The effect of root end etching on microleakage of gray mineral trioxide aggregate using light polarizing microscope

الملخص EN

Background : This in vitro study confirmed to compare the sealing ability of gray MTA in phosphoric acid etched and non-etched root surface, using light polarizing microscope.

Material and methods : Twenty freshly extracted single rooted teeth with mature apices were selected.

Root end preparations were made using straight fissure carbide bur in a high speed turbine hand piece with a depth of 3mm.

Their final diameter was determined by the radius of the bur.

Ten root ends were filled with grey MTA after etching the root surface with phosphoric acid for 20 seconds and the other ten root ends were filled with grey MTA with no acid etching.

Specimens were examined using light polarizing microscope to determine the interface between the tested material and tooth structure among the two groups.

All teeth were coated with one layer of nail varnish and two layers of sticky wax and immersed in a plastic tube containing Pelikan ink for 48 hours.

The leakage in all the roots was examined by means of stereomicroscope at X2 magnification.

Results : Root surfaces etched with phosphoric acid gel gave a statistically significant decrease in apical microleakage when compared to non-etched root surfaces filled with grey colored MTA.

Conclusions : Acid etching of root-end surfaces affect the apical microleakage differently.

Examination with polarized light microscope showed that marginal gaps around the root–end filling were less in the etched group.

Acid etching has an effect on marginal adaptation of MTA when used as a retrograde filling material..