Effect of Reciprocating Systems and Working Lengths on Apical Microcrack Development: a micro-CT Study

Abstract The objective of this study was to evaluate the effect of root canal preparation with single-file reciprocating systems at different working lengths on the development of apical microcracks using micro-computed tomographic (micro-CT) imaging. Forty extracted human mandibular incisors were randomly assigned to 4 groups (n=10) according to the systems and working length used to prepare the root canals: Group A - WaveOne Gold at apical foramen (AF), Group B - WaveOne Gold 1 mm short of the AF (AF-1 mm), Group C - Unicone (AF) and Group D - Unicone (AF-1 mm). Micro-CT scanning was performed before and after root canal preparation at an isotropic resolution of 14 µm. Then, three examiners assessed the cross-sectional images generated to detect microcracks in the apical portion of the roots. Apical microcracks were visualized in 3, 1, 1, and 3 specimens in groups A, B, C, and D, respectively. All these microcracks observed after root canal preparation already existed prior to instrumentation, and no new apical microcrack was detected. For all groups, the number of slices presenting microcracks after root canal preparation was the same as before canal preparation. Root canal preparation with WaveOne Gold and Unicone, regardless of the working length, was not associated with apical microcrack formation.

Resumo O objetivo deste estudo foi avaliar o efeito da instrumentação de canais radiculares utilizando sistemas reciprocantes de lima única em diferentes comprimentos de trabalho sobre o desenvolvimento de microfissuras apicais utilizando imagens de microtomografia computadorizada (micro-CT). Quarenta incisivos inferiores humanos extraídos foram distribuídos aleatoriamente em 4 grupos (n=10) de acordo com os sistemas e comprimentos de trabalho utilizados para preparar os canais radiculares: Grupo A - WaveOne Gold no forame apical (FA), Grupo B - WaveOne Gold 1 mm aquém do FA (FA-1 mm), Grupo C - Unicone (FA) e grupo D - Unicone (FA-1 mm). Escaneamentos de micro-CT foram realizados antes e após o preparo dos canais a uma resolução isotrópica de 14 μm. Em seguida, três examinadores avaliaram as imagens de secção transversal geradas para detectar microfissuras na porção apical das raízes. Microfissuras apicais foram visualizadas em 3, 1, 1 e 3 espécimes nos grupos A, B, C e D, respectivamente. Todas essas microfissuras observadas após o preparo dos canais radiculares já existiam antes da instrumentação e não foi detectada nenhuma nova microfissura apical. Para todos os grupos, o número de cortes apresentando microfissuras após o preparo dos canais radiculares foi o mesmo verificado antes do preparo dos canais. A instrumentação de canais radiculares utilizando WaveOne Gold e Unicone, independentemente do comprimento de trabalho, não foi associada à formação de microfissuras apicais.

Prevalence of endodontic diseases: an epidemiological evaluation in a Brazilian subpopulation

Aim: To determine the prevalence of pulp and periradicular diseases in a Brazilian subpopulation, correlating the prevalence with sex, age and most affected teeth. Methods: Data collected from medical records of patients treated at the Clinic of Specialization in Endodontics of the Federal University of Pernambuco between 2003 and 2010. The following variables were recorded for each patient: sex, age, affected teeth and diagnosed endodontic disease. Using Pearson's chi-square and Fisher's exact tests, the collected data analysis was set at a 5% significance level. Results: From all the treated teeth, 57% were diagnosed with pulp diseases, with the symptomatic irreversible pulpitis being the most prevalent (46.3%), while among the diagnosed periradicular diseases (43%), chronic apical periodontitis was the most prevalent (81%). Pulp diseases were detected in men and women in an unequal mode (p=0.008). Subjects under 40 years old had higher prevalence of pulp disease (p=0.286), and patients over 50 years were most affected by periradicular diseases (p=0.439). Maxillary incisors and mandibular first molars were the most affected teeth by endodontic diseases. Conclusions: In the evaluated subpopulation, the endodontic diseases were more prevalente in the maxillary incisive, affected indiscriminately individuals of different age groups and chronic apical periodontitis was the most prevalent diagnosed disease (Au)

