Temperature changes on the root surfaces of mandibular incisors after an 810-nm high-intensity intracanal diode laser irradiation.

UNLABELLED: Temperature changes caused by laser irradiation can promote damage to the surrounding dental tissues. In this study, we evaluated the temperature changes of recently extracted human mandibular incisors during intracanal irradiation with an 810-nm diode laser at different settings. Fifty mandibular incisors were enlarged up to an apical size of ISO No. 40 file. After the final rinse with 17% ethylenediaminetetraacetic acid, 0.2% lauryl sodium sulfate biologic detergent, and sterile water, samples were irradiated with circular movements from apex to crown through five different settings of output power (1.5, 2.0, 2.5, 3.0, and 3.5 W) in continuous mode. The temperature changes were measured on both sides of the apical and middle root thirds using two thermopar devices. A temperature increase of 7 °C was considered acceptable as a safe threshold when applying the diode laser. RESULTS: The results showed that only 3.5-W output power increased the outer surface temperature above the critical value. CONCLUSION: The recommended output power can be stipulated as equal to or less than 3 W to avoid overheating during diode laser irradiation on thin dentin walls.

Bactericidal effects of two parameters of Er:YAG laser intracanal irradiation: ex-vivo study.

The success of endodontic treatment depends on the complete elimination of microorganisms from the root canal system, thus the search for new procedures to eliminate them is justified. The aim of this study was to assess bacterial reduction after intracanal irradiation with the Er:YAG laser. The canals of 70 extracted human maxillary canines were prepared up to file #40 using 1% NaOCl, irrigated with 17% EDTA, and then washed with physiological solution activated by ultrasound. The roots were sterilized by autoclaving, inoculated with 10 µl of a suspension containing 1.5 × 10(8) CFU/ml of Enterococcus faecalis ATCC 29212 and incubated at 37°C for 72 h. The canals were irradiated with the Er:YAG laser using two energy settings: 60 mJ and 15 Hz, and 100 mJ and 10 Hz. The remaining bacteria were counted immediately and 48 h after laser irradiation. The results showed a high bacterial reduction at both time points. With 60 mJ and 15 Hz there was an immediate reduction of 99.73% and the reduction was 77.02% after 48 h, and with 100 mJ and 10 Hz there was an immediate reduction of 99.95% and the reduction was 84.52% after 48 h. Although the best results were observed with 100 mJ of energy, the difference between the two settings was not statistically significant. The count performed 48 h after irradiation showed that E. faecalis were able to survive, and can grow even from small numbers.

The assessment of infection control in dental practices in the municipality of São Paulo.

OBJECTIVE: The goal of this study was to evaluate the infection control measures actually implemented by dental surgeons during dental practice, as patients and professionals are exposed to high biological risk in dental care environments. METHOD: 614 questionnaires (90.69%) were answered by professionals registered in updating or in post-graduate courses in the Municipality of São Paulo. RESULTS: Out of surveyed professionals 30.62% admitted that surface protection barriers were not used, whereas 34.17% were using non ideal or outdated pre-disinfection practices. The autoclave was used by 69.38% of participants, although 33.80% were not monitoring control of the sterilization cycles. Chemical and biological indicators were not used simultaneously by 83.21% of respondents and were not employed on a daily or weekly basis by at least 81.75%. Dubious methods of sterilization were cited by 44.77%. Occupational accidents caused by cutting and piercing objects were reported by 47.88%; however, the biologic risk was underestimated by 74.15% of the professionals who suffered the accidents. Irritant solutions were used as an antiseptic agent by 18.55%. CONCLUSIONS: Infection control measures reported by dental surgeons during their practices are deficient. It is necessary to educate, raise awareness of professionals, and promote constant updating courses on procedures which aim at improving safety of dental care.

Accuracy of working length determination using 3 electronic apex locators and direct digital radiography.

