Microscopia eletrônica de varredura da presença de resíduos na superfície de corte de instrumentos NITI / Sem analysis in cutting blades of unused ni-ti rotary endodontic instruments

Atualmente o uso de instrumentos rotatórios é uma realidade, porém, estes apresentam restos de resíduos na superfície de corte. Sendo assim, o objetivo deste trabalho foi avaliar por meio de microscopia eletrônica de varredura (MEV), a presença de resíduos na superfície de corte de 20 instrumentos rotatórios de NiTi sem uso. Foram divididos em quatro grupos, a saber: Grupo A - TwistedFile® (n=5), Grupo B - BioRaCe® (n=6), Grupo C - Mtwo® (n=4) e GrupoD - EndoWave® (n=5). As pontas dos instrumentos foram microfotografadas com aumento de 190X a partir do diâmetro inicial para verificar a presença de resíduos. Em seguida, os instrumentos passaram por um rigoroso processo de limpeza e novamente microfotografados com o mesmo padrão de aumento, observando-se a ponta do instrumento e a 5mm da ponta do instrumento. Os dados obtidos foram tabulados e submetidos à análise percentual e estatística valendo-se do teste Exato de Fisher e nível de significância de 5%. No que se refere à sujidade ocorreram diferenças estatisticamente significantes entre as limas Mtwo® com os outros instrumentos (p<0,05). Concluiu-se que todos os instrumentos estavam sujos, exceto a marca Mtwo® e que após os procedimentos de limpeza a superfície de corte estava isenta de resíduos.

Currently the use of rotary instruments is a reality, however, they have leftover residue on the cut surface. Thus, the aim of this study was to evaluate by means of scanning electron microscopy (SEM), the presence of residues on the surface of cut 20 NiTi rotary instruments unused. Were divided into four groups as follows: Group A - TwistedFile® (n = 5) Group B - BioRaCe® (n = 6) Group C - Mtwo® (n = 4) Group D - EndoWave® (n = 5). The tip of the instruments was photomicrographed with 190X at magnification from the initial diameter for the presence of residues. Then, instruments passed through a rigorous cleaning and again photomicrographed with the same magnification observing the tip of the instrument and 5mm from the tip of the instrument. Data were tabulated and analyzed statistically percentage and taking advantage of the Fisher exact test and a significance level of 5%. With regard to dirt statistically significant differences between the files Mtwo® with other instruments (p <0.05). It was concluded that all instruments were dirty except Mtwo® brand and after cleaning procedures the cut surface was free of residues.

Effects of diode laser irradiation and fibroblast growth factor on periodontal healing of replanted teeth after extended extra-oral dry time.

AIM: The search for effective protocols to reduce the incidence of root resorption and allow periodontal ligament repair is still challenging, given the unpredictable outcome of late tooth replantation. The aim of this study was to assess the effects of both high-power diode laser irradiation (DL) and basic fibroblast growth factor (FGF) on the periodontal healing of replanted teeth after extended extra-oral dry time. METHODS: Maxillary incisors of 50 male rats were extracted and assigned to three experimental and two control groups (n = 10). DL: root surfaces treated with DL (810 nm, continuous mode, 1.0 W, 30 s), FGF: topical application of FGF gel to the root surface and in the alveolar wound, DL + FGF: DL and topical application of FGF gel, C+: no treatment after extraction and immediate replantation and C-: no treatment after extraction and replantation after 60 min. In the experimental groups, the specimens were kept dry for 60 min, the pulps were removed and the canals were filled with calcium hydroxide paste prior to tooth replantation. The animals were euthanized after 60 days. The specimens were processed for radiographic, histological and immunohistochemical analyses. RESULTS: The radiographic analysis showed fewer resorptive areas in DL + FGF (P < 0.05). The histological and immunohistochemical analyses showed that the DL group had lower mean values of ankylosis, replacement and inflammatory resorption when compared to C-, not differing statistically from C+. DL + FGF produced significantly more collagen fibers (type I and type III) than C-, not differing from C+ in the case of type I fibers (P < 0.05). CONCLUSIONS: DL, with or without FGF, reduced the occurrence of external root resorption and ankylosis. Periodontal healing was favored and some fiber reinsertion occurred only when FGF was used.

Analysis of stress in the walls of simulated artificial root canals during instrumentation with reciproc system: a pilot study using a photoelastic model / Análise de estresse nas paredes de canais artificiais simulados durante a instrumentação com sistema reciproc: um estudo piloto usando um modelo fotoelástico