SEGUNDOS MOLARES DECÍDUOS: REABSORÇÃO FISIOLÓGICA E PATOLÓGICA / Second deciduous molars: physiological and pathological resorption

Objetivo: Este estudo retrospectivo avaliou a perda dos segundos molares decíduos, por rizólise fisiológica ou patológica, em pacientes atendidos nas Clínicas de Odontopediatria I e II da Universidade Federal de Pernambuco. Foram examinados 112 prontuários, sendo os dados registrados em fichas individuais. Método: Foram analisadas as seguintes variáveis: gênero, faixa etária, tipo de tratamento (invasivo ou não invasivo), tipo de reabsorção dentária (patológica ou fisiológica) e arco dentário. Resultados: A reabsorção fisiológica foi mais frequente que a reabsorção patológica em ambos os arcos. Foi observado que existe associação estatisticamente significante entre a faixa etária de 2 a 4 anos e a reabsorção dentária (p<0,001). A média de idade dos pacientes para reabsorção fisiológica foi de 6,65 e 4,49 anos para a reabsorção patológica dos segundos molares decíduos. Conclusão: Houve perda precoce de segundos molares decíduos. Há grandes possibilidades de comprometimento da oclusão funcional do indivíduo.

Aim: This retrospective study evaluated the loss of the second deciduous molars either by physiological or pathological root resorption in patients enrolled at the Pediatric Dentistry Clinic I and II at the Federal University of Pernambuco. Methods: A review of 112 patient records were assessed and registered in a form. The following variables were analyzed: gender, age, type of treatment (invasive or no invasive), type of resorption (physiological or pathological) and region (maxillary or mandibular). Results: The physiological resorption was more observed than the pathological resorption in both arches. It was noted that there was a statistically significant association between the age group of 2-4 years old and the resorption (p<0.001). The mean age of patients for physiological resorption was 6.65 and 4.49 years old for pathological resorption of the second deciduous molars. Conclusion: It can be concluded that there was an early deciduous second molars loss. There are great possibilities of impaired functional occlusion of the individual.

Changes in root canal anatomy using three nickel-titanium rotary system: a cone beam computed tomography analysis

AIM: Cone beam computed tomography (CBCT) was used to evaluate the ability of three NiTi rotary systems to maintain the original root canal anatomy. METHODS: Sixty mesiobuccal canals of human mandibular first molars were divided into three groups with 20 root canals each. All teeth were scanned by CBCT before instrumentation. The images were captured digitally for further analysis using the Image Tools Software. The images were sectioned in three points, located at 9 mm, 6 mm and 3mm from the apex. In Group 1, the root canals were instrumented with ProTaper UniversalTM rotary system; in Group 2, with Twisted FileTM rotary system; and in Group 3, with MtwoTM rotary system. Instrumented teeth were scanned again using CBCT and the images of the uninstrumented canals were compared with images of the instrumented canals. The results were statistically analyzed using the one-way ANOVA test. A level of significance of 0.05 was adopted. RESULTS: The means of D1 at distances of 9 mm, 6 mm, and 3 mm from the apex were, respectively: Group 1: 0.88±0.257, 1.00±0.000, and 1.00±0.000; Group 2: 0.79±0.745, 0.65±0.669, and 0.25±0; Group 3: 0.50±0.745, 0.33±0.472, and 0.03±0.104. The means of D2 at distances of 9 mm, 6mm, and 3mm from the apex were respectively: Group 1: 1.00±0.00, 1.00±0.00, and 1.00±0.00; Group 2: 0.41±0.299, 0.30±0.428, and 0.50±0.707; Group 3: 0.58±0.910, 0.85±1.857, and 0.31±0.643. CONCLUSIONS: The CBCT analysis revealed that the ProTaper UniversalTM produced centered preparations and while the Twisted FileTM and MtwoTM rotary systems produced canal deviation.

