Diagnostic Efficacy of Four Methods for Locating the Second Mesiobuccal Canal in Maxillary Molars.

INTRODUCTION: The major cause for failure of root canal therapy is the inability to recognize the presence of all canals of the root canal system. Auxiliary tools, such as magnifying loupe, operative microscope and computed tomography (CT) images are used to facilitate the location of canals. The objective of the present survey was to evaluate the diagnostic efficacy of four methods for detecting the second canal of mesiobuccal roots (MB2) of permanent maxillary molars. METHODS AND MATERIAL: A total of 147 extracted human maxillary molars were assessed. The floor of the pulp chamber was inspected by an endodontist to find MB2 canals. Analyses were performed without magnification (direct visual method), using a loupe (with 3.5× magnification), and using a microscope (with 16× magnification). A fourth analysis was conducted using cone-beam computed tomography (CBCT) images. Teeth were sectioned horizontally into three parts (cervical, medial and apical thirds) to confirm the presence of MB2 canals (reference standard method). Sensitivity, specificity, and positive/negative predictive values were calculated for each method. RESULTS: No statistically significant differences were observed in the frequency of MB2 found between the microscope and the reference standard or between CBCT and the reference standard. CBCT had higher sensitivity (0.88), specificity (0.88), positive (0.84) and negative (0.91) predictive value than the other three methods. CONCLUSION: CBCT was the most accurate method for detecting the MB2 and it had a diagnostic efficacy similar to that of the reference standard method.

Unusual foraminal position in a mandibular molar / Posição foraminal atípica em molar inferior

Knowledge of possible morphological variations of the root canal system is crucial to achieve endodontic success. The radiographic apex is traditionally used as a reference point for establishing the apical limit of root canal instrumentation and obturation. However, frequently it does not coincide with the major apical foramen. This article describes the rare case of a mandibular molar with necrotic pulp and apical periodontitis exhibiting an unusual foraminal position with a distance from the radiographic apex of about 7 mm. The left mandibular molar of a 46-year-old female patient was referred for endodontic treatment. Following radiographic suspicion of apical calcifi cation, comparison with the mandibular molar on the opposite side, electronic working length determination and visualization of a size #15 fi le emerging through the foramen in the working length radiograph, the anatomical variation was confi rmed, and endodontic procedures were performed according to conventional techniques. Following chemomechanical preparation, intracanal medication with calcium hydroxide, and obturation, total regression of the periapical lesion was verifi ed after 7 years of follow-up. According to the literature, the distance between the root canal foramen and the root apex may range from 0 to 3 mm, but in this specifi c case the distance reached 7 mm. Dentists should be aware of this atypical anatomical situation when treating mandibular molars.

O conhecimento das possíveis variações morfológicas do sistema de canais radiculares é crucial para alcançar o sucesso endodôntico. O ápice radiográfi co é usado como ponto de referência para estabelecer o limite apical da instrumentação e obturação dos canais radiculares. No entanto, é bem sabido que frequentemente ele não coincide com o forame apical maior. Este estudo apresenta um raro caso de molar inferior com necrose pulpar e periodontite apical, exibindo uma posição incomum do forame com uma distância do ápice radiográfi co de cerca de 7 mm. O molar inferior esquerdo de uma paciente de 46 anos foi encaminhado para tratamento endodôntico. Após suspeita radiográfi ca de calcifi cação apical, comparação com o molar inferior do lado oposto, determinação eletrônica do comprimento de trabalho e visualização de uma lima #15 emergindo através do forame na radiografi a odontométrica, a variação anatômica foi confi rmada, e os procedimentos endodônticos foram realizados de acordo com técnicas convencionais. Após preparo químicomecânico, medicação intracanal com hidróxido de cálcio e obturação, a regressão total da lesão periapical foi verifi cada após 7 anos de acompanhamento. Segundo a literatura endodôntica, a distância entre o forame do canal radicular e o ápice radicular pode variar de 0 a 3 mm, mas neste caso específi co, a distância alcançada foi de 7 mm. Os dentistas devem estar cientes desta situação anatômica atípica ao tratar molares inferiores.

Tissue characterization following revascularization of immature dog teeth using different disinfection pastes.