Objective: The aim of this pilot study was to perform in vitro analysis of the stress related to instrumentation of artificial root canals with Reciproc System by using the photoelasticity method. Material and Methods: Photoelastic models consisted of two epoxy resin blocks simulating root canals, which were attached with cyanoacrylate adhesive to a base and placed at the centre of a circular polariscope in a darkfield configuration. The Reciproc R25 instrument was mounted to a VDW motor and used in block 1 up to 12 mm (working length) and then the same instrument was used in block 2. The images were captured by video camera and analysed at the time of the fourth penetration. Isochromatic fringes were observed in the cervical, middle and apical thirds at mesial and distal regions of each block. Therefore, they were divided into cervical-mesial (CM), cervicaldistal (CD), middle-mesial (MM), middle-distal (MD), apical-mesial (AM) and apical-distal (AD). Results: In the first instrumentation, it was found that the greatest stress occurred at the middle-distal region (1.38), followed by middle-mesial (1.20), apicaldistal (1.20) and apical-mesial regions (1.20). In the second instrumentation, the greatest stress occurred at the middle-mesial (1.20), apical-distal (1.20), apical-mesial (1.20) and middle-distal regions (0.90). Conclusion: The greatest stress occurred in the middle and apical thirds during the first instrumentation. Reutilization caused less stress.

O objetivo deste estudo piloto foi realizar a análise in vitro do estresse relacionado a instrumentação de canais artificiais utilizando o sistema de instrumentação Reciproc por meio da fotoelasticidade. Material e Métodos: Modelos fotoelásticos de dois blocos de resina epóxi com um canal simulado foram fixados com adesivo de cianoacrilato sobre uma base no centro de um polariscope circular na configuração de campo escuro. O instrumento Reciproc R25 foi inserido no motor VDW e utilizado no bloco 1 até 12 mm (comprimento de trabalho) e, sem seguida, o mesmo instrumento foi utilizado no bloco 2. As imagens foram captadas pela câmara de vídeo e analisadas no tempo da quarta penetração. As franjas isocromáticas foram observadas nos terços cervical, médio e apical, em regiões mesial e distal de cada bloco. Sendo assim, divididos em: CM - cérvico-mesial, CD - cérvicodistal, MM - médio-mesial, MD - médio-distal, AM - apical-mesial e AD - apical-distal. Resultados: Na primeira utilização do instrumento, o maior estresse ocorreu na região médio-distal (1,38), seguido por médio-mesial (1,20), apical-distal (1,20) e apicalmesial (1,20). No segundo uso, o maior estresse ocorreu na região médio-mesial (1,20), apical-distal (1,20), apical-mesial (1,20) e médio-distal (0,90). Conclusão: O maior estresse ocorreu nos terços médio e apical na primeira utilização, sendo que a reutilização promoveu menos estresse.

Análise da dureza Vickers da superfície de dentes artificiais em resina poliéster / Vickers hardness laboratory analysis surface of artificial teeth resin

Avaliou-se a microdureza Vickers de 5 dentes artificiais de resina contendo canais simulados e câmara pulpar (17, 21, 24, 33 e 44) valendo-se de microdurômetro.Os dentes foram acondicionados em embutidora metalográfica, sendo adicionada resina fenól-aldeído de cura a quente e que por efeito de temperatura e pressão ocorre à fusão do pó de resina fenólica e a cura da resina resulta em corpo de prova com o dente embutido. Após isso, lixado e polido e levados a um suporte para fixação dos mesmos na plataforma na base do equipamento. A seguir, realizou-se os ensaios da dureza Vickers (HV) em cada um dos 5 dentes embutidos valendo-se de microdurômetro equipado por uma base, penetrador com carga de 100gf que entrava em 5 pontos aleatoriamente escolhidos na superfície do dente durante 15 segundos. Posteriormente as leituras cujo valor numérico foram calculado no visor digital conectado no microscópio. As endentações são deixadas na superfície da amostra sob a forma de losango regular cujas diagonais foram medidas. Não ocorreu diferença estatisticamente significante entre os valores das médias das amostras dos dentes artificiais em resina de poliéster testados, o que significa que na média dos 5 pontos de cada amostra as durezas são equivalentes (p>0,05), exceção feita entre os dentes 17 X 21 e do 17 X 44 (p<0,05). Concluiu-se que, a média dos valores dos dentes artificiais de resina poliéster apresentou dureza Vickers equivalentes, exceção feita entre dois pares de amostras dos dentes artificiais que apresentaram microdureza Vickers diferentes

Were evaluated the Vickers hardness of 5 artificial resin teeth containing simulated canals and pulp chamber (17,21,24,33 and 44) making use of microdurometer. The teeth were placed in metallographic embedded being added phenol-aldehyde heat curing and the effect of temperature and pressure is the fusion of powdered phenolic resin and curing the resin results in the specimen with the embedded tooth. After that, sanded and polished and brought to a stand for fixing the equipment platform at the base of the machine. Next, was performed tests of Vickers hardness (HV) in each of the 5 inlaid teeth making use of microhardness tester equipped with a base indenter with a load of 100gf that came in 5 randomly chosen points on the tooth surface for 15 seconds. Later readings whose numerical value was calculated on the digital display connected to the microscope. The indentations are left on the sample surface in the form of regular rhombus whose diagonals were measured. There was no statistically significant difference between the mean values of the samples of artificial teeth in polyester resin tested, which means that the average of 5 points for each sample hardships are equivalent (p>0.05), except between teeth 17X21 and the 17X44 (p<0.05). It was concluded that the average values of the polyester resin artificial teeth showed equivalent Vickers hardness, except between two pairs of samples of artificial teeth that presented different Vickers hardness

Tooth discoloration induced by endodontic phenothiazine dyes in photodynamic therapy.