Estudo comparativo entre a utilização de luvas únicas e duplas em três especialidades odontológicas / Comparative study between single and double gloving at three odontological specialities

Introdução - Para que sejam devidamente respeitadas as normas de biossegurança em atendimentos odontológicos, é necessária a utilização de equipamentos de proteção individual,tais como o uso de luvas. No entanto, as perfurações em luvas são comuns, embora, não sejam frequentemente detectadas pelos cirurgiões-dentistas. O presente estudo propôs-se avaliar ecomparar a ocorrência de perfurações quando da utilização de uma ou duas luvas durante a prática odontológica; e a correlação dos índices de perfurações com as especialidades de Odontopediatria, Dentística e Endodontia. Material e Método - Foi avaliada a integridade de 540 luvas de procedimento, sendo 60 luvas utilizadas de forma única e 120 utilizadas deforma dupla, por cada especialidade em estudo, através do método de pressão de água e com a utilização do corante Rodamina B diluído. Resultados - Do total de luvas analisadas, 18,7% apresentaram pelo menos uma perfuração. Não houve diferenças estatisticamente significantes entre o número de perfurações por grupo: Odontopediatria (21,7%); Dentística (15,5%); e, Endodontia (18,9%). Observou-se maior número de perfurações nas luvas únicas do que nas luvas internas das luvas duplas e, com exceção do grupo de Dentística, as diferenças entre estas proporções foram estatisticamente significantes. Do total das perfurações encontradas em todos os grupos, 52,9% situavam-se na mão não dominante. Conclusões - Houve, portanto, uma maior efetividade da barreira quando se utilizou duas luvas, sendo indicada esta forma de uso de luvas em procedimentos considerados de risco, mas, não se evidenciou correlação entre as diferentes especialidades odontológicas e o índice de perfurações em luvas

Introduction - To be duly complied with biosafety Standards during odontologicalprocedures, it is necessary the use of equipment of personal protection, as well as the use of gloves. However, the perforations on gloves are common, although, they are not often detected by dentists. The present study aimed to evaluate and to compare the occurrence of perforations at double and single gloving during the odontological practice; and, to correlate the Odontopediatrics, Dentistics and Endodontics specialities with the perforations indexes. Methods - It was evaluated the integrity of 540 procedures gloves, which 60 gloveswere used by single gloving and 120, used by double gloving, for each speciality that was studied, through the water pressure’s method and using Rodamina B dissolved. Results - About the total of gloves analysed, 18,7% presented perforation. There weren’t statistical significative differences between the number of perforations for group: Odontopediatrics (21,7%); Dentistics (15,5%), and, Endodontics (18,9%). It was observed a larger number of perforations on single gloves than on the internal gloves of the double gloving and, excepting the group of Dentistics, the differences between these proportions were statistical significatives. About the total of perforations occurred at all groups, 52,9% were situated at not dominant hand. Conclusions - There was, therefore, a most effectivity of the barrier when was used double gloves. Then, it has been indicated double gloving at risk procedures, but, it was not evidenced relationship between the different odontological specialities and the perforations’ indexes on gloves. More studies are suggested

Effect of sterilization methods on the absorption capacity of absorbent paper points / Efeito dos métodos de esterilização na capacidade de absorção de pontas de papel absorvente

The purpose of the present study was to analyze the influence of sterilization methods on the absorption capacity of different brands of standardized absorbent paper points, testing the hypothesis that there is a positive correlation between the percentage of increased absorption capacity and sterilization method. Standardized endodontic absorbent paper points (size rank from #15 to #40) from three different brands of three manufacturers were used for this study (Dentsply, Endopoints, Tanari). Twenty absorbent paper points of each size were used. The initial weight (iw) of each absorbent paper point was recorded using a digital scale. After sterilization, the dry weight (dw) of each absorbent paper point was determined. Each paper point was then introduced into a 2% methylene blue solution during 20 seconds until complete saturation. The paper points were removed from the solution and the wet weight (ww) was determined, with absorption capacity calculated from a difference between ww-dw. Data was statistically analyzed using Tukey’s test and the Student’s t-test (p<0.05). Tanari paper points exhibited the best absorption capacity among the brands analyzed, but the difference was non-significant. Sterilization process did not influence the absorption capacity of absorbent paper points