OBJECTIVES: The objectives of this study were to assess the accuracy of working length determination using 3 electronic apex locators and direct digital radiography and to compare the results with those obtained using the visual method (control measurement). STUDY DESIGN: Twenty extracted human maxillary premolars were selected: 17 two-rooted and 3 single-rooted (total of 37 canals). Working length was measured using electronic apex locators Elements Diagnostic, Root ZX, and Just II. Subsequently, teeth were positioned in the alveolar bone of a dry skull and submitted to direct digital radiography. A variation of ±1 mm was considered as acceptable. Results were analyzed using the Wilcoxon and the χ(2) tests. RESULTS: Results presented an accuracy of 94.6% for Elements Diagnostic, 91.9% for Root ZX, 73.0% for Just II, and 64.9% for direct digital radiography when considering the margin of ±1 mm in relation to the control measurement. Comparisons with the actual control measurements resulted in accuracy results of 13.51%, 13.51%, 10.10%, and 2.70%, respectively. CONCLUSIONS: Root ZX and Elements Diagnostic are more accurate in determining working length when compared with Just II and Schick direct digital radiography.

The assessment of infection control in dental practices in the municipality of São Paulo

OBJECTIVE: The goal of this study was to evaluate the infection control measures actually implemented by dental surgeons during dental practice, as patients and professionals are exposed to high biological risk in dental care environments. METHOD: 614 questionnaires (90.69 percent) were answered by professionals registered in updating or in post-graduate courses in the Municipality of São Paulo. RESULTS: Out of surveyed professionals 30.62 percent admitted that surface protection barriers were not used, whereas 34.17 percent were using non ideal or outdated pre-disinfection practices. The autoclave was used by 69.38 percent of participants, although 33.80 percent were not monitoring control of the sterilization cycles. Chemical and biological indicators were not used simultaneously by 83.21 percent of respondents and were not employed on a daily or weekly basis by at least 81.75 percent. Dubious methods of sterilization were cited by 44.77 percent. Occupational accidents caused by cutting and piercing objects were reported by 47.88 percent; however, the biologic risk was underestimated by 74.15 percent of the professionals who suffered the accidents. Irritant solutions were used as an antiseptic agent by 18.55 percent. CONCLUSIONS: Infection control measures reported by dental surgeons during their practices are deficient. It is necessary to educate, raise awareness of professionals, and promote constant updating courses on procedures which aim at improving safety of dental care.

Accuracy of three electronic apex locators in the presence of different irrigating solutions.

The present study compared the accuracy of three electronic apex locators (EALs) - Elements Diagnostic®, Root ZX® and Apex DSP® - in the presence of different irrigating solutions (0.9% saline solution and 1% sodium hypochlorite). The electronic measurements were carried out by three examiners, using twenty extracted human permanent maxillary central incisors. A size 10 K file was introduced into the root canals until reaching the 0.0 mark, and was subsequently retracted to the 1.0 mark. The gold standard (GS) measurement was obtained by combining visual and radiographic methods, and was set 1 mm short of the apical foramen. Electronic length values closer to the GS (± 0.5 mm) were considered as accurate measures. Intraclass correlation coefficients (ICCs) were used to verify inter-examiner agreement. The comparison among the EALs was performed using the McNemar and Kruskal-Wallis tests (p < 0.05). The ICCs were generally high, ranging from 0.8859 to 0.9657. Similar results were observed for the percentage of electronic measurements closer to the GS obtained with the Elements Diagnostic® and the Root ZX® EALs (p > 0.05), independent of the irrigating solutions used. The measurements taken with these two EALs were more accurate than those taken with Apex DSP®, regardless of the irrigating solution used (p < 0.05). It was concluded that Elements Diagnostic® and Root ZX® apex locators are able to locate the cementum-dentine junction more precisely than Apex DSP®. The presence of irrigating solutions does not interfere with the performance of the EALs.

Accuracy of three electronic apex locators in the presence of different irrigating solutions

