Successful conservative endodontic treatment of fused maxillary incisors: a case report

Fusion is a rare developmental dental anomaly and its definitive diagnosis is of great importance for successful endodontic treatment. A twenty-five-year old female attended the Endodontic Department with the chief complaint about dysmorphic right front tooth and a history of vague pain since the previous 11 months, which had ceased during last one month. Oral cavity examination was performed, endodontic oriented sensitivity tests including cold, hot, and electric pulp tests were conducted, and periapical radiography was also ordered. Oral cavity examination revealed an enlarged permanent right maxillary incisor with deep caries on the lingual surface. All vitality tests were negative. Examinations were normal except for one missing tooth in the total count in the upper right quadrant. Periapical radiography clarified a fused maxillary central and adjacent lateral incisor with large coronal radiolucency involving the pulp and a periapical radiolucent area suggestive of a chronic apical periodontitis. The final diagnosis was established as fused maxillary incisors with necrosis and chronic apical periodontitis. A conservative non-surgical root canal therapy was planned and careful negotiation and obturation were performed after obtaining the informed consent, followed by the esthetic reconstruction. A six month follow-up revealed that periapical radiolucency had almost disappeared, the teeth were in function, and the patient reported no complaint

[ in vitro evaluation of the accuracy of two electronic apex locators Foramatron V and Ipex in determining working length]

Accurate determination of working length in root canal therapy is very important for success of the process. Different methods such as electronic apex locators have been introduced for determination of working length. The aim of this in vitro study was comparison of the accuracy of two electronic apex locators, Foramatron V and Ipex, in determination of working length in human single root teeth. In this in vitro study, 100 human single root, single canal maxillary incisors with developed apex without curve were used. The teeth were cleaned after extraction and stored in normal salin. After preparing access cavity, the actual length of each canal was determined by an anatomic method placing a k-file into the canal so that the file tip touched the apical foramen. After preparing the experimental environment, the teeth were placed in the model at the level of CEJ and the length of the teeth were determind with Ipex and Formatron V according to their code. The acceptable limitation was +/- 0.5 millimeter to the actual working length. After collection of data, Mac Nemar and Paired t-test were used for statistical analysis. According to the results of this study, the accuracy of length determination was 64% and 63% for Foramatron V and ipex, respectively in the range of canal length +/- 0.5 mm. There was no significant statistical difference between these two devices. There was no significant difference between Ipex and Foramatron V. Therefore, Foramatron V may be used for working length determination

[Comparison of residue materials after retreatment of filled canals with resilon and gutta-percha]

Retreatment procedures in endodontics requires the complete removal of the original root filling materials. The most common materials that must be removed during retreatment are gutta-percha and sealers. The aim of this in vitro-experimental study was to compare the amount of residual filling material after retreatment of the root canal walls which were obturated with gutta-percha or Resilon. Thirty extracted premolar single root human adult teeth were selected and prepared by race rotary tiles up to MAF#35. Then, they were divided into two groups of 15 [A and B]. Group A was obturated with gutta-percha and AH26 sealer and group B with Resilon system by lateral condensation technique. After 4 weeks all the canals were retreated by Race rotary files and the use of chloroform and master apical file increased to #40 file. Then, the teeth were split longitudinally and the remaining materials on the surface of the canals were visualized with streomicroscope with 20 magnification and digital photographs captured. The amount of residual materials and time of retreatment were analyzed with Mann-Whitney and Freidman tests. The highest residual material value was in Resilon group and the difference between the two groups was significant [p <0.001]. The time required for retreatment was not significant between the two groups [p =0.381]. Orthograde retreatment of Resilon was less efficient than gutta- percha with more residual materials on the surfaces of the root canals that were filled with Resilon

[Evaluation of adhesion and morphologic changes of human osteoblasts exposed to gray MTA, white MTA and Portland cement]

Osteoblasts and periodontal ligament cells play a major role in wound healing after root end resection. The interaction of osteoblasts with filling materials is critical in healing of surgical lesions. The aim of this study was to evaluate the morphology and adhesion of human osteoblasts [MG-63 cell line] in contact with IRM, gray MTA, white MTA and Portland cement [PC] as root end filling materials. In this in vitro study, human osteoblasts of osteosarcoma were provided from the cell bank of Iran Pasteur Institute, and cultured in RPMI 1640 medium. Test materials were mixed according to the manufacturer's instructions and placed in contact with osteoblast cells. After the first, third and seventh days discs of materials with grown cells were fixed and examined by scanning electron microscopy. Results showed that after 7 days most of the osteoblasts were attached to the surface of both gray and white MTA and PC and appeared flat or round, however cells adjacent to IRM were round without any adhesion and spread. Based on the results of this study, human osteoblasts have a favorable response to gray and white MTA and Portland cement compared to IRM

[Evaluation of adhesion and morphology of human osteoblasts to white MTA/Gray MTA and IRM as root end filling materials by scanning electron microscopy]

Osteoblast and periodontal ligament cells are major cells for wound healing after root end resection. The interaction of osteoblast with directly contact filling materials could plays a critical role in healing of surgical lesion. Adhesion and spreading of cells on material surface are the initial phase for cellular function. The purpose of the present study was the evaluation of morphology and attachment of human osteoblasts in presence of Gray MTA, white MTA and IRM as root end filling material. This study was a descriptive study the human osteoblasts [MG-63 cell line] were prepared from Iranian Pasteur Institute; Cellular Bank, were grown in PRMI 1640 medium. The testing materials were mixed according to the manufacture's instruction, inserted into the wells of 24-well flat-bottomed plate, and condensed to disk of 1mm thickness and 1×1mm diameter. Cells were added to the materials after two weeks. During 1,3,7 days intervals, the disk of materials along with cells were grown on their surface, examined by a scanning electron microscopy. First day: After first day cells in presence of white and gray MTA showed adhesion and normal morphology, in presence of IRM were totally round. Third day: After third day osteoblasts adjacent to white and gray MTA were flat with adhesion to both materials. In presence of IRM they were round and with no attachment. Seventh day: In seventh day cells appeared with adhesion and normal morphology. Adjacent to IRM cells were round with no attachment. The results indicate that human osteoblasts have a favorable response to gray and white MTA compared with IRM