OBJECTIVE: This study sought to assess if discoloration of tooth structures occurs after photodynamic therapy (PDT) and to determine the efficacy of a protocol to remove the photosensitizers. BACKGROUND DATA: PDT has been used in root canal treatment to enhance cleaning and disinfection of the root canal system. PDT uses a low power laser in association with a dye as a photosensitizer. Photosensitizers can induce staining of the dental structures, resulting in an unaesthetic appearance. METHODS: Forty teeth were randomly divided into four groups according to the photosensitizer used and pre-irradiation time: 0.01% methylene blue for 5 min (MB5); 0.01% methylene blue for 10 min (MB10); 0.01% toluidine blue for 5 min (TB5); and 0.01% toluidine blue for 10 min (TB10). Specimens were irradiated with a 660 nm diode laser with a 300 µm diameter optical fiber, at 40 mW power setting for 3 min. Immediately after, the photosensitizers were removed with Endo-PTC cream+2.5% sodium hypochlorite (NaOCl). The shade was measured by a Vita Easyshade spectrophotometer based on the CIELAB color system (L*a*b* values) at three different experimental times: before PDT (T0), immediately after PDT (T1), and after removal of the photosensitizer (T2). RESULTS: The results showed a decrease in the averages of the L*a*b* coordinate values after PDT (T1) in all the groups, when compared with the number at T0, with a significant statistical difference in group MB10. After photosensitizer removal (T2), all the values of the coordinates increased with significant statistical differences (p<0.05) between T1 and T2 in L* and a*. CONCLUSIONS: It can be concluded that both methylene blue and toluidine blue dyes cause tooth discoloration, and that Endo-PTC cream associated with 2.5% NaOCl effectively remove these dyes, regardless of the pre-irradiation time used for PDT.

Pesagem de dentes humanos úmidos, com cones de papel e estufa / Weight of wet human teeth, with paper cones and greenhouse

Introdução: A secagem do canal radicular após o preparo químico-cirúrgico com cones de papel absorvente é importante, pois, é imprescindível a obtenção de uma superfície sem umidade. O objetivo desta pesquisa é comparar os pesos de dentes humanos extraídos, considerando dentes úmidos, secos com papel absorvente e estufa. Método: Utilizaram-se 30 dentes humanos extraídos nos quais se executaram o acesso à câmara pulpar, à odontometria e o preparo químico-cirúrgico e, em seguida, foram mergulhados em frascos individuais contendo água destilada, por uma semana. Após isso os dentes foram pesados em balança analítica digital com os dentes umedecidos (Pu), a segunda os dentes secos com cones de papel absorvente (Pa) e depois secagem dos dentes na estufa durante 12 horas a 500C (Pe) e pesagem. Resultados e conclusões: Ao fazer a comparação entre dentes secos com papel absorvente e secos na estufa, o teste ?t? de Student mostrou que os pesos em grama dos dentes secos na estufa são menores do que os secos com papel absorvente (?t? = 6,3992) com P=0,0001. Concluiu-se que os dentes apresentaram ordem decrescente de peso: dentes umedecidos, dentes secos com cones de papel absorvente e dentes secos em estufa e, portanto, a secagem dos dentes em estufa mostra-se como de suma importância para a remoção maior de líquidos do sistema de canais radiculares

Introduction: The drying of the root canal after chemical-surgical preparation with absorbent paper cones is important because it is essential to obtain a surface free of moisture. The aim of this study is to compare the weights of extracted human teeth, whereas teeth wet, dry on paper towels and oven. Method: Were used thirty extracted human teeth which were carried out access to the pulp chamber odontometry and chemical-surgical preparation, and then were immersed in individual bottles containing distilled water for one week. After that teeth were weighed on an analytical balance with digital teeth moistened (Pu), the second teeth dry with absorbent paper cones (Pa) and then drying the teeth in the oven for 12 hours at 500C (Pe) and weighing. Results and conclusion: In making the comparison between teeth dry with absorbent paper and dried in the oven, the ?t? Student test showed that the weights in grams of dry teeth in emissions are lower than those dried with absorbent paper (?t? = 6.3992 ) with P = 0.0001.It was concluded that the teeth, in descending order of weight of wet teeth, teeth dried with absorbent paper cones teeth and dried in an oven, and therefore the drying kiln of the teeth of the utmost importance to remove most of the root canal fluid system

Root surface treatment using diode laser in delayed tooth replantation: radiographic and histomorphometric analyses in rats.

