title: Using mineral trioxide aggregate powder as an apical barrier: a bacterial leakage study.
abstract: Mineral trioxide aggregate (MTA) has been used successfully for the treatment of necrotic immature teeth as part of a 2-step apical barrier. Recently, some researchers have used MTA powder instead of wet-mix MTA. It has also been used in a single-step approach in order to decrease the number of patient appointments. The aim of this study was to evaluate the bacterial microleakage of MTA powder in comparison with wet-mix MTA, in single or 2-step barrier approaches. This ex vivo study was carried out on 70 extracted single-rooted teeth. The canals were enlarged to simulate immature teeth. The prepared specimens were assigned to 4 experimental (n = 15) and 2 control (n = 5) groups. In Group 1, a wet paper point was placed in the canal following placement of wet-mix MTA. In Group 2, a dry paper point was placed on wet-mix MTA. In Group 3, the samples were treated similar to Group 1, but MTA powder was used instead of wet-mix MTA. In Group 4, the same procedures were followed as Group 3 except that a dry paper point was used. Microleakage of the samples was compared using a 2-chamber bacterial leakage apparatus. Results showed that there were no significant differences in the number of leaked samples or rate of leakage over time (P > 0.05) among the experimental groups. It can be concluded that MTA used in a single step approach has the same resistance against bacterial penetration as in a 2-step approach, and MTA powder provides the same sealing ability as wet-mix MTA.
authors.forename: Amin Salem
authors.initials: AS
authors.lastname: Milani
authors.forename: Mohammad Asghari
authors.initials: MA
authors.lastname: Jafarabadi
authors.forename: Mahdi Vahid
authors.initials: MV
authors.lastname: Pakdel
mesh_terms: D017607:Aluminum Compounds; D018407:Bacterial Physiological Phenomena; D017610:Calcium Compounds; D016022:Case-Control Studies; D004338:Drug Combinations; D006801:Humans; D010087:Oxides; D011208:Powders; D017640:Silicates; D019227:Tooth Apex
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D010087:Oxides; D011208:Powders; D017640:Silicates; C086631:mineral trioxide aggregate
keywords: Enterococcus faecalis; MTA; sealing ability; single appointment