In a literature search no study evaluating implant-supported posterior restorations using zircon crowns with straight and angled abutments was found. In this study, the stress distribution of a zircon-crown restoration that will be prepared by using an angular and straight abutment in a mandibular second-molar deficiency, under functional forces, stress over zircon crown and environmental tissues of implant will be evaluated using the finite-element analysis (FEA) method. The FEA result showed that the use of straight implants contributes to the lowest stresses. The selection of a straight and angular abutment is very important for the balance of distributed loading.