adaptation, lateral condensation and final obturation. The conventional radiographs were observed on a film viewer, surrounded by a dark card, and measured with magnifying glass and a millimeter ruler; the indirect digitized images were evaluated on the Digora® for Windows software, with free utilization of the bright/contrast tool. Unlike the conventional radiographic images, all indirect digitized images were considered as having a high quality. The distance between the filling material and the root apex was 0.117 mm larger, on average, for the Digora® system (p<0.01). The measurements achieved by the investigated radiographic methods were clinically similar and they are thus equivalent. Changes in brightness and contrast of the images using Digora®software improved the diagnosis.

This study evaluated the sealing ability of apical plugs made of white and gray MTA-Angelus® and white Portland cement placed via the root canal and having different thicknesses (2, 5 and 7 mm). Ninety extracted human single-rooted teeth were instrumented using a size 40 K-file to standardize the foraminal opening by the stepback technique. The teeth were assigned to 3 groups (n=30), according to the material used for fabrication of the apical plugs: A = gray MTA; B = white MTA; C = white Portland cement. The groups were subdivided into groups of 10 teeth each according to the apical plug thickness (2, 5 and 7 mm). Marginal apical dye leakage was assessed using 0.2% Rhodamine B solution in which the specimens were immersed for 72 hours at 37ºC. The roots were sectioned longitudinally in a buccolingual direction for apical plug exposure, and digital photographs were taken and analyzed by Image Tool image-analysis software. Data were analyzed statistically by Kruskal-Wallis and Dunn's tests. Significance level was set at 5%. The least percent leakage was observed for 5- and 7-mm-thick plugs (p<0.05). No significant difference (p>0.05) was found between gray MTA and white Portland cement. Among the three materials analyzed, white MTA presented the highest marginal leakage (p<0.05). The findings of the present study showed that gray MTA and Portland cement had better sealing ability than white MTA when used as apical plugs. Dye leakage was smaller for 5- and 7-mm-thick plugs compared to 2-mm-thick plugs.

OBJECTIVE: The efficiency of rotary, manual and ultrasonic root canal instrumentation techniques was investigated in proximally flattened root canals. MATERIAL AND METHODS: Forty human mandibular left and right central incisors, lateral incisors and premolars were used. The pulp tissue was removed and the root canals were filled with red die. Teeth were instrumented using three techniques: (i) K3 and ProTaper rotary systems; (ii) ultrasonic crown-down technique; and (iii) progressive manual technique. Roots were bisected longitudinally in a buccolingual direction. The instrumented canal walls were digitally captured and the images obtained were analyzed using the Sigma Scan software. Canal walls were evaluated for total canal wall area versus non-instrumented area on which dye remained. RESULTS: No statistically significant difference was found between the instrumentation techniques studied (p<0.05). CONCLUSION: The findings of this study showed that no instrumentation technique was 100% efficient to remove the dye.

Este trabalho tem como objetivo testar a solução de nitrato de gálio, um inibidor da reabsorção, como curativo intracanal para dentes reimplantados tardiamente. Trinta incisivos centrais superiores direitos de ratos foram avulsionados e mantidos a seco por trinta minutos. Todos os dentes tiveram os canais radiculares instrumentados e a superfície radicular tratada com hipoclorito de sódio a 1%, seguido de fluoreto de sódio a 2%. Após isso, os dentes foram divididos em dois grupos de acordo com a medicação intracanal: no grupo I, foi usada solução de nitrato de gálio e grupo II, pasta de hidróxido de cálcio. Todos os dentes foram, então, reimplantados em seus respectivos alvéolos. Passados 15, 30 e 60 dias do reimplante, os animais foram sacrificados e as peças obtidas, processadas em laboratório para análise microscópica e morfométrica. Os resultados mostraram que a solução de nitrato de gálio e a pasta de hidróxido de cálcio limitaram a reabsorção radicular, mas não impediram a sua ocorrência. Conclui-se que ambos os medicamentos têm ação semelhante.

The purpose of this study was to test a gallium nitrate solution, a resorption inhibitor, employed as a root canal dressing in teeth submitted to late replantation. Thirty maxillary right central incisors of rats were avulsed and kept dry for thirty minutes. The teeth were instrumented and the root surfaces were treated with 1% hypochlorite solution followed by application of 2% sodium fluoride. Thereafter, the teeth were divided into two groups according to the root canal dressing: Group I, solution of gallium nitrate; and Group II, calcium hydroxide paste. The teeth were then replanted in their respective sockets. The animals were killed at 15, 30 and 60 days after replantation and the samples were processed for morphometric and microscopic analysis. The results demonstrated that the gallium nitrate solution and the calcium hydroxide paste limited the root resorption, yet they did not impair its occurrence. It may be concluded that gallium nitrate solution and calcium hydroxide paste demonstrated similar performance.