UNLABELLED: BACKGROUND AIM: The aim of this study was to evaluate, by radiographic and histomorphometric analyses, the effects of high-power diode laser irradiation on the root surfaces of delayed replanted rat teeth. MATERIAL AND METHODS: Maxillary right incisors were extracted from 60 Wistar rats and kept dry for 60 min. Subsequently, the root canals were prepared and filled with calcium hydroxide paste. According to the root surface treatment before the replantation, the teeth were assigned to four groups (n = 15): G1 (negative control) - no root surface treatment; G2 (positive control) - treated with 2% sodium fluoride solution; G3 - irradiated with a high-power diode laser (810 nm, continuous mode, 1.0 W, 30 s); and G4 - irradiated with a diode laser using the same parameters as those used for G3 but in pulsed mode. The rats were euthanized after 15, 30, and 60 days of replantation. The specimens were digitally radiographed and processed for histomorphometric analysis to determine the average root resorption areas and to evaluate the histological events. RESULTS: The percentage of root resorption was in the following order: G1 > G2 > G4 > G3. Both histomorphometric and radiographic analyses showed significantly lower means (P < 0.05) of the occurrence of root resorption in the irradiated groups (G3 and G4) when compared to the control groups (G1 and G2). Replacement resorption and ankylosis were observed in histological sections only after 30 and 60 days; however, such events were not observed in G3. CONCLUSION: Root surface treatments with high-powered diode laser irradiation prior to delayed replantation reduced the occurrence of external root resorption compared to no treatment or sodium fluoride treatment at up to 60 days.

Evaluation of a strategic practice demonstration method applied to endodontic laboratory classes / Avaliação de um método estratégico de demonstração prática aplicado nas aulas de endodontia laboratorial

PURPOSE: To evaluate a strategic method of real time visual demonstration of the operatory procedures using an intraoral camera system and monitor videos, comparing them to those of conventional laboratory classes. METHODS: Fifty-two structured, multiple choice questionnaires were applied to undergraduate students of the 4th year (G1) and 3rd year (G2) submitted to the traditional and strategic teaching methods, respectively. These tests were also able to detect the main problems faced by the students during the training of this operatory phase. RESULTS: Students of both groups (G1- 30.8% and G2- 34.6%) considered the access cavity to be one of the most difficult phase of endodontic treatment. The results of the evaluation among the 3rd year students demonstrated that 23.1% graded the new method as excellent, 38.4% as very good and 38.5 % as good, whereas none of the students (0%) considered the method to be regular, bad or very bad. A minor accident occurrence (P<0.05) was reported by the 3rd year students (G1- 50% and G2- 34.6%). CONCLUSION: The new strategy was found to favor learning, reduce the incidence of errors and was appraised as efficient by the students.

OBJETIVO: Avaliar um método estratégico nas aulas práticas, utilizando micro câmeras e monitores de vídeo para transmitir demonstrações da técnica operatória, comparando-o com o método de ensino aprendizagem clássico. METODOLOGIA: Foram aplicados 52 questionários direcionados aos alunos do 4º ano (grupo 1) submetidos a esta nova prática e aos do 3º ano (grupo 2) submetidos a metodologia de ensino tradicional. Este questionário também possibilitou detectar os principais problemas enfrentados pelos discentes durante o aprendizado desta etapa operatória. RESULTADOS: A fase de cirurgia de acesso foi considerada de difícil execução por ambos os grupos (G1- 30,8 % e G2- 34,6%), sendo a manobra de localização dos orifícios de entrada dos canais a etapa mais complicada. Quanto à avaliação da metodologia empregada no 3º ano, 23,1% dos alunos a consideraram excelente, 38,4% ótima, e 38,5% boa, ao passo que nenhum dos estudantes (0%) consideraram o método como regular, ruim ou péssimo. Uma menor ocorrência de erros (P<0,05), foi relatada pelos alunos do 3º ano (G1- 50% e G2- 34.6%). CONCLUSÃO: A nova estratégia de ensino favoreceu a aprendizagem, diminuiu a incidência de erros e foi considerada eficaz pelos alunos.

Perda de corte da lima protaper quanto a esterilização e número de uso / Analysis the cutting loss of instruments protaper in relation the number of use and effect of sterilization

Objetivo: Este estudo propõe-se avaliar a perda de corte do instrumento rotatório ProTaper® em função do número de uso e esterilização em autoclave. Método: Foram estudados 10 canais simulados de resina acrílica transparente com ângulo de curvatura de 45º, valendo-se de instrumentos Protaper® de numeração S1, S2, F1, F2 e F3, substituindo o Sx pelas brocas de Largo #1. Os blocos foram pesados em balança analítica digital, anotando-se o peso inicial. A seguir, houve o preparo com motor elétrico Endo Pro-Torque® da Driller com reverso automático submetido ao ajuste e controle da velocidade em 350 rpm, torque de 1N, com engate para contra-ângulo modelo Kavo®, tomando-se o cuidado de padronizar o tempo de ação de cada instrumento em 3 minutos. Usou-se o creme de Endo-PTC durante o preparo do canal simulado e após seu tempo de ação, lavava-se o canal com hipoclorito de sódio. Depois, o bloco era lavado com detergente neutro, seco com gaze, canal aspirado, seco com cone de papel absorvente, pesado, anotando-se o peso final. A cada uso as limas rotatórias eram limpas com gaze embebido em álcool e, posteriormente, lavadas com detergente neutro e secas também com gaze e levadas em envelope descartável para processo de esterilização em autoclave com ciclo de 20 minutos. Resultados: Os instrumentos utilizados perderam a sua capacidade de corte em função do número de uso. Conclusão: O instrumento perde a capacidade de corte em função do uso, e só a partir do sé¬timo uso, o instrumento ProTaper® perde consideravelmente sua efetividade, recomendando-se seu descarte

