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

Anti-microbial and micro-leakage properties of orthodontic cement

Glass Ionomer Cement (GIC) is used for cementing orthodontic bands because of its anti-cariogenic property, which is attributed to the release of fluoride. Therefore, it is of interest to assess the antimicrobial property and micro-leakage of GIC incorporated with different concentration of N-acetylcysteine (N-AC) and copper nanoparticle (Cu-NP). Our study composed of 5 groups i.e. group I is control with different concentration of N-AC and Cu-NP involving each group with 8 samples. We found that, group V showed the highest zone of inhibition; while the micro-leakage was seen highest for group I with a score of 2.2 ± 1.09 and the least score was recorded for Group III (0.8± 0.37). Thus, addition of 2% Cu-NP and 15% N-AC resulted in minimal micro-leakage. We conclude that increase in concentration of N-AC and CU-NP antimicrobial property efficiency also increases; on the other hand, increase in the concentration of N-AC and CU-NP did not decrease the micro-leakage.

Comparison of Apical Sealing Capacity of ActiV GP/Glass Ionomer Sealer Versus Resilon/RealSeal and Gutta Percha/AH plus Sealers

BACKGROUND

In recent years, concerns have arisen regarding the sealing efficacy of traditional root canal obturation materials such as gutta-percha (GP) and various sealers. The resin-based obturation complexes like RealSealTM (SybronEndo, Orange, CA) and ResilonTM (Resilon Research LLC, Madison, CT) had been developed as replacements for conventional obturation materials, gutta-percha, and various types of sealers. Additionally, ActiV GPTM (Brasseler USA, Savannah, GA), a glass-ionomer-based obturation system, has gained attention.

AIM

This in vitro study's objective was to evaluate ActiV GPTM/GI (glass ionomer) sealer's sealing capacity and compare it to that of ResilonTM/RealSeal TM as well as gutta-percha/AH PlusTM (Dentsply International Inc, York, PA) taken as a control.

METHODS AND MATERIALS

In this in vitro investigation, 90 freshly excised single-rooted human premolars of the mandible were chosen. According to the substance used to seal the root canals, the teeth were randomly separated into three separate groups (n=30). Group 1: The ActiV GPTM obturation system was used to seal and obturate the canals. Group 2: ResilonTM/RealSealTM was used to obturate and block the canals. Group 3: GP points and AH PlusTM were used to seal the canals employing the lateral condensation methodology. All of the root surfaces-aside from the last 2 mm of the root-were painted with two coats of nail polish before being submerged in 2% methylene blue for a duration of 24 hours at a temperature of 37°C. The highest amount of dye leakage was determined using a stereomicroscope at 20X magnification.

RESULTS

The extent of dye penetration at the apical region in specimens of the ActiV GPTM category was 4.93±1.48 mm. The depth of dye penetration at the apical region in specimens of the ResilonTM category was 2.78 ±1.62 mm. The extension of penetration of dye was 0.48± 0.46 mm in specimens of the GP/AH PlusTM category. The degree of microlikeage was maximum in ActiV GPTM specimens and it was minimum in GP/AH PlusTM specimens. The microlikeage in specimens of the Resilon category was greater than GP/AH plusTM while it was lower than ActiV GPTM specimens. The observations were statistically meaningful (p<0.001).

CONCLUSION

Based on the results of the dye penetration examination, it can be concluded that the root canal wall sealing capabilities of ActiV GPTM with GI Sealer were inferior to those of GP/AH PlusTM and ResilonTM with RealSealTM.