O objetivo do presente estudo foi analisar a influência dos métodos de esterilização sobre a capacidade de absorção de diferentes marcas de cones de papel absorvente, testando a hipótese de que existe uma correlação positiva entre o percentual de maior capacidade de absorção e o método de esterilização. Cones de papel absorvente padronizados (calibre de # 15 a # 40) de três marcas comerciais diferentes foram usados para este estudo (Dentsply, Endopoints, Tanari). Vinte pontas de papel absorvente de cada calibre foram utilizadas. O peso inicial de cada cone de papel absorvente foi aferido utilizando uma balança digital. Após a esterilização, o peso seco de cada cone de papel absorvente foi determinado. Em seguida, cada cone de papel foi introduzido em uma solução de azul de metileno a 2% durante 20 segundos até a saturação completa. Os cones de papel foram removidos da solução e o peso úmido foi determinado, e a capacidade de absorção calculada a partir da diferença entre peso úmido menos o peso seco. Os dados foram analisados estatisticamente pelo teste de Tukey e o teste t de Student (p <0,05). Os cones Tanari exibiram a melhor capacidade de absorção entre as marcas analisadas, mas a diferença não foi significativa. O processo de esterilização não influenciou a capacidade de absorção dos cones de papel absorvente>

Comparison of the centering ability of the ProTaper Universal, ProFile and Twisted File Rotary Systems

Aim: To determine the centering ability of Twisted File™ rotary system compared with ProTaperUniversal™ and ProFile™ rotary systems by evaluating pre- and postoperative cross-sectionalimages of the apical root canals third. Methods: Thirty mesiobuccal canals of human mandibularfirst molars were divided into three groups with 10 root canals each according to the instrumentused: group 1, ProTaper Universal™ rotary system; group 2, ProFile™, and group 3, TwistedFile™. Pre- and postoperative images of the apical thirds were viewed with a stereoscopicmagnifier with ×10 magnification and were captured digitally for further analysis using the ImageTools Software. The results were analyzed statistically by the Kruskal-Wallis test and the Mann-Whitney test. A level of significance of 0.05 was adopted. Results: The means of the buccolingualmeasurement ranged from 0.79 to 1.5. The largest deviation was registered to instrument 25.06in group 2. The means of the mesiodistal measurement ranged from 0.86 to 1.52, with the largestdeviation being registered to instrument 25.04 in group 3; however, there were no statisticallysignificant differences (p>0.05) among the three groups or among the instruments in the samegroup in terms of centering ability. Conclusions: None of the rotary systems evaluated in thisstudy was totally effective in performing biomechanical preparation of the root canals.

Comparison of root canals obturated with ProTaper gutta-percha master point using the active lateral condensation and the single-cone techniques: a bacterial leakage study

Aim: The aim of the present study was to assess the recontamination time of root canals filled with ProTaper gutta-percha master point using the active lateral condensation and the single-cone techniques. Methods: Fifty premolars, after biomechanical preparation, were randomly divided into six groups according to the obturation technique and the diameter of the gutta-percha point. For leakage evaluation, the roots were mounted in a dual-chamber leakage model system using Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli, and Staphylococcus aureus. The Kaplan-Meier and Long-Rank tests were employed at the .05 level of significance. Results: The recontamination was detected between the 13th and 80th days. The active lateral condensation produced less infiltration than the single cone technique, though without statistically significant differences between them. Conclusions: It may be concluded that there was no difference in bacterial penetration between the two root canal filling techniques. The mean root canalcontamination time was 67 days.

Arsenic content in Portland cement: A literature review.

Portland cement (PC) is a hydraulic binding material widely used in the building industry. The main interest in its use in dentistry is focused on a possible alternative to mineral trioxide aggregate (MTA) because PC is less expensive and is widely available. In dentistry, PC has been used in dental procedures such as pulpotomy, pulp capping, repair of root perforation and root-end filling. The purpose of this article is review the dental literature about the PC, its composition with special attention to arsenic content, properties, and application in dentistry. A bibliographic research was performed in Bireme, PubMed, LILACS and Scopus data bases looking for national and international studies about the PC composition, properties and clinical use. It was observed that PC has favorable biological properties very similar to those of MTA. The PC has shown good cell proliferation induction with formation of a monolayer cell, satisfactory inflammatory response, inhibitory effect of prostaglandin and antimicrobial effect. Studies have shown that PC is not cytotoxic, stimulates the apposition of reparative dentin and permits cellular attachment and growth. Regarding arsenic presence, its levels and release are low. PC has physical, chemical and biological properties similar to MTA. Arsenic levels and release are low, therefore, unable to cause toxic effects.