Aims: This investigation aims to evaluate the cutting loss and sterilization of rotary ProTaper® instrument for sterilization process in autoclave. Method: Were studied ten substrate resin simulated canals blocks numbered 1 to 10 with angle of 45º. Before and after instrumentation were used with ProTaper® files numbering S1, S2, F1, F2, F3, is substituting for the Sx Largo drills # 1. These blocks were weighted using an analytical digital scale model Mettler AJ 100 and following it were analyzed of the amount of resin removed in each sample were noted both initial and final weight. The instrumentation was made with Endo-Pro-Torque engine-driven Driller system with automatic reverse and speed control in 350 rpm, torque 1N using stop watch for standardize the 3 minutes time of each instrument. Cream Endo-PTC was used during instrumentation e after that, washing the canals with 5mL the distillate water with plastic syringe. The blocks were washed with detergent, dry with gauze, aspirated canal, dried with paper absorbent points, weighted and noted final weight. In each use the files were clean with gauze alcohol soaked and later washed with detergent and dried with gauze and put in recipient discard able for sterilization in autoclave Sercon model during 20 minutes. Results: The instruments used have lost the cutting ability in relation to the number of use. Conclusions: It?s concluded that occurred a loss of efficiency of the cutting instrument, however the instrument ProTaper loses its cutting ability in use only after the seventh use and thus it?s recommended its discard

Effectiveness of photodynamic therapy against Enterococcus faecalis, with and without the use of an intracanal optical fiber: an in vitro study.

BACKGROUND AND OBJECTIVE: Photodynamic therapy (PDT) is a new technique introduced in endodontics that combines the action of a photosensitizer (dye) and a low intensity light source. Currently, there are no PDT studies evaluating the microbial disinfection of root canals in order to compare the effects of light delivery systems in the photosensitizer activation. The aim of this study was to evaluate the PDT effectiveness in reducing Enterococcus faecalis, with and without the aid of an intracanal optical fiber. METHODS: Extracted single-rooted teeth were selected, instrumented, inoculated with E. faecalis and divided into six groups: one control group (untreated), one conventionally-treated group (1% NaOCl irrigation) and four PDT-treated groups. Irradiation (diode laser) was performed with (OF) or without an intracanal optical fiber (NOF) using two different irradiation times: 1 min and 30 sec (IT(90)) or 3 min (IT(180)). Samples were collected before and after testing procedures and CFU/mL was determined. RESULTS: The greatest reduction of E. faecalis (99.99%) was achieved with irrigation with 1% NaOCl. PDT also significantly reduced E. faecalis in the following decreasing order: OF/IT(180), NOF/IT(180), OF/IT(90) and NOF/IT(90), with no significant statistical difference among the groups. CONCLUSIONS: These results suggest that PDT was effective against E. faecalis, regardless of the use of an intracanal optical fiber.

Effect of chemical substances in removing methylene blue after photodynamic therapy in root canal treatment.

BACKGROUND AND OBJECTIVE: The disadvantage of photodynamic therapy (PDT) is in the photosensitizing agents that may stain the tooth structure. There is no register of PDT studies evaluating protocols to minimize that concern. The present study evaluated the efficiency of chemical adjuncts in methylene blue dye (MB) removal after PDT. MATERIALS AND METHODS: Forty single-rooted teeth, after root canal preparation, were filled with 0.01% MB for 5 min, and irradiated with diode laser 660 nm at 40 mW for 240 sec (total energy 9.6 J). The specimens were divided into four groups (n = 10), according to the chemical adjuncts used for dye removal: (a) 2.5% sodium hypochlorite (NaOCl); (b) 2.5% NaOCl + Endo-PTC cream; (c) 70% ethyl alcohol and (d) saline (control). The crowns were sectioned and fixed in a device. Photographs were taken before the PDT (T0), immediately after (T1) and upon dye removal (T2). The chromatic alterations were evaluated using Adobe Photoshop and K values were determined in four fixed points of each crown. RESULTS: K values (dental staining) increased in all groups when comparing T0 and T1. The effectiveness of the tested adjuncts was, in decreasing order: G1 (-3.11) > G2 (-2.97) > G3 (-1.28) > G4 (-1.19), not observing significant statistical differences (p < 0.05) between G1 and G2 and also between G3 and G4. CONCLUSIONS: Protocols to remove photosensitizing dyes should be applied after PDT in order to minimize dental stain. The protocols tested in this study by using 2.5% NaOCl, associated or not with Endo-PTC cream, were effective in avoiding tooth staining caused by MB during PDT.

