Push-out bond strength of a self-adhesive resin cement used as endodontic sealer

In-Vitro Comparative Adhesion Evaluation of Bioceramic and Dual-Cure Resin Endodontic Sealers Using SEM, AFM, Push-Out and FTIR

(1) Background: Which are the adhesion characteristics of four root canal sealers: two experimental (dual cure resin based endodontic sealer (E1-DCR) and bioceramic based sealer (E2-BC)), and two commercial (RealSeal and TotallFill BC (FKG Germany)). (2) Methods. One-hundred-twenty extracted monoradicular teeth received mechanic-antiseptic preparation and then endodontic filling using gutta-percha in combination with one of the four sealers. Samples from the apical third were selected from each tooth and were randomly distributed for Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and push-out bond strength. Fourier Transform Infrared (FTIR) Spectroscopy was made exclusively for experimental sealers. (3) Results. The two experimental materials did not present a significant difference in apical sealing ability based on SEM evaluation. Gaps were identified in case of RealSeal samples and also lower penetration into the dentinal tubules compared to TotalFill BC. On AFM analysis a more pronounced penetration into the tubules was observed in case of E2-BC sealer was observed. E1-DCR registered a lower bond strength (0.7177 ± 0.55) in the apical third compared to Total Fill BC (p = 0.01). (4) Conclusions. Within the limitations of the current study, it can be stated that the two experimental sealers’ characteristics are comparable to that of the two consecrated materials.

Push-out Bond Strength of Two Types of Dental Post Luted with Two Types of Cement at Two Different Root Levels

OBJECTIVE

Endodontically treated teeth may require posts for retaining the core and replacing the coronal structures that have been lost. The objective of this study was to evaluate and compare the push-out bond strength between different types of post cemented with different types of luting cement at different types of root level.

MATERIALS AND METHODS

In this in-vitro study, a total of 48 single-rooted permanent human teeth were decoronated, and the roots were treated endodontically. Following post space preparation, the sample was divided into four groups (n= 12 each) based on the types of post and cement. Two different types of post [GC everStick®POST (ES) and Parapost® Fiber LuxTM (PF)], and two different types of cement [G-CEMTM (G), and RelyXTM Unicem (R)] were used according to the manufacturer's instructions. All roots were sectioned at the coronal and middle thirds with a thickness of 3±0.1mm. The Push-out bond strength (PBS) test was performed using a universal testing machine at a cross-head speed of 0.5mm/ min. The bond strength values were recorded, and the data were analyzed using the SPSS program. Apart from descriptive statistics, three-way ANOVA was used for the interaction of the independent variables (post, cement, and root level). For differences between the groups, the Mann-Whitney U test was used. A P-value of less than 0.05 was considered significant for all analyses.

RESULTS

Push-out bond strength of samples at the middle level (11.38±10.31 MPa), with PF posts (11.18±9.98 MPa), and of those luted with RelyXTM Unicem cement (13.26±8.73 MPa) was higher than that of their counterparts. The PBS means of RelyXTM Unicem cement at both root levels were much higher than PBS means of G-CEMTM cement. Three-way ANOVA test revealed a significant effect for each variable with a higher effect of cement (Sum of Squares= 1310.690; P< 0.001). No significant difference (P= 0.153) was found between the coronal and middle parts and between ES and PF posts (P= 0.058). However, a highly significant difference (P< 0.001) was found between RelyXTM Unicem and G-CEMTM cements.

CONCLUSION

The type of cement had a significant effect on push-out bond strength with RelyXTM Unicem which had higher values than G-CEMTM. However, the type of post and root level had no significant effect on PBS, although Parapost® Fiber LuxTM and middle root level had higher values than their counterparts.

Comparison of push-out bond strength of three different obturating systems to intraradicular dentin: An In vitro study

Background:

To increase the push-out bond strength of endodontic materials, newer obturation materials and obturation techniques are being introduced.

Aim:

The present study aimed to evaluate the push-out bond strength of three different obturating materials using a universal testing machine (UTM).

Materials and Methods:

A total of thirty freshly extracted maxillary anterior teeth were collected and randomly divided into three groups of ten each. Biomechanical preparation was done in all the teeth, and they were then divided into three experimental groups according to the obturation material and technique used, as follows: Group I: gutta-percha (GP) with AH Plus root canal sealer (lateral condensation); Group II: thermoplasticized GP technique – noncarrier based (CALAMUS^®) with AH Plus sealer (backfill); and Group III: C-points (self-sealing root canal obturating system) with bioceramic sealer (single cone). Each specimen was subjected to push-out test using the UTM, where the punch moved in an apical to coronal direction at a crosshead speed of 0.5 mm/min, which resulted in the displacement of the filling material. The depth of dye penetration was examined under a stereomicroscope at ×30 magnification.

Results:

All the analyses were performed using SPSS software version 16. P < 0.05 was considered statistically significant. Comparisons of mean values were done using ANOVA with post hoc Games–Howell test and ANOVA with post hoc Tukey's test. Group III demonstrated the highest mean push-out bond strength and Group I exhibited the least bond strength. A statistically significant difference was found between Group III and Group I with regard to the push-out bond strength assessment.

Conclusion:

Push-out bond strength differs among different obturation materials and obturation techniques.

Influence of Infected Root Dentin on the Bond Strength of a Self-adhesive Resin Cement

AIM

The aim of this study was to determine the bond strength (BS) of a self-adhesive resin cement to the contaminated root dentin.

MATERIALS AND METHODS

The crown and apical third of twenty single-rooted teeth were removed. The root canals were flared and 1-mm-thick root sections were obtained. The sections were rinsed, dried, and sterilized. The control group (n=20) was composed of one section of each third, which remained immersed in sterile trypticase soy broth (TSB) for 2 months. The other sections comprised the experimental group (n = 40) and were immersed in a suspension of Enterococcus faecalis. The culture medium was changed at every 4 days for 2 months. The sections were rinsed with distilled water, dried, and the root canal space was filled with the self-adhesive resin cement RelyX™ U200. After 24 h, the push-out test was performed and the types of interface failure were observed on a stereo microscope.

STATISTICAL ANALYSIS

Data were statistically analyzed by the nonparametric Mann-Whitney test (α=5%).

RESULTS

A significant reduction was observed in the BS of resin cement to the contaminated dentin compared to the healthy dentin, for both thirds analyzed (P < 0.05). The BS was significantly greater at the cervical third compared to the middle third for specimens in the experimental group (P < 0.05). Adhesive and mixed failures were observed more frequently in specimens contaminated with E. faecalis.

CONCLUSION

Bacterial contamination negatively infl uenced the BS of the self-adhesive resin cement to the root dentin, and there was a predominance of adhesive and mixed failures.

Effect of photon induced photoacoustic streaming (PIPS) on bond strength to dentine of two root canal filling materials

OBJECTIVES

The aim of this study was to evaluate the effect of photon induced photoacoustic streaming (PIPS) technique in combination with EDTA on bond strength of gutta-percha/AH Plus and Resilon/RealSeal SE root canal fillings to root dentine.

MATERIALS AND METHODS

Forty freshly extracted human maxillary anterior teeth with intact straight roots, were instrumented endodontically with rotating ProTaper instruments and randomly divided into two experimental groups. In group 1 (n = 20), root canals were rinsed for 1 minute with 2 ml of 17% EDTA. In group 2 (n = 20), Er:YAG laser, with a 14 mm long 400 μ diameter tapered PIPS tip, was used for 1 minute with 2 ml of 17% EDTA. The laser parameters used were: 20 mJ per pulse, 15 Hz, 50 microsecond. In each experimental group, half of the root canals (n = 10) were obturated with gutta-percha/AH Plus and other half (n = 10) with Resilon/RealSeal SE. A micropush-out test was performed on sectiond specimens of the filled roots using a universal testing machine and resistance to failure plus failure modes were determined.

RESULTS

Both gutta-percha/AH Plus groups had higher bond strength to root dentin than the Resilon/RealSeal SE groups (P < 0.05). The smear layer removal protocol, with EDTA only or combining PIPS technique with EDTA, had no influence on bond strength of either gutta-percha/AH Plus, or Resilon/RealSeal SE (P > 0.05).

CONCLUSION

Within the limitations of this study, it was found that the application of the PIPS technique did not have an affect on the push-out bond strength of Resilon/RealSeal SE root canal filling to dentin nor on the gutta-percha/AH Plus. A significant difference in bond strength was noted between the two root canal filling materials. Lasers Surg. Med. 48:951-954, 2016. © 2016 Wiley Periodicals, Inc.