RESUMO
Objetivo: Avaliar, com o corante azul-de-metileno, a microinfiltração marginal na interface de dentes preparados para coroas totais metalocerâmica e copings, fixados com diferentes cimentos resinosos. Método: Quarenta dentes foram preparados e moldados paraconfeccionar copings em níquel-cromo. A amostra foi dividida em 4 grupos, conforme o agente de cimentação: Grupo I: copings cimentados com Scothbond e RelyX ARC; Grupo II: copings fixados com Single Bond e RelyX ARC; Grupo III: colados com RelyX U100; Grupo IV: fixados com Pavavia F. Os dentes foram armazenados por 6 meses em água destilada a 37OC, submetidos à ciclagem térmica e recolocados na água por mais 6 meses. Exceto nas margens, foram impermeabilizados externamente e imersos em soluçÆo de azul-de-metileno a 1%, por 72 horas. Os copings foram seccionados com discos de carborundum e avaliados com e sem cimento resinoso na superfície do preparo, sendoaplicado para cada face um escore de infiltraçÆo, variando de 0 a 4.Resultados: Na análise com cimento, o grau 0 ocorreu em 65% dasobservaçães do grupo I; 52% no Grupo IV; 42,5% no II e 5% no Grupo III. Na avaliaçÆo sem cimento, ocorreu 95% de graus 0 nas observaçães do Grupo IV; 90% para o I, 57% no Grupo II e 50% no III. Por meio do teste de Kruskal Wallis foi constatada diferença estatisticamente significante entre os grupos (p<0,05), sendo os Grupos I e IV superiores aos demais. ConclusÆo: Antes e após a remoçÆo do cimento, o Panavia F e o Scothbond Multiuso + RelyX ARC apresentaram maior resistência a penetraçÆo do corante...
Objective: To evaluate marginal microleakage at the interface of teethprepared for full metal-ceramic crowns and copings fixed with differentresin cements, using methylene blue staining. Method: Forty teeth were prepared and impressions were obtained to fabricate Ni-Cr copings. The sample was assigned to four groups,according to the luting agent: Group I: coping cemented with Scotchbond and RelyX ARC; Group II: copings fixed with Single Bond and RelyX ARC; Group III: copings fixed with RelyX U100; Group IV: copings fixed with Pavavia F. The teeth were stored in distilled water at37 ºC for six months, subjected to a thermocycling regimen and storedagain in water for another six months. The tooth surfaces were rendered waterproof except for the margins and were immersed in a 1% methylene blue solution for 72 h. The copings were sectioned with carborundum disks and evaluated with or without resin cement on the prepared dental surface. Each face was scored 0 to 4 for leakage.Results: Analysis of the samples with cement revealed that score 0 wasattributed to 65% of the samples of Group I; 52% of Group IV; 42.5% ofGroup II and 5% of Group III. In the analysis of samples without cement,score 0 was attributed to 95% of the samples of Group IV; 90% of Group I; 57% of Group II and 50% of Group III. Statistically significant difference among the groups was found by the Kruskal-Wallis test (p<0.05). Groups I and IV were superior to the others. Conclusion: Before and after removal of the cement, Panavia F and Scotchbond + RelyX ARC presented greater resistance to dyepenetration...