The present study compared the accuracy of three electronic apex locators (EALs) - Elements Diagnostic®, Root ZX® and Apex DSP® - in the presence of different irrigating solutions (0.9 percent saline solution and 1 percent sodium hypochlorite). The electronic measurements were carried out by three examiners, using twenty extracted human permanent maxillary central incisors. A size 10 K file was introduced into the root canals until reaching the 0.0 mark, and was subsequently retracted to the 1.0 mark. The gold standard (GS) measurement was obtained by combining visual and radiographic methods, and was set 1 mm short of the apical foramen. Electronic length values closer to the GS (± 0.5 mm) were considered as accurate measures. Intraclass correlation coefficients (ICCs) were used to verify inter-examiner agreement. The comparison among the EALs was performed using the McNemar and Kruskal-Wallis tests (p < 0.05). The ICCs were generally high, ranging from 0.8859 to 0.9657. Similar results were observed for the percentage of electronic measurements closer to the GS obtained with the Elements Diagnostic® and the Root ZX® EALs (p > 0.05), independent of the irrigating solutions used. The measurements taken with these two EALs were more accurate than those taken with Apex DSP®, regardless of the irrigating solution used (p < 0.05). It was concluded that Elements Diagnostic® and Root ZX® apex locators are able to locate the cementum-dentine junction more precisely than Apex DSP®. The presence of irrigating solutions does not interfere with the performance of the EALs.

Estudo comparativo da reação tecidual conjuntiva de ratos, frente a três cimentos endodônticos resinosos / Comparative study of rat's connective tissue reaction, against three endodontic resin cements

Objetivo - Este estudo avaliou in vivo a biocompatibilidade dos cimentos AH Plus, Acroseal e EndoREZ, após a implantação em tecido subcutâneo de 16 ratos Wistar. Métodos - Os cimentos foram colocados no interior de tubos de polietileno e implantados em locais específicos no subcutâneo do dorso dos animais. Os blocos de tecidos foram removidos após 24 horas, 72 horas, 7 dias e 21 dias, processados histologicamente e analisados através da observação microscópica óptica. Resultados - Os resultados indicaram que todos os cimentos induziram reações inflamatórias discretas, que diminuíram ao longo do experimento. Conclusões - O cimento Acroseal apresentou o melhor comportamento biológico, seguido pelo AH Plus e EndoREZ.

Objective - The purpose of this study was evaluate in vivo the biocompatibility of the cements AH Plus, Acroseal and EndoREZ, after implantation in connective tissue of sixteen Wistar rats. Methods - The cements were put in the polyethilene tubs and implanted in specific areas in animal's dorsal subcutaneous. The block of tissues was removed after 24 hours, 72 hours, 7 days and 21 days, histological processes was conducted and analyzed under optical microscopic observation. Results - The results indicated that all cements induced mild inflammatory reaction, that decreased with the experiment time. Conclusions - The Acroseal cement showed the best biological reaction, followed by AH Plus and EndoREZ.

Apical leakage of three resin-based endodontic sealers after 810-nm-diode laser irradiation.

OBJECTIVE: To evaluate the influence of 810-nm-diode laser irradiation, applied before root canal filling, on apical sealing ability of three different resin-based sealers (AH Plus, EndoRez, and RealSeal). BACKGROUND: Lasers have been widely used in endodontics. The dentin wall changes caused by laser irradiation could improve the sealing ability of endodontic cements. METHODS: Sixty single-rooted human teeth were divided into six groups, according to the endodontic sealer used and previous 810-nm-diode laser irradiation. The protocol for laser irradiation was 2.5 W in a continuous wave, in scanning mode, with four irradiations per tooth. After sample preparation, they were analyzed according to apical leakage with silver nitrate impregnation. RESULTS: The RealSeal sealer achieved minimum leakage rates (1.24 mm), with significant differences at the 1% level (Tukey's test, p<0.01) from AH Plus (1.84 mm) in nonirradiated groups. When the laser was used, there were also significant differences at the 5% level (p<0.05) between irradiated groups (1.31 and 1.78 mm, respectively). CONCLUSION: The 810-nm-diode laser irradiation did not promote significant differences in apical leakage.

Morphologic changes and removal of debris on apical dentin surfaces after Nd:YAG laser and diode laser irradiation.