Antimicrobial activity of chlorhexidine in root canals instrumented with the ProTaper Universal™ System

Aim: The purpose of the present study was to evaluate the antimicrobial activity of 0.2%, 1%, and2% chlorhexidine in root canals instrumented with the ProTaper Universal™ system. Methods:Fifty human mandibular premolar teeth were infected with a mixture of Candida albicans,Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus aureus. The specimens were randomly divided into 5 groups with 10 root canals according to the irrigant used. All root canals were instrumented with the ProTaper Universal™ system. Assessment of the antimicrobial action of the irrigant was performed before, during, and after instrumentation. Data were analyzed statistically by Chi-squared test and the Fisher exact test at 5% significance level. Results: The0.2% chlorhexidine solution was ineffective against all test microorganisms. The 1% chlorhexidinesolution was effective in eliminating P. aeruginosa and C. albicans after the use of the F1 and F3instruments, respectively. The 2% chlorhexidine solution was effective at killing S. aureus, P.aeruginosa and C. albicans after the use of the S1 instrument. There were statistically significant differences (p<0.05) between the concentrations of chlorhexidine and the instruments used.Conclusions: The 0.2% chlorhexidine solution in combination with rotary instrumentation was ineffective against all test microorganisms. The 1% chlorhexidine solution was ineffective against S. aureus and E. faecalis. The 2% chlorhexidine solution was not sufficient to inactivate E.faecalis.

Soluções irrigadoras utilizadas para o preparo biomecânico de canais radiculares / Irrigating solutions used in the biomechanical preparation of root canals

Introdução: Os microrganismos desempenham um importante papel na etiologia e manutenção das infecções endodônticas. Esta população microbiana deverá ser eliminada durante o preparo biomecânico por meio da ação mecânica dos instrumentos endodônticos, das propriedades físico-químicas e anti microbianas das soluções irrigadoras auxiliares e pela ação da medicação intracanal. Objetivo: O presente trabalho se propôs a avaliar, através de uma revisão da literatura, as principais soluções irrigadoras utilizadas na Endodontia para o preparo biomecânico do sistema de canais radiculares, bem como, a utilização de novas soluções irrigadoras. Conclusões: O hipoclorito de sódio (NaOCl) continua sendo a solução irrigadora de eleição na Endodontia. O NaOCl a 1% com 16% de cloreto de sódio (NaCl) deve ser utilizado durante o preparo biomecânico dos canais radiculares devido à sua atividade anti microbiana, capacidade solvente de matéria orgânica e baixa citotoxicidade. A clorexidina a 1% e a 2% é utilizada apenas quando o único requisito é a atividade antimicrobiana, em casos de microrganismos resistentes ao tratamento endodôntico e em lesões refratárias. Uma solução de ácido etilenodiaminotetracético sal dissódico (EDTA) a 17% deverá ser utilizada como coadjuvante do preparo biomecânico de canais radiculares infectados, no tratamento de canais atresiados e calcificados e para remoção do smear layer contaminado. Todas as soluções irrigadoras apresentam limitações. A procura por uma solução irrigadora ideal deverá ser contínua. Isto apenas poderá ser alcançado com o desenvolvimento e pesquisas de novas substâncias.