Esta pesquisa avaliou a capacidade seladora de dois cimentos temporários (Cimpat branco e IRM) e um cimento restaurador em canais preparados para pinos intra-radiculares. Foram usadas 60 raízes palatinas de primeiros molares superiores humanos. Elas foram divididas em 3 grupos, conforme os cimentos usados: grupo I (Cimpat), grupo II (IRM) e grupo III (ionômero de vidro). As raízes foram impermeabilizadas, preenchidas com os respectivos cimentos e em seguida imersas em tintura de Rhodamina B a 0,2% e mantidas por 72 horas em uma estufa a 37ºC. A micro infiltração foi mensurada com um microscópio de luz nas raízes cortadas longitudinalmente, na direção vestíbubo-lingual. Os resultados mostraram que o grupo I apresentou, de modo significante, mais infiltração do que os grupos II e III, enquanto que entre estes não houve diferença significante.

This research evaluated the sealer ability of 2 temporary filling materials (white Cimpat and IRM) and 1 restorative cement (glass ionomer), in canals prepared for root posts. Sixty human palatal roots of maxillary first molars were used. They were divided into 3 groups, according to the cements used: Group I (Cimpat), Group II (IRM) and Group III (glass ionomer). The roots were rendered impermeable, filled with the respective cements and soon after immersed into 0.2% Rhodamine B dye and maintained for 72 hours in an oven for 37°C. Microleakage was measured with a light microscope, cutting the roots longitudinally in buccolingual direction. The results showed that Group I presented significantly more leakage than Groups II and III, which were not significantly different from each other.

Considerando estudos anteriores sobre a similaridade entre a composição química do agregado de trióxido mineral e o cimento Portland, o objetivo deste estudo foi investigar a resposta pulpar de dentes de cães após pulpotomia e proteção pulpar direta com MTA Angelus e cimento Portland branco. Trinta e oito remanescentes pulpares foram recobertos com esses materiais. Cento e vinte dias após o tratamento, os animais foram sacrificados e os espécimes removidos e preparados para análise histológica. Ambos os materiais demonstraram os mesmos resultados quando utilizados como materiais de capeamento pulpar, induzindo a formação de ponte de tecido mineralizado e mantendo a vitalidade pulpar em todos os espécimes. Ambos matérias se mostraram efetivos como protetores pulpares após pulpotomia em dentes de cães.

Considering previous studies on the similarity between the chemical composition of the mineral trioxide aggregate and the Portland cement, the purpose of this study was to investigate the pulp response of dog's teeth after pulpotomy and direct pulp protection with MTA Angelus and white Portland cement. Thirty eight pulp remnants were protected with these materials. One hundred and twenty days after treatment, the animals were sacrificed and the specimens removed and prepared for histological analysis. Both materials demonstrated the same results when used as pulp capping materials, inducing hard tissue bridge formation and maintaining pulp vitality in all specimens. The MTA Angelus and the white Portland cement showed to be effective as pulp protection materials following pulpotomy.

O objetivo deste trabalho foi avaliar a influência do posicionamento da placa óptica do Digora em relação ao eixo dentário na determinação do comprimento de dentes. Sessenta dentes humanos extraídos foram avaliados, divididos em: dez incisivos superiores, dez incisivos inferiores, dez pré-molares superiores, dez pré-molares inferiores, dez molares superiores e dez molares inferiores. Eles foram radiografados com placa óptica do sistema de imagem digital Digora em duas posições: com seu longo eixo paralelo ao comprimento da placa óptica e com seu longo eixo paralelo à largura da mesma. As medidas radiográficas digitais foram obtidas com recursos do programa Digora for Windows, utilizando-se as imagens padrão, negativa e 3D. Os resultados mostraram que não houve diferenças estatisticamente significantes entre as medidas radiográficas digitais obtidas nas duas posições, com exceção do grupo dos pré-molares superiores e da raiz distal dos molares inferiores, embora essa diferença não tenha sido clinicamente significante, ou seja, superior a 0,5 mm.

The aim of this article was to investigate the influence of the position of the imaging plate of the Digora digital system in the determination of tooth length. Sixty extracted human teeth were evaluated, divided into: ten maxillary incisors, ten mandibular incisors, ten maxillary bicuspids, ten mandibular bicuspids, ten maxillary molars, and ten mandibular molars. They were radiographed with the Digora imaging plate in two positions: long axis of the tooth parallel to the length of the plate, and long axis of the tooth parallel to the width of the same. The digital radiographic measurements of the specimens were obtained with the Digora system. The results showed no statistically significant differences between the digital radiographic measurements in either position, except for maxillary bicuspids and distal root of mandibular molars, although this difference was not clinically significant.