OBJECTIVE: To verify the effects of laser energy on intracanal dentin surfaces, by analyzing the morphologic changes and removal of debris in the apical third of 30 extracted human teeth, prepared and irradiated with the Nd:YAG laser and diode laser. BACKGROUND DATA: Lasers have been widely used in endodontics. The morphologic changes in dentin walls caused by Nd:YAG and diode laser irradiation could improve apical seals and cleanliness. MATERIALS AND METHODS: The protocol used for Nd:YAG laser irradiation was 1.5 W, 100 mJ, and 15 Hz, in pulsed mode, and for diode laser was 2.5 W in continuous mode. Each specimen was irradiated four times at a speed of 2 mm/sec with a 20-sec interval between applications. Five calibrated examiners scored the morphologic changes and debris removal on a 4-point scale. RESULTS: In analyzing the scores, there were no statistically significant differences between the two types of laser for either parameter, according to Kruskal-Wallis testing at p = 0.05. The SEM images showed fusion and resolidification of the dentin surface, with partial removal of debris on the specimens irradiated with the Nd:YAG laser and the diode laser, compared with controls. CONCLUSION: Both lasers promote morphologic changes and debris removal. These alterations of the dentin surface appeared to be more evident in the Nd:YAG laser group, but the diode laser group showed more uniform changes.

Periodontite apical assintomática: relato de caso clínico / Assymptomatic apical periodontitis: clinical report

O presente trabalho relata a história clínica de uma paciente de 37 anos de idade, que se apresentou a Universidade Paulista (UNIP), queixando-se de uma "espinha no queixo que não sarava". O exame radiográfico mostrou uma extensa área radiolúcida envolvendo os dentes anteriores, que através do mapeamento com cone de guta-percha e radiografia, detectou-se que a espinha no queixo era uma fístula extra-oral associada ao dente 41. O tratamento proposto foi o endodôntico com curativos à base de hidróxido de cálcio. Durante o tratamento deste dente, a paciente se queixou de uma "bolinha" na região lingual. Com novo mapeamento constatou-se outra fístula, intra-oral, correspondente a uma lesão periapical no dente 34. Foi proposto o mesmo procedimento com curativos à base de hidróxido de cálcio. Observou-se o desaparecimento das duas fístulas. O tratamento endodôntico à base de curativos de hidróxido de cálcio foi eficaz e a proservação foi necessária para acompanhar a reparação neste tipo de patologia.

The present study relates a clinical history of a 37 years old patient that presented to the University Paulista (UNIP) reporting "a pimple in her chin that never dried". A radiographic exam showed a large radiolucense area involving the anterior teeth that traced with a gutapercha point showed that it was an extraoral fistula, concerning the 41 tooth. The treatment proposed was the endodontic with intracanal medication of calcium hydroxide. During the treatment the patient reported a pimple in the lingual region. With a new traced radiography, it was constacted another fistula, intraoral, corresponding to a periapical lesion in the 34 tooth. It was proposed the same treatment with calcium hydroxide. It was observed the cure of the both fistulas. The endodontic treatment with intracanal medication of calcium hydroxide was effective and it was necessary to accompany the cure in this patology.

Influence of Nd:YAG and diode laser irradiation on apical sealing when associated with AH plus and EndoREZ endodontic cements.

OBJECTIVE: This study aims to evaluate the influence of Nd:YAG and diode laser irradiation on apical sealing when applied before root canal filling done with two different resin-based cements (AH Plus and EndoREZ). BACKGROUND DATA: Lasers have been widely used in endodontics. The morphologic changes in dentin walls caused by Nd:YAG and diode laser irradiation could improve sealing ability of endodontic cements. METHODS: Eighty canine teeth were analyzed by apical leakage of methylene blue dye and by scanning electron microscope (SEM) images of the filling's adaptation to the apical third dentin walls. The laser irradiation parameters for the Nd:YAG laser were 100 mJ, 15 Hz, and 1.5 W, and for the diode laser was 2.5 W (continuous mode). RESULTS: The apical leakage results showed statistically significant differences at the 5% level of significance (Tukey's test, p < 0.05) among the different root canal wall treatments, independently of the root canal filling cement used. The cements also showed significant differences between them on the lased groups. The SEM analysis revealed better filling adaptation for AH Plus and the Nd:YAG laser group, confirming the microleakage results. CONCLUSION: We concluded that the combination of the Nd:YAG laser and AH Plus showed the best results.

Study of the areas and thicknesses of mesiobucal root canals prepared by three endodontic techniques.

