ABSTRACT
Abstract This study aimed to analyze the root and root canal morphology of mandibular first and second molars using CBCT images. A total of 2,400 mandibular molars exams were selected from 600 patients aged between 18 and 75 years. The number of roots, number of root canals, and root canal configuration according to the Vertucci classification were verified. Overall, 94.92% of mandibular first molars and 90.17% of mandibular second molars had two separate roots. Among the biradicular molars, the first molars showed a greater incidence of type IV canals in the mesial root and type I in the distal root. In the second molars, the most common canal form was type IV in the mesial root and type I in the distal root. In the triradicular molars, the type IV and type I configurations were the most common in the mesial root of the first molar and second molar, respectively. In both triradicular molars, there was a prevalence of type I canal in the distal and DL roots. Statistical analysis was performed at a significance level of 0.05. The number of roots was correlated with gender (Spearman test), and the canal's configuration with gender and bilaterality (Wilcoxon test). The subpopulation studied has a high incidence of bilateral symmetry and mandibular molars with two roots with two distinct mesial canals and one distal canal. The bilateral configuration is possible to estimate the number of canals, especially in images that are difficult to visualize, such as atresic canals.
ABSTRACT
O objetivo deste trabalho foi avaliar a capacidade seladora de um material restaurador provisório, Villevie, e de uma resina composta, Tetric Ceram, associada a dois tipos de sistema adesivos, XENO III e Single Bond. Quarenta incisivos inferiores unirradiculares foram distribuídos em três grupos de dez dentes cada e cinco dentes para cada grupo controle, positivo e negativo. Os espécimes, após a cirurgia de acesso, foram preparados por meio de sistema de instrumentação rotatória e irrigados com água destilada e deionizada. A porção externa dos dentes foi impermeabilizada até 2 mm aquém da margem externa da cirurgia de acesso. Colocou-se no interior do canal radicular um cone de papel seguido de uma pensa de algodão impregnados com solução alcoólica de dimetilglioxima 1%. A cavidade endodôntica foi selada de acordo com os seguintes grupos: GA- sistema adesivo autocondicionante XENO III + resina composta; GB- sistema adesivo Single Bond + resina composta; e GC- selador provisório. Os espécimes foram imersos em recipientes contendo solução de sulfato de níquel 5% e submetidos à ciclagem térmica por 72h. Os testes de Kruskal-Wallis e Dunn foram utilizados para análise dos resultados com nível de 5% de signifcância. O menor nível de microinfltração foi observado no grupo do restaurador provisório (GC), com diferença estatística signifcante em relação aos demais grupos (P<0,001). Os grupos A e B mostraram-se semelhantes ao controle positivo (P>0,05), com os maiores índices de microinfltração. Concluiu-se que nenhum dos materiais avaliados foi capaz de impedir a microinfltração coronária.
The purpose of this study was to evaluate the sealing capacity of a temporary restorative material (Villevie) and a composite resin, Tetric Ceram, associated with two adhesive systems (XENO III and Single Bond). Forty single-rooted mandibular incisors were distributed into three experimental groups of 10 teeth each, and two control groups (positive and negative) of 5 teeth each. After preparation of the access cavities, the canals were instrumented with a rotary system and irrigated with distilled deionized water. The external surfaces of the teeth were rendered water-proof up to 2 mm from the external margins of the access cavities. A paper point and a coton mesh impregnated with an alcoholic 1% dimethylglyoxime were placed inside the root canals, and the endodontic access cavities were sealed according to the following groups: GA- XENO III self-etch adhesive system + composite resin; GB- Single Bond etch-and-rinse adhesive system + composite resin; and GC- temporary restorative material. The specimens were immersed in receptacles containing a 5% nickel sulfate solution and subjected to a thermal cycling regimen during 72 h. The Kruskal-Wallis and Dunn's tests were used for statistical analysis of the results at 5% signifcance level. The group restored with the temporary restorative material (GC) presented statistically signifcant less coronal leakage than the other groups (p<0.001). GA and GB were statistically similar to the positive control (p>0.05), showing the highest levels of coronal leakage. None of the tested materials was able to prevent the occurrence of coronal leakage.
