Background: To evaluate tooth discoloration by newly developed calcium silicate-based materials, and to examine the pre-application of dentin bonding agent (DBA) for preventing discoloration caused by mineral trioxide aggregate (MTA).
Methods: The roots of 50 premolars were randomly divided into five groups (n=10) and cavities were prepared from resected root surfaces. MTA was placed in the cavities of teeth belonging to the ProRoot MTA (Pr) and RetroMTA (Rt) groups. For teeth belonging to the DBA + ProRoot MTA (B-Pr) and DBA + RetroMTA (B-Rt) groups, DBA was first applied to the cavities prior to the addition of MTA. Teeth in the control group were restored with composite resin only (i.e., without MTA). After 12 weeks, MTA was removed from the Pr and Rt teeth and bleaching agents were applied for 3 additional weeks. Color assessments were recorded at baseline, and 1, 4, and 12 weeks, as well as after bleaching.
Results: Following 12 weeks of MTA treatment, there was a significant difference between the discoloration in the Pr and B-Pr groups. However, no significant difference was observed between the Rt and B-Rt groups. Following bleaching, the color changes (ΔE values) of the Pr group were not significantly different from those of the B-Pr group. The difference of ΔE between the Rt group after internal bleaching and the B-Rt group also was not significant.
Conclusions: RetroMTA caused significantly less discoloration than ProRoot MTA. Pre-application of DBA prevented discoloration by ProRoot MTA. MTA discoloration was improved equally well between DBA pre-application and post-bleaching. Clinical Relevance Tooth discoloration by mineral trioxide aggregate (MTA) limits its use in esthetic region. The pre-application of dentin bonding agent (DBA) and the newly developed RetroMTA prevented discoloration caused by MTA, thus expanding its use in esthetic applications.