Effect of advanced irrigation protocols on self-expanding Smart-Seal obturation system: A scanning electron microscopic push-out bond strength study

A Comparative Evaluation of Push-Out Bond Strength of Six Different Root Canal Sealers: An In-Vitro Study

BACKGROUND

Adhesiveness with radicular dentin is absent with gutta-percha, leading to microleakage and hence re-infection. Root canal sealer helps to achieve an adhesive interface between gutta-percha and root dentin thereby resisting the displacement forces during the functioning of teeth which is evaluated by the push-out test. The aim of this study is to compare the push-out bond strength and to assess the relative bond failure between dentin-sealer, sealer-main cone of (1) epoxy resin, (2) silicon, (3) mineral trioxide aggregate (MTA), (4) calcium hydroxide, (5) bioceramic, (6) zinc oxide eugenol containing root canal sealers.

METHODOLOGY

Sixty human permanent lower premolars with one root were collected, disinfected, and decoronated at cemento-enamel junction. Instrumentation was done with a K3 40,0.06 Ni-Ti rotary file and obturated using the main cone and sealer. Based on the sealer utilized, six groups were created: Group 1: AH-Plus, Group 2: RoekoSeal, Group 3: MTA Fillapex, Group 4: Apexit, Group 5: Smart Paste Bio, and Group 6: Procosol. One slice each was obtained from the coronal, middle, and apicalsections of all the obturated canals. Push-out bond strength and failure modes were studied. Statistics involved analysis of variance (ANOVA) followed by the post hoc Tukey test.

RESULTS

All three sections exhibited the highest strength for Smart Paste Bio sealer and the least was for RoekoSeal. With all the sealers, the apical section had the highest strength followed by the middle and coronal.

CONCLUSION

The smart seal system was superior to all other sealers and displayed a good bond to dentin.

The Effect of Increased Temperatures of QMix and EDTA on the Push-out Bond Strength of an Epoxy-resin Based Sealer

BACKGROUND

Bond strength of root canal sealers is mainly influenced by the surface tension of the root canal wall. Heat, or the use of a surfactant might reduce surface tension and it is known that surface tension of an EDTA solution significantly affected from temperature rise. QMix is a novel endodontic irrigant for smear layer removal containing EDTA, chlorhexidine and a detergent. There is no data regarding the influence of the temperature of the EDTA and QMix on the push-out bond strength of root canal sealers.

AIM

To evaluate effect of temperatures of QMix and EDTA on the bond-strength of AH Plus.

MATERIALS AND METHODS

Sixty premolars were prepared with ProTaper F4. During preparation 3% NaOCl was performed. Specimens were divided into 4 groups as follows: 5-mL 17% EDTA at 22°C and 37°C; 5-mL QMix at 22°C and 37°C. Three specimens from each group were prepared for observation using SEM. Remaining roots were obturated and prepared for a push-out test. Data was analysed using Anova and Bonferroni tests (p<0.05).

RESULTS

Samples irrigated with QMix had higher push-out bond strength values than those irrigated with EDTA (p=0.01), regardless of temperature. Samples irrigated with 37°C EDTA resulted in higher bond-strength values than those irrigated with 22°C EDTA (p<0.001).

CONCLUSION

Temperature of the final irrigant does affect the bond strength values of AH plus to root dentin irrigated with EDTA. Bond strength of AH Plus sealer to root canal dentin may improve with QMix.