THE INFLUENCE OF POST PREPARATION ON APICAL SEALING DEPENDING ON THE TYPE OF OBTURATION

Abstract

In endodontically treated teeth, often due to the loss of a large part of the hard dental tissue, the placement of an intracanal post is indicated, which serves as a retention for the prosthetic crown. During the preparation for the post, the chain of asepsis can very easily be interrupted. According to the literature, teeth restored with a post have a less favorable prognosis than those that have been endodontically treated and restored with crown only. The most likely reason for this is the violation of the integrity of the canal filling during the preparation for the post, which can easily be displaced, damaged or extruded, especially in the case when the previous filling was unsuccessful. The aim of this study was to compare the apical sealing after the preparation for the post with the two types of filling techniques applied. Methods: In this in vitro study, 200 single rooted teeth were used. After endodontic treatment, the teeth were randomly assigned into two groups of 100 teeth each. according to the obturation technique used: warm vertical compaction (WVC), or single cone (SC) techniques. Then, the coronal root filling material was removed in order to create a post space. 80 specimens from both groups received post preparation, while 20 teeth serving as controls were treated endodontically only. The quality of the apical filling was analyzed by microleakage tests using dye penetration of 2% methylene blue solution. All specimens were sectioned at 2.5 mm from the tooth apex. Transverse sections were photographed and analyzed using a computer program to determine micropermeability by dye amount. Results: Regarding the filling before post preparation, microleakage was more frequently notices in teeth in which the single cone filling technique was used compared to teeth treated with the warm vertical condensation technique, but the difference was not statistically significant (36.25 vs 28.5 %, p >0 .05); The preparation for the post significantly damages and reduces the quality of the remaining filling in the root canal (p < 0.05) The technique with which the canal is filled before preparation affects the quality of the remaining filling, but in both techniques, a significant increase in microleakage occurs (P<0.05). Conclusion: The quality of the root canal filling is important for the integrity of the apical seal. The post space preparation negatively influenced the apical integrity of the filling materials in the both groups. Obturation with warm vertical showed lower microleakage compared to single cone obturating technique after post preparation.