Qualitative SEM/EDS analysis of microleakage and apical gap formation of adhesive root-filling materials

Abstract

ObjectiveThe aim of this study was to compare the correspondence between gap formation and apical microleakage in root canals filled with epoxy resin-based (AH Plus) combined or not with resinous primer or with a dimethacrylate-based root canal sealer (Epiphany). Material and MethodsThirty-nine lower single-rooted human premolars were filled by the lateral condensation technique (LC) and immersed in a 50-wt% aqueous silver nitrate solution at 37ºC (24 h). After longitudinal sectioning, epoxy resin replicas were made from the tooth specimens. Both the replicas and the specimens were prepared for scanning electron microscopy (SEM). The gaps were observed in the replicas. Apical microleakage was detected in the specimens by SEM/energy dispersive spectroscopy (SEM/EDS). The data were analyzed statistically using an Ordinal Logistic Regression model and Analysis of Correspondence (α=0.05). ResultsEpiphany presented more regions containing gaps between dentin and sealer (p<0.05). There was correspondence between the presence of gaps and microleakage (p<0.05). Microleakage was similar among the root-filling materials (p>0.05). ConclusionsThe resinous primer did not improve the sealing ability of AH Plus sealer and the presence of gaps had an effect on apical microleakage for all materials.

Bond strength to root dentin and fluid filtration test of AH Plus/gutta-percha, EndoREZ and RealSeal systems

“…In a root canal there is a highly unfavorable configuration factor (ratio of bonded to unbounded resin surfaces) 6 that contributes to maximizing the polymerization stress of resin-based materials along the root canal walls; this may even exceed the bond strength of dentin adhesives to dentin, resulting in gap formation along the surfaces 4,6,8 . Along these lines, Souza, et al 28 (2012) report that there is a correspondence between the presence of gaps and microleakage.…”

An in vitro Comparison of Bond Strength of Different Sealers/Obturation Systems to Root Dentin Using the Push-Out Test at 2 Weeks and 3 Months after Obturation

“…The push-out bond strength of G4 and G5 decreased further at 3 months compared to 2 weeks after obturation and remained the lowest in bond strength among all groups. A possible explanation for this could be the percolation of fluid through the gaps along the surface, which in turn leads to plasticization and hydrolysis of the resin [22] . In addition, collagen degradation may occur due to host-derived matrix metalloproteinases in dentin that are slowly released over time when self-etching adhesives are used.…”

Volumetric Evaluation of Void/Gap Formation and Microleakage Cementing Fiber Posts on Extracted Teeth with Three Different Cements

“…In these studies, different methods were employed for the measurement of voids/gaps and leakage; invariably, however, the presence of voids/gaps was measured on 2D images. Some of these studies revealed a positive relationship or correlation between the presence of voids/gaps and leakage . One study revealed a general tendency for increased microleakage in root canals with filling defects, but the authors reported that not all teeth with filling defects leaked .…”

“…Current knowledge of the relationship between leakage and the presence of voids within filling/luting materials or gaps on their interfacial surfaces derives from studies in which endodontic, restorative, and prosthetic materials and techniques were tested. [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] In these studies, different methods were employed for the measurement of voids/gaps and leakage; invariably, however, the presence of voids/gaps was measured on 2D images. Some of these studies revealed a positive relationship or correlation between the presence of voids/gaps and leakage.…”

“…Some of these studies revealed a positive relationship or correlation between the presence of voids/gaps and leakage. [21][22][23][24][25][26]29,32 One study revealed a general tendency for increased microleakage in root canals with filling defects, but the authors reported that not all teeth with filling defects leaked. 19 Similarly, other researchers have observed similar degrees of leakage in fillings/cements with more gaps and those with fewer gaps; in other words, the two parameters were not correlated.…”