Introduction: Microorganisms play an important role in the etiology and persistence of endodontic infections. This microbial population should be eliminated during the biomechanical preparation by the mechanical action of the endodontc instruments, the physicochemical and antimicrobial properti ES of the auxiliary irrigating solutions, and the action of intracanal medications. Objective: This literature review addresses the main endodontic irrigating solutions used in the biomechanical preparation of the root canal system, as well as the use of irrigating solutions. Conclusions: Sodium hypochlorite (NaOCl) sti ll is the endodontic irrigant of choice. The combination of 1% NaOCl with 16% sodium chloride (NaCl) should be used during biomechanical preparati on of root canals due to its anti microbial activity, organic matter solving capacity and low cytotoxicity. Chlorhexidine at 1% and 2% is used when only anti microbial activity is required, in cases of microorganisms resistant to endodontic treatment and refractory lesions. A 17% disodium ethylenediaminetetraacetic acid (EDTA) should be used as an auxiliary in the biomechanical preparation of root canals, in the treatment of narrow and calcified canals, and for removal of contaminated smear layer. All irrigating solutions presente limitations. There must be a continuous search for the ideal solution endodontic irrigant, which will be reached only with the investigation and development of new substances.

Assessment of canal walls after biomechanical preparation of root canals instrumented with protaper universalTM rotary system

OBJECTIVE: The aim of this study was to examine the instrumented walls of root canals prepared with the ProTaper UniversalTM rotary system. MATERIAL AND METHODS: Twenty mesiobuccal canals of human first mandibular molars were divided into 2 groups of 10 specimens each and embedded in a muffle system. The root canals were transversely sectioned 3 mm short of the apex before preparation and remounted in their molds. All root canals were prepared with ProTaper UniversalTM rotary system or with NitiflexTM files. The pre and postoperative images of the apical thirds viewed with a stereoscopic magnifier (X45) were captured digitally for further analysis. Data were analyzed statistically by Fisher's exact test and Chi-square test at 5 percent significance level. RESULTS: The differences observed between the instrumented and the noninstrumented walls were not statistically significant (p<0.05). CONCLUSIONS: The NitiflexTM files and the ProTaper UniversalTM rotary system failed to instrument all the root canal walls.

Resinas compostas: concentração e profundidade de polimerização: [revisão] / Composed resins: contraction and depth of polymerization: [review]

A evolução das resinas compostas tem sido constatada na melhoria do seu comportamento estético e no aumento da sua resistência à compressão e à abrasão. O objetivo do presente trabalho foi realizar uma revisão da literatura abordando os aspectos da contração e profundidade de polimerizaçao. Apesar dos avanços alcançados, a contração de polimerização, inerente à resina composta, continua sendo uma grande deficiência e, por enquanto, impossível de ser evitada.

The evolution of resins has been evidenced in the improvement of its aesthetic behavior and in the increase of its compressive strength and the abrasion. The aim of the present work was to carry through a revision of literature approaching the aspects of the contraction and depth of polymerization. Despite the reached advances, the contraction of polymerization, inherent to the composed resin, continues being a great deficiency and, for the time being, impossible to be prevented.

Materiais retrobturadores utilizados na cirurgia paraendodôntica / Root - end filling materials used in endodontics surgery

A cirurgia paraendodôntica é o tratamento de lesões perirradiculares através de um conjunto de procedimentos por meio cirúrgico, cujo objetivo entre outros visa resolver complicações decorrentes do tratamento endodôntico mal sucedido. A obturação retrógrada, uma das modalidades da cirurgia paraendodôntica, cnsiste na remoção do ápice da raiz, seguida de um preparo de uma cavidade e obturação desse espaço com material adequado. Vários materiais tem sido propostos, com o objetivo de promover o selamento do canal radicular por via retrógrada, dentre os quais podemos citar o Super EBA, o amálgama de prata e o MTA. Este trabalho se propõe através de uma revisão de literatura determinar entre os materiais retrobturadores, aquele que apresenta propriedades aceitáveis para a sua utilização na prática cirúrgica.

Endodontic surgery is the treatment of periradicular lesions by any surgical procedure to solve complications of unsucccessful the endodontic treatment. Retrograde filling, one of the surgery modalities, consists in removing the apex of the root, followed by the preparation of the cavity and its filling with appropriate materials such as Super-EBA, amalgam and MTA. The purpose of this literature review is determinate among the root-end filling materials witch one presents acceptable properties for it uses in surgical practice.

