Date of Graduation


Document Type


Degree Type



School of Dentistry


Not Listed

Committee Chair

John Thomas.


EDTA has long been the gold standard for smear layer removal in endodontics. Recently Ballal has suggested maleic acid as a more effective alternative to EDTA, but more research is needed before it can be used in clinical practice. This study focused on comparing EDTA to maleic acid when removing the smear layer from curved root canals in human posterior teeth. Fifty-one posterior teeth were randomly selected and assigned to three groups: 17% EDTA, 7% maleic acid, and a 0.9% saline control. The teeth were prepared using K-files to an ISO size 40 MAF, step-backed to an ISO size 60 and irrigated with NaOCl between each file size. A final irrigation was performed with 5 mL of the respective group solution over 1 minute. The teeth were then dried and stored in a humidor until time for sectioning. The teeth were dehydrated, mounted and gold-palladium sputtered. Photomicrographs were taken using a SEM at 1,000 x, then 144 images were analyzed by digital image software to assess the surface area in pixels2 of open dentin tubules. The data was analyzed with a repeated measure ANOVA. It was found that the maleic acid produced greater surface area of open tubules than EDTA at the three defined canal regions (A. Coronal, B. Middle, C. Apical) but the difference was only significant in section B of the canal, where respectively, maleic acid was 120,433 pixels2 compared to EDTA with 66,399 pixels 2. Maleic acid needs to be seriously considered as an alternative to EDTA.