root fracture injuries affect up to 7% of permanent teeth. this type of injury is rarely seen in teeth with open apices and depending on the fracture site, the prognosis is good. this case report describes a horizontal intra-alveolar root fracture in the middle third of a maxillary central incisor associated with an extrusive luxation of the coronal segment and its treatment in a 6-year-old gir...

although esthetic is a relative issue, depending upon the country and culture, almost all around the world, there is a consensus that a beautiful set of teeth is the one which is white and bright and is aligned regularly. in iran also the main feature of a beautiful tooth is its whiteness. during the past decades and centuries, tooth discoloration was considered as an esthetic issue and differe...

o bjectives: correct determination of working length is an important step for suc- cess of endodontic therapy. conventional radiography has limitations in providing the accurate location of apical foramen. for this reason, electronic apex locators (eals) were developed to shorten the treatment time and decrease the radiation dose. the aim of this study was to evaluate the accuracy of root zx ea...

Laser Powder Bed Fusion (LPBF) is one of the most commonly used and rapidly developing metal Additive Manufacturing (AM) technologies for producing optimized geometries, complex features, lightweight components, in contrast to traditional manufacturing, which limits those characteristics. However, this technology faces difficulties with regard construction overhang structures warping deformatio...

Orthodontic forces are known to have various effects on the alveolar process, such as cell deformation, inflammation, and circulatory disturbances. Each of these conditions affecting cell differentiation, cell repair, and cell migration, is driven by numerous molecular and inflammatory mediators. As a result, bone remodeling is induced, facilitating orthodontic tooth movement. However, orthodon...

Endosseous oral implant is applied for orthodontic anchorage in subjects with multiple tooth agenesis. Its effectiveness under orthodontic loading has been demonstrated clinically and experimentally. This study investigates the deformation and stress on the bone and implant for different bite forces by three-dimensional (3D) finite element (FE) methods. A numerical simulation of deformation and...

Objectives To assess the effect of two of the most commonly used sterilization techniques on 3D printed clinical objects. Materials & Methods The two sterilization methods used in our hospital and investigated in this paper are: Steam heat and Gas plasma. Three objects were printed and tested in this study: a tooth replica, an orthognathic final splint, a surgical cutting guide for the purpos...

As the most important working area of gear, teeth play the role of transmitting load and power. Tooth line and tooth profile are the two main characteristics of the tooth surface, which affect the shape of the tooth surface, tooth meshing characteristics and contact characteristics. Taking the elliptical cylinder gear pair in the reversing device of a new type of drum pumping unit as the resear...

background and aims. hypodontia is a common developmental abnormality of dentition. this study aimed to determine tooth width in patients affected with mild hypodontia and compare the results with a control group without tooth agenesis. materials and methods. the orthodontic records of 25 patients with congenital missing of one or two teeth (hypodontia group), and 25 subjects with full dentitio...