Influence of ultrasonic agitation on bond strength, marginal adaptation, and tooth discoloration provided by three coronary barrier endodontic materials.

Abstract

The effect of ultrasonic agitation (UA) on bond strength and adaptation of cervical plugs prepared with MTA Angelus (MTA), MTA Repair HP (MTAHP), and Biodentine (BIO) was evaluated. Dentin discoloration caused by the materials/treatment was also assessed. Seventy-two single rooted teeth were divided into six groups depending on the materials/treatment. After cervical plug preparation, dentin discs were excised for the push-out test; additional discs were analyzed under the confocal microscope to determine adaptation (gaps occurrence). For dentin discoloration analysis (ΔE), blocks of bovine incisors had cavities prepared and filled with the materials/treatment (from 7 to 180days). Both bond strength and adaptation were positively influenced by UA (P < 0.05). Comparison between materials showed an advantage for BIO when compared to MTAHP (P < 0.05). The best and worst results were provided by BIO/UA (12.66MPa and 1.87%) and MTAHP (2.54MPa and 28.58%), respectively. For ΔE, significant differences were observed throughout the periods. Just the MTA without UA exhibited noticeable discoloration at 180days (P < 0.05). UA favored a better adaptation of the materials to the dentin root, resulting in higher bond strength and adaptation of the materials to the root canal walls. Moreover, UA reduced MTA discoloration, keeping it imperceptible over the period evaluated. The better adaptation and higher bond strength provided by UA can be considered clinically relevant due to the importance of maintaining blood clot integrity and the possible esthetic compromise provided by reparative materials when used as coronary barrier in regenerative procedures.