Effect of nitric oxide inhibitor and donor substances on the inflammatory process caused by endodontic irrigants.

UNLABELLED: Nitric oxide (NO) has been considered a key molecule in inflammation. OBJECTIVE: The aim of this study was to evaluate the effect of treatment with L-NAME and sodium nitroprussiate, substances that inhibit and release NO, respectively, on tissue tolerance to endodontic irrigants. MATERIAL AND METHODS: The vital dye exudation method was used in a rat subcutaneous tissue model. Injections of 2% Evans blue were administered intravenously into the dorsal penial vein of 14 male rats (200-300 g). The NO inhibitor and donor substances were injected into the subcutaneous tissue in the dorsal region, forming two groups of animals: G1 was inoculated with L-NAME and G2 with sodium nitroprussiate. Both groups received injections of the test endodontic irrigants: acetic acid, 15% citric acid, 17% EDTA-T and saline (control). After 30 min, analysis of the extravasated dye was performed by light absorption spectrophotometry (620 nm). RESULTS: There was statistically significant difference (p<0.05) between groups 1 and 2 for all irrigants. L-NAME produced a less intense inflammatory reaction and nitroprussiate intensified this process. CONCLUSIONS: Independently of the administration of NO inhibitors and donors, EDTA-T produced the highest irritating potential in vital tissue among the tested irrigating solutions.

Effect of nitric oxide inhibitor and donor substances on the infammatory process caused by endodontic irrigants

Nitric oxide (NO) has been considered a key molecule in infammation. OBJECTIVE: The aim of this study was to evaluate the effect of treatment with L-NAME and sodium nitroprussiate, substances that inhibit and release NO, respectively, on tissue tolerance to endodontic irrigants. MATERIAL AND METHODS: The vital dye exudation method was used in a rat subcutaneous tissue model. Injections of 2 percent Evans blue were administered intravenously into the dorsal penial vein of 14 male rats (200-300 g). The NO inhibitor and donor substances were injected into the subcutaneous tissue in the dorsal region, forming two groups of animals: G1 was inoculated with L-NAME and G2 with sodium nitroprussiate. Both groups received injections of the test endodontic irrigants: acetic acid, 15 percent citric acid, 17 percent EDTA-T and saline (control). After 30 min, analysis of the extravasated dye was performed by light absorption spectrophotometry (620 nm). RESULTS: There was statistically signifcant difference (p<0.05) between groups 1 and 2 for all irrigants. L-NAME produced a less intense infammatory reaction and nitroprussiate intensifed this process. CONCLUSIONS: Independently of the administration of NO inhibitors and donors, EDTA-T produced the highest irritating potential in vital tissue among the tested irrigating solutions.

Evaluation of coronal microleakage: bacterial versus dye infiltration tests

The aim of this study was to verify, in vitro, two methodologies of coronal microleakage after endodontic access cavity filling with temporary restorative material. Twenty-four extracted single rooted teeth were selected, of which four specimens were used for methodology control. Standard access cavities were prepared in 20 teeth, followed by root canal instrumentation and coronal access sealing with temporary restorative material (Villevie-Dentalville, Joinville, Santa Catarina, Brazil). The teeth were externally waterproofed and submitted to infiltration tests. Fourteen samples were used for microbiology infiltration analysis with Enterococcus faecalis. The other 10 samples were used for dye leakage analysis with 1% rhodamine B tracer. The results demonstrated no infiltration of Enterococcus faecalis in any of the samples at the end of 30 days. However, dye leakage analysis showed infiltration through the temporary restoration in all samples (mean of infiltration = 84.3%). Significant statistical differences (p < 0.05) were found between the two methodologies. In conclusion, bacterial and dye leakage methodologies showed contradictory results and the type of performed methodology can significantly influence the results of coronal microleakage analysis

Endodontic sealers: Intratubular penetration and permeability to Enterococcus faecalis.

AIM: Evaluate in vitro the intratubular penetration and permeability of endodontic sealers in teeth contaminated with Enterococcus faecalis. MATERIALS AND METHODS: Human canines were filled with AHPlus , Endo CPM-sealer or EndoRez sealers. To evaluate permeability, the coronary portion of each tooth was contaminated with E. faecalis, then the apical portion was immersed in brain heart infusion (BHI) broth, and medium turbidity was observed for thirty days. Scanning electron microscope (SEM) was used to evaluate the intratubular penetration of each sealer at the cervical, middle, and apical thirds of the tooth. RESULTS: Only one tooth from the Endo CPM-sealer group presented broth contamination. EndoRez showed increased intratubular penetration compared to AHPlus and Endo CPM-sealer. CONCLUSIONS: Endo CPM-sealer showed greater permeability to E. faecalis and EndoRez showed increased intratubular penetration.