Analysis of the adhesive interface of dentine treated with carbodiimide and chitosan before cementation of fiberglass posts with different resin cements

The objective of this study is to evaluate the effect of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and chitosan (CHI) on the adhesive interface of resin cements to root dentine. Forty-five upper canines were sectioned, endodontically treated, prepared and divided into three groups according to dentine treatment (distilled water-DW, CHI 0.2% and EDC 0.5) and in three subgroups according to resin cement: RelyX ARC, Panavia F 2.0 or RelyX U200. Slices were obtained, with five slices of each third submitted to the analysis of the adaptation of the adhesive interface through scores and the perimeter with gaps in confocal laser scanning microscopy and one slice of each third later evaluated qualitatively in scanning electron microscopy. The results were analyzed using with Kruskal-Wallis and Spearman correlation tests. There was no difference in adaptation for the different resin cements (p = .438). EDC presented better adaptation when compared to the groups treated with DW and CHI (p < .001), while the CHI and DW presented similar adaptation values (p = .365). No difference was observed in the perimeter referring to the gap areas for the different resin cements (p = .510). EDC showed a lower percentage of perimeters with gaps when compared to CHI (p < .001), with the percentage of perimeter with gaps of teeth treated with CHI being lower than DW (p < .001). A positive correlation coefficient equal to 0.763 was obtained between the perimeter with gaps and the adaptation data of the adhesive interface (p < .001). EDC resulted in better adaptation of the adhesive interface and a lower percentage of perimeters with gaps compared to chitosan.

Micro-computed tomography analysis of gap and void formation in different prefabricated fiber post cementation materials and techniques

Objective

The study was built around the objective of determining the variances in the gap and void formation around cemented prefabricated fiber posts with two different cementation materials and techniques with micro-computed tomography (μCT).

Methods

Standardized acrylic resin roots (N = 40) with prefabricated fiber posts (RelyX™ Fiber Post 3D) were split into four sets (n = 10) based on many types of cementation materials and techniques. In the first group, resin cement (RelyX™ Unicem) was inserted to the canals via root canal tips. In the second group, the same cement was injected, and a microbrush was used to distribute the cement inside the canal. In the third group, dual polymerizing resin cement (MultiCore® Flow) was injected into the canals by using root canal tips. In the fourth group, the same cement was injected, and a microbrush was used to distribute the cement inside the canal. The gap and void formation in the cement and the root canals was evaluated with μCT. IBM SPSS Statistics was used to perform the statistical evaluation, then the Kolmogorov-Smirnov test of normality and Kruskal-Wallis H test to compare these variables with respect to the all groups significant difference (a = 0.05).

Results

The study outlined no difference of significance when evaluating the gap and void formation within the experimental groups (P > 0.05).

Conclusion

There was a certain amount of void and gap formation inside all of the tested specimens. However, no significant variances were found.

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

OBJECTIVE

To evaluate the push-out bond strength and failure modes of different sealers/obturation systems to intraradicular dentin at 2 weeks and 3 months after obturation compared to AH Plus®/gutta-percha.

MATERIALS AND METHODS

A total of 180 root slices from 60 single-canal anterior teeth were prepared and assigned to 5 experimental groups (n = 36 in each group), designated as G1 (AH Plus®/gutta-percha), G2 (TotalFill BC™ sealer/BC-coated gutta-percha), G3 (TotalFill BC™ sealer/gutta-percha), G4 (EndoREZ® sealer/EndoREZ®-coated gutta-percha), and G5 (EndoREZ® sealer/gutta-percha). Push-out bond strengths of 18 root slices in each group were assessed at 2 weeks and the other 18 at 3 months after obturation using a universal testing machine. Data were analyzed using repeated measures ANOVA. An independent t test was used to compare the mean push-out bond strength for each group at 2 weeks and 3 months after obturation.

RESULTS

The mean push-out bond strengths of G4 and G5 were significantly lower than those of G1, G2, and G3 (p < 0.05) at both 2 weeks (G1: 1.46 ± 0.29 MPa, G2: 1.74 ± 0.43 MPa, G3: 1.74 ± 0.43 MPa, G4: 0.66 ± 0.31 MPa, G5: 0.74 ± 0.47 MPa) and 3 months after obturation (G1: 1.70 ± 1.05 MPa, G2: 3.69 ± 1.20 MPa, G3: 2.84 ± 0.83 MPa, G4: 0.14 ± 0.05 MPa, G5: 0.24 ± 0.10 MPa). The mean push-out bond strengths of G2 (3.69 ± 1.20 MPa) and G3 (2.84 ± 0.83 MPa) were higher at 3 months compared to 2 weeks after obturation (G2: 1.74 ± 0.43 MPa, G3: 1.33 ± 0.29 MPa).