The purpose of this study was to compare, in vitro, by means of computerized analysis of digital radiographic images, the anatomic alterations produced in the mandibular molar tooth dentinal walls of mesiobucal canals with severe curvature by three different endodontic techniques: Progressive Preparation, Staged and Serial Preparation. A selection was made of 45 extracted, human, mandibular molars, with root curvatures greater than 25 degrees. They were divided into three groups for every technique studied, which were then sub-divided into three sub-groups in accordance with the position of the curvature along the root: cervical, median or apical. After access surgery and tooth length determination, the canals were filled with 100% Barium Sulphate radiological contrast and the teeth were then radiographed with a direct digital radiography system, using a special apparatus capable of keeping the samples in the same spatial position during the different radiographic takes. After the above-mentioned endodontic techniques had been performed, the teeth were again filled with Barium sulphate and were also radiographed under the same previously mentioned conditions. The pre- and post-operative digital images were then analyzed in two computerized programs, AutoCAD 2004 and CorelDraw 10, to assess, respectively, the areas and the horizontal alterations which occurred in the internal and external walls of the root canals. The results indicated that although no significant differences among the techniques were shown in the statistical analysis, in a descriptive analysis the Progressive Preparation technique was shown to be more regular, uniform and effective.

Composição e avaliação de aplicativo hipermídia como recurso educacional na graduação de Endodontia / Composition and evaluation of applicatory hypermedia as educational resource in Endodontics graduation

Introdução - O computador tornou-se uma necessidade no mundo em que vivemos, e o ensino representado pela universidade, na missão de preparar o aluno para a carreira profissional, sente a responsabilidade de não fechar os olhos para essa realidade. Atualmente, a presença da informática na didática de ensino representa novas configurações e metodologias para a condução do processo de ensino e aprendizado, bem como a difusão das diferentes formas de conhecimentos. No desenvolvimento da computação, a hipermídia retrata com fidelidade, som, texto, imagem e animação. Aplicados em sala de aula esses recursos caracterizam interatividade e interferência na seqüência de apresentações. Frente a esta nova temática, o presente estudo teve como objetivo a introdução de um CD-ROM como coadjuvante no estudo da Endodontia, especificamente a técnica endodôntica, a fim de verificar os benefícios da hipermídia dentro do contexto educacional. Material e Métodos - A hipermídia em formato de CD-ROM foi desenvolvida a partir da coleta de todo material endodôntico, bem como o tratamento das mídias com auxílio de softwares específicos. Possibilitando assim, a realização de um arquivo auto-executável quando inserido no drive do computador, permitindo uma navegação da hipermídia de forma não linear pelo usuário. Resultados- A avaliação do CD-ROM foi realizada com alunos da disciplina de Endodontia onde foi verificada a sua aplicabilidade. Conclusão - Os resultados estatísticos mostraram que o uso da hipermídia pode ser uma ferramenta motivadora no ensino da Endodontia

Location and angulation of curvatures of mesiobucal canals of mandibular molars debrided by three endodontic techniques.

The aim of this study was to assess the correlation between the degree of angulation and the position of root curvatures and their influence on the comparative results between the performances of the Progressive, Staged and Serial Preparation Techniques. The mesiobucal canals of 70 extracted mandibular molars were filled with a radiological contrast of 100% Barium sulphate and radiographed with a direct digital radiographic system, in an apparatus that guarantees that the samples remain in the same spatial position at all times. The images were then analyzed in the Coreldraw 10 program (MicroSafe, RJ, Brasil) in accordance with two criteria: the methods of Berbert, Nishiyama(1) (1994) and Schneider11 (1971) to determine the position and the angle of the root curvatures, respectively. Initially, the possibility of correlation between these two variables was studied. The teeth were then selected according to angulation (greater than 25 degrees) and position of root curvatures (cervical, median and apical) in order to perform the endodontic techniques. After preparation, the samples were radiographed again and the images were superimposed in order to compare the pre- and post-operative areas. The difference between them showed the percentage of widening for each technique. The results showed that there was no correlation between the angulations and the root curvature positions, and that the different positions did not interfere in the performance of the techniques. The Progressive Preparation technique produced the highest widening values for all the groups, irrespective of the root curvature position.

