an in vitro comparison of marginal adaptation of mta and mta-like materials in the presence of pbs at one-week and two-month intervals.

this study compared the marginal adaptation of mineral trioxide aggregate (mta) and mta-like materials as root-end fillings after incubation in phosphate buffer saline (pbs), a synthetic tissue fluid, for either 1 week or 2 months.in this experimental study, seventy-two extracted human single-rooted teeth were prepared and obturated with gutta-percha and ah26 sealer. the apical 3 mm of the roots were resected. root-end cavities were prepared with an ultrasonic retrotip. the specimens were randomly divided into three groups (n=24) and filled with either proroot mta, orthomta, or retromta. half of the specimens in each group were stored in pbs for 1 week the other half for 2 months. epoxy resin replicas from the resected root-end surfaces and longitudinally sectioned roots were fabricated. the gaps at the material/dentin interface were measured using a scanning electron microscope (sem). transversal, longitudinal, and overall gap sizes were measured. the data were analyzed using kruskal-wallis and mann-whitney tests. the significance level was set at p 0.05). in addition, the test groups were not significantly different regarding the overall mean gap values (p > 0.05).under the conditions of this study, there was no difference between the marginal adaptation of proroot mta, orthomta, and retromta as root-end filling materials after exposure to pbs for either 1 week or 2 months.