Revascularization of immature teeth with necrotic pulps traditionally involves the use of triple antibiotic paste, which may sometimes lead to undesirable complications. The objective of this study was to assess tissue repair in immature dog teeth with apical periodontitis subjected to revascularization, comparing two different pastes used for root canal disinfection. Apical periodontitis was induced in 30 dog premolars. Teeth were randomly divided into three experimental groups: root canals filled with triple antibiotic paste (n = 10); root canals filled with 1% propolis paste (n = 10); and no medication (n = 10). An additional group (n = 10, no intervention) was used as control. After 7 months, the jaws were histologically evaluated for the following variables: newly formed mineralized tissue (present/absent); vital tissue in the canal space (absent/periodontal ligament-like/pulp-like); apical extension of root (present/absent); and severity of inflammatory process (absent/mild/moderate/severe). There were no statistically significant differences among the experimental groups in new mineralized tissue formation and apical root development. The formation of vital tissue in the canal space, in turn, was statistically different between the triple paste and propolis groups: vital tissues were present in all revascularized teeth disinfected with propolis paste (100%), compared to 71% of those disinfected with the triple paste. Severity of inflammatory process was different between the triple paste and no medication groups. The new tissues formed onto canal walls and in the root canal space showed characteristics of cementum and periodontal ligament, respectively. Propolis may have some advantages over the triple paste for the revascularization of immature teeth.

Tissue characterization following revascularization of immature dog teeth using different disinfection pastes

Abstract Revascularization of immature teeth with necrotic pulps traditionally involves the use of triple antibiotic paste, which may sometimes lead to undesirable complications. The objective of this study was to assess tissue repair in immature dog teeth with apical periodontitis subjected to revascularization, comparing two different pastes used for root canal disinfection. Apical periodontitis was induced in 30 dog premolars. Teeth were randomly divided into three experimental groups: root canals filled with triple antibiotic paste (n = 10); root canals filled with 1% propolis paste (n = 10); and no medication (n = 10). An additional group (n = 10, no intervention) was used as control. After 7 months, the jaws were histologically evaluated for the following variables: newly formed mineralized tissue (present/absent); vital tissue in the canal space (absent/periodontal ligament-like/pulp-like); apical extension of root (present/absent); and severity of inflammatory process (absent/mild/moderate/severe). There were no statistically significant differences among the experimental groups in new mineralized tissue formation and apical root development. The formation of vital tissue in the canal space, in turn, was statistically different between the triple paste and propolis groups: vital tissues were present in all revascularized teeth disinfected with propolis paste (100%), compared to 71% of those disinfected with the triple paste. Severity of inflammatory process was different between the triple paste and no medication groups. The new tissues formed onto canal walls and in the root canal space showed characteristics of cementum and periodontal ligament, respectively. Propolis may have some advantages over the triple paste for the revascularization of immature teeth.

Histologic Analysis of the Influence of a Gelatin-based Scaffold in the Repair of Immature Dog Teeth Subjected to Regenerative Endodontic Treatment.

INTRODUCTION: Regenerative endodontic treatment is a new and promising approach to manage immature teeth with necrotic pulps and apical periodontitis. The use of scaffolds is essential to treatment success, but many materials are difficult to acquire and have a high cost. This study assessed tissue repair in immature dog teeth with necrotic pulps and apical periodontitis after using a gelatin-based scaffold (Gelfoam; Pharmacia & Upjohn Co, Kalamazoo, MI). METHODS: Apical periodontitis was induced in 20 immature dog teeth. After disinfection with triple antibiotic paste for 2 weeks, canals were irrigated, dried, and filled with a blood clot alone (10 teeth) or combined with Gelfoam (10 teeth). Another 10 teeth were used as negative controls (no intervention). After 7 months, the dogs were euthanized. Histologic sections were stained with hematoxylin-eosin and analyzed in relation to tissue repair. Categoric data were analyzed using the Fisher exact test (P < .05), numeric data (histomorphometric analysis), and the Mann-Whitney U test. RESULTS: Histologic analysis revealed a higher percentage of roots with new cementumlike mineralized tissue and connective tissue inside the canal in the blood clot + Gelfoam group (P < .001). Histomorphometric analysis showed a higher area of mineralized tissue in the same group (P = .029). Apical extension of root and inflammation were similar between the experimental groups. The new tissue formed onto canal walls and in the root canal space showed characteristics of cementum and periodontal ligament, respectively. CONCLUSIONS: The use of a gelatin-based scaffold (Gelfoam) combined with a blood clot improved repair in immature dog teeth with apical periodontitis subjected to regenerative endodontic treatment.

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.

Análise entre diferentes métodos de limpeza de limas endodônticas no trans e pós-operatório / Analysis among differente endodontic file cleaning methods at the trans and post surgery

Este estudo analisou através da microscopia eletrônica de varredura, a eficácia de diferentes técnicas empregadas para a limpeza de limas endodônticas durante e após o preparo dos canais radiculares, bem como a associação destas. Durante o preparo testaram-se dois dispositivos: o clean-stand com espuma de poliuretano de densidade 38 e o dispositivo Endométric. Após o preparo testaram-se duas técnicas, que foram associadas aos dispositivos usados durante o preparo, sendo uma a gaze embebida em Biosafe mais a escovação manual e outra a escovação manual mais o ultra-som com detergente enzimático. O Endométric foi o dispositivo mais eficiente durante o preparo. Quando se associou as técnicas usadas durante e após o preparo a mais eficiente foi a que utilizou o Endométric com posterior escovação seguida do ultra-som com detergente enzimático.

This study analysed through scanning electron microscope, the efficacy of different tecnics employed at the endodontic file cleaning during and after the root canal preparation, as well as these tecnic associations. During preparation, two devices were tested: clean-stand with polyurethane foam of density 38 and Endometric. After the preparation two cleaning technics which were associated to the used devices during preparation were tested, being one of them a gauze soaked in Biosafe plus hand brushing, and the other, hand brushing plus the ultra sound with enzimatic detergent. Endometric was the most efficient cleaning device during preparation. When the tecnics used during and after preparation were associated, the most efficient one was when Endometric was used with posterior brushing followed by ultra sound with enzimatic detergent.

Avaliação in vitro da eficácia do localizador apical Bingo 1020® / Evaluation in vitro of the efficacy of the apex locator Bingo 1020®

Os autores avaliaram in vitro a precisão do localizador apical Bingo 1020 ao mensurar dentes humanos unirradiculares frente a diferentes concentrações do hipoclorito de sódio. Foram selecionados 30 dentes humanos permanentes, com canal único e raízes completamente formadas, extraídos por indicação terapêutica. Para determinar o comprimento de trabalho, foram utilizados dois métodos de mensuração: método radiográfico e método eletrônico. Os dados foram submetidos à análise estatística pelo teste de análise de variância(ANOVA), que demonstrou não haver diferença estatisticamente significativa entre os grupos. Os resultados per-mitem concluir, dentro da metodologia empregada neste estudo in vitro, que o aparelho audiométrico Bingo 1020® apresentou resultados satisfatórios em 90% dos casos e as diferentes concentrações de hipoclorito de sódio não influenciaram na precisão do localizador apical.

The objective of the current study was to evaluate in vitro the accuracy of the apex locator Bingo 1020 in measuring human teeth with single canals concerning different concentrations of sodium hypochlorite. Thirtyhuman teeth with single canals and roots completely formed extracted by several reasons were selected. To determine the length of work, two methods of measurement were used: radiographic and electronic method. Thedata had been submitted to the analysis statistics for the test of variance analysis (ANOVA) that it demonstrated not to have statistically significant difference between the groups. It is concluded that Bingo 1020 presented satisfactory results in 90% of the cases and the different concentrations of sodium hypochlorite did not influence the results.

Eficácia de duas técnicas de instrumentação com sistema rotatório / Two techniques of rotate instrumentation

Os autores procuraram analisar nos três terços de vinte e quatro condutos radiculares, o desgaste obtido através de duas técnicas de instrumentação rotatória, uma proposta pelo fabricante do sistema Kavo ENDOflash e outra sugerida pelos autores, utlizando condutos radiculares distais de molares inferiores em forma de rim. Através da técnica proposta por PEREIRA(10) et al. (1997), os condutos foram radiografados com incidência vestibulo-lingual e mésio-distal. Os dados morfométricos tomaram forma de uma série de medidas lineares, provenientes dos quinhentos e setenta a seis pontos de referência. A mensuração do diâmetro dos condutos foi realizada antes e após a instrumentação destes, permitindo conhecer o desgaste realizado pela limagem de cada uma das técnicas instrumentação. Através da quantificação do desgaste nos três terços dos condutos foi possível realizar a análise estatística entre os grupos e intragrupos, sendo utilizado os testes ANOVA e t de Student, onde o nível de significância foi de 5 por cento. A análise estatística mostrou que a instrumentação combinada produziu maior desgaste de dentina nos três terços dos condutos quando comparada com a técnica proposta pelos autores. Verificou-se também, em todos os exemplares, que a instrumentação rotatória proposta pelo fabricante conferiu preparos mais centralizados e não limpou toda a extensão dos condutos com forma de rim, enquanto que a instrumentação proposta pelos autores preparou toda a extensão desses condutos