Location and angulation of curvatures of mesiobucal canals of mandibular molars debrided by three endodontic techniques

The aim of this study was to assess the correlation between the degree of angulation and the position of root curvatures and their influence on the comparative results between the performances of the Progressive, Staged and Serial Preparation Techniques. The mesiobucal canals of 70 extracted mandibular molars were filled with a radiological contrast of 100 percent Barium sulphate and radiographed with a direct digital radiographic system, in an apparatus that guarantees that the samples remain in the same spatial position at all times. The images were then analyzed in the Coreldraw 10 program (MicroSafe, RJ, Brasil) in accordance with two criteria: the methods of Berbert, Nishiyama¹ (1994) and Schneider11 (1971) to determine the position and the angle of the root curvatures, respectively. Initially, the possibility of correlation between these two variables was studied. The teeth were then selected according to angulation (greater than 25 degrees) and position of root curvatures (cervical, median and apical) in order to perform the endodontic techniques. After preparation, the samples were radiographed again and the images were superimposed in order to compare the pre- and post-operative areas. The difference between them showed the percentage of widening for each technique. The results showed that there was no correlation between the angulations and the root curvature positions, and that the different positions did not interfere in the performance of the techniques. The Progressive Preparation technique produced the highest widening values for all the groups, irrespective of the root curvature position.

O objetivo deste trabalho foi verificar a correlação entre o grau de angulação e a posição das curvaturas radiculares, e a sua influência nos resultados comparativos entre os desempenhos das técnicas do Preparo Progressivo, Escalonada e Seriada. Os canais mésio-vestibulares de 70 dentes molares inferiores extraídos foram preenchidos com um contraste radiológico de sulfato de Bário a 100 por cento e radiografados em um sistema de radiografia digital direta, em um aparato que garantia que as amostras ficassem sempre na mesma posição espacial. As imagens foram, então, analisadas no programa Coreldraw 10 (MicroSafe, RJ, Brasil) segundo dois critérios: os métodos de Berbert, Nishiyama¹ (1994) e de Schneider11 (1971) para determinação da posição e do ângulo das curvaturas radiculares, respectivamente. Estudou-se inicialmente a possibilidade de correlação entre essas duas variáveis. Os dentes foram, então, selecionados segundo a angulação (superior a 25 graus) e posição das curvaturas radiculares (cervical, mediana e apical) para a realização das técnicas endodônticas. Após os preparos, as amostras foram novamente radiografadas e as imagens sobrepostas para a comparação das áreas pré e pós-operatórias. A diferença entre elas mostrou a porcentagem de alargamento para cada técnica. Os resultados mostraram não existir correlação entre as angulações e as posições das curvaturas radiculares, e que as diferentes posições não interferem no desempenho das técnicas. A técnica do Preparo Progressivo mostrou maiores valores de alargamento para todos os grupos, independentemente da posição da curvatura radicular.

Avaliação da radiopacidade de cimentos endodônticos pelo Sistema RVG-Radiovisiografia / Valuation of radiopacity of endodontic sealers by a Radiovisiography System - RVG

Introdução - O objetivo deste estudo foi avaliar a radiopacidade de diferentes cimentos endodônticos através do Sistema de Radiovisiografia - RVG-ui, com as ferramentas do próprio sistema, no intuito de facilitar a interpretação radiográfica. Materiais e Métodos - Cinco amostras de cimentos - N-Rickert (Fórmula e Ação), Intrafill (SSWhite), AH Plus (Dentsply), Endorez (Ultradent) e Epiphany (Pentron) foram radiografadas em um sistema de radiografia digital direta - o RVG-ui (Trophy Radiologie, França). As imagens digitais foram então examinadas por ferramentas fornecidas pelo próprio sistema, a análise densitométrica em número de pixels e dos pontos de equidensidade em cores, comparando os resultados fornecidos por elas. Resultados - Todos os cimentos apresentaram uma radiopacidade superior a aquela requeridas pela norma ISO 6876 - 2001. A diferença entre os resultados foi pequena, mostrando que clinicamente, seria difícil a diferenciação entre as amostras. No entanto, a comparação dos resultados mostrou que os cimentos N-Rickert e Epiphany apresentaram maior e menor radiopacidade, respectivamente, e o Endodez a menor homogeneidade. Conclusões - O Sistema de Radiovisiografia, RVG-ui, fornece ferramentas excelentes para avaliar a radiopacidade das imagens radiográficas

Study of the areas and thicknesses of mesiobucal root canals prepared by three endodontic techniques