PCR e o perfil microbiológico das infecções endodônticas: realidade ou utopia? / PCR and the microbiological profile of endodontic infections: reality or utopy?

A influência dos microorgaismos nos processos patológicos, principalmente, infecciosos que envolvem a polpa e o periápice, está bem estabelecida nas falhas dos tratamentos endodônticos; entretanto, o real papel que cada microorganismo exerce dentro do processo infeccioso ainda é capaz de levantar discussões. Dentro desse contexto, o uso de novas técnicas moleculares, mais sensíveis e de maior especificidade na identificação desses patógenos abre novas perspectivas no campo da pesquisa, diagnóstico, tratamento e desenvolvimento de novos materiais endodônticos. O objetivo desse trabalho é o de discutir, à luz da literatura, as reais abrangências e possibilidades de uma dessas técnicas - a PCR (poliymerase chain reaction) - dentro do âmbito do conhecimento e identificação dos patógenos responsáveis pelas infecções endodônticas.

The influence of microorganisms in pathological processes is well established in the flaws of endodontic treatment, especially infectious processes involving the pulp and periapex. However, the actual role that each microorganism exercises within the infectious process remains open for discussion. Thus, the use of new molecular methods with greater sensitivity and specificity in the identification of these pathogens broadens perspectives in the s of research, diagnosis, treatment and the development od new endodontic materials. The aim of the present study was to discuss the scope and possibilities of one such method - PCR (polymerase chain reaction) - regarding knowledge and the identification of pathogens that cause endodontic infection.

Avaliação da capacidade de plastificação dos cones principais de Guta-Percha / Evaluation of the plastecized capacity of main Gutta-Percha cones

A utilização das técnicas de termoplastificação da Guta-Percha traz consigo a necessidade de avaliação do comportamento deste material em temperaturas elevadas. Desta forma, o presente trabalho objetivou avaliar a capacidade de plastificação dos cones de Guta-Percha principais, dos calibres 25, 30, 35 e 40 das marcas: Dentsply, Endopoints, Tanari e Newstetic. Cada calibre, dividido em dois grupos de dez espécimes, foram submetidos às temperaturas: 45°C e 50°C, sob a ação de uma força vertical e para baixo de 4,20 Newtons, durante 60 segundos. Os resultados demonstraram que dos cones analisados apenas os das marcas Dentsply e Tanari podem ser utilizados nas técnicas de termoplastificação, por apresentarem comportamento mais uniforme quando submetidos às temperaturas estudadas.

The use of thermoplasticized tecniques of gutta-percha brings with it the necessity of evaluation of this material's behaviour in high temperatures. This way, this work's objective was to evaluate the plasticized capacity of main gutta-percha cones, calibres 25, 30, 35 and 40 from different trademarks: Dentsply, Endopoints, Tanari e Newstetic. Each calibre was divided into two groups formed, each one, with ten cones. The cones were subjected of two different temperatures: 45°C and 50°C, under the action of a vertical down weight, during sixty seconds. The results showed which only the trademarks, Dentsply and Tanari can be used in the thermoplasticized tecniques, because presents more uniform behaviour when submitted iri the temperatures studied.

Estudo comparativo do selamento apical de diferentes cones de guta-percha / Comparative study of apical sealing of different gutta-percha points

O objetivo da presente pesquisa foi avaliar o selamento apical dos cones FM calibrados e dos cones ProTaper™ em canais instrumentados pelo sistema rotatório ProTaper™, por meio da infiltração apical de nanquim preto. Os espécimes foram imersos até o terço cervical no corante por 7 dias à temperatura de 37°C ± 1 e umidade absoluta. Em seguida foram seccionados no sentido vestíbulo-lingual e avaliados, por meio de lupa esteriomicroscópica com 40X de magnificação, por três examinadores independentes calibrados. Os dados foram analisados pelos testes de Kruskall-Wallis e U-Mann-Withney com grau de significância α=0,05. Observou-se infiltração em 30% dos espécimes no grupo dos cones FM calibrados e em 10% no dos cones ProTaper™. Contudo, a diferença não foi estatisticamente significante.

