Objective. The objective of this study was to evaluate the efficacy of two retreatment NiTi systems (protaper universal retreatment files, R-Endo), when compared to manual technique in removing Gutta-percha obturated with two sealers. Study Design. Sixty extracted single-rooted premolars were instrumented with Protaper rotary files till F3. The specimens were divided into six groups. Groups 1, ...

INTRODUCTION Cyclic fatigue is the common reason for breakage of rotary instruments. This study was conducted to evaluate the effect of cryogenic treatment (CT) in improving the resistance to cyclic fatigue of endodontic rotary instruments. METHODS AND MATERIALS In this in vitro study, 20 RaCe and 20 Mtwo files were randomly divided into two groups of negative control and CT. CT files were st...

INTRODUCTION File fracture is one of the main procedural mishaps in endodontic treatment. The aim of this in vitro study was to compare the fracture rate of three NiTi rotary systems; Hero 642, Mtwo and FlexMaster in artificial canals. METHODS AND MATERIALS In this study, bovine long bone was used. After primary preparation of bones, longitudinal sections with 4-cm diameter were cut and encod...

INTRODUCTION The aim of this study was to compare several metallurgic properties of Neoniti instrument with four other commonly used endodontic rotary files. METHODS AND MATERIALS Neoniti A1 (25/0.08), RaCe (25/0.06), Mtwo (25/0.06), Twisted file (25/0.06) and ProTaper Next X2 (25/0.06) were examined by differential scanning calorimetry (DSC) before and after heat treatment at 500°C. X-ray di...

introduction: this study was carried out to compare the capability of k-files with mtwo rotary file in terms of negotiation as well as depth of penetration in second mesiobuccal (mb2) canal of maxillary first molar. materials and methods: a total of 32 mb2 canal of maxillary first molars having different root curvatures (not more than 30 degree) and root lengths were selected and then detected ...

Aim- To evaluate the removal of gutta percha by hand file system, rotary system and reciprocating from root canals using CBCT. Materials Method: Root 42 extracted human mandibular premolars were prepared ProTaper Universal then obturated. filling quality was confirmed on CBCT images. Specimens divided into 3 groups (n = 14) according to used for removal, group 1: H File, 2: MTwo retreatment fil...

AIM To compare the shaping ability of Mtwo instruments with K3 and RaCe instruments. Part 1 of this two-part report describes the efficacy of these nickel-titanium instruments in simulated curved root canals. METHODOLOGY Simulated canals with 28 degree and 35 degree curves in resin blocks were prepared with Mtwo instruments using a single length technique and with K3 and RaCe instruments usin...

OBJECTIVE The objective of this study was to compare the smear layer formed on root canal walls during canal preparation of extracted human teeth by Twisted, Mtwo, and ProTaper rotary nickel titanium instruments. MATERIALS AND METHODS Sixty single rooted human premolar teeth with root curvature <25(0) were selected and randomly divided into three Groups (n= 20 teeth per Group). Three types of...

OBJECTIVE The goal of present study was to determine the effect of different nickel-titanium file systems on the amount of apically extruded debris during endodontic retreatment: D-RaCe retreatment systems, EdgeFile XR retreatment rotary files, and Reciproc R40. MATERIALS AND METHODS Thirty-six single-rooted prepared mandibular premolar teeth were filled with Gutta-percha and AH Plus sealer. ...