The purpose of this study was to compare, in vitro, by means of computerized analysis of digital radiographic images, the anatomic alterations produced in the mandibular molar tooth dentinal walls of mesiobucal canals with severe curvature by three different endodontic techniques: Progressive Preparation, Staged and Serial Preparation. A selection was made of 45 extracted, human, mandibular molars, with root curvatures greater than 25°. They were divided into three groups for every technique studied, which were then sub-divided into three sub-groups in accordance with the position of the curvature along the root: cervical, median or apical. After access surgery and tooth length determination, the canals were filled with 100 percent Barium Sulphate radiological contrast and the teeth were then radiographed with a direct digital radiography system, using a special apparatus capable of keeping the samples in the same spatial position during the different radiographic takes. After the above-mentioned endodontic techniques had been performed, the teeth were again filled with Barium sulphate and were also radiographed under the same previously mentioned conditions. The pre- and post-operative digital images were then analyzed in two computerized programs, AutoCAD 2004 and CorelDraw 10, to assess, respectively, the areas and the horizontal alterations which occurred in the internal and external walls of the root canals. The results indicated that although no significant differences among the techniques were shown in the statistical analysis, in a descriptive analysis the Progressive Preparation technique was shown to be more regular, uniform and effective.

Objetivou-se comparar, in vitro, através de análise computadorizada de imagens radiográficas digitais, as alterações anatômicas promovidas nas paredes dentinárias de canais mésio-vestibulares com curvatura severa de molares inferiores por três técnicas endodônticas diferentes: Preparo Progressivo, Escalonada e Seriada. Foram selecionados 45 molares inferiores humanos extraídos, com curvaturas radiculares superiores a 25°, que foram divididos em três grupos para cada técnica estudada e subdivididos em três subgrupos de acordo com a posição da curvatura ao longo da raiz: cervical, mediana ou apical. Após cirurgia de acesso e odontometria, os canais foram preenchidos com contraste radiológico de sulfato de Bário a 100 por cento e os dentes então foram radiografados por um sistema de radiografia digital direta, utilizando-se um aparato capaz de manter as amostras na mesma posição espacial nas diferentes tomadas radiográficas. Após a realização das técnicas endodônticas supracitadas, os dentes foram novamente preenchidos com o sulfato de Bário e radiografados nas mesmas condições anteriores. As imagens digitais pré e pós-operatórias foram então analisadas em dois programas computadorizados, o AutoCAD 2004 e o CorelDraw 10, para verificar, respectivamente, as áreas e as alterações horizontais ocorridas nas paredes internas e externas dos canais radiculares. Apesar de não ter havido diferenças significantes entre as técnicas na análise estatística, em uma análise descritiva a técnica do Preparo Progressivo mostrou-se mais regular, uniforme e eficaz.

Análise comparativa "in vitro" entre os localizadores apicais eletrônicos Just II e Root ZX / Comparative analysis \"in vitro\" of root apex locators Just II and Root ZX

Introdução - Com o advento dos métodos eletrônicos para odontometria não há de se discutir as vantagens no que diz respeito ao tempo de trabalho do procedimento clínico e menor irradiação do paciente. Assim, o presente estudo teve por objetivo avaliar a acurácia dos aparelhos eletrônicos localizadores apicais Just II e Root ZX, utilizados na odontometria de dentes extraídos. Material e Métodos - Foram utilizados vinte dentes pré-molares superiores extraídos. Após cirurgia de acesso, sempre com irrigação de hipoclorito de sódio a 1%, lima do tipo K#10 foi inserida nos canais até que sua ponta pudesse ser observada nivelada ao forame apical, por meio de lupa de 4,0 aumentos. Recuando-se 1,0 mm deste ponto foi obtido o comprimento de trabalho (padrão ouro). Sequencialmente os dentes foram posicionados em uma esponja presente em um recipiente plástico com solução fisiológica. A nova medida do comprimento de trabalho foi realizada, com os canais preenchidos por NaOCl 1% por três examinadores, com os aparelhos localizadores apicais Just II e Root ZX respectivamente regulados para 1,0 mm aquém forame. Os dados foram tabulados e analisados. Resultados - O localizador Just II quando comparado ao padrão ouro obteve 64,86% de medidas aquém, 24,33% de medidas além e 10,81% de medidas iguais. O localizador Root Z, quando comparado ao padrão ouro , obteve 35,14% de medidas aquém, 51,35% de medidas além e 13,51% de medidas iguais. Conclusão - Os dois localizadores não foram precisos em estabelecer a medida 1,0 mm aquém forame, "in vitro"