An evaluation of the standardization of endodontic files according to the ISO-3630-1 specification

O objetivo do presente estudo foi avaliar a padronização dos diâmetros D das limas endodônticas de acordo com a especificação ISO-3630-1 da International Standard Organization. Seiscentas e seis limas endodônticas tipo K e Hedstroen de primeira e segunda série com 25 mm de comprimento das três marcas comumente encontradas no mercado brasileiro: Dentsply-Maillefer (Ballaigues, Swiss), Dyna Endodontics Instruments (Bourges-France) and Kerr Dentistry (Romulus, USA). Com auxílio de um paquímetros D dos instrumentos avaliados. Os resultados demonstraram pouca correspondência entre os diâmetros D das limas endodônticas e o que preconiza a normal ISO-3630-1 da Intrnational Standard Organization.

The objective of this study was to evaluate the standardization of the diameters (D) of endodontics files in accordance with the recommendation of the International Standard Organization in its specification ISO-3630-1...

Morfologia interna do primeiro molar inferior através da radiografia e da diafanização / Internal morphology of the first mandibular molar by radiography and transparent teeth

Na presente pesquisa foram utilizados 103 primeiros molares inferiores obtidos no Banco de Dentes do Curso de Odontologia da UFPE com o objetivo de avaliar, através de radiografias periapicais e da diafanização, a morfologia interna das raizes mesial e distal e classificá-las de acordo com Vertucci (1984). Na raiz mesial foram identificados dois canais em 96,12% dos casos, curvos para a distal em 79,91%, tipo II em 60,20%. A raiz distal apresentou canal único em 91,26% dos casos, reto em 73,15%, tipo I em 69,90%. A técnica radiográfica e a diafanização mostraram-se bastante efetivas para o estudo e visualização da morfologia interna do sistema de canais radiculares.

In this research were selected hundred three human mandibular molars, obtained from Banco de Dentes do Curso de Odontologia da UFPE, the root canal morphology were evaluated by X-rays examination and of the transparent teeth of the mesial and distal of the first mandibular molar root, and classifying them according to Vertucci (1984). Two channels into the mesial root were detected at 96,12%, curved for the distal at 79,91%, type II of the Vertucci at 60,20%. The distal root presented a single root channel at 91,26%, straight at 73,15% and the Vertucci's type I at 69,90%. The radiographic technique and the transparent teeth were effective for the study and observation of the internal morphology of root canals system.

Influência do cimento obturador na contaminação de canais expostos ao meio bucal / Influence of the sealer in the root canal contamination after exposure to human saliva

O objetivo deste estudo in vitro foi avaliar a infiltração de saliva em canais radiculares obturados pela técnica da condensação lateral ativa associada a um cimento à base de resina epóxica (AH-Plus™) e outro à base de hidróxido de cálcio (Sealer 26®). Após a obturação dos canais radiculares os espécimes foram montados em um aparato contendo a saliva artificial a qual foram acrescidas o E. faecalis, St. aureus, P. aeruginosa e C. albicans. O número total de dias necessários para que ocorresse a recontaminação dos espécimes foi registrado. A avaliação foi conduzida por 120 dias. O grupo do Sealer 26® apresentou contaminação em 33,3% dos espécimes, enquanto que no grupo do AH-Plus™ observaram-se 6,1% dos espécimes contaminados. O AH-Plus™ apresentou significantemente menor índice infiltração (p<0,05).

The purpose of this in vitro study was to evaluated the coronal leakage of artificial salive into root canals filled by lateral condensation of gutta-percha using two root canal sealer one of this was based on epoxy resin (AH-Plus™) and other contained calcium hydroxide (Sealer 26®). Obtured canals with gutta-percha and either AH-Plus™ or Sealer 26® were mounted in an apparatus and then exposed to saliva. The number of day required for total recontamination of the root canals were record. Evaluation was conducet to 120 days. Third-three point three percent of the specimes of sealer 26 group showed entire recontamination at 120 days. Six point one percent of the root canaIs obtured with AH-Plus shoed completed recontamination at 120 days. AH-Plus present significantly less leakage then Sealer 26 (p<0.05).