temperature is one of the effective parameters in erosion of spark plug electrodes. in this research, temperature of spark plug was measured in engine's different operation conditions with two types of fuels: compressed natural gas and gasoline. test results showed that, temperature of center electrode is lower than ground electrode and maximum difference between them is 110ºc that occurs ...

This is the report of a case of four upper incisors with multiple internal/external resorptions after a falling accident in the childhood and subsequent violation of the biologic width by incorrect individual coronal restorations. Endodontic orthograde retreatment was performed and mineral trioxide aggregate (MTA) was placed as apical plug and to repair the large internal resorption. In order t...

Dental trauma sometimes causes fractures in the maxillary anterior teeth leading to esthetic, functional and phonetic quandaries. In this report, we describe the treatment of middle third root fracture of maxillary centrals and cervical third crown fracture of lateral incisor simultaneously fractured due to dental trauma. Treatment involved reattachment and splinting of fractured fragments with...

Objectives Adequate knowledge about canal anatomy is necessary for clinicians to prevent any damage to the periodontium. The aim of this study was to evaluate the canal and apical complexities of the mandibular first and second premolars in an Iranian population. Methods One-hundred mandibular first (n=50) and second (n=50) premolars were collected. After access cavity preparation, 2% methylen...

Introduction : The traditional treatment of immature permanent teeth with necrotic pulp involves creating an apical barrier by using calcium hydroxide or MTA plug for extended period time. A novel therapeutic approach called regenerative endodontic procedures (REP) is used to allow root development continue. Aim To investigate the response and REP a modified clinical protocol involving minimal ...

Abstract: Mine ventilation system is critical for maintaining safe working conditions in an underground coal mine. At present, there exist some problems in developing mine ventilation software such as long development cycle, redevelopment, low commercialization and weak extensibility. The traditional digital mine ventilation systems is complicated to be modified or extended after published unle...