19 The biological basis of endodontics is well established and underlines the dominant role of bacteria in the initiation, development and persistence of periapical disease (Kakehashi S et al, 1965) or apical periodontitis (AP) according to the terminology currently in use. The aim of clinical procedures is to prevent or eliminate bacterial infection from the root canal system (Orstavik D, Pitt...

This in vitro study compared the ultrastructural quality of the apical seal achieved with Resilon/Epiphany and gutta-percha/AH Plus. Single-rooted extracted human teeth were prepared using a crown-down technique, debrided with NaOCl and EDTA, and obturated with either Resilon/Epiphany or gutta-percha/AH Plus. They were examined for gaps along canal walls using SEM, and for apical leakage using ...

One-visit mineral trioxide aggregate (MTA) apexification is gaining in popularity over the use of calcium hydroxide barriers. This study examined the sealing properties of two MTA apexification procedures using an in vitro apexification model. White MTA was introduced into instrumented single-rooted canals with standardized artificially created open apices to form 3- to 5-mm-thick orthograde ap...

Introduction: After endodontic procedures, root canal reinfection is a main concern for dentists. However, application of a proper apical seal can prevent such contamination. Therefore, it seems necessary to study the factors affecting the development of a suitable apical seal. Materials and Methods: In this study, 64 extracted human single-canal premolars were used. An equal length of roots wa...

background: the final objective of root canal therapy is to create a hermetic seal along the length of the root canal system. for this purpose, many methods and materials have been introduced. the purpose of this study was to compare the apical microleakage in a new obturation technique (true-tug-back) with two other obturation techniques (lateral condensation and chloroform dip technique). met...

there is lack of consensus among endodontic specialists about the necessity of tug back. in this regard, we designed a study in which 44 single rooted teeth with closed apex were selected and filed up to file #50. the teeth were obturated with lateral condensation method while in half of them there was not any tug back and in the other half tug back was achieved. apical leakage was assessed by ...

We present here a new model for epithelial morphogenesis, which we call the 'cortical tractor model'. This model assumes that the motile activities of epithelial cells are similar to those of mesenchymal cells, with the added constraint that the cells in an epithelial sheet remain attached at their apical circumference. In particular, we assert that there is a time-averaged motion of cortical c...

Obtaining a complete seal of the root canal system is a major problem in performing root canal treatment in nonvital teeth with incomplete root development and wide open apices. The aim was to study apexification using mineral trioxide aggregate (MTA), clinically and radiographically over a period of 15 months. MTA was used in four cases of teeth with incomplete root development in order to ach...

The objective of this research was to determine if gutta-percha points with calcium hydroxide [Ca(OH)2] improve the apical seal after root canal filling and if the master point does it alone. Human single recently extracted teeth were biomechanically prepared and the root canals filled by the lateral condensation technique with ZOE and gutta-percha points, with or without calcium hydroxide. The...