Avaliação da escolha dos testes de sensibilidade pulpar por clínicos gerais da cidade de Taubaté / Evaluation of the choice of pulp sensitivity tests by practitioners of Taubaté city

Introdução: A proposta desta pesquisa é avaliar os recursos complementares de que os clínicos gerais da cidade de Taubaté lançam mão na determinação da sensibilidade pulpar. Método: Foram entrevistados ao acaso 106 cirurgiões-dentistas da cidade de Taubaté valendo-se de um questionário elaborado pelo autor. Tais profissionais eram de diferentes épocas de graduação, portadores de especialidade ou não e de diversas faculdades de Odontologia. Os questionários apresentavam uma lista de testes com a seguinte pergunta: ?Qual ou quais os recursos suplementares mais utilizados na avaliação da sensibilidade pulpar deque você lança mão durante o exame do paciente??. Os dados foram organizados de modo a facilitar sua subdivisão em teste pelo frio, calor, elétrico, cavidade, anestesia e outros, permitindo estabelecer percentuais de utilização destes em função do número de citações. Resultados: Como inferência estatística utilizou-se teste binomial para proporção, sendo o nível de significância de 5%.Na comparação entre a proporção de clínicos gerais que utilizam guta-percha (90,56%) e bastão de gelo (77,35%) o teste apresentou pvalor<0,05 indicando que a proporção de clínicos gerais que usam guta-percha aquecida é maior do que aqueles clínicos que usam bastão de gelo. Conclusão: De posse dos resultados obtidos, concluiu-se que a guta-percha aquecida foi o recurso auxiliar preferido pelos clínicos gerais (90,56%) seguido do bastão de gelo (77,35%), gases refrigerantes 64,15%), jato de ar (41,5%), teste de anestesia (38,67%), teste de cavidade (31,13%), água fria (24,52%), brunidor aquecido (4,71%), teste elétrico (1,88%) e algodão embebido em álcool (0,94%).

Introduction: The purpose of this study is to assess which methods that the general practitioners of the Taubaté city used to determine the pulpal sensitivity. Method: Were interviewed 106 randomly dentists of Taubaté city making use of a questionnaire prepared by the author. These professionals were from different times of graduation, expert or not and from various dentistry colleges. The questionnaires presented a list of tests with the following question: which additional resources do you prefer during the evaluation of pulpal sensitivity during of the patient exam??. The data were organized to facilitate their subdivision: cold test, heat test, electric test, anesthesia test and cavity test, to establish rates of use of these depending on the number of citations. Results: Because of statistical inference was used the binomial proportion with the significance level of 5%. The proportion of general practitioners using heat gutta-percha (90.56%) and ice stick (77.35%) tests presented pvalue<0.05 indicating that the proportion of general practitioners using heat gutta-percha is higher than those clinicians that using ice stick. Conclusion: It was concluded that heat gutta-percha were the test preferred by practitioners (90.56%) followed by ice stick (77.35%), refrigerants (64.15%), air jet (41.5%), test of anesthesia (38.67%) test cavity (31.13%), cold water (24.52%), heated burnisher (4.71%), electrical test (1.88%) and alcohol swab (0.94%).

Attachment of cultured fibroblasts and ultrastructural analysis of simulated cervical resorptions treated with high-power lasers and MTA.

OBJECTIVE: The present study evaluated the fibroblast attachment and the morphologic changes of simulated cervical root resorptions after irradiation with high-power lasers and the use of mineral trioxide aggregate (MTA). STUDY DESIGN: Standardized cavities were done on the coronal third of 40 single-rooted teeth and assigned into 4 groups according to the treatment applied: (1) untreated control, (2) use of MTA, (3) irradiation with Er:YAG laser (42 mJ, 10 Hz, 10 s), and (4) irradiation with high-power diode laser (1 W, 10 s). Fragments were prepared for SEM analysis: 6 samples of each group were plated with human gingival fibroblasts and 4 samples were used for ultrastructural analysis. RESULTS: The cells' attachment was in decreasing order: G3 > G4 > G1> G2, with statistical differences among all groups (P < .05). The samples irradiated with Er:YAG exhibited roughness on the dentinal surface, no smear layer, and open dentinal tubules; those irradiated with diode laser exhibited a smooth surface, more smear layer, and closed dentinal tubules; and the control group showed high amount of smear layer and closed dentin tubules. CONCLUSIONS: Irradiation with Er:YAG and diode lasers caused morphologic changes on the dentinal surfaces of simulated resorptions that favored cells' adhesion. MTA showed lower biocompatibility than irradiated groups but allowed cells' adhesion.

Treatment options for teeth with open apices and apical periodontitis.

Three clinical cases involving teeth with open apices and apical periodontitis were treated using different protocols. The first case was managed with intracanal calcium hydroxide paste for 12 months before obturation with gutta-percha and sealer. In the second case, an apical plug of mineral trioxide aggregate (MTA) was used before obturation with gutta-percha and sealer and treatment was completed during 2 appointments. In the third case, the tooth, which had a divergent root canal system, was completely obturated with MTA and treatment was also completed over 2 appointments. In all 3 cases, signs of bone healing were observed after treatment.

