A passive seismic monitoring campaign was carried out in the frame of a CO2-Enhanced Oil Recovery (EOR) pilot project in Alberta, Canada. Our analysis focuses on a two-week period during which prominent downhole pressure fluctuations in the reservoir were accompanied by a leakage of CO2 and CH4 along the monitoring well equipped with an array of short-period borehole geophones. We applied state...

introduction: blood contamination of the canal during preparation can be a major problem in endodontics; this may result in apical microleakage. the aim of this in vitro study was to evaluate the effect of blood on apical microleakage of a resin-based root canal sealer (ah26) and a polymer-based root canal sealer (epiphany). materials & methods: in this experimental study, 50 decoronated centra...

OBJECTIVES The aim of this study was to compare apical sealing ability of alpha and beta phases of gutta-percha by means of bacterial leakage model. MATERIALS AND METHODS Fifty single-rooted human premolars were selected. The root canals were prepared with Mtwo rotary instruments up to apical #35.04. Forty teeth were randomly divided into two groups (n= 20). The root canals were obturated by ...

OBJECTIVES The purpose of this in vitro study was to assess the effect of root canal preparation size and taper on the amounts of glucose penetration. MATERIAL AND METHODS For conducting this experimental study, eighty mandibular premolars with single straight canals were divided randomly into 2 experimental groups of 30 samples each and 2 control groups. Using K-files and the balance force t...

BACKGROUND Several techniques have been proposed for root canal filling. New rotary files, with non-standardized taper, are appearing, so, points adapted to the taper of the last instrument used to prepare the canal can help in the obturation process. The aim of this study is to assess the sealing ability of different root canal filling techniques. MATERIAL AND METHODS Root canals from 30 tee...

Treatment of the immature pulpless tooth presents both an endodontic and restorative challenge. A more favorable long-term prognosis may be achieved with a mineral trioxide aggregate (MTA) apexification procedure followed by an internal bonding technique. We investigated the efficacy of this treatment option by testing the sealing ability and retention characteristics of MTA when placed as an a...

The purpose of this study was to evaluate whether intracoronal delivery of an apical barrier of mineral trioxide aggregate (MTA) placed ultrasonically, non-ultrasonically, or ultrasonically with the addition of an intracanal composite resin provided a better seal against bacterial leakage. A second purpose was to determine whether intracanal composite resin or gutta-percha and sealer placed aga...

BACKGROUND Endodontically treated teeth often lack sufficient support for a permanent restoration. During post space preparation, it is important not to disturb the integrity of the apical seal. AIM This study compared the effect of immediate versus delayed post space preparation on the apical seal using four different sealers. MATERIALS AND METHODS One hundred and thirty single rooted teet...

BACKGROUND AND AIM The aim of this in vitro study was to compare Er, Cr: YSGG laser with ultrasonic preparation on the seal of retrograde cavities. MATERIALS AND METHODS Twenty-eight maxillary anterior teeth were used in this study. After removing the crowns, the canals were prepared with the step-back technique and filled with guttapercha. Three millimeters below the apex; each root was cut ...