Sealing Efficacy of Single-cone Obturation Technique with MTA and CEM Cement: An in Vitro Bacterial Leakage Study

Effect of obturation technique with immediate and delayed post space preparation on apical voids and bond strength of apical gutta-percha

Objective

The purpose of this study was to evaluate the effect of immediate and delayed post space preparation on the sealing ability of two root canal obturation techniques by using micro-computed tomography imaging and a push-out test.

Methods

The root canals of 40 human maxillary premolar teeth were instrumented and divided into four groups: (A) single cone (SC) followed by immediate post space preparation, (B) continuous wave of condensation (CWC) followed by immediate post space preparation, (C) SC followed by delayed post space preparation, and (D) CWC followed by delayed post space preparation. Micro-CT scans were performed for volumetric analysis of voids and filling materials in the apical 4-mm portion. A push-out test was performed, and failure modes (adhesive, cohesive, or mixed) were assessed. Data were analyzed using the Kruskal-Wallis test and one-way analysis of variance.

Results

No significant differences were observed among the four groups in terms of the percentage volume of voids of the apical 4 mm or the bond strength of apical gutta-percha.

Conclusions

The percentage volume of voids and bond strength of apical gutta-percha were similar and were not significantly influenced by the timing of post space preparation or the obturation technique.

Solubility and bacterial sealing ability of MTA and root-end filling materials

Objective

To evaluate solubility and sealing ability of Mineral Trioxide Aggregate (MTA) and root-end filling materials.

Material and Methods

The materials evaluated were: MTA, Calcium Silicate Cement with zirconium oxide (CSC/ZrO₂), and zinc oxide/eugenol (ZOE). Solubility test was performed according to ANSI/ADA. The difference between initial and final mass of the materials was analyzed after immersion in distilled water for 7 and 30 days. Retrograde cavities in human teeth with single straight root canal were performed by using ultrasonic tip CVD 9.5107-8. The cavities were filled with the evaluated materials to evaluate sealing ability using the bacterial leakage test with Enterococcus faecalis. Bacterial leakage was evaluated every 24 hours for six weeks observing the turbidity of Brain Heart infusion (BHI) medium in contact with root apex. Data were submitted to ANOVA followed by Tukey tests (solubility), and Kruskal-Wallis and Dunn tests (sealing ability) at a 5% significance level.

Results

For the 7-day period, ZOE presented highest solubility when compared with the other groups (p<0.05). For the 30-day period, no difference was observed among the materials. Lower bacterial leakage was observed for MTA and CSC/ZrO₂, and both presented better results than ZOE (p<0.05).

Conclusion

MTA and CSC/ZrO₂ presented better bacterial sealing capacity, which may be related to lower initial solubility observed for these materials in relation to ZOE.

Bacterial Leakage of Mineral Trioxide Aggregate, Calcium-Enriched Mixture and Biodentine as Furcation Perforation Repair Materials in Primary Molars

Introduction:

Adequate seal of iatrogenically perforated area within the root canal system can improve the long term treatment prognosis. This in vitro study evaluated the sealing ability of mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) cement and Biodentine in repair of furcation perforation in primary molars.

Methods and Materials:

A total of 61 freshly extracted primary mandibular second molars were randomly divided into three groups (n=17) and 10 teeth were put in negative (without perforation, n=5) and positive (perforated without repair, n=5) control groups. Turbidity was used as the criteria of bacterial leakage, when detected in the model of dual-chamber leakage. Data were analyzed using the Chi-Square and Kaplan-Meier survival analysis in SPSS software. The level of significance was set at 0.05.

Results:

All positive samples showed turbidity, whereas none of the negative samples allowed bacterial leakage. There was no significant difference between the number of turbidity samples in repaired teeth with all test materials (P=0.13). No significant difference was also detected in the mean survival time (P>0.05).

Conclusion:

CEM cement and Biodentine showed promising results as perforation repair materials and can be recommended as suitable alternatives of MTA for repair of furcation perforation of primary molars.