Análise da infiltração apical de um novo cimento endodôntico a base de mta / Apical leakage analysis of a new mta endodontic sealer

O MTA apresenta várias vantagens quando usado no selamento de perfurações e em obturações retrogradas. Recentemente, um cimento endodôntico a base de MTA foi introduzido no mercado com o objetivo de obturar o canal radicular. Sendo assim, a proposta deste trabalho foi analisar o selamento apical do novo cimento Endo-CPM-Sealer® a base de MTA, comparando-o com outros cimentos de uso endodôntico. Para tanto, se valeu do modelo de infiltração do corante Rodamina B 1% em 44 dentes unirradiculares, divididos em 4 grupos experimentais (n=10) e 2 grupos controle (n=2) a saber: G1, AH-Plus®; G2, Endo-Rez®; G3, Endo-CPM-Sealer®; G4, Sealapex®; controle positivo sem cimento; controle negativo, AH-Plus e totalmente impermeabilizado. Após a instrumentação e obturação dos canais radiculares, as amostras foram impermeabilizadas, exceto o forame apical, e imersas no corante por 48 horas. Os cortes foram digitalizados para medição da infiltração linear do corante por meio do programa ImageLab. Os resultados da análise de infiltração apical, em ordem crescente, foram: AH-Plus® (0.495 mm) < Endo-Rez® (0.585 mm) < Sealapex® (0.776mm)< Endo-CPM-Sealer® (1.032 mm). A análise estatística pelo teste de Kruskal-Wallis mostrou diferenças estatisticamente significantes entre AH-Plus® x Endo-CPM-Sealer® no nível de 0,1 %, AH-Plus® x Sealapex® no nívelde 1% e Endo-CPM-Sealer® x Endo Rez® no nível de 1%, não ocorrendo diferenças estatisticamente significativas entre as demais interações. Foi possível observar infiltração em todas as amostras, sendo que o cimento a base de MTA apresentou maior penetração de corante.

The MTA was developed as a material to seal the communications between the root canal system and the externalsurface of the tooth. Recently, an new MTA- based endodontic sealer was developed to be used into the root canal. The objective of this study was to analyse the apical sealing of the Endo-CPM-Sealer®, and compare it with other sealers for endodontic use. This study used the model of infiltration of the dye rhodamine B 1% in 44 single root teeth, divided into 4 experimental groups (n=10) and 2 controls groups (n=2): G1-AH-Plus; G2-Endo-Rez®; G3- Endo-CPM-Sealer®; G4-Sealapex®; positive control without sealer; negative control, AH-Plus. After the instrumentation and filling the root canal, the samples were completely coated of nail varnish except the apical foraminal area and immersed in the dye for 48 hours. The sections were digitalized for measurement of the linear infiltration of the dye by ImageLab program. The results in increasing sequence were: AH-Plus® (0.495 mm) < Endo-Rez® (0.585 mm) < Sealapex® (0.776 mm)< Endo-CPM-Sealer® (1.032 mm). The Kruskal-Wallis analysis test showed statistical significant differences between AH-Plus® x Endo-CPM-Sealer® (p< 0.001); AH-Plus® x Sealapex® (p<0.01) and Endo-CPM-Sealer® x Endo-Rez((p<0.01). No statistical significant difference was observed between the other interactions. It was possible to observe infiltration in all the samples and the Endo CPM sealer® presented greater penetration of dye.

Surface finishing of unused rotary endodontic instruments: a SEM study.

During endodontic therapy, cleaning of root canals is performed using endodontic files and auxiliary chemical substances, and it is important that the endodontist be familiar with the instruments used in daily practice. This study evaluated, under scanning electron microscopy (SEM), the quality of the surface finishing of unused rotary endodontic instruments. Fifty sizes 20, 25 and 30 rotary files from different commercial brands (ProFile, Protaper, Race, Hero and K3 Endo) were removed directly from their packages and had their final 3 mm examined with a scanning electron microscope at x190 magnification with no previous preparation. The images were evaluated by 3 skillful, calibrated, blinded observers according to the following criteria: cutting edge, debris, grooves, microcavities, tip shape, tip position, scraping and transition angle. Data were recorded in worksheets designed for the study. Irregular edges were observed in 50-100% of the files. Except for ProFile, all commercial brands presented surface debris in 100% of samples. Only Race files showed no grooves or microcavities. K3 Endo files presented the best tip centralization. Excetp for ProTaper files, all commercial brands presented blunt-cutting edges in 100% of samples. All types of files presented surface scraping. K3 Endo files and Protaper had a high percentage of transition angle. Based on the evaluation criteria used in the present study, most samples presented a minimum of 2 alterations and a maximum of 7 alterations per instrument. Under the tested conditions, the quality of the surface finishing of the examined instruments was not as expected, given that no instrument was free of imperfections and most of them presented at least 2 and up to 7 types of surface defects. These results suggest that the manufacturing process and the packaging conditions of rotary endodontic instruments are far from ideal.