Effect access cavity preparation and taper instrumentation on upper premolar fracture

Background : Fractures are the most undesirable thing in endodontically treated teeth. The main reason teeth has a considerable risk for fractures is loss of tooth structure. Objective This study aims to determine effect access cavity preparation and instrument taper percentage on upper premolar fractures. Material Methods Twenty-four samples were stored sterile saline solution. sample was divided into 2 large groups which then two each group by random allocation. Twelve contracted endodontic (CEC) preparations remaining twelve using traditional (TEC) techniques. Each prepared with 6 4% instrumentation 8% instrumentation. irrigated 5 ml NaOCl. After that, tested universal testing machine. Result CEC showed significant reduction fracture rates compared TEC (p <0.05), but there no difference tapering (p> 0.05). Conclusion Preparation concept minimally invasive provides better resistance while does not affect premolars.