Background and aims. The manufacturing process of rotary Ni-Ti file can influence its resistance to fracture. The rotary ProFile (Dentsply-Maillefer, Baillagues, Switzerland) is manufactured by grinding mechanism whereas Twisted File (Sy-bron Endo, USA) is manufactured with a twisting method. The purpose of this study was to comparatively evaluate the effect of manufacturing process on distorti...

STATEMENT OF THE PROBLEM Vertical root fractures are catastrophic events that often result in tooth extraction. Many contributing factor are associated with increasing incidence of vertical root fracture. Root canal preparation is one of the predisposing factors which can increase the root susceptibility to vertical fracture. PURPOSE The aim of this study was to compare the effects of three d...

BACKGROUND The aim of this study was to evaluate the fracture rates of ProTaper rotary files used in the endodontics extension clinic of the Undergraduate Dentistry Course of the Pontifical Catholic University of Minas Gerais during the prior eight years. MATERIAL AND METHODS Control record data regarding file usage by students were collected and analyzed by semester. For each period, the tot...

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...

Objectives This study evaluated the amount of remaining root canal filling materials after retreatment procedures performed by undergraduate students using manual, rotary, and reciprocating techniques through micro-computed tomographic analysis. The incidence of instrument fracture and the instrumentation time were also evaluated. Materials and Methods Thirty maxillary single rooted teeth wer...

OBJECTIVES The aim of the present study was to investigate the incidence of deformation and fracture of twisted file adaptive nickel-titanium instruments after repeated clinical use and to identify and check whether the three instruments within the small/medium sequence showed similar or different visible signs of metal fatigue. MATERIAL AND METHODS One-hundred twenty twisted file adaptive (T...

The use of reciprocating movement (RM) was claimed to increase the resistance of nickel-titanium (NiTi) file to fatigue in comparison to continuous rotation (CR). Recently two new brands of NiTi file have been marketed for use in a RM mode. The purpose of this study was to compare the cyclic fatigue resistance and torsional resistance of these two files; Reciproc and WaveOne. Cyclic fatigue tes...

AIM To investigate and compare the fracture strength and fracture mode in eleven groups of currently, the most commonly used multilayer three-unit all-ceramic yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) fixed dental prostheses (FDPs) with respect to the choice of core material, veneering material area, manufacturing technique, design of connectors, and radii of curvature of FDP co...

background. efficient canal preparation is the key to successful root canal treatment. this study aimed to assess the cleaning and shaping ability, preparation time and file deformation of rotary, reciprocating and manual instrumentation in canal preparation of primary molars. methods. the mesiobuccal canals of 64 extracted primary mandibular second molars were injected with india ink. the samp...

introduction: the aim of the present study was to compare hand stainless steel k-files and nickel-titanium profile 0.04 taper 29 series rotary instruments for their efficiency, procedural errors and time consumed in preparation of root canal system. materials and methods: a total of 46 maxillary and mandibular first premolars extracted for orthodontic purposes were collected (two contralateral ...