ABSTRACT
Objetivo: Estudou-se a ação das soluções de EDTA 17%, CDTA 17% e EGTA 17% sobre a microdureza da dentina radicular. Material e métodos: Foram utilizados cinco dentes incisivos centrais superiores humanos, recém-extraídos, os quais tiveram suas coroas seccionadas na junção cemento-esmalte e posteriormente desprezadas. As raízes foram incluídas em acrílico de rápida polimerização, adaptadas à máquina de corte e seccionadas transversalmente de um em um milímetro. O primeiro corte foi desprezado e o segundo dividido em quatro quadrantes. Cada quarto de dentina foi colocado sobre um disco de resina acrílica, obtendo-se quatro corpos-de-prova para cada raiz. Cinqüenta microlitros da solução a ser testada foram depositados sobre o corpo-de-prova por meio de uma pipeta micrométrica, permanecendo por cinco minutos. A medição da microdureza da dentina foi obtida em um aparelho de dureza Vickers com peso de cinqüenta gramas de carga e tempo de quinze segundos de aplicação. Resultados: Após análise estatística, os resultados mostraram que todas as soluções testadas foram efetivas quanto à redução da microdureza dentinária, mas estatisticamente diferentes entre si (p<0.05). A solução de EGTA 17% promoveu maior redução, seguida pela solução de CDTA 17%. A solução de EDTA 17% foi a menos efetiva. Conclusão: Pode-se concluir que as soluções quelantes testadas no experimento foram efetivas quanto à redução da microdureza dentinária.
Objective: In this work the action of 17 % EDTA solution, CDTA 17 % solution and EGTA 17% solution had been studied on human radicular dentin microhardness. Material and methods: Five freshly extracted human maxillary incisors were transversely sectioned at the cement-enamel junction; the crowns were discarded. The roots were embedded in blocks of resin polymerization rapidly, which were adaptated in the cut machine and seccionated transversely in 1 to 1 milimeter. The first cut was discarded and the second divided into four quadrants. Each quarter of dentin was placed on a disc of acrilic resin, resulting in four samples for each root. Fifty microliters of the tested solutions were deposited on the specimen using a micrometer pipete, staying for five minutes. The measurement of dentin microhardness was in a unit of Vickers hardness with 50 grams of weight and load time of 15 s of application. Results: After statistical analysis, results showed that all solutions were efective in reducting dentin microhardness, but statistically diferent from each other (p<0.05). The 17 % EGTA solution was more efective, followed by 17 % CDTA solution. 17 % EDTA solution was the less efective. Conclusion: It was possible to conclude that all the chelants solutions were efective in reduction of the radicular dentin microhardness.
ABSTRACT
The effect of chelating solutions EDTA, EGTA and CDTA on human dentin adhesiveness and microleakage with 4 sealers (Sealer 26, Sealapex, N-Rickert and Endofill) was evaluated in vitro. Whether or not there was a mathematical correlation between the tests of adhesiveness and microleakage was also evaluated. A total of eighty maxillary and mandibular molars were used to test adhesiveness. After wearing of the occlusal surface to obtain a flat surface, the sealer was placed with an aluminum cylinder (10 mm x 6 mm). Adhesiveness was evaluated with a 4444 Instron universal testing machine. Microleakage was evaluated in 160 maxillary canines after root canal instrumentation, obturation and clearing. The penetration of India ink in the apical region was measured with a measurescope. The teeth were divided into 4 groups: group 1, distilled water, group 2, EDTA; group 3, EGTA; group 4, CDTA. Sealer 26 and EDTA had the best results (p<0.01) for adhesiveness and microleakage. There was no correlation between the test for adhesiveness and microleakage.