Ability of different methods to fill retrograde cavities with MTA

Resumo

The Mineral Trioxide Aggregate (MTA) has excellent
biological property. However, its consistency makes it difficult to
be inserted into retrograde cavities. Objective: To evaluate the
ability of different methods to fill retrograde cavities with MTA.
Material and methods: Root canals of thirty single-rooted resin
teeth were prepared and filled. After the cut of 3 mm short of
apical third, retrograde cavities with 3 mm deep were prepared
using an ultrasound device and retrotips (CVD, São José dos
Campos, SP, Brazil). The retrograde preparation was evaluate
by using an operative microscope (D.F. Vasconcellos, São Paulo,
SP, Brazil). The teeth were randomly divided into three groups
(n = 10), according to the method: 1) condenser (Trinity, São
Paulo, SP, Brazil); 2) MTA applicator (Angelus, Londrina, Brazil)
+ condenser; 3) condenser associated with ultrasound (CVD,
São José dos Campos, SP, Brazil). After the filling of retrograde
cavities with white MTA (Angelus, Londrina, Brazil), teeth were
radiographed using a digital system (Kodak RVG 6000, Rochester,
NY, USA). The images were analyzed by UTHSCSA Image Tool 3.0 software. The percentage of filling was calculated by the
proportion between the total area of retrograde cavity and the filled
area. The radiographic density mean of each third of retrograde
cavity filled with MTA was measured by using the histogram tool
of the software. The results were submitted to ANOVA and Tukey
tests, with 5% of significance. Results: There was no difference in
percentage of filling among the groups (p > 0.05) (approximately
85%). By comparing the thirds, the condenser and MTA applicator
groups showed higher density for apical and middle third than
cervical third (p < 0.05). The ultrasound group presented similar
density among the thirds. Conclusion: The filling ability was
similar for the studied methods. Ultrasound promoted better
distribution of MTA in retrograde cavity, but did not increase
the density of material.