Bond strength of different endodontic sealers to dentin: push-out test

Abstract

ObjectiveThe aim of this in vitro study was to evaluate the bond strength of different root canal sealers to dentin. Material and MethodsForty extracted single-rooted human teeth were examined and the coronal and middle thirds of the canals were prepared with a 1.50 mm post drill (FibreKor Post System, Pentron). The teeth were allocated in two experimental groups, irrigated with 2.5% NaOCl+17% EDTA or saline solution (control group) and instrumented using Race rotary files (FKG) to a size #40 at the working length. Then, the groups were divided into four subgroups and filled with Epiphany sealer (Group 1), EndoREZ (Group 2), AH26 (Group 3) and Grossman's Sealer (Group 4). After 2 weeks of storage in 100% humidity at 37ºC, all teeth were sectioned transversally into 2-mm-thick discs. Push-out tests were performed at a cross-head speed of 1 mm/min using a universal testing machine. The maximum load at failure was recorded and expressed in MPa. ResultsMeans (±SD) in root canals irrigated with 2.5% NaOCl and 17% EDTA were: G1 (21.6±6.0), G2 (15.2±3.7), G3 (14.6±4.5) and G4 (11.7±4.1).Two-way ANOVA and Tukey's test showed the highest bond strength for the Epiphany's group (p< 0.01) when compared to the other tested sealers. Saline solution decreased the values of bond-strength (p<0.05) for all sealers. ConclusionEpiphany sealer presented higher bond strength values to dentin in both irrigating protocols, and the use of 2.5% NaOCl and 17% EDTA increased the bond strength values for all sealers.

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

“…For the whole sample, this distribution was similar among the three sealers used (Chi 2 =2.45, p=0.65), and the four root levels (Chi 2 =4.66, p=0.58) (Table 3). …”

“…For the whole sample, statistically significant differences were detected with respect to the root level (Friedman's test, Chi 2 =23.93; p<0.001). Pairwise comparisons gave differences among all levels, with increased µPush-out values from cervical to apical except between M1 and M2 levels.…”

“…Manual instrumentation until 40 ISO width produce very limited widening of the canal in the apical section, making it impossible to perform µPush-out tests without values having a frictional component with the canal walls. Previous authors have tested apices, but no realistic enlargements were made regarding canal preparation with drills for a post 2 or using a tapered diamond bur 18 .…”

“…No correlation has been found between apical microleakage and sealer bond strengths to intraradicular dentin in vitro 1,2 . While we assume that preventing effective microleakage is perhaps more important for endodontic application than bond strength 26 , there is no universally accepted method for the evaluation of leakage 33 .…”

Comparative Evaluation of Push-out bond Strength of Three Endodontic Sealers with and without Amoxicillin-An Invitro Study

“…Ideally, one of the key roles of the sealer is to aggregate the root filling material, maintain it as compact mass with no gaps which adheres to the canal walls and provides a single block configuration that seals hermetically the root canal space [16]. This adhesion process involves mechanical forces that yield the intertwining of the material with the dentin structures and may result in a greater sealing ability, thus reducing the risk of root canal micro leakage and maintaining a cohesive filling mass.…”