Nickel-titanium (NiTi) instruments are commonly used for shaping the root canal system in endodontic practice. They are more flexible and have better cutting efficiency than conventional stainless steel files. The superelasticity of NiTi rotary files allows the clinicians to produce the desirable tapered root canal form with a reduced tendency to canal transportation and instrument fracture. Hy...

INTRODUCTION The aim of this study was to compare different obturation techniques in terms of the percentage of gutta-percha filled areas (PGFA), sealer filled areas (PSFA), and voids in straight root canals prepared with different instruments. METHODS One hundred sixty extracted single-rooted mandibular premolars with straight canals were allocated into 10 groups (n = 16 teeth per group): A,...

introduction: the aim of this study was to compare the formation of dentinal crack and craze lines in the root dentin during root canal preparation with three different niti endodontic systems, naming reciproc (rcp), protaper universal (ptu) and mtwo. methods and materials: one hundred extracted mandibular premolars with single canals were selected and decoronated. the teeth were randomly divid...

AIM To evaluate the cyclic fatigue resistance of five NiTi rotary systems in an abrupt apical curvature. METHODOLOGY Cyclic fatigue testing was performed in stainless-steel artificial canals with a 2-mm radius of curvature and an angle of curvature of 90 degrees constructed to the dimensions of the instruments tested. The middle of the simulated curvature was 2.5 mm from the tip of the instru...

introduction: the success of endodontic retreatment is related to the complete removal of the obturation material from the root canal system. the aim of this study was to evaluate the efficacy of mtwo r and protaper retreatment files in removing the resilon/epiphany system with or without chloroform during retreatment. materials and methods: sixty distal roots of first mandibular molars were pr...

PURPOSE To evaluate the cement thickness around oval and circular posts luted in oval post spaces prepared with different drills/tips. METHODS Extracted premolars were endodontically treated and obturated, then randomly divided into three groups (n = 5) according to the tips/drills used for post-space preparation and to the type of fiber post luted: medium grit oval tip + oval posts, fine gri...

introduction: the aim of this in vitro study was to evaluate the effect(s) of three canal lubricants i.e. sodium hypochlorite, rc-prep as the paste form of ethylenediaminetetraacetic acid (edta) and aqueous edta, on the occurrence/incidence of fracture, deformity and metal slivering of protaper rotary instruments. methods: a total of 120 mesial canals ( i.e. mesiobuccal and mesiolingual) of fir...