CONCLUSION

The TotalFill BC™ obturation system (G2) and the TotalFill BC™ sealer/gutta-percha (G3) showed comparable bond strength to AH Plus®. Their bond strength increased over time, whereas the EndoREZ® obturation system (G4) and EndoREZ sealer (G5) had low push-out bond strength which decreased over time.

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

OBJECTIVES

To investigate the bond strength and seal ability produced by AH Plus/gutta-percha, EndoREZ and RealSeal systems to root canal dentin.

MATERIAL AND METHODS

Sixty extracted single-root human teeth, instrumented manually to size 40, were divided into three groups (n=20) according to the sealer used; G1: AH Plus, G2: EndoREZ, and G3: RealSeal sealers. After filling using the lateral condensation technique, each sealer group was randomly divided into two subgroups according to the tests applied (n=10 for µPush-out test and n=10 for fluid filtration test). A fluid filtration method was used for quantitative evaluation of apical leakage. Four 1-mm-thick slices (cervical and medium level) were obtained from each root sample and a µPush-out test was performed. Failure modes were examined under microscopy at 40x, and a one-way ANOVA was applied to analyze the permeability. Non-parametrical statistics for related (Friedman's and Wilcoxon's rank tests) or unrelated samples (Kruskal-Wallis' and Mann-Whitney's tests) allowed for comparisons of µPush-out strength values among materials at the different levels. Statistical significance was accepted for p values <.05.

RESULTS

There are no significant differences among fluid filtration of the three sealers. The sealer/core material does not significantly influence the µPush-out bond strength values (F=2.49; p=0.10), although statistically significant differences were detected with regard to root level (Chi2=23.93; p<0.001). AH Plus and RealSeal obtained higher bond strength to intraradicular dentin in the medium root slices.

CONCLUSIONS

There are no significant differences between the permeability and global µPush-out bond strength to root canal dentin achieved by AH Plus/gutta-percha, EndoREZ and RealSeal systems.

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

Objectives

To investigate the bond strength and seal ability produced by AH Plus/gutta-percha, EndoREZ and RealSeal systems to root canal dentin.

Material and Methods

Sixty extracted single-root human teeth, instrumented manually to size 40, were divided into three groups (n=20) according to the sealer used; G1: AH Plus, G2: EndoREZ, and G3: RealSeal sealers. After filling using the lateral condensation technique, each sealer group was randomly divided into two subgroups according to the tests applied (n=10 for µPush-out test and n=10 for fluid filtration test). A fluid filtration method was used for quantitative evaluation of apical leakage. Four 1-mm-thick slices (cervical and medium level) were obtained from each root sample and a µPush-out test was performed. Failure modes were examined under microscopy at 40x, and a one-way ANOVA was applied to analyze the permeability. Non-parametrical statistics for related (Friedman's and Wilcoxon's rank tests) or unrelated samples (Kruskal-Wallis' and Mann-Whitney's tests) allowed for comparisons of µPush-out strength values among materials at the different levels. Statistical significance was accepted for p values <.05.

Results

There are no significant differences among fluid filtration of the three sealers. The sealer/core material does not significantly influence the µPush-out bond strength values (F=2.49; p=0.10), although statistically significant differences were detected with regard to root level (Chi²=23.93; p<0.001). AH Plus and RealSeal obtained higher bond strength to intraradicular dentin in the medium root slices.

Conclusions

There are no significant differences between the permeability and global µPush-out bond strength to root canal dentin achieved by AH Plus/gutta-percha, EndoREZ and RealSeal systems.