ABSTRACT
This study evaluated the persistence of eugenol-containing (PR, Provy) or eugenol-free (RT, Relyx Temp, and TB, Temp Bond) temporary cement residues and its effects on push-out bond strength and dentinal penetration of the self-adhesive resin cement (Relyx U200). Eighty human roots were endodontically treated and post space prepared. Fourty specimens were distributed in four groups (n = 10): Control (CO), without any clinical procedure, PR, RT, and TB, where a metallic post was cemented with one of the temporary cements. After metallic post removal, hemi sections post space were submitted to SEM analysis. Another specimens were distributed in similar groups, but fiberglass post was cemented using Relyx U200 cement and submitted to push-out bond strength and dentinal penetration cement analysis, in post space thirds. SEM analysis were evaluated by Kruskal-Wallis and Dunn tests, while bond strength and dentinal penetration were evaluated by ANOVA One-Way and Tukey test (p < .05). Only in apical thirds, PR, RT, and TB showed higher persistence of residues than CO. In bond strength, PR, RT, and TB showed lower values than CO, in all post space thirds (p < .05). But to dentinal penetration, PR, RT, and TB presented lower values than CO only in apical thirds (p < .05). There is the greatest persistence of temporary cement residues only in apical post space third, providing less dentinal penetration of the self-adhesive resinous cement. However, the previous use of temporary cements has negative effects on the bond strength cementation system, regardless of the third evaluated.
Subject(s)
Cementation , Resin Cements , Adhesives , Dentin , Glass , HumansABSTRACT
Avaliar a resistência flexural e a adaptação marginal dos materiais restauradores provisórios Clip F (CF),Bifix Temp (BT), Systemp.onlay (SO), Fill Magic Tempo (FT) e Provi Master F (PF), na dentina da coroa dentária de dentes tratados endodonticamente. Métodos: Inicial-mente, foram confeccionados dez espécimes de cada um dos materiais restauradores, que foram individualmente submetidos ao teste de resistência flexural, na máquina de ensaio eletromecânica. Para avaliar a adaptação marginal,a câmara pulpar de cinquenta pré-molares superiores foi restaurada com um dos materiais avaliados (n=10). Após sete dias, a interface entre a dentina e o material restaurador, no terço médio da coroa dentária, foi submetida à análise em microscopia eletrônica de varredura. A extensão de desadaptação dos materiais e os gaps formados com a dentina foram mensurados com o software Image J.Resultados: CF e BT demonstraram o maior e o menor valor de resistência flexural, respectivamente (p<0,05).Os valores demonstrados por SO, FT e PF foram similares entre si (p>0,05). Por outro lado, CF demonstrou a menor extensão de desadaptação marginal (em porcentagem)e extensão de gaps (em µm) (p<0,05) na interface com a dentina. BT apresentou valor intermediário, mas menor do que os dos SO, FT e PF (p<0,05) que, por sua vez, foram similares entre si (p>0,05). Conclusões: O CF demonstrou o maior índice de resistência flexural e menor extensão de desadaptação marginal e gaps, em comparação aos demais materiais restauradores provisórios (AU).
Objectve: This study evaluated the flexural strength and marginal adaptation of Clip F (CF), Bifix Temp (BT), Systemp.onlay (SO), Fill Magic Tempo (FT) and Provi Master F (PF) in endodontically-treated coronal dentin. Methods: Firstly, ten specimens of each restorative material were prepared, and submitted to flexural strength test using eletromechanical testing machine. Then, the pulp chamber of 50 maxillary premolar were restored using one of the provisional restorative materials (n = 10) in order to evaluate the marginal desadaptation extension. After 7 days, the interface between dentin and temporary restorative material, in crown middle third, was subjected to scanning electron microscopy (500X). Marginal desadaptation and gaps extensions in dentin-temporary restorations interface were measured using Image J software. Results: CF and BT presented the highest and the lowest flexural strength values, respectively (p <0.05). SO, FT and PF showed similar values (p> 0.05). In relation to marginal desadaptation (%) and gap extensions (µm), CF presented the lowest marginal desadaptation and gaps incidence values (p < 0.05). BT showed intermediate values, but lower than SO, FT e PF (p < 0.05), which were similar among them (p > 0.05). Conclusion: CF presented the best flexural strength and the lowest marginal desadaptation and gaps extension (AU).
Subject(s)
Humans , Microscopy, Electron, Scanning , Dental Materials , Dental Restoration, Temporary , Flexural Strength , Tooth Crown , Adaptation to Disasters , EndodonticsABSTRACT
The aim of the study was to evaluate the effects when acid etching on the dentin surface was immediately performed (I) or 7 days (D) after calcium silicate-based sealer (MTA Fillapex) removal, using 95% ethanol (E) or xylol (X). First study, 60 bovine incisor dentin specimens were impregnated with sealer and divided into six groups (n = 10): (EI), E + I; (XI), X + I; (ED), E + D; (XD), X + D, (UN), untreated and (MR), mechanical removal of sealer. Scanning electron microscopy (SEM) images (500×) were obtained from each specimen and scores assessed the sealer residues persistence. Second study, 60 specimens were similarly treated; however, the specimens were restored with composite resin after the removal protocols. Hybrid layer formation was evaluated using confocal laser microscopy (1,024×). Third study, 60 specimens were similarly obtained and subjected to micro-shear test to evaluate the effects of removal protocols on the bond strength of etch-and- rinse adhesive system to dentin. XI showed the highest persistence of sealer residues (p < .05), similar to MR (p > .05). EI showed the greatest hybrid layer extension, except in relation to UN (p < .05). XI and MR presented the lowest bond strength adhesive system to dentin (p < .05). Acid etching immediately after calcium silicate-based endodontic sealer removal using xylol presented the highest residues persistence and negatively affected the adhesive interface between dentin and etch-and-rinse adhesive system.
