RESUMO
The purpose of this study was to assess the fracture resistance of extensively damaged teeth after two root canal preparation techniques (hand and rotary files) and after two filling techniques (active and passive compaction). Sixty-eight maxillary canines roots with an apical diameter equal to that of a #25 K-file were embedded in acrylic resin and the periodontal ligament was simulated by using a polyether impression material. The roots were randomly distributed into four groups (n=17): hand preparation and active compaction (HA), hand preparation and passive compaction (HP), rotary preparation and active compaction (RA), and rotary preparation and passive compaction (RP). All roots were restored with glass fiber post and metallic crown. The specimens were mechanically cycled (500,000 cycles, 45°, 37°C, 133 N, 2 Hz) and then subjected to a fracture resistance test. A single blinded examiner analyzed the external root surface and classified the failure pattern as favorable or unfavorable. The fracture resistance values ranged between 621.15 N (HP) and 785.71 N (HA). However, the Kruskal-Wallis test did not reveal differences in the fracture resistance values among the four groups (p =0.247). Under the tested conditions, root canal preparation and filling techniques had no influence on the fracture resistance of extensively damaged teeth restored with fiber post and metallic crown.
O objetivo deste estudo foi avaliar a resistência à fratura de dentes amplamente destruídos após duas técnicas de preparo (limas manual e rotatória) e após duas técnicas obturadoras (compactação ativa e passiva). Sessenta e oito raízes de caninos superiores com diâmetro apical igual a uma lima K #25 foram embutidas em resina acrílica e o ligamento periodontal foi simulado utilizando um material de moldagem à base de poliéter. As raízes foram distribuídas aleatoriamente em quatro grupos (n=17): preparo manual e compactação ativa (MA), preparo manual e compactação passiva (MP), preparo rotatório e compactação ativa (RA) e preparo rotatório e compactação passiva (RP). Todas as raízes foram restauradas com pino de fibra de vidro e coroa metálica. Os espécimes foram ciclados mecanicamente (500.000 ciclos, 45°, 37°C, 133 N, 2 Hz) e depois submetidos ao teste de resistência à fratura. Um único examinador cego analisou a superfície externa das raízes e classificou o padrão de falha em favorável ou desfavorável. Os valores de resistência à fratura variaram entre 621,15 N (MP) e 785,71 N (MA). Entretanto, o teste de Kruskal-Wallis não revelou diferença nos valores de resistência à fratura entre os quatro grupos (p=0,247). Diante das condições testadas, as técnicas de preparo e de obturação do canal radicular não influenciam na resistência à fratura de dentes amplamente destruídos restaurados com pino de fibra de vidro e coroa metálica.
Assuntos
Humanos , Tratamento do Canal Radicular , Fraturas dos Dentes , Dente Canino , MaxilaRESUMO
Objetivos: El propósito de este trabajo fue analizar la adaptación y homogeneidad de la obturación en los tercios cervical, medio y apical depremolares inferiores unirradiculares, utilizando las técnicas de condensación lateral e híbrida de Tagger con los cementos de Grossman y AH 26. Materiales y métodos: Se utilizaron 32 premolares inferiores humanos extraídos, unirradiculares, con ápice maduro. Las piezas fueron instrumentadas con sistema Protaper Universal hasta F3. Luego fueron divididas aleatoriamente en 4 grupos de 8 muestras cada uno. Grupos A y B se obturaron con técnica de condensación lateral, grupos C y D con técnica híbrida de Tagger. En A y C su uso cemento deGrossman, en B y D AH 26. Se realizaron cortes transversales a nivel coronario, medio y apical que se evaluaron con microscopio quirúrgico a X 2,5. Se realizó test no paramétrico U de Mann-Whitney. Resultados: Para determinar si existía diferencia entre las dos técnicas de obturación al usar cemento de Grossman se utilizó Test deMann-Whitney. Se observó diferencia significativa entre las medianas de scoring de ambos grupos (U=192; p<0,05). Al evaluar las dos técnicas utilizando AH 26 existió diferencia significativa entre las medianas de scoring de ambos grupos (U=191,5; p<0,05). Conclusión: Los conductos ovales obturados con técnica híbrida de Tagger, presentaron mejor homogeneidad y mayor adaptación a lasparedes en los tres tercios que los obturados con técnica de condensación lateral. Al utilizar cemento de Grosmann o AH 26 como sellador no se observó diferencia significativa en ninguna de las dos técnicas.
Objectives: The purpose of this study was to analyze the adaptation and homogeneity of the filling in the thirds cervical, middle and apical of single-rooted premolars, using lateral condensation technique and Tagger's hybrid technique with Grossman sealer and AH 26. Materials and Methods: We used 32 extracted human premolars, single-rooted, with mature apex. The pieces were instrumented with ProTaper Universal system to F3. Then they were randomly divided into 4 groups of 8 samples each. Groups A and B were filled with lateral condensation technique, groups C and D with Tagger's hybrid technique. In A and C Grossman sealer were use, in B and D AH 26. Crosscuts were made at coronary, medium and apical level and all were evaluated with 2.5 X surgical microscope. We performed nonparametric Mann-Whitney test. Results: To determine if there was difference between the two filling techniques using Grossman sealer was used Mann-Whitney test. Significant difference was observed between the medians of scoring from both groups (U = 192, p <0.05). In evaluating the two techniques using AH 26, significant difference observed between the medians of scoring from both groups (U = 191.5, P <0.05). Conclusion: The oval canal sealed with Tagger's hybrid technique, showed better homogeneity and better adaptation to the walls in the three thirds that filling with lateral condensation technique. Using Grosmann sealer or AH 26 sealer there was no significant difference in any of the two techniques.