Scanning electron microscopy (SEM) can be used to analyze the presence of debris and smear layer on the internal walls of root canal. This study evaluated the debris and smear removal in flattened root canals using SEM after use of different irrigant agitation protocols. Fifty mandibular incisors were distributed into five groups (n = 10) according to the irrigant agitation protocol used during chemomechanical preparation: conventional syringe irrigation with NaviTip needle (no activation), active scrubbing of irrigant with brush-covered NaviTip FX needle, manual dynamic irrigation, continuous passive ultrasonic irrigation, and apical negative pressure irrigation (EndoVac system). Canals were irrigated with 5 mL of 2.5% NaOCl at each change of instrument and received a final flush with 17% EDTA for 1 min. After instrumentation, the roots were split longitudinally and SEM micrographs at ×100 and ×1,000 were taken to evaluate the amount of debris and smear layer, respectively, in each third. Data were analyzed by Kruskal-Wallis and Dunn's post-hoc tests (α = 5%). Manual dynamic activation left significantly (p < 0.05) more debris inside the canals than the other protocols, while ultrasonic irrigation and EndoVac were the most effective (p < 0.05) for debris removal. Regarding the removal of smear layer, there was no statistically significant difference (p > 0.05) either among the irrigant agitation protocols or between the protocol-canal third interactions. Although none of the irrigant agitation protocols completely removed debris and smear layer from flattened root canals, the machine-assisted agitation systems (ultrasound and EndoVac) removed more debris than the manual techniques.

This study aimed to evaluate, by scanning electron microscopy (SEM), the cleaning of canal walls with moderate curvature subjected to biomechanical preparation with different final diameters using apical negative pressure irrigation. Thirty-two mesiobuccal roots of molars were divided into 4 groups (n=8) according to the instrument's final diameter: GI: 30.02, GII: 35.02, GIII: 40.02 and GIV: 45.02. Irrigating procedure was performed at each change of instrument with 1% NaOCl using the Endovac system. Final irrigation was conducted with 17% EDTA for 5 min. The SEM photomicrographs were evaluated under 35× and 1000× magnification, by three calibrated examiners, in a double-blind design. Data were submitted to Kruskal-Wallis and Dunn's post hoc tests (α=0.05). Canals instrumented with 30.02 and 35.02 final diameters showed more debris, statistically different from the other groups (p<0.05). Comparing each root canal third, for the cervical and apical portions no statistically significant difference (p>0.05) was found among the four groups. Regarding the presence of smear layer, canals with 30.02 final diameter showed the highest scores, statistically different from the 45.02 group (p<0.05) and similar to the 35.02 and the 40.02 groups (p>0.05). Although none of the studied diameters completely removed debris and smear layer, it may be concluded that instrumentation with higher final diameters was more effective in cleaning the root canals with moderate curvature.

Objetivo: Avaliar o conhecimento de professores do ensino fundamental sobre as condutas nos casos de avulsão dentária em escolares. Materiais e Métodos: O estudo descritivo foi realizado em uma amostra de conveniência com 52 professores, de quatro escolas de ensino fundamental em Ribeirão Preto, SP, e que responderam a um questionário com perguntas sobre os seus dados pessoais e os conhecimentos sobre a avulsão dentária. Resultados: Os participantes do estudo tinham, em média, 41 (±9,4) anos de idade, e 96,2% eram do gênero feminino. Sobre os procedimentos a tomar em caso de avulsão dentária, 73,1% disseram que não os conheciam, 40,4% já haviam testemunhado uma avulsão no ambiente escolar, no entanto, apenas 23,5% tentariam fazer o reimplante. Recolheriam o dente avulsionado e levariam a criança e o dente ao dentista parao diagnóstico correto, 34,6% dos participantes, contudo, apenas 9,6% deixariam o dente menos de 1 hora for a da cavidade bucal. Material seco (gaze, jarra de vidro, algodão) foi a escolha de 42,6% dos entrevistadospara transportar o dente ao dentista, enquanto a água e o leite tiveram menor percentual de resposta (13,1%). Conclusão: O conhecimento dos professores sobre as condutas mais apropriadas a serem tomadas frente àavulsão dentária é inadequado e a maior capacitação desses profissionais poderia levar ao correto tratamento e ao melhor prognóstico.Descritores: Avulsão dentária. Traumatismos dentários. Docentes.INTRODUÇÃO