In vitro sealing properties of calcium-enriched mixture and mineral trioxide aggregate orifice barriers during intra-coronal bleaching

This study aimed at evaluating the sealing properties of calcium-enriched
mixture (CEM) compared to mineral trioxide aggregate (MTA) as a cervical barriers in
intra-coronal bleaching. Methods and Materials: In this in vitro study, endodontic
treatment was performed on 60 extracted human incisors and canines without canal
calcification, caries, restorations, resorption or cracks. The teeth were then randomly
divided into two experimental groups and two control groups (n=15). Then, CEM cement
and MTA were applied as 3-mm intra-orifice barriers in the test groups; a mixture of
sodium perborate and 30% hydrogen peroxide bleaching agents were placed within the
pulp chamber for one week. Dye penetration method was used to evaluate the sealing
ability of agents. Statistical analysis was performed using SPSS software. The Kendall
coefficient was used to evaluate inter-observer agreement. The chi-squared test was used
for statistical analysis. Results: The results showed that the penetration rates of CEM and
MTA were the same as positive control group, with no significant differences (P=0.673
and P=0.408, respectively). However, there was a significant difference between the
negative control group and CEM and MTA groups (P=0.001 for both groups). In addition,
the sealing ability of MTA and CEM cement were not significantly different (P=0.682).
Conclusion: During intra-coronal bleaching procedures CEM cement can be used as a
cervical barrier with sealing properties comparable to that of MTA.