Análise comparativa das técnicas de desobturação ultrassônica e com o laser Diodo de alta intensidade, em função do tempo e quantidade de material removido / Comparative analysis of ultrasonic and Diode laser technique on gutta-percha removal, according to the time and amount of removed material

Introdução - O objetivo deste estudo foi comparar duas técnicas de desobturação (ultrassônica e com laser de Diodo 810 nm) em relação ao tempo gasto para atingir o CRT (comprimento real de trabalho) e quantidade de material removido. Material e Métodos - Utilizaram-se 50 canais simulados,obturados com três diferentes técnicas (termocompactação por McSpadden com guta-percha convencional e com guta-percha TP e por condensação lateral). Dividiu-se a amostra em dois grupos. O Grupo G1, desobturado com ponta de ultra-som, que penetrava com movimento de translação ao redor do canal até chegar ao CRT, foi dividido em três subgrupos conforme a técnica deobturação: G1Mc (McSpadden e guta-percha convencional), G1Mt (McSpadden e guta-perchaTP) e G1Cl (condensação lateral). No Grupo 2 (G2) foi utilizado o laser de Diodo (3W em modo contínuo) para desobturação, penetrando a fibra no canal pelo centro da obturação com movimento de entrada e retrocesso pontual e leve até alcançar o CRT e com movimentos helicoidais ápicocoronais na retirada da fibra. Este também foi dividido em três subgrupos segundo as técnicas de obturação (G2Mc, G2Mt e G2Cl). As massas dos canais foram mensuradas antes e após a desobturação, calculando-se a diferença das massas. Também foi medido o tempo necessário para se alcançar o CRT pré-estabelecido (22 mm). Realizou-se análise de variância ANOVA. Resultados - Com relação à diferença de massa houve significância estatística (p = 0,001) entre os grupos G1Cl>G2Cl, G1Mc>G2Mc e G1Mt>G2Mt. Com relação ao tempo (p = 0,001) também houve diferença estatisticamente significante sendo G1Mc>G2Mc, G1Mt>G2Mt e G1Cl>G2Cl. Conclusão - Ambas as técnicas são válidas para a remoção de material obturador, sendo que a técnica ultrassônica removeu maior quantidade de guta-percha, enquanto que o laser de Diodo alcançou ocomprimento de trabalho em menos tempo, independente da técnica obturadora.

Introduction - The aim of this study was to compare two gutta-percha removal techniques (ultrasound and with Diode laser - 810 nm), analyzing the time spent to reach the work length and the amount of removed material. Material and Methods - Fifty simulated canals filled with three different techniques (McSpadden with conventional and TP gutta-percha and lateral condensation) were divided in two groups. The Group G1 was desobturaded with an ultrasound tip, which penetrated with translation movement around the canal to achieve the work length. It was divided in three subgroups, according to the filling technique: G1Mc (McSpadden and conventional guttapercha), G1Mt (McSpadden and gutta-percha TP) and G1Cl (lateral condensation). The Group 2(G2) used the Diode laser (3W in continuous wave), penetrating the fiber in the center of the canal with punctual and gentle entrance movements until the work length was reached and with translation movements on the fiber removal. This group was also divided in three subgroups according to the filling technique (G2Mc, G2Mt and G2Cl). The canals mass were measured before and after the filling removal, calculating the mass difference. It was also measured the necessary time to reach the established work length (22 mm). The results were statistically analyzed using one-way ANOVA test. Results - Regarding the mass difference average, there were significant statistical differences (p = 0,001) between the groups: G1Cl>G2Cl, G1Mc>G2Mc and G1Mt>G2Mt. Regarding time (p = 0,001), there were also significant statistical differences: G1Mc>G2Mc,G1Mt>G2Mt and G1Cl>G2Cl. Conclusion - Both techniques are useful to remove the filling material,and the ultrasonic technique removed a larger amount of gutta-percha, while the Diode laser reached the work length in less time, independent of the obturation technique.