Comparative evaluation of sealing ability and adaptation of gel form of MTA to dentinal walls: an in-vitro study

Abstract

Context: Mineral Trioxide Aggregate (MTA) is a calcium silicate-based cement that potentially exhibits improved washout resistance when carboxymethyl chitosan or gelatin is incorporated. Gel-form MTA is a novel mineral trioxide aggregate formulated using construction industry-based technology. The present study was conducted to comparatively evaluate the sealing ability and adaptation to dentinal walls of gel-form MTA.

Materials and methods: This in-vitro study consisted of two groups: gel-form MTA and the conventional powder-liquid MTA. 10 samples per group were used for each of the tested parameters. Adaptation of the MTA to the dentinal walls was tested under the light microscope and measured using Image J software. Sealing ability was evaluated using a single aerobic bacterial leakage model. Appropriate statistical analysis was done for the obtained data. Adaptation of the MTA was analyzed using independent t-test and Friedman test, whereas the bacterial leakage was analyzed using chi-square test.

Results: On comparison of the adaptation property at coronal and apical thirds, there was no statistically significant difference between the groups (p = 0.071 and p = 0.638, respectively). However, while comparing the same in the middle one-third of the root, lesser gaps were identified in the gel-form MTA group (p = 0.013). One sample belonging to the conventional powder-liquid MTA group showed significant turbidity during bacteria leakage evaluation (p = 0.001) with the presence of E. faecalis in the count of 10³ colony forming units/milliliter.

Conclusion: The gel-form MTA shows a better adaptation to the dentinal walls at the middle third of the root and exhibits better sealing ability against bacterial leakage when tested for E. faecalis. The adaptation of gel-form MTA at coronal and apical third of the root was comparable to the conventional powder-liquid MTA.

Fig. 1

Flow chart illustrating the distribution of samples across the groups and tested parameters.

Fig. 2. Radiographic images taken after filling the apical ends.

A Conventional powder-liquid MTA. B Gel-form MTA.

Fig. 3. The bacterial microleakage apparatus.

A The upper chamber of the apparatus was prepared using a plastic syringe and acrylic. The tooth is inserted such that the apical end is exposed. B The lower chamber of the apparatus- McCartney bottle. C The apparatus assembled together with sterile Muller Hinton broth in the lower chamber and upper chamber inoculated with E. faecalis.

Fig. 4. Longitudinally split sections of obturated teeth.

A Conventional powder-liquid MTA. B Gel-form MTA.