In endodontics, treatment of an open apex tooth with necrotic pulp is a problem. It seems that with promotion of remnants of Hertwig's epithelial sheath or rest of malassez accompany with a good irrigation of root canal we can expect root formation. (Iranian Endodontic Journal 2008;3:42-43).

Coordination between the Hertwig’s epithelial root sheath (HERS) and apical papilla (AP) is crucial for proper tooth root development. The hedgehog (Hh) signaling pathway and Nfic are both involved in tooth root development; however, their relationship has yet to be elucidated. Here, we establish a timecourse of mouse molar root development by histological staining of sections, and we demonstra...

objective: vertical root fracture (vrf) is among the most common causes of endodontic treatment failures. this study aims to compare charge-coupled devices (ccd) and photostimulable phosphor plates (psp) for detection of vertical root fractures in endodontically treated teeth.   methods: in this diagnostic in vitro study, 40 maxillary anterior teeth were selected and after preparation and root ...

Introduction. Tooth avulsion in the young permanent dentition is a frequent finding, and its prognosis depends on the treatment of the avulsed tooth before replantation, the extra-alveolar time, the storage medium, and the patient's general health. The present report describes management of an immature avulsed lower central incisor 90 minutes after the accident. Methods. A right lower central i...

The establishment of a pre-pattern or competence to form new organs is a key feature of the postembryonic plasticity of plant development, and the elaboration of such pre-patterns leads to remarkable heterogeneity in plant form. In root systems, many of the differences in architecture can be directly attributed to the outgrowth of lateral roots. In recent years, efforts have focused on understa...

This study evaluated factors that affected pulpectomy (PE) success and its effect on the succedaneous tooth's eruption and enamel formation. Sixty-five of 250 patients with PEs met the selection criteria and yielded 81 zinc oxide-eugenol PEs (30 incisors, 51 molars) followed a mean time of 90.8 months. Overall PE success was 77.7% with no difference between molars and incisors (P = 0.53). Ename...

abstract : horizontal root fractures in permanent teeth are uncommon injuries among dental traumas. the principle of treating horizontal root fractures of permanent teeth is repositioning and fixation of fractured segment. diagnosis of tooth fractures based on radiographic findings and the fracture healing process are affected by factors before and after injury. the present case reports the tre...

The role of the various cellular components associated with root formation has been controversial since Malassez' and Hertwig2 presented their theories. The advent of isotopes such as tritiated thymidine has made it possible to study cellular turnover and migratory patterns with much greater accuracy than was previously possible. Such technics have been applied to studies of mitotic activity as...

The aim of this study was to document variation of deciduous tooth formation and eruption. The material comprises 121 individuals of known or estimated age (using tooth length) from Spitalfields in London, and radiographs of 61 healthy living children aged 2-5 years. Other skeletal material from two medieval Scottish archaeological sites (Whithorn, N=74; Newark Bay, N=59) was also examined. Sta...

The mammalian tooth forms by a series of reciprocal epithelial-mesenchymal interactions. Although several signaling pathways and transcription factors have been implicated in regulating molar crown development, relatively little is known about the regulation of root development. Four genes encoding nuclear factor I (NFI) transcription-replication proteins are present in the mouse genome: Nfia, ...