Relationship between the size of patency file and apical extrusion of sodium hypochlorite.

Background: Sodium hypochlorite (NaOCl) is the most widely used endodontic irrigant because of its excellent antimicrobial, organic tissue dissolving, and lubricating properties. However, it is highly cytotoxic to the periapical tissues. Aim: This study evaluated in vitro the extrusion of 5.25% NaOCl through the apical foramina of mesiobuccal (MB) root canals of maxillary first molars in two experimental conditions: Before apical debridement and after apical debridement with different instrument sizes to ensure direct access to the apical foramen (apical patency). Materials and Methods: Coronal accesses were prepared in 17 teeth and the apical foramina of the distobuccal and palatal root canals were sealed. The teeth were held in acrylic receptacles with the roots turned upwards to reproduce their position in the maxillary dental arch. The receptacles were filled with a starch/KI solution (a reagent that changes its color to blue after contacting NaOCl) covering the roots. The experiment had two phases: P1: Irrigation of the MB canals with 5.25% NaOCl without previous establishment of apical patency; P2: Canal irrigation after use of size 10 K-file and size 15 Flexofile as patency files. Only specimens with no NaOCl extrusion in P1 were assigned to P2. NaOCl was delivered pressureless at the canal entrance. The moment that the starch/KI solution contacted NaOCl was captured on digital photographs. Results and Conclusions: There was no NaOCl extrusion in nine specimens in P1, but all of these teeth had irrigant extrusion in P2. The 5.25% NaOCl used as an endodontic irrigant showed great capacity to extrude beyond both intact and small-sized apical foramina of MB root canals of maxillary first molars.

Development of two oral contrast materials for CT evaluation of the esophagus.

BACKGROUND: Computed tomography (CT) is a widely available modality in evaluating benign and malignant diseases of the esophagus. To date, there is no substantial consensus on the optimal and widely available method for opacifying the esophageal lumen exists for CT OBJECTIVE: The present study was performedf or complete and continuous opacification of the esophagus using two developed oral contrast materials and a commercial barium paste formulated for CT MATERIAL AND METHOD: One hundred and seven adult patients were sent for spiral routine CT scan of the chest (Light speed plus; General Electric Medical System, Milwaukee, Wis., USA) to evaluate variety of clinical conditions at Ramathibodi Hospital. They were divided into three groups. Two developed oral contrast materials, 1.5%(wt/vol) carboxy-methyl cellulose sodium paste containing 2%(wt/vol) barium sulfate and 5.5%(wt/vol) potato starch containing 2%(wt/vol) barium sulfate, and a commercial barium paste were randomly administered Data collection and analysis of the CT findings were performed double blindly. Results: The patients undergoing CT scan of the chest were performed with one of the oral contrast material. No streak artifact was present in any of the CT slices. Of the grade 1, contrast present without luminal distension and grade 2, contrast present with luminal distension, 1.5% CMC containing 2% barium sulfate was opacified in 36.48% and 17.45/o, respectively. Opacification with 5.5% starch containing 2% barium sulfate was of 36.41% and 19.71% while that of 3% commercial barium paste was of 36.68% and 27.54%, respectively. Acceptable taste was also achieved However, mild to moderate difficulty in swallowing occurred in 35% with no medication or intervention needed CONCLUSION: All oral contrast materials tested were less continuous and did not opacified the esophageal lumen as much when compared with the prior studies. However, acceptable taste, only mild to moderate difficulty in swallowing during the procedure, and significantly cheaper cost enable them to be used in selected cases in CT scan of the neck, chest, and upper abdomen for clarification of the problem areas.