introduction: vertical root fracture (vrf) is common in endodontically treated teeth. conventional and digital radiographies have limitations for detection of vrfs. cone-beam computed tomography (cbct) offers greater detection accuracy of vrfs in comparison with conventional radiography. this study compared the effects of metal artifacts on detection of vrfs by using two cbct systems. methods a...

Chang 8 oil deposit, developed in Hohe and Jihe oil fields at the southern Yi-Shan Slop of Ordos Basin, is regarded as a kind of typical sand reservoir formation with super-low porosity, poor permeability, strong anisotropy as well as locally natural faults and fractures. The previous studies believed that matrix reservoir has a good permeability, whereas fracture reservoir has a reverse manner...

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...

bacterial leakage and root fractures are the most important reasons of root canal treatment failure. due to the lack of adhesion of gutta percha to the canal walls, resilon has been introduced as a root-filling material able to bond to the root walls. metal posts may predispose the tooth walls to oblique and vertical fracture which usually leads to tooth loss; whereas, fiber posts may reinforce...

For the characteristics of horizontal fractures in shallow low-permeability oil layers after hydraulic fracturing in multilayer reservoirs, horizontal fractures are taken equivalent to an elliptical cylinder with the reservoir thickness using the equivalent permeability model; then, upon the elliptic seepage theory, the seepage field which has led by a vertical well with horizontal fractures is...

OBJECTIVE The purpose of this study was to evaluate fracture resistance of teeth with immature apices treated with coronal placement of mineral trioxide aggregate (MTA), bioaggregate (BA), and Biodentine. MATERIALS AND METHODS Forty-one freshly extracted, single-rooted human premolar teeth were used for the study. At first, the root length was standardized to 9 mm. The crown-down technique wa...

This case report aims to describe a long-term follow-up after the immediate treatment of multiple dental injuries. A 15-year-old female patient was admitted private clinic 30 minutes an accident at school. After clinical and radiographic examinations, tooth 21 diagnosed with enamel fracture horizontal root fracture, 22 lateral luxation, teeth 12, 11, 23 were subluxation. Teeth presented pulp ne...