Avaliação da influência da agitação ultrassônica na adaptação marginal e descoloração dentinária proporcionadas por três cimentos reparadores endodônticos

Abstract

This investigation evaluated the root canal walls and the dentinal discoloration caused by the white MTA-Angelus (MTA), MTA Repair HP (MTAHP), and Biodentine (BIO). Moreover, it was evaluated the variations in this discoloration when ultrasonic agitation (UA) was employed. Sixty single rooted human teeth received instrumentation of their cervical thirds, and were then divided in six groups according to the type of material/treatment to be used. An apical plug (material+fluorophore) was placed into the root canal, and its adaptation was evaluated using dentin slabs extracted from the roots observed with confocal microscopy. The discoloration analysis was performed using dentin blocks extracted from the crown of bovine incisors. A cavity was prepared in the lingual face of these blocks, and then it was filled with one of the materials/treatments tested, and covered with dental composite. The variation of color (ΔE) was verified using a spectrophotometer at the days 0, 7, 14, 30, and 180. The analysis of adaptation demonstrated positive influence of the USA when considering the treatment alone (P<0.05). The comparison among the different materials tested showed disadvantage in using MTAHP when compared to the BIO (P<0.05). The lowest and highest rates of cracks were seen on the BIO/UA (1.87%) and on the MTAHP (28,58), respectively. Regarding the ΔE, significant differences were observed when comparing the experimental times. The MTA group was the only one in which the discoloration was above the clinically noticeable level, being it significantly different from the other groups at the experimental time day 180 (P<0.05). The results allowed the conclusion that the materials tested did not completely adapt to the dentinal walls when applied alone. However, a better adaptation was seen when the materials were applied with the aid of UA. Moreover, the UA reduced the effects of ΔE caused by the MTA, maintaining the changes in a non